Vol%- I TEXT BOUND
A palynological study of the Ordovician to Devonian sediments of the Anti Atlas, Morocco
Michael G. SnapeM. Sc.
Submittedin partial fulfilment of the requirementsfor the degreeof Doctor of Philosophy
Iti *a SjAksFF iL4ý-O
Vol%- I TEXT BOUND
INTO
THE SPINE CONTAINS
PULLOUTS Summary
Approximately 300 field and well samplesfrom the Ordovicianto Devonianinterval of the Anti Atlas, Morocco havebeen preparedfor palynologicalinvestigation. Of these,118 were selectedfor detailed analysisbased on the quality of the palynologicalrecovery, an attemptto achievethe beststratigraphic coverageas possiblefrom the materialavailable and also basedon the presenceof macrofossildata.
A rapid palynological preparation technique for observation by light microscopy has been developed to analyse thermally mature, brittle assemblages,such as those encountered.
Reviewsof the Acritarcha, the fossil Prasinophytaand the Chitinozoaare presentedwith discussionof their morphology,biological affinity and classification. Taxa from thesegroups are treatedsystematically with 389 describedspecies recorded, assignable to 115genera. A total of 71 unpublishedforms are describedin opennomenclature. Miospores; have also beenrecorded to enhancebiostratigraphic resolution and environmentalinterpretation of the assemblagesstudied. The miosporetaxa recordedare illustratedwith their authorscited in the plate captions.
Semi-quantitativeanalyses of the assemblageshas enabled the recognitionof 33 PalynologicalAssociations from the Ordovicianthrough Devonianbased on the presence,absence and abundanceof the tax&recorded. Cluster analysisof the sampleshas been undertaken to assistin the recognitionand to quantify the similarity of the assemblages.The Ordovicianfield samplesyielded poorly preservedassemblages from which 12 Associationsare recognised.The Silurian to Lower Devonianfield samplesyielded moderateto well preservedassemblages despite the high thermalgrade of the material. Twelve Associationsare defined from this interval, the agesof which are all highly constrainedby the generallyrich graptoliteassemblages. Nine Associationsare recognisedfrom the Devonianassemblages recovered from Well Oum Doul-I core samples. Theseassemblages are well preservedwith abundantand often diversemarine and terrestrial elementspresent. 'Me ageinterpretations of the 33 Associationsare basedon both macrofaunalevidence, when present,and on comparisonwith previouspalynological studies, primarily thosefrom Northern Gondwana.
A generalpalaeoenvironmental, interpretation of the formationsstudied is attemptedfrom the semi quantitativeanalysis of the relative proportionsof environmentallysensitive palynomorph groups and the relative proportionsof morphotypeswithin palynomorph groups. The major bathymetricfluctuations in the environmentof depositionwhich are evident from the palynological,assemblages (e. g. the deepwater event in the early Silurian) are believedto be eustaticallycontrolled during the Ordovicianto Devonianin the Anti Atlas.
The broad natureof the study, geographicallyand stratigraphically,has revealedmuch potential for future work, of both academicand commercialinterest, in the North African and Middle East region. Acknowledgments
Simon PetroleumTechnology Ltd. are gratefully acknowledgedfor their funding of my scholarship. SeveralSPT personnelhave beenof great assistanceas the project evolved, namely Dr. J.P. G. Fenton, Mr. G. Wade, Dr. P.H. Swire, Prof. D. S. Wood, Dr. R. J. Davey, Dr. N. Butler and Mr. P. C. Hughes.
Many peopleat my host institution are thankedfor their hospitality and friendship. I thank in particular my supervisorDr. E. G. Spinnerfor his guidance,and Prof. C. Downie, Dr. D. W. Jolley, Mr. D. McLean and Dr. M. Romanofor their valuable discussion. I also thank the technicalstaff Ms. D. Darwin, Mr. S.J. Ellin, Mr. P Higham and Mr. B. Piggot for their help. Prof. R. A. Spearsis gratefully acknowledged for the use of the departmentalfacilities.
Thanks are extendedto Dr. T. P. Young for invaluablediscussion in the secondyear of the project and for the loan of his personalset of Moroccan geologicalmaps. Thanks also to Dr. R. B. Rickards for the days hospitality in Cambridgeon my visit to collect samplesfrom him.
The last three and a half yearshave been made all the more enjoyablethanks to the companyof my colleaguesMr. N. M. Hogg and Mr. S.W. Smith. The week's 'fieldwork' in Teignmouthwill live long in the memory. Long may our friendshiplast.
And to my parents,Mr. G.J. Snapeand Mrs. S.M. Snape,thank you both for your constantsupport. Contents Volume I
Chapter 1. Introduction I Geographicsetting I Previouswork 4 Tectonicand palaeogeographicevolution 5 Lithostratigraphicframework 9
Chapter 2. Aims and objectives 22
Chapter 3. Techniques 23
Chapter 4. The Acritarcha 27 Introduction 27 Morphology 27 Biologicalaffinity 34 Classification 34 Systematics 38 GenusAcanthodiacrodium 38 GenusActinodissus 43 GenusActinophasis 45 GenusAmmon1dium 46 GenusArbusculidium 48 GenusBaltisphaeridium 49 GenusBaltisphaerosum 53 GenusBeudingisphaeridium 54 GenusCaldariola 55 GenusCandelasphaeridium 55 GenusComasphaeridium 56 GenusCoqphidium 57 GenusCrassiangulina 58 GenusCraterisphaeridium 59 GenusCrystallinium 60 GenusCýmatiogalea 60 GenusCýmbosphaeridium 64 GenusDacrylofusa 67 GenusDaillydium 68 GenusDasypilula 69 GenusDateriocradus 69 GenusDeflandrastrum 71 GenusDemorhethium 72 GenusDicrodiacrodium 73 GenusDictyotidlum 73 GenusDiexallophasis 76 GenusDuvernaysphaera 81 GenusEphelopalla 82 GenusFlorisphaeridium 83 GenusFrankea 84 GenusGoniosphaeridium 84 GenusGorgonisphaeridium 88 GenusHapsidopalla 91 GenusHeliosphaeridium 91 GenusImpluviculus 92 GenusLeiofusa 92 GenusLeiosphaeridia 94 GenusLeiovalia 95 GenusLophosphaeridium 96 Genus Maranhites 100 Genus Marrocanium 103 Genus Micrhystridium 105 Genus Mulliplicisphaeridium 105 Genus Muralicavia 112 Genus Navifusa 112 Genus Neoveryhachium 113 Genus Onondagella 114 Genus Oppilatala 115 Genus OrdoWcidium 117 Genus Orygmahapsis 117 Genus Ozotobrachion 118 Genus Palacanthus 119 Genus Peteinosphaeridium 119 Genus Pirea 120 Genus Polyedryxium 121 Genus Polygonium 122 Genus Pratulasphaera 124 Genus Quadraditum 125 Genus Quadrisporites M Genus Quisquilites 126 Genus Salopidium 127 Genus Solisphaeridium 127 Genus StelUchinatum 129 Genus Stelliferidium 130 Genus Stellinium 133 Genus Striatotheca 134 Genus Tetraporina 135 Genus 7hysanoprobolus 136 Genus Tongzia 137 Genus Trematophora 137 Genus Triangulina 138 Genus Trichosphaeridium 139 Genus Tunisphaeridium 139 Genus Tylotopalla 140 Genus Umbellasphaeridium 141 Genus Uncinisphaera 142 Genus Veliferiles 143 Genus Veryhachium 143 Genus Villosacapsula 154 Genus Virgatasporites 155 Genus Visbysphaera 156 Genus Vogilandia 159 Genus Vulcanisphaera 159 Genus Winwaloeusia 160 Acritarch Forms A-U 161
Chapter 5. The Prasinophyta 169 Introduction 169 Fossil prasinophyte morphology 169 Phycoma development 170 Classification 170 Systematics 172 Genus Cymatiosphaera 172 Genus Pterospermella 176 Genus Tasmanites 177 Chapter 6. The Chitinozoa 179 Introduction 179 Morphology 179 Biological affinity 182 Classification 184 Systematics 186 Genus Ancyrochitina 186 Genus Angochitina 191 Genus Armoricochitina 195 Genus Belonechitina 195 Genus Bursachitina 197 Genus Calpichitina 197 Genus Ongulochitina 199 Genus Conochitina 202 Genus Cyathochitina 203 Genus Desmochitina 206 Genus Eisenackitina 207 Genus Eremochitina 208 Genus Fungochitina 208 Genus Gotlandochitina 209 Genus Hoegisphaera 210 Genus JenAdnochitina 210 Genus Lagenochitina 211 Genus Margachitina 213 Genus Muscochifina 214 Genus Plectochitina 215 Genus Pogonochifina 216 Genus Pseudoclathrochilina 216 Genus Pterochitina 217 Genus Rhabdochitina 217 Genus Sagenachitina 218 Genus Sphaerochitina 219 Genus Urnochitina 220 Genus Velatachitina 220 Chitinozoan Form A 221
Chapter 7. Stratigraphic palynology 222 Ordovician field samples 225 Silurian to Lower Devonian field samples 238 Oum Doul-I core samples (Devonian) 251
Chapter 8. Environmental palynology 263
Chapter 9. Conclusions 274
Chapter 10. Further work 277
References 279
Appendix I. Ile samplesstudied 328 Appendix 111.The topographicmaps used 361 Appendix HI. The geologicalmaps used 363
VolumeH. Plates1-103
Volume III Plates104-200 L0ist of figures and enclosures.
Figures.
1. Geographicmap of Morocco showingthe positionsof the topographicmaps utilised. 2 2. The physiographicregions of Morocco. 3 3. An early Ordovicianpalaeogeographic reconstruction of Northern Gondwana,from Paris 1990.6
4. Global palaeogeographicreconstructions for the latest Ordovician(Ashgill) and middle Silurian (Wenlock), from Scotese& McKerrow 1990. 7 S. Global palaeogeographicreconstructions for the early Devonian(Gedinnian) and late Devonian(Famennian), from Scotese& McKerrow 1990. 8 6. The lithostratigraphicframework for the OrdovicianSystem showing the comparison betweenthe publishedlithostratigraphy_ and that proposedby the RobertsonGroup in 1985. 11
7. The lithostratigraphicframework for the Silurian Systemshowing the comparison betweenthe publishedlithostratigraphy and that proposedby the RobertsonGroup in 1985. 14
8. The lithostratigraphicframework for the DevonianSystem showing the comparison betweenthe publishedlithostratigraphy and that proposedby the RobertsonGroup in 1985. 18 9. Palynologicalprocessing flowchart. 24 10. Acritarch morphology. 30 11. Acritarch morphology(continued). 32 12. Ile life cycle of Pterosperma. 171 . 13. Chitinozoanmorphology. 180 14. A comparisonof chitinozoanbiozonations from Northern Gondwanapublished pre 1982, from Paris 1981. 224 15. A comparisonof the Tremadocaged acritarch zonation of a. Rasul 1979, b. Naumova1950, c. Jardinaet aL 1974and d. Elaouad-Debbaj1988, from Elaouad-Debbaj1988. 226 16. A correlationof the standardgraptolite zonesand the Northern Gondwanan chitinozoanzones with the palynologicalassociations defined herein from the Ordovician. 228 17. A correlationof the standardgraptolite zonesand the Northern Gondwanan chitinozoanzones with the palynologicalassociations defined herein from the Silurian. 239 18. A correlationof the standardammonoid, conodont and graptolite zones,the Northern Gondwananchitinozoan zones and the O.R. S. continentspore zones with the palynologicalassociations defined herein from the Devonian. 250 19 Palynomorphdistribution acrossthe continentalshelf for the Ordovician(Caradoc) and the Silurian (Wenlock). 264 20 Palynomorphdistribution acrossthe continentalshelf for the Devonian(Givetian) and the early Carboniferous(Tournasian). 265 21 First and secondorder global cyclesof relative changeof sealevel during Phanerozoictime, from Vail, Mitchum & Thompson1977.269
Endosures (enclosedat the backof VolumeI) I Tilia graphof the percentagesof taxa recordedfrom the Tremadocto earliestArenig agedfield samples. 2. Tilia graph of the numbersof taxa recordedfrom the macrofossildated Arenig aged field samples. 3. Tilia graphof the percentagesof taxa recordedfrom samplesJW 4 andJW 5 of Arenig age. 4. Tilia graph of the percentagesof taxa recordedfrom samplesDW 291 and DW 307 of Arenig age. 5. Tilia graphof the percentagesof taxa recordedfrom samplesDW 303 and JD 29 of Arenig age. 6. Void. 7. Tilia graphof the percentagesof taxa recordedfrom samplesDW 309 and DW 3 10 of Llanvirn age. 8. Tilia graph of the percentagesof taxa recordedfrom the Caradocaged field samples. 9. Tilia graph of the percentagesof taxa recordedfrom the Caradocaged field samples. 10. Tflia graph of the percentagesof taxarecorded from the Ashgill agedfield samples. 11. Tilia graphof the percentagesof taxa recordedfrom the Llandoveryto Wenlock agedfield samples. 12. Tilia graphof the percentagesof taxa recordedfrom the early Ludlow agedfield samples. 13. Tilia graph of the percentagesof taxa recordedfrom the Pridoli to Lower Devonian agedfield samples. 14. Tilia graph of the percentagesof taxa recordedfrom Oum Doul-1 core samples. Chapter 1. Introduction.
The kingdom of Morocco occupiesan areaof approximately731000 squarekm situatedat the north- west margin of the African continent. It housesa populationof about25,000 peopleand is ruled by a stabledemocratic monarchy. The economyof Morocco was initially developedon the basisof agricultureand fishing but in more recentyears it hasbecome significant in the internationalmarket placewith industrial developmentsprimarily in the form of engineeringand computertechnology.
Despitethe relatively low energyconsumption per capitaof its inhabitants,Morocco is still almost entirely dependanton imported energyresources. This problemwas addressedby the governmentin 1981with the establishmentof the Office National de Rechercheset d'Exploitations Petrolieres, commonlyreferred to by its acronymONAREP. This organisation,based at its headquartersin Rabat, is the stategovernment oil companywhich has total responsibilityfor all petroleumexploration activities and all exploitationof discoveredhydrocarbons in Morocco.
The presentstudy is basedon samplesfrom the Anti Atlas region which were collectedby The RobertsonGroup (now SimonPetroleum Technology) for a study commissionedby ONAREP in 1985. The samplesutilised are from the Ordovicianto Devonianstratigraphic interval and are predominantly from outcrop and shallowwater wells. Thesesamples are supplementedby core from a single explorationwell from the southof the region, Oum,Doul-1. A full list of the samplesanalysed is given in Appendix I, with the geographicand stratigraphicposition given for each. In the courseof the South Atlas Study, The RobertsonGroup sub-contractedmacropalaeontological. work to expertsin their respectivefields, namelyDr. Mike Romano(University of Sheffield)and Dr. Tim Young (University of Cardifo who looked at the Ordovicianshelly faunasand Dr. Barry Rickards(University of Cambridge)who looked at the Silurian-LowerDevonian graptolitic assemblages.The datarelevant to the presentstudy generatedby theseworkers is integratedwith the palynologicalinvestigations undertaken. The resultsof their analysiscan also be found in Appendix 1.
The geographic setting.
The study areais situatedin the Anti Atlas region of Morocco (figs. I and 2). This region is bounded to the north by the SouthAtlas Fault Zone which extendsfrom the coastalresort of Agadir in an ENE direction. This boundaryseparates the High Atlas mountainousregion to the north from the more varied topographyof the Anti Atlas to the south (fig. 2). The Anti Atlas is dominatedby the high topographicrelief of the Anti Atlas mountainswhich are composedprimarily of Precambrianand Lower Palaeozoicrocks. However, in someareas, tectonic influences have resultedin large scale depressionswithin the Palaeozoicaged landscape which are commonlyinfilled with Mesozoic sedimentsand Tertiary and Quaternarydesert deposits. To the south of the Anti Atlas, the relatively Figure 1. Geographic Morocco the the topographic map of showing positions of CP niaps utillsed.
Spain % Tangier I Atlantic Ocean sia
Rabat Fes "1, Algeda UUbbyy aa Cassablanca ;
Mauritania I Mail Niger Safie MMarrakecharrakec
4 51617
8g g 10 Agadir E1312 r-3ý 14
2
Tarfaya Tindoufindouf 1:100,000 topographic maps uti lised 1. Hassi Bou Al Wawa N 2. Fask 3. Tleta de Tagmonte 3ýý' 4. Boumalne 5. Msissi 6. Erfoud 7. Agdz 8. Aqdz Dakhla 9. Tazzarine 10. Tarhbalt 11. Foum Zguit 12. El Gloa 13. Mdaouer 14. Zaouia
2 Figure 2. The physiographic regions of Morocco.
F Spain
Tangier Atlantic Oceaný-M-/oroc, -oo
l; "'a' . __
Tindouf 1: 100,000 topographic maps util ised 1. Hass!Bou Al M'amra 2. Fask 3. Tleta de Tagmonte 4. Boumalne 5. Msissi 6. Erfoud 7. Agdz Dakhla 8. Agdz 9. Tazzarine 10. Tarhbalt 11. Foum Zguit 12. El Gloa 13. Mdaouer 14. Zaouia
3 subduedtopography of the Draa plain is composedprimarily of the relatively soft Silurian shalesand post Alpine superficialdeposits.
The main centres of commerce and trade in the Anti Atlas include the towns of Agadir, Tiznit, Taroudannt and Ouarzazatein the central and western parts of the region, together with Zagora and Erfoud further to the east. There is a good network of tarred roads between these centres which are supplementedby manywell useddirt tracksfor communicationwith the more rural towns and villages.
Severalsets of topographicmaps at various scalesexist for Morocco which are publishedby the government. The seriesutilised in the presentstudy, the 1:100,000 series, is that usedby Robertsons' geologistsin the field. The relevantsheets are thoseon which the samplesanalysed here are located which are listed in figure 1.
Previous work on the Lower Palaeozoicand Devonian rocks of the Anti Atlas.
7be Anti Atlas is essentiallythe type areafor the Lower Palaeozoicand Devonianinterval of Morocco (Destombes,Hollard & Willefert 1985). Geologicalresearch in the region was initiated in the early part of this centurywith discoveriesof Cambrian(Bourcart 1927,Bondon & Neltner 1933), Ordovician (Roch 1933)and Silurian (Savornin1921) faunas. Work in the latter half of the centuryin Morocco has becomefocused on the Anti Atlas with the realisationof the near completesuccession of Lower Palaeozoicrocks in that area.
From 1959onward, Destombesbecame the most prolific worker in the anti Atlas with over 30 publicationsto his name. His work in the region culminatedin 1985with a summaryof the Lower Palaeozoicrocks of Morocco (Destombes,Hollard & Willefert 1985)in which a comprehensivereview of the Lower Palaeozoicstratigraphy is madeupto that date. In addition, a wealth of unpublisheddata generatedby him, e.g. field guides,have benefited geologists working in the area(T. P. Young pers. comm. 1992).
From 1942and upto 1947, Choubertestablished the first type sectionfor the Ordovicianin the Anti Atlas, but it was not until 1954that the first Tremadoc(earliest Ordovician) sedimentswere recognised from the Agdz region (Choubert, Hindermeyer & Hupe 1955). Several palynological investigations of the Ordovician successionof Morocco are evident in the literature, the earliest of these was made by Cramer et aL (1974) from subsurface material from the Tadla basin. More recently, several publications by Elaouad-Debbaj (1984,1986,1988a & 1988b) focused on the palynology of the
Ordovician successionin the Anti Atlas which address both the acritarch and chitinozoan assemblages.
The namesassociated with early faunal discoveriesof Silurian agein the Anti Atlas include Bondon, Clariond & Neltner (1934). Hollard and Willefert in conjunctionwith Destombeshave been largely
4 responsiblefor establishingthe Silurian stratigraphicnomenclature of the area(e. g. Destombes, Hollard & Willefert 1959& 1985). It is interestingto note that the prolific Silurian agedgraptolitic faunasin the region are largely undescribed(Destombes, Hollard & Willefert 1985)and that several new lineagesare evidentfrom the Silurian to early Devonianmaterial analysedhere (R.B Rickards 1990). pers. co .
Hollard (e.g. 1965)has also beeninstrumental in establishingthe Devonianstratigraphy of the Anti Atlas. The Devonian palynology of Oum Doul-1, a well utilised, in the present study, has been previously analysedby Grignani & Mantovani (1964), howeverthe authorsonly accountedfor the chitinozoancomponents of the palynologicalassemblages in their contribution. No further publications on this stratigraphicinterval in Morocco are apparentin the literature, however, in-housepalynological investigationshave been undertaken in recentyears by organisationswith commercialinterests in the region (R. Rozza,Agip Ltd., pers. comm. 1991).
A brief summary of the tectonic and palaeogeographicevolution of the Anti Atlas region.
The tectonic evolution of the Anti Atlas is ratherunique in that the region has experiencedthe effectsof the Pan-AfricanEvent and eachof the Caledonian,Hercynian and Alpine orogenies.
Morocco is positionedon the northernmargin of the West African Cratonwhich was cratonisedin the early Proterozoic. The cratonoccupies most of West Africa and has actedas a core through the late Proterozoicand Phanerozoicinterval.
The Pan-AfricanEvent occurredduring the late Proterozoicand early Palaeozoicin the Anti Atlas and can be recognisedas an east-westtrending set of thrustsand faults effecting the Precambrianbasement and overlying early Palaeozoicsediments. This eventis largely maskedby youngersedimentary cover, howeverit is believedthat the Anti Atlas region is entirely underlainby the rocks of the Pan-African basementcomplex.
The palaeogeographicposition of Morocco during the Ordovicianwas at the northern margin of Gondwanawhich, through that system,migrated towards the southernmagnetic pole (figs. 3& 4). By the culminationof the Ordovician(Ashgill), Morocco was situatedat or near to the pole which is evident from the glacio-marinesediments recorded in the Anti Atlas of that age (Destombes,Hollard. & Willefert 1985).
The Caledonian Orogeny can be regarded generally as the result of the collision between Laurentia and Eurasiaduring the Silurian and early Devonian(figs. 4& 5). Morocco is believedto havebeen effectedby the collision of one or more microplateswith the northern,margin of the West African Craton (e.g. the 'Avalon-Florida microplate[Matte 1986] forming a northeast-southwesttrending folds Figure 3. An early Ordovician palaeogeographicreconstruction of Northern Gondwana, from Paris 1990.
LAURENTIA
52
tl.3 -k2
4- 414"4:555, ; 3 40 46- '37 6LTICA 45 B A:; -. emmly, -
...... 6c 0 EAN 11 31!
oQW SOQ 10 Jx0 : , 11,11tn 6, 2 4.-- 3 <1
29.
GONDWANA
12
13
6 Figure 4. Global palaeogeographic reconstructions for the latest Ordovician (Ashoill) and middle Silurian (Wenlock), from Scotese& McKerrow 1990.
QkKA -V -wr^-P I 4n nr%
Latest Ordovician (Asýgill)
o & McKerrow 199C
WiddleSilurian (Weniock) Figure 5. Global palaeogeographicreconstructions for the early Devonian(Gedinnian) and late Devonian(Famennian), from Scotese& McKeffow 1990.
Rnntim--im A KAt-t Early Devonian (Gedmian) Lý --6 -- - McKerrow 1990 Late Devonian(Farnenriian) and thrusts. Accommodationof existing crustalmaterial between these the colliding continentalarea is believedto havebeen achieved by northwarddipping subductionat the northern margin of the West African Craton. 7be effectsof the HercynianOrogeny, generally regarded to be the result of the collision of Gondwana and Laurasia,are more in evidencein the Anti Atlas. This is believedto be a near continuationof the CaledonianOrogeny with continuednortherly directedsubduction beneath the Laurasiancontinent. Evidencefor the early phaseof this episodeOate Devonian-early Carboniferous) is bestexposed in the westernpart of the Anti Atlas. Continuedsubduction and subsequentcollision of Laurasiaand Gondwanagave rise to the Mauritanidemountain range and folded sedimentsin a similar southeast- northwesttrend to that of the Caledonianphase. I.Ater in the Hercynianorogeny (mid-late Carboniferous),continued collision of the continentsgave rise to the Appalachianswith associatedlarge scaledextral movementswhich occurredmainly along the SouthAtlas and Elbe faults during the collision stage. By the closeof the HercynianOrogeny, the super-continentof Pangeahad formed. Relative continentalmovements resumed in the Middle Jurassicwith the openingof the Atlantic and the Tethys Oceans. The Tethys Oceanis envisagedas being a relatively narrow seawaythat extendedbetween the continentsof Africa and Eurasia. The spreadingof thesecontinents from eachother was reversedin the Late Cretaceousand, as a consequence,collision of thesetwo landmassestook placein the Neogene period and continuesto the presentday. This phase,known as the Alpine Orogeny,has had a major influenceon shapingthe Atlas Mountainsof Morocco as we seethem at the presentday. The lithostratigaphic framework. By the mid 1960's, the lithostratigraphicframework for the Anti Atlas region was well established, sincethen minor alterationshave been made. Chubert(1963) establishedthe principal componentsof the Precambrianand Iower Palaeozoicframework, while Hollard (1963) was primarily responsiblefor formalising the stratigraphyof the Devonianpart of the succession.Hollard in 1977revised this part of the sequencehimself. An overview and revision of the lithostratigraphyof the Ordovicianand Silurian stratigraphyof the Anti Atlas region can be found in Destombes,Hollard & Willefert (1985). Although well established,The RobertsonGroup (1985) in the courseof their South Atlas study found that the publishedlithostratigraphic framework required modification "in order to expressmore clearly the various aspectsof the geologywhich are important to any considerationof the petroleumpotential of southernMorocco". In the report, considerableeffort was madeto preserveas much of the existing frameworkas was practically possible. However changeswere considerednecessary to producea is but flexible, schemethat rational that is practicablefor surfaceand subsurfaceanalysis (i. e. field, 9 well and seismic) and that has greater consideration for lateral facies variation. A direct comparison between the published and the proposed Robertson Group lithostratigraphic schemesis given in figs. 6, 7&8. The presentstudy utilises the more flexible RobertsonGroup schemefor the reasonsof practicability. A brief descriptionof the relevantformations to the study follows with the publishedequivalents of the formationsindicated. The formationsare describedin stratigraphicorder: (Publishedequivalent: Outer Feijas ShalesGroup [part]). This group is a coarsening upward sequencecomposed of shales of the Fezouata Formation and Zini culminates in the western and central parts of the South Atlas region in the deposition of the (sandstone)Formation. Fezouata(shale) Formation. (Publishedequivalents: Lower FezouataShales Formation, Upper FezouataShales Formation). Age: Tremadoc4ateArenig. Thickness: Upto 400m Lithology: Greenishsilty mudstonesthat were depositedon a shallow marine shelf. Ilese sedimentsare generallypoorly exposed. Zini (sandstone)Formation. (Publishedequivalent: Zini SandstoneFomation). Age: Late Arenig. Thickness: Upto 450m. Lithology: Sandstonesand quartzites interbedded with mudstones. This formation is laterally impersistant and is composed of a number of coarsening upward sequences. Deposition is thought to have taken place under shallow marine, storm dominated conditions. Note: A non-sequenceis apparentat the top of the FezouataGroup indicatedby the absenceof uppermostArenig faunasin the Anti Atlas region. 10 0 V) LLJ V, ý a- Ma LU ui U D 0 :3 &E < ý- EXISTING FORMATIONS PROPOSED FORMATIONS LU ýO LITHOLOGIES a- 0 B P >- 5<- clý . . Ln of cc0 (j LUO West Members East West Central East Members 438 u Upper Second Rant C, Upper Spcond Rant(Sandýtonp) z Lower `lyccotidBani L(-)\&erScco Q, Fe Upper Kl.wua T 2 U-) IT. < 1,J 0 ()k 1 0 PA01 11p F 448 - u Rvm( Jpper I I,li it it it),, Klaoua (Sandstoneand Yialv) 0 6- L) lower Ktao(ja day ýawktorlp V cy- u Fe-Fe --Fe' z 458- < 1.7gouiren 0 FFe, CC) ()ý -- ULJz :.:... I.: . . -- - -i z Ouininut-hen . ýýr , ýý:::: :: -, - Uj -t 0 rn i- lp 7prt F I irýt Rant (ýandstonv) Q , ; 7,, F Taddriýt F Fe 468- lauuta u Lit > ct 0 T ar h i ll a Shal(, ý I A(hilla (Shale) c) 478 - ýAitql`Al OP t, j()T PROVLN ul o U lit ', tit ,7 u1i L 0- )l)per FeMtratil ShAIPS < CY D 0 Feouata (Shale) clD ...... 0 LIj Lower rpinilata Shali-s Lij > 0 505- c: llu -i LU-1 ýARSFN T 0 OR !l rl NOT FR( )V[ 14 7 - LLJ z 0 z 0 clý < co ji-bel I-tTigay,, Argillo mat jrhel Lrngay-;rnat 7- At ero(cous 525- Z A < _ ,, ag u "Ratleyella" Arg Aren labanite (Sandstone) c- .7 r Pidi Klifila SS U 1 -u 11-111 --- - al I :. ' :: z J, bcl Afraou (ýandýlnnp and Shalý) I Lj ...: . -..... ', LU V, awloonp of Jvbrl Aftaou 0 Z-1 ry LU 7 z -- U-1 Figure 6. The lithostratigraphic framework for the Ordovician System showing the comparison between the published lithostratigraphy and that proposed by the Robertson Group (1985). Bani Group. (Published equivalents:Outer Feijas ShalesGroup [part], First Bani SandstoneGroup, Ktaoua Clay and SandstoneGroup, SecondBani SandstoneGroup). This group is characterised.by numerousclean and argillaceoussandstone units intercalatedwith shales and silts. Tachilla (shale)Formation. (Publishedequivalent: Tachilla ShalesFormation). Age: Llanvirn. Thickness: 50-1150M. Lithology: Greenish silty mudstones. This formation is generally poorly exposed. Where the Zini Formation has not been deposited, distinction between the underlying Fezouata Formation from the Tachilla Formation on lithological grounds alone is a problem. However the later can be distinguished by the presence of Llanvirn aged macrofaunas. First Bani (sandstone) Formation. (Published equivalents: Taddrist Formation, Bou Zeroual Formation, Igzert Formation, Ounnrhen Formation, lzgouiren Formation). Age: Llandeilo. Thickness: Upto,550m. Lithology: Sandstonesand quartzitesintercalated with greenishsilty sandstoneswith frequent ironstones. This formation comprisesa seriesof coarseningupwards sequences that are frequently cappedby ironstones. The marinemacrofaunas suggest a shallow shelf marinesetting for depositionof the sandylithologies and the frequentoolitic ironstoneunits are thought to representperiods of very slow sedimentationor omissionsurfaces. TaourzoMember. Age: Earliest Llandeilo. Thickness: Upto 50M. Lithology: Oolitic ironstonesinterbedded with mudstones. Ktaoua(sandstone and shale)Formation. (Publishedequivalents: Lower ktaouaClay-Sandstone Formation which includesthe Foum Zguid, the Lower Tiouririne and the Bou Hajaj Members,Upper Tiouririne Formation, Rioud AssaFormation, Upper KtaouaFormation). 12 Age: Caradoc-Ashgill. Thickness: 250-500m. Lithology: Sandstonesand quartzitesinterbedded with mudstones.The formation comprises coarseningupwards sequences of largely shallow marinesediments with occasionalcoquinas and bryozoandebris horizons. lAterally equivalent deep water mudstonesaccumulated to considerable thicknessesin more offshore settings. Note: Lower Ashgill faunashave not, as yet, beenrecovered from the Anti Atlas region which suggests a possiblenon-sequence or hiatusat this level. Lower SecondBani (sandstone)Formation. (Publishedequivalent: Lower SecondBani Formation). Age: Late Ashgill. Thickness: Upto 160m. Lithology: Sandstone. This coarsening upwards sequencehas its upper surface truncated by an erosional surface. UgR2rSecond Bani (sandstone)Formation. (Publishedequivalent: Upper secondBani Formation). Age: Late Ashgill. Thickness: Upto loom. Lithology: Coarse,locally pebbly sandstones.These fining upwardssandstones are believedto be glacio-marinein origin (Destombes,Hollard & Willefert, 1985)and are probably the time equivalentof glacial sedimentswhich characterisethe upper Ashgill elsewherein North Africa. Tizi Ambed Group. ' (Publishedequivalent: Taskala Group [part]). This group representsa marinetransgression that occurredover the Anti Atlas region in the early Silurian. Mie sedimentsrest disconformablyon the glaciatedpalaeotopography of the late Ashgill. 7be formationsof the Tizi AmbedGroup haverestricted lateral distribution and are normally overlappedby the overlying CarbonaceousShale Formation. 13 0 L) T- LLI ý^ , Ma V) (L LU ll-UJI LU 4 D _ cc f- EXISTING FORMATIONS 0D B P ý0 LITHOLOGIES 0-0 PROPOSED FORMATIONS . . >- LU R ac 0 0ýý West (),f East West Central East a_ Mernbers Amer tx)h 1-tl z II Ansar w Z Lr Bernha ct Er RemliA l"I'I'lour 0 Mesd, ...... P1 Scheb ýJr mdlour Kkr CY' Still I - T 14,1o,11m, 391- ...... L mý, CL m 7A Seheh el U Aksai Rhaswl Mer7A Akhýai - < > 0 < Assa Assa r-T LLJ -. 1 a lhandar handar 401------ I fid I'lerzaric, rnln, R111,141d 0 - __-- -= --- 7 1 ---, --- 0U 40 (Iriqui ) sup . =S------sh, il, 0 -- 'A rn 0ý ------= 7..= D Upper Shales ------414- and Limestones ------It I(Ikjl ------Z: Eý 3= d, ------Oitlvyýras 0 -- 77,ý- Limeqonp Shal, ------Or thwrras ...... bmestmes D At Shale 421- gilla, eou; < ...... Qý 0 z Anv; aifikh Plaut Lij 0 ----- < Car bonareous Shale 428 - - U) ------z Ain Chebi Uj C) > V Sandstone 0 z Nit hek ...... Q 0 jj ')and Ip AmhedA .. hd ,,: Fcf)Ij %tone Shale 0 Am AinýT (), it r, S1, Delouiriv D clouinclouine(cl unc c ý - L4 r 438 1 11 r, - I -- Fý= Figure 7. The lithostratigraphic framework for the Silurian System showing the comparison between the published lithostratigraphy and ihat proposed by the Robertson Group (1985). Ain DelouineFormation. (Publishedequivalent: Ain DelouineFormation). Age: Latest Ordovician(G. persculptusZone)- Rhuddanian. Thickness: Upto 6m in the type section. Lithology: Well induratedlaminated mudstones, greenish grey, violet, pink or mauve-whitein colour. Sandstone-ShaleFormation. (Publishedequivalent: Tizi Ambed Formation?). Age: Rhuddanian-Aeronian. Thickness: Unknown. Lithology: Sandstonesand siliceousshales with epiclasticvolcanic elements. Ain Chebi (Sandstone) Formation. (Published equivalent: Ain Chebi Formation). Age: Aeronian. Thickness: Very variable over short lateral distances, upto 40m in the type section but upto 200m further to the west. Lithology: Sandstone,normally grey, violet or yellowish in colour. Ferruginousnodules occur towardsthe baseand the sequencefines upwardswith numerousclay partingstowards the top. Amsailikh Plain Group. (Publishedequivalent: Taskala Group [part]). Ile black mud deposits of the lower formation of this group represent maximum flooding of the Early Silurian transgression. However, continued deposition of coeval arenaceous;sediments, attributable to the underlying Tizi Ambed Group, do occur locally, for example at Iriqui. CarbonaceousShale Formation. (Publishedequivalent: Amsailikh Plain Formation [part], TarnaghroutFormation [part]). Age: Aeronian-early Wenlock. Thickness: ? The thickest sections occur in the Plains du Draa of the central and eastern Anti Atlas. Lithology: Carbonaceousand graptolitic black-greyshales. The shalesare white-pink when This formation is believed weathered. to be the oldestpotential sourcerock in the region. is AreillaceousShale Formation. (Publishedequivalent: Amsailikh Plain Formation [part], TarnaghroutFormation [part]). Age: Wenlock-earlyLudlow. Thickness: Unknown. Lithology: Generallygrey, micaceousshale with rare intercalationsof carbonatenodules. Grey- white shales,argillaceous sandstones and iron rich arenitesare lesscommon. The ArgillaceousShale Formation is generally distinguished from the underlying CarbonaceousShale Formation by its less homogeneous, lighter coloured micaceous lithology. However in the Tazzarine area, the former is a black organically rich shale which sits on a much reduced thickness of the CarbonaceousShale Formation. 7be graptolitic faunas present indicate a mid Wenlock-lower Ludlow age for these sediments which suggeststhat the early Silurian maximum flooding occurred later in this area. Trigui Group. (Publishedequivalent: Taskala Group [part]). OrthocerasLimestone-shale Formation. (Publishedequivalent: Orthoceras Limestone Formation) Age: Late Ludlow. Thickness: Upto approximately30m. Lithology: Normally black argillaceouslimestones with abundantorthoconic cePhalOpods, intercalatedwith shales. This forms the most easily recognisablemarker horizon in the Silurian sequence. CalcareousShale Formation. (Publishedequivalents: Upper Shalesand LimestoneFormation, ?Scyphocrinites Limestones Formation). Age: Late Ludlow-?early Gedinnian. Thickness: Unknown. The Formationis thickestin the Akka/Foum el Hassanregion. Lithology: Grey calcareousshales. ArgillaceousSandstone Shale Member. Age: Pridoli? Thickness: Unknown. Lithology: Argillaceousfine sandstone. 16 ýMhrocrinites Member. Age: Early Lochkovian? Thickness: Unknown. Lithology: Sandylimestones and calcareoussandstones with Scyphrocrinites.This member forms a useful markerhorizon at the top of the CalcareousShale Formation from Ain (oui-n) Delouine in the south-westto the Erfoud region in the ENE. Black ShaleMember. Age: Early Lochkovian? Thickness: Unknown. Lithology: Black organicrich shale. This can be found to ENE of the SouthAtlas region towardsthe top of the CalcareousShale Formation. Ile Devonianlithostratigraphic nomenclature proposed by the RobertsonGroup in their SouthAtlas study follows Hollard's and other workers ideasin being split up into threemajor east-westtectonically relatedregions, namely the Draa, Maider and Tafilalt. 7be well sectionfrom which the majority of the Devoniansamples analysed in the presentstudy came,Oum Doul-1, lies to the west of the Anti Atlas region. It is the Devonianlithostratigraphy of this westernregion that is describedbelow. 7be lithological descriptionsand formation thicknessesgiven are basedon datafrom Oum Doul-1. Rich Group. (Publishedequivalent: Rich Group [part]). Lmhaifid Formation. (Published equivalent: Lmhaifid Formation). Age: Gedinnian-early Siegenian. Thickness: Greater than 407m. Lithology: Grey and brownish grey mudstoneswith occasionalintercalated white or light grey sandstones.Both of theselithologies are locally calcareous. 17 1A UJ Ma UJI LU EXISTING FORMATIONS 0 PROPOSEDFORMATIONS li- w 0 LITHOLOGIES 0- 0 B. P. >_ LU 157<601 0 &A 4/1 cc 0ý 41A - L) West Members East West Central East Members - z < n < Oued 0 Oued D Znaigui Znatgui 0 D N 0 < 0 360- ....qwý. ! -Z- ýý ...... Tazout I Fezzou .7 ...... ar Fezzou Aoufital z Aoufilal < Lerngai z T W Y lbaOU, ne IJ Draa lbaouine wD _ H Doulya 0 C L. Inc ...... LLJCL 0. Anisid non 0Y 367- CL - def'o... ce - IIII 0 D Z' ____ - Z < z Afrou 0 z Afrou 1/3 _j < Ano6 rI-!, Q C-L Anoci Smaira < 0ý Smaira Z 11111 z 374- 05 w Megsen, Bou Dib z Medal I IIII w Bou-Dib i Z Sal L f_ III Y CS 5 Uj - ____ _. _ _ > 0 - C5 LU LU Taboo- _:I:---I- Tabou- C) Ahrerouch 380- ma kl ou f z 0 __Z7-: _-_ _=_ .. < z Tý T(ha ra ine 0 ui M ý > . Ui C Fl Otfal N ' Kheila El Otfal v r) C 0 Assa Assa Assa _j (L lhandar ...... lhandar 401- ...... z Lmhaificl Lfnha, fid Lrnha,fid Herzane 0 J2; ------Scyphocrinles Black ------'= ------408- 5cyphorrindes irnestonpý -- A, (Iriqui sup. ) _ M CalcareousShale V ------Of ------CL Upper Shales 1, cr_l 414- and impsiones ------Iff(pio .... T-7r =r. = R% ------lu Orthoceras Limestone Shale 0 ------Or 01c)(praS ...... 0 Limestones D _j Argillaceous Shale 421- - T - r Shalp L Carhonarpous Figure 8. The lithostratigraphic framework for the Devonian System showing the comparison between the published lithostratigraphy and that proposed by the Robertson Group (1985). AssaFormation. (Publishedequivalent: Assa Formation). Age: Siegenian. Thickness: 190M. Lithology: Dark grey mudstones with occasional intercalated white or yellowish brown sandstones. Both of these lithologies are locally calcareous. Merza Akhsai Formation. (Publishedequivalent: Akhsai Formation). Age: Late Siegenian. Thickness: 145m. Lithology: Intercalateddark grey mudstonesand white and light grey sandstoneswith light to mediumgrey limestonesbeds towards the top of the formation. Iron staining is evident in the sandstonelithology Mdaour el Kbir Formation. (Publishedequivalent: Mdaour el Kbir Formation). Age: Emsian. Thickness: 150m. Lithology: Dark grey mudstoneswith commonfine grained, calcareoussandstones. El Ansar Formation. (Publishedequivalent: Kebchia Formation [part]). Age: Emsian. Thickness: 150M. Lithology: Dark grey mudstoneswith commonfine grained, calcareoussandstones. N'Kheila Formation. (Publishedequivalent: Kebchia Formation [part], Yeraifia Formation). Age: Late Emsian-Eifelian. Thickness: 345m. Lithology: A coarseningupward sequencewith carbonaceousdark grey mudstonespredominating at the basewith fine grained,calcareous silty sandstonesmore commontowards the top. 19 Megsem-MdarsalGroujR. (Publishedequivalent: Megsem-Mdarsal Group, Draa Group). AhrerouchFormation. (Publishedequivalent: Ahrerouch Formation). Age: LatestEmsian-Givetian. Thickness: 200m. Lithology: Medium to dark grey mudstoneswhich are occasionallysilty and calcareouswith minor silty, calcareous,fine sandstones. Anou SmairaFormation. (Publishedequivalent: Anou SmairaFormation). Age: Givetian-Frasnian. Thickness: 1000M. Lithology: Dark grey, carbonaceousmudstones with rare fine sandstoneinterbeds. Draa Formation. (Publishedequivalents: 0. Amstil Formation, El Douiya Formation, LemgairinatFormation). Age: Famennian. Thickness: 264m. Uthology: Medium to dark grey or brownish grey, carbonaceousmudstones with rare fine light grey sandstoneinterbeds. Lefdar Formation. (Publishedequivalent: Tazout 1 Formation). Age: Late Famennian. Thickness: 157. Lithology: Dark grey, carbonaceousmudstones with rare fine sandstoneinterbeds. No group nameshave been proposed by the RobertsonGroup for their Carboniferouslithostratigraphic framework. 20 Tazout Fomiation. (Publishedequivalent: Tazout 2 Formation, Tazout 3 Formation). Age: Tournasian. Thickness: 239m. Lithology: Light grey and brownish grey calcareousfine to mediumgrained. sandstones with intercalatedmedium to dark grey or olive grey mudstones. 21 Chapter 2. Aims and Objectives. Ile aims and objectivesof the thesisfall into two categories. The first categoryincludes those that were set out at the start of the project which are essentiallythe reasonsfor the conceptionof the project by my sponsors,Simon Petroleum Technology (SPT). The secondset of aims and objectivesare those which aroseduring the courseof the study. The initial aims and obiectives. 1. The primary aim of the project is to extractpalynomorph assemblages from the Ordovicianto Devonianmacrofossil dated field samplesfrom the Anti Atlas of Morocco, in order to calibratethe palynomorph assemblagesagainst the macrofossil assemblages. 2. To refine techniquesfor the palynologicalpreparation of the Lower and middle Palaeozoicrocks with a view to their applicationin the field of industrial palynology. 3. To producea palynologicalzonation for the Ordovicianto Devonianinterval. Aims and obiectivesarising during the courseof the Rroiect. 1. To selectadditional samples(field or well) to thosethat are macrofossildated, with suitable lithologies for palynology, to fill in the stratigraphicgaps between the macrofossildated samples made available. 2. To establishthe lithostratigraphicposition of the field samplesutilised with the aid of field note books, the RobertsonGroup SouthAtlas Studyreport (1985) and the geologicalmaps of Morocco. 3. To refine the techniqueof oxidising palynological.preparations by the use of fuming Schulz's solution. 4. To analyse the practicability of suprageneric schemescurrently in use for the acritarchs and chitinozoans. 5. To adopta genericand specific taxonomyfor the acritarchsand chitinozoansthat is practicableto palynologistsworldng with a light microscopealone (i. e. not with SEM) which conformswith the rules of the ICBN. 6. To makegeneral palaeoenvironmental interpretations of the site of depositionof the samplesusing from the assemblagesrecorded, paticularly the relative abundancesof palynomorphgroups. 22 Chapter 3. Techniques. Palynological processingprocedure. The procedurefor the palynologicalpreparation of rock samplesfor the presentstudy is illustrated in the accompanyingflowchart (fig. 9). Ile techniquesemployed are practical and time-efficient, notably the oxidation of the thermally maturesamples. Thesetime-efficient techniquesare seenas flexible for use in future academicresearch or for use in the time consciousfield of industrial palynology. Between20 and 50g of dry rock, (dependingon the quantity of rock availableand the lithology; shales 20-30g, siltstonesand sandstones30-50g) were crushedto peasize or smallerfragments with a pestle andmortar. The rock was then testedfor the presenceof calcium carbonate(CaCo3) with dilute (10%) hydrochloric acid (HCI). If the samplereacted, it was immersedin 35 % HCI until the effervescent reactionwas complete. The samplewas then decantedseveral times until neutral. The non calcareoussample was then immersedin approximately100-200ml of 40 % hydrofluoric acid to breakdown the silicate minerals. It was left to standin the fume cupboardfor a period of between two daysand threeweeks. The samplewas stiffed twice daily and the HF replacedweekly in the cases where the rock was more indurated. Recent developments in microwave rock digestion technology, a technique currently under investigation at Sheffield University, has shown that the time taken for this part of the processing procedure can be drastically shortened, rock digestion usually taking less than 20 minutes. This technique, which was not available for the present study, will surely become more widely used in the near future. Post the HF digestion, the samplewas sievedthrough a 10umnylon mesh. If abundantorganic residue was retainedby the sieve, two kerogenslides were mounted(see below for the slide mounting procedure). The 10umplus residuewas then oxidisedfor between30 minutesto I hour in 70 % nitric acid. This was done primarily to remove any pyrite in the sample that may occur within the palynomorphs. The presence of pyrite within the palynomorphs would cause them to sink during heavy liquid separation. The sample was then neutralised. The organic residuewas separatedfrom the remainingmineral matterusing heavy liquid separation. The into samplewas pipetted a centrifugetube and the heavyliquid, zinc chloride (SG 1.54) added. The for 15 tube was centrifuged approximately minutesat 2000 RPM. The floating organic residue was then 23 Figure 9. Palynological processing flowchart. 24 beaker, transferredto a glass acidified slightly with two drops of HCI and sieveduntil neutral. Two slidesof the residuewere then mounted. If further any sampleremained, oxidation of the samplewas carried out. The Ordovician, Silurian and Lower Devonianfield samplesprepared in the presentstudy were found to be of high thermalmaturity and requiredintense oxidation. Extendedoxidation using Schulze'ssolution was found to be unsuccessfulin attemptingto bring aboutsome degree of transparencyof the palynomorphs. Breakage occurredprior to them becomingtransparent using this oxidation agent. However, a techniqueusing finning Schulze'ssolution, commonlyemployed on the high maturity Carboniferousassemblages of southernEire (Higgs and other workers) which was recentlydeveloped upon by researchersat SouthamptonUniversity (R. Knight and P. lake pers. comm. 1990)proved to be very successful.The solution is composedof fuming nitric acid (98 %) saturatedwith potassiumchlorate. The blood red coloured fuming Schulze'ssolution was addedto the organic residuefor betweenfive and 15 minutes. This achieveda more than adequatedegree of transparency,with limited breakage,for detailed taxanomicanalyses of the palynomorphs. This techniquewas found to be of particular value in chitinozoananalysis as thinning of the vesiclerevealed the detail of surfaceornamentation inmany specimens.Mounted and unmountedresidues treated with fuming Schulze'sare apparentlyprone to reversionback to a the black, opaquecondition if subjectedto prolongedatmospheric temperatures (R. Knight & P. Lake pers. comm. 1989). For this reason,the residuesand slidesare presentlystored in a refrigerator. Samplestreated with fuming Schulze'sapproximately two yearsago havenot yet reverted under refrigeratedconditions. The Devoniancore samplesfrom Oum.Doul-I were found to respondbetter to normal Schulze's solution than did the field samples. The downholesamples were oxidisedwith normal Schulze'sfor a maximumof 16 hours with samplesfrom the upholeLate Devonianinterval only requiring approximatelyfive minutesoxidation. Research into microwave stimulated oxidation of palynological residues, also at Sheffield University, is being developed Initial presently . results suggest that acid concentration and oxidation time can both be greatly reduced using the microwave technique (S. Ellin & D. McLean pers. comm. 1990-1992). The research is ongoing. An additional two slides, as a minimum, were mountedafter the major oxidation stage. If any residuewas remaining,it was split using a 53um sieveto isolatethe chitinozoa. The 53um plus fi-actionwas then mountedon a slide. 25 The Slide mounting: neutral organic residue was immersed in poly-vinyl alcohol (PVA) to disperse the palynomorphs and pipetted onto a cover slip positioned on a hot plate. The cover slip, when dry, was then mounted on a biological slide using petropoxy 154 as the mounting medium. Amdytical procedure. 17hepreparation procedure employed produced upto four setsof slidesfor eachsample: 1. Post HF kerogenslides. 2. Post nitric slides. 3. Schulze'sor fuming Schulze'sslides. 4.53urn slides. For every sample, post nitric slides were mounted, with Schulze's or faming Schulze's slides made up if any residue remained. The slide from which a palynomorph count was made was selected from one of these two sets, selection depending on which contained the better preserved palynomorphs. A standard count of 250 palynomorphs (acritarchs, chitinozoans, prasinophytes and spores) was made from the selected slide and at least two, and upto five slides were scanned for additional or well preserved photogenic specimens. The 53um slides, if available, were also scanned for supplementary chitinozoan taxa. Photography. The photomicrographsof the palynomorphswere takenon a Reichert-JungPolyvar microscopewith an 80B colour correctionfilter. Kodak KodacolourGold 100 or 200 ASA film was usedand the films were processedat MasterlabLtd., Sheffield. The final plateswere printed by Mr. B. Piggot, University of Sheffield. Computer applications. The computingpackage Tilia hasbeen used to generatethe illustrations of the presenceand relative abundancesof palynornorphsrecorded and the clusteranalyses of the assemblagesfrom the samples analysed. The manuscripthas been produced using the IBM compatableword processingapplications Word 5.1 and Wordfor Windows. 26 Chapter 4. The Acritarcha Evitt 1963. Introduction. The first collective name for this group of microfossils, prior to the introduction of the term acritarch, was the 'hystrichospheres'. The Group Acritarcha was erected by Evitt (1963) in order to accommodate the numerous miscellaneous hystrichospheres that were not assignable to recognised plant groups at that time e. g. the Dinophyceae, the Prasinophyceae, and the land plant spores. Since 1963, several groups of morphotypes within the Acritarcha have been reinterpreted as having affinity to recognised plant groups, some of these interpretations, in my opinion, are correct, some are incorrect. Ile Acritarcha can be viewed as an amorphous amoeboid collection of microfossils that we should aim to reduce in size. This we should do by reassigning morphotypes within it that, on the basis of research can be reassigned, without question, to a recognised biological group. The Group Acritarcha (Evitt 1963)was originally definedas "Small microfossilsof unknownand probably varied biological affinities consistingof a centralcavity enclosedba wall of single or multiple layers and chiefly of organiccomposition; symmetry, shape, structure, and ornamentationvaried; central cavity closedor communicatingwith the exterior by varied means,for example:pores, a slit like or irregular rupture, a circular opening(the pylome)." This definition was restrictedby Fensome et al. (1990) to accountfor the introduction of the colonial spheromorphgroup, the CryptarchaDiver & Peat(1979, p. 404). The restricteddefinition of Fensomeet al. (1990, p. 3) is as follows: "unicellular, or apparentlyunicellular, non colonial organic-walledmicrofossils of unknownor highly questionableaffinity, occurring in palynologicalassemblages'. The acritarchsare a polyphyletic group of fossils (Evitt 1963; Downie, Evitt & Sadeant1963) which are commonlythe dominantgroup of microfossilsin Palaeozoicrocks. Various aspectsof the group, including morphology,possible biological affinity and classificationare discussedin the following sections. Acritarch momhology. Ile morphologicalterminology adopted for the descriptionof the Acritarchahas been somewhat inconsistent. Severalglossaries of termshave been published, e. g. Lister 1970, Kjellstrom.1971a. Unfortunately, theseglossaries include somedinoflagellate cyst terms for acritarchmorphological featuresthat are potentially misleading. 7he functional implications of someof the dinoflagellatecyst terms used e. g. cyst, cingulum, if applied to acritarchs, may be interpreted as having a dinoflagellate style of function for the acritarch specimen in question. The potential for this type of confusion to arise can be avoided by using terms that have no implication for the mode of life of the acritarchs, as we are presently unaware of the true affinities of forms included in this group. The alternative terms used here keep dictionary are those already available so as to the of descriptive terms to a minimum. 27 A glossary of terms follows which is drawn from three sources, the published glossaries of Kjellstrom (1971) and Lister (1970) mentioned above with the addition of information personally conveyed by Professor C. Downie. Central body: Mie test minus the processes.Synonymous with vesicle. Cluster. Discoid or sphericalshaped agglomeration of similar individuals. Distal: In an outward direction from the geometriccentre of the vesicle. A term commonlyused with referenceto the processes. Epibystra: A circular opening positioned at the apex of a cone shapedprocess. Epityche: A flap-like openingat the lateral margin if a flattenedvesicle. Equatofial split: An openingformed be the splitting of a sphericalvesicle into two equalhemispheres. Heteromorphic. Processeshaving a variablemorphology on a specimen. Homomorphic. Proceweshaving the samemorphology on a specimen. Lippedpylome: Circular openingof the vesiclewith a raisedrim at the margin. Longitudinal split: A slit-like opening running parallel to the longitudinal axis of the vesicle. Marginal split: A slit-like openingat the lateral margin of a flattenedvesicle. Me,diwn split: An openingformed by the splitting of an elongatedvesicle into two more or lessequal halves. Opening: A regularly shaped aperture in the wall of the vesicle. It is commonly regarded as the aperture through which the vesicle contents (the protoplasm) escapedto continue the life cycle of the acritarch, i. e. having a similar function as the archaeopyle in dinoflagellate cysts. Cýýculwn: The part of the vesiclewall lost in the formation of a pylome, an epitycheor an epibystra. Orn,ament: projectionson, or sculptureof the test. Elements2um in height and lessare consideredto be be ornamentation. Onuu=tation may scabrate,granulate, baculate, echinate or in the form of ridges. 28 Process: A prominentprojection from the vesicle, here consideredto be greaterthan 2um in height. Process base: That part of the process adjacent to the vesicle. Ibe process base may be angular, curved or constricted. Processbranching: Ile furcation of the processdistally. Branchingmay be bifurcate, trifurcate, palmate,ramusculose/multifurcate, floreate or digitate. Processdistribution: Processesdistribution may be regular, apical, linear, bipolar or unipolar Processshaft: That part of the processbetween the processbase and the processtermination. Ile shaft may be conical, cylindrical or inflated. Process termination: Ile distal part of the process. The process termination may be accuminate, truncated, capitate, bulbous, rounded or, branched. Praximal: In an inward direction towardsthe geometriccentre of the vesicle. A term commonlyused with referenceto the processes. Pylome: A circular openingof the vesicle. Plug: An accumulationof organic matterat the baseof a processdividing the processcavity from the vesicle interior. Stigmata: An openingof the vesiclein the centreof one of the flattenedsurfaces of a flattenedvesicle. Test: The organic test as a whole. Testshape: The overall shapeof the acritarch. The termsused here are acanthomorphicwith a roundedvesicle, acanthomorphicwith a polygonalvesicle, acanthomorphicwith an elongatedvesicle, polygonal, spherical,fusiform, cylindrical, flattenedor discoid. Vesicle: The test minus the processes.Synonymous with centralbody. Vesick 7be communication: separationor non-separationof the processcavity from the interior of the vesicle. 29 Figure 10. Acritarch morphology. Acrltar. Qh-W-"r hoLM a. a. A briefly labelled specimenof Die-rallqphaýissp. Q- vesiclewall U) Test sh=. C, omament b. Acanthomorphwith roundedvesicle C. Acanthomorphwith polygonal vesicle d. Polygonal e. Spherical L Acanthomorphwith elongatedvesicle g. Fusiform h. Cylindrical ee i. Flattened j. Discoid QptningtyprL fg k. Pylome, with the correspondingoperculum, 1. Lipped pylome m. Epibystra n. Stigmata 0. Marginal split Openfnatypes. P. Epityche q. Medium split k. r. longitudinal split S. Equatorial split e s. 30 31 Figur* 11 (cc>ntinuej). - Acritärch Mrphology Processcsto Vesic1crelationship. a. Freecommunication between the process cavity and the vesicle b. Solid processes C. Scaled. 7be processcavity Is scaledfrom the vesicle by the inner wall 12)'Cf- d. Plugged.Ile baseof theprocess cavity Is pluggedby an accumulationof Oftlr'1*4 matter Processesdistribution. C. Regular f. Apical g. Linear h. Dipolar 1. Unipolar Processbase. J. Angular k. Curved 1. Consuicted M. Conical n. Cylindrical 0. Inflated Rrocess terminations. P. Accuminate. q. Truncated. r. Capitatc. S. Bulbous. t. Rounded. Process branching. U. Simple, not branched. V. Bifurcatc. W. Trifurcate. X. Palmate. Y. Ramusculoseor multifurcate. Z. Floreate. aa. Digitate. 32 TEXT BOUND INTO THE SPINE Acritarch m Process-vesicle relationship. a. b. C. d. Distributionof thp,.pMOMM 9. -of Process bases. Process shafts. I. k. . M. n. 0. Process terminations, p- q. S. Process branchina. 1 cla 33 Wall: 7le organic wall of the test which consists of one or more layers. Where two wall layers occur, they are simply referred to as the inner and outer layers. If three layers occur, the middle layer is referred to as such. Biologicalaffinity. Acritarchs are, by natureof their definition, a group of microfossilsof unknown or uncertainaffinity. However, many acritarchsshow closely comparablemorphological features to recognisedmicrofossil groups. The Dinophyceaeshow a remarkablesimilarity in morphologyto many generapresently included in the Acritarcha. This similarity was investigatedto a considerableextent by Lister (1970) who proposed tabulationconfigurations for speciesof Cymbosphaeridiumwhich he recordedfrom the Ludlow of Shropshire. The anomalousoccurrence of Arpylorus Calandra1964 emend. Sadeant 1978 in the Silurian, which is consideredto be a dinoflagellatecyst genus(Lentin & Williams 1989; Fensomeet al. 1990), suggeststhat perhapsmore generaof acritarchsmay be demonstratedto be closely relatedto the dinoflagellatesby future research. A numberof acritarchsshow closemorphological similarities to the phycomastage in the life cycle of someprasinophyte genera. Although somegenera that were originally included in the acritarchsare now universally acceptedas prasinophytes, e. g. TasmanitesNewton 1875,Pterospermella Eisenack 1975, many are still in dispute(Colbath 1979; 1983), seethe Prasinophyceanalgae chapter herein. Comparisonand transfersof acritarchsto the Chlorophytais also apparentin the literature (rappan 1980). A notablegenus which is relevantto this study is DeflandrastrumCombaz 1962. This is a four celled form which, althoughappearing superficially similar to the presentday Pediastrum,can not be placedin the Chlorophytawithout question. For this reasonDeflandrastrum is includedin the Acritarchahere. Spheromorphicacritarchs with low ornamentationor a smoothvesicle wall may in somecases be relatedto the land plants. From middle Ordovicianrecords and younger, the time of land plants development,it is quite possiblethat suchspherical bodies may be aletemiospores of land plant origin. Detailed investigationof the wall ultrastructureof suchbodies would have to be undertakento elucidate suchquestions. Acritarch classification. Evitt For purely practical reasons, (1963) recommendedthat the Acritarcha should be treatedunder the sameclassificatory code as the dinoflagellateswhich is the InternationalCode of Botanical Nomenclature(ICBN). Earlier, Downie, Williams & Sadeant(1961) had proposedthat fossil organic 34 shelledmicroplankton, which includedthe dinoflagellatesand the then namedhystrichospheres, should be classifiedas plants and subjectto the rules of the lCBN- Evitt, in 1963, endorsedthis view. Prior to the introduction of the Acritarcha, severalfamily nameswere in use for the hystrichospheres e.g. LeiosphaeridaeEisenack 1954, Hystrichosphaeridae Wetzel 1933, Diplotestidae,Cookson & Eisenack1960. In order to reorganisethe supragenericframework post the introduction of the group Acritarcha, Downie, Evitt & Sadeant(1963) published 13 subgroupsof acritarchs. The subgroups were recognisedas not conformingto the rules of the ICBN by the authorsbut were proposedas a purely mechanicalmeans of supragenericgrouping. A list of the 13 subgroupsof Downie Evitt & Sadeantfollows with an indication of the correspondingpre 1963 family namesfollows. The present systematicposition of the subgroupis indicatedif it is no longer included in the Acritarcha. SubgroupACANTHOMORPHITAE Downie, Evitt & Sadeant1963, equivalentto the Hystrichosphaeridae(pars) Wetzel 1933a. Subgroup POLYCONOMORPHrrAE Downie, Evitt & Sarjeant 1963, equivalent to the Hystrichosphaeridae (pars) Wetzel 1933a. SubgroupSPHAEROMORPHrrAE Downie, Evitt & Sadeant1963, equivalentto the Leiosphaeridae Eisenack1954. SubgroupNETROMORPHITAE Downie, Evitt & Sadeant1963, equivalentto the Netromorphitae Eisenack1938a. SubgroupDIACROMORPHITAE Downie, Evitt & Saxjeant1963, equivalentto the Dicrodiaceae Timofeev 1958, the DiomatosphaerideaDownie 1958and the TrachydiacrodidaeDeflandre & Deflandre-Rigaud1962. SubgroupHERKOMORPHITAIE Downie, Evitt & Sadeant1963. Someauthors believe that all species that are accommodatedin this subgroupare assignableto the ClassPrasinophyceae Round 1971, e.g. Tappan1981. The presentauthor believes only someof the speciesincluded here can bejustifiably transferredat the presenttime. Subgroup PTEROMORPHITAF. Downie, Evitt & Saýeant 1963, equivalent to the Pterospermopsidae (pars) Eisenack 1954a. Speciesincluded here are now assignable to the Class Prasinophyceae. SubgroupPRISMATOMORPHrrAF, Downie, Evitt & Sadeant1963. SubgroupOOMORPHrrAE Downie, Evitt & Sadeant1963. 35 Subgroup STEPHANOMORPHITAF. Downie, Evitt & Sadeant 1963. Species included here are now included in the Class Dinophyceae Fritsch 1929. Subgroup DISPHAEROMORPHITAE Downie, Evitt & Sadeant 1963. Subgroup DINETROMORPHITAE Downie, Evitt & Sarjeant 1963, equivalent to the Diplotestidae (pars) Cooksonand Eisenack1960. Speciesincluded here are now included in the ClassDinophyceae. SubgroupPLATYMORPHITAE Downie, Evitt & Sarjeant1963. Speciesoriginally assignedhere are now included in the ClassDinophyceae. In addition to the initial 13 subgroupings,Staplin Jansonius & Pocock 1965published the subgroups Baltisphaeritae,which is essentiallya subsetof the Acanthomorphitae,the Leiosphaeritae,which is identical to the Sphaeromorphitaeand the Tasmsinataewhich is equivalentto the family Tasrnqnaceae Sommer1956. In 1967, Seagrovespublished the subgroupSchizomorphitae which incorporated spherornorphswith an equatorialsplit. Brito introducedthe subgroupsScutellomorphitae (Brito 1967a) and the Retractomorphitae,(Brito 1969), the former to accommodateMaranhites type forms, the latter for TrianguUnatype forms. The only other subgroupingsthat havebeen published are the ReticulasphaeromorphitaeSinha 1969which includesreticulate spheromorphs, as the nameimplies, and the CoryphomorphitaeVavrdova 1973which includespad shapedforms with decoratedapices. In 1979, Cramer& Diez publisheda comprehensivekey to generawhich utilises someof the subgroupingspublished previously. They divided the acritarchsinto threebroad units as follows: Unit 1. Sphaeromorphitae:Unit consistingof spheromorphswith a smoothor little ornamented vesiclewall. Unit 2. Ilose acritarchsthat do not belongto the spheromorphs(Unit 1) and the acanthomorphs(Unit 3). Unit 3. Acanthomorphiticacritarchs: Acritarchspossessing processes. This overwhelminglylarge unit was subdividedinto threesubunits. a. The Netromorphitae. Fusiform acanthomorphs. b. Diacromorphitae Acanthomorphswith a bipolar distribution of processes. c. Acanthomorphitae.Acanthomorphs with a regular distribution of processes. The main criticism of this key is the total disregardfor the methodof openingas a morphological featureof the acritarchs. It would appearlikely from comparisonwith other algal groups, e.g. the is Dinophyceae,that this phenomenon biologically significant and should, therefore,not be ignored. 36 An unpublished suprageneric schemeof Downie, personally conveyed to the students on the 1988-89 palynology M. Sc. course at the University of Sheffield, has some very interesting aspects. The scheme splits the acritarch genera into 19 complexes based not only on morphology, as did the scheme of Downie, Evitt & Sadeant 1963, but on both morphology and their distribution in time. The restriction of a particular morphotype to a relatively narrow time interval may well indicate a biological relationship between taxa falling into that complex. Providing further information as to the possible biological relationship between taxa is probably the major benefits of constructing a morphological suprageneric scheme. As for the other supposedbenefit of a suprageneric scheme, i. e. rapid location and retrieval of taxa, it is hard to imagine a purely morphological scheme in which taxa are more easily located than in a system where taxa are listed alphabetically. The author believesthat the supragenericordering of acritarchson a morphologicalbasis will only createproblems for future workerswishing to use this pieceof work. The publishedscheme of Downie, Evitt & Sadeant1963 is far from ideal, as indicatedby the additionalwork of Downie (pers. comm. 1989). This suggeststhat alterationswill be madeor alternativeschemes will be usedby future workers. Evolution of suchartificial supragenericschemes leads to frustration and time wasting for workers wishing to locatea particular taxonburied in a schemethat is out of date. For thesereasons, acritarchtaxa are listed alphabeticallyin this thesis. 37 Acritarch systematics. In this section all taxa are listed alphabetically for the reasons outlined in the previous chapter. All size dimensions given are based on five specimensmeasured, unless stated otherwise. Synonomyfor the Acritarchalargely follows that of Fensomeet al 1990. However, where there is disagreementwith this publication, remarksare madeunder the tax&concerned. Selectivesynonomy lists for thesecontroversial taxa are included. The agesstated here for the holotypesof the speciesare thosesited by their authors. Group Acritarcha Evitt 1963. GenusAcanthodlacrodium Timofeev 1958 emend. Deflandre & Deflandre-Rigaud 1962. Synonomy: 1961,Priscotheca, Deunff, p. 42-43. Type species: Acanthodiacrodium dentiferum Timofeev 1958. Genericdescription: Timofeev 1958,p. 831; Deflandre& Deflandre-Rigaud1962, p. 194. Remarks: The genusActinodissus Loeblich & Tappan1978 includes species with a thinner wall than thoseincluded in Acanthodiacrodiwn. PriscothecaDeunff 1961is here consideredto be a junior synonymof the Acanthodiacrodiumas suggestedby Cramer& Diez (1979). Acanthodiacrodiumamplium Rasul 1979. Plate 1, figs. 1&2. Description: Rasul 1979,p. 64, pl. 2, fig. 1. Holotype: Rasul 1979, pl. 2, fig. 1. Age: Tremadoc. Remarks: Acanthodiacrodiumwnplium differs from A. computulumRasul 1979by having broaderand longer processes. 38 Acanthodiacrodiumangustizonale Burmann 1968. Plate 1, figs. 3 & 4. Description: Burmann1%8, p. 641, pl. 1, fig. 8. Holotype: Burmann1968, pl. 1, fig. 8. Age: Late Llanvim. Remarks: Morphologically similar speciesinclude A. plenum Timofeev 1959and A aciferum Timofeev 1959.The former appearsto haveless rigid processesand a more sphericalcentral body. Acanthodiacrodiumaciferum has a very similar body shapeand processmorphology to A. angustizonalebut, from the illustration of the holotypeby Timofeev 1959, it appearsto have considerablyfewer processes. Acanthodiacrodiumconstrictum (Deunff) Downie & Sadeant1965. Plate 1, figs.5 & 6; pl. 14, fig. 1. Description: Deunff 1961a,p. 43-44, pl. 3, fig. 8; for an English translationsee Eisenack, Cramer & Diez 1979,p. 13. Holotype: Deunff 1961a,pl. 3, fig. S. Age: Tremadoc. Remarks: Specimensof A. constriciumrecorded here have a varying degreeof equatorialconstriction. In addition to thoseclosely resemblingthe holotype, a considerablenumber of specimensincluded here have a similar morphologyto A. (Diornatosphaera)cf. constricrumsensu Deunff 1961which has a less markedconstriction of the centralbody at the girdle. Acanthodiacrodiumcostatum Burmann 1968. Plate 1, figs.9,10 & 11. Description: Burmann1968, p. 640, pl. 1, fig. 5. Holotype: Burmann1968, pl. 1, fig. 5. Age: Late Llanvim. 39 Remarks: Acanthodiacrodium costatum is distinguished from the majority of Acanthodiacrodium species by the presence of longitudinally arranged ribs in the region of the girdle. Acanthodiacrodium latizonale Burmann 1969 and A. rectinerve Burmann 1968 also possessribs but these two species differ by having more prominent spines than A costatum. Acanthodiacrodium tassefil Martin 1968 also possessesfeint ribs but the processesof this species are also longer and greater in number. Acanthodiacrodiumraia (Deunff) EisenackCmmer & Diez 1979. Plate 1, figs.7 & 8. Synonomy: 1961, Priscotheca raia, Deunff, p. 42-43, pl. 3, fig. 2. Description: Deunff 1961a,p. 42-43, pl. 3, fig. 2; for English translationsee Eisenack, Cramer & Diez 1979, p. 20. Holotype: Deunff 1961a,pl. 3, fig. 2. Age: Tremadoc. Remarks: Fensomeet al. 1990retained the genusPriscotheca Deunff 1961, of which 'P. raia' is the type species,for the sole reasonthat Volkova 1988published another species in that genus. The presentauthor sideswith Cramer& Diez 1979in this case(p. 89) in discardingthe genusPriscotheca and accommodatingall speciesof that genuswithin Acanthodiacrodium. A numberof specieswhose morphology varies only slightly from that of A. raia havebeen split on very minor variationsin the shapeof the baseof the process,shape of the centralbody and size. Susceptibilityof theseelongate forms to folding and distortion in compressionmakes splitting of this group of morphotypeson suchcharacteristics rather arbitrary. 7be speciesA. prismatic (Deunfo Eisenack,Cramer & Diez 1979,A. minima (Deunff) Eisenack,Cramer & Diez 1979and A. compliant (Deunff) Eisenack,Cramer & Diez 1979are all closely comparableand require biometrical analysisof their populationsto establishthe legitimacy and the scopeof thesespecies within this complexof forms. 40 Acanthodiacrodium seleawn Timofeev 1959. Plate2, figs. 1&2. Description: Timofeev 1959b,p. 75, pl. 6, fig. 34. Holotype: Timofeev 1959b,pl. 6, fig. 34. Age: Late Cambrian. Remarks: Specimensassigned here have a rather thick, robust wall. Acanthodiacrodiumuniforme Timofeev 1959. Plate 2, figs. 3,4 & 5. Synonomy: 1959, Acanthor oldodiacrodium serotinwn Timofeev, p. 82, pl. 7, fig. 9. . 1959,Acanthorytidodiacrodium diffuswn Timofeev, p. 86, pl. 7, fig. 27. Description: Timofeev 1959b,p. 69, pl. 6, fig. 2. Holotype: Timofeev 1959b,pl. 6, fig. 2. Age: Mid-Late Cambrian. Remarks: Of the 51 speciesof Acanthodiacrodiumand 34 speciesof 'Acanthorytidodiaaodium' (the majority of the speciesoriginally describedin Acanthoryt"iaaodium are now accommodatedin Acanthodiacrodium,[Fensome et al. 1990]) describedby Timofeev (1959) from the Soviet Cambrian, thereis much room for synonomyas one might expect. Specimenshave an ovoidal centralbody with roundedapices. Spine length varies between2-Sum in length and breakageof the spinesis common.7be girdle occupiesapproximately 1/4-1/3 of the length of the body. 7bere are no longitudinal ribs or striationsin the region of the girdle. 7be vesicleis 30- 45um in length. Acanthodiacrodiumcostatum Burmann 1968 is similar in overall shapebut differs in having ribs id the areaof the girdle. 41 UNIVErI-U"Cý 4 Acanthodiacrodium varvrdovae Cramer & Diez 1977. Plate2, fig. 6. Description: Cramer & Diez 1977a, p. 343, pl. 5, figs. 4,5 & 9. Holotype: Cramer& Diez 1977a,pl. 5, fig. 5. Age: Early Arenig. Remarks: A morphologicallysimilar speciesis A. petrovi Timofeev 1959which differs in having markedly fewer processesat eachpole. AcanthodiacrodiumcL vulgareTimofeev 1959ex Downie & Sadeant1965. Plate2, fig. 10. Holotype: Timofeev 1959b, pl. 7, fig. 27. Age: Late Cambrian. Remarks: Comparewith Timofeev 1959b,p. 86, pl. 7, fig. 27 and Downie & Sadeant1965, p. 81. Specimensassigned here have a squatcylindrical centralbody, a girdle occupyingapproximately 1/3 of the body length and short stout processesat the poles. Specimensare 35-40umin length. The holotype of A. vulgarehas a similar body shapeand processmorphology to A. cf. vulgarebut it hasnoticeably fewer processes.The type materialis also larger in size, the centralbody ranging in length between51-40urn compared to 35-40umin length here. Acanthodiacrodiumsp. 1. Plate2, figs.7,8 & 9. Description: Acanthomorphicacritarchs with processesconcentrated at eachpole of the centralbody. The centralbody has a strongly polygonalaspect as a result of the conical shaped'Goniosphaeridium type' processes.17he body is as broad as it is long (the length rangesbetween 22-3 lum). The girdle is poorly definedand occupiesapproximately 1/4 of the length of the centralbody. The processesare coneshaped, upto 10umlong and upto 7um wide at the basetapering distally to truncatedor accuminatetips. The wall is composedof a single wall layer and the processescommunicate freely with the centralbody. The wall is smooth.No regular form of openingis apparent. 42 Remarks: This specieshas similar process morphology and a similar polygonal aspect to the central body as has A. constriawn described above. However, Acanthodiacrodiwn sp. I has a more equidimensional central body and little, if any, constriction at the girdle. Acanthodiacrodiumsp. 2. Plate 2, figs. 11-14. Description: Acanthomorphicacritarchs with processesconcentrated at eachpole of the centralbody. The centralbody is flattened(as in Veryhachium)and has a strongly polygonal aspectas a result of the Tolygonium type' processes.The body is generallyequidimensional. The girdle occupies approximately3/4 of the centralbody and the length of the body rangesbetween 22-29um. Processes are long, upto l5um in length, with broad polygonalbases and accuminatetips. The wall is composed of a single wall layer and the processescommunicate freely with the centralbody. The wall is smooth. No regular form of openingis apparent. Remarks: This speciesis distinguishedfrom other speciesof Acanthodiacrodiumby the flattened polygonalbody and 'whip-like' processes.It closely resemblessome of the Polygoniumspp. observed from the Tremadoc-Arenigaged samples in the presentstudy. The most notablesimilarity is with A gracile vars. 2&3 describedbelow. This form also has a polygonal centralbody but they differs in having a more regular distribution of processes. GenusAcdno&ssus Loeblich & Tappan 1978. Type species:Actinadissus longitaleosus Loeblich & Tappan1978. Generic description: Loeblich &Tappan 1978, p. 1236-1238. Remarks: Actinodissusis distinguishedfrom Acanthodiacrodiumin possessinga thinner vesiclewall. 43 Actinodissusrectinerve (Burmann) comb. nov. Plate 14, figs.2,3 & 4; pl. 40, figs. 1,2 & 3. Synonomy: 1968,Acanthodiacrodium rectinerve Burmann,p. 641, pl. 1, fig. 7; pl. 7, fig. S. Description: Burmann1968, p. 641, pl. 1, fig. 7; pl. 7, fig. 5. Holotype: Burmann1968, pl. 1, fig. 7; pl. 7, fig. S. Age: Late Llanvim. Remarks: This ffiin walled, granulatediacrodian species described from the Llanvirn by Burmann (1968) is better accommodatedin the genusActinodissus. Specieswithin the genusAcanthodiacrodium are generallymore robust in appearancewith a thicker wall. In addition, Acanthodiacrodiumspecies generallyoccur in older sediments(usually Late Cambrian-Arenigin age)than the thinner walled Actinodissusspecies. Actinodissus sp. 1. Plate 3 1, fig. 1. Description: Acanthomorphicacritarchs with processesconcentrated at eachpole of the centralbody. The body is elongateellipsoidal and measures35-40um in length and 20-25umwide at the girdle, the girdle occupyingapproximately 1\4 of the length of the body. Eachpole has a concentrationof about 20 processesmeasuring between 10-15um in length and upto 3um wide at their base. 7be processesare simplewith accuminatetips and they communicatefreely with the centralbody. 7be wall is thin and composedof a single layer with a smoothor granulatesurface. No regular form of openingis apparent. Remarks: Actinodissuscrassus Loeblich & Tappan1978 has a more equidimensionalcentral body and has a longer and more slenderprocesses than Acrinodissus sp. 1. The former also differs in possessing striationson the centralbody. Actinodissuslongitaleosus Loeblich & Tappan 1978has more straight sidedprocesses which gives a more polygonalaspect to the shapeof the central body of this species. In addition processesare longer, more slenderand are ornamentedwith fine grana. Actinodissusubuii (Martin) Fensomeet al. 1990has shorterspine-like processes and a striate centralbody. 44 Actinodissussp. 2. Plate 14, fig. 5. Description: Acanthomorphicacritarchs with the processesconcentrated at eachpole of the central body. Ile body is elongateellipsoidal and measures35-44um in length and 25-35umwide at the girdle. The girdle occupiesapproximately 1\3 of the length of the body. Eachpole has a concentration of about 15 processesmeasuring up to 15umin length and up to 4um wide at the base. Ile processes are broad with accuminatetips and they communicatefreely with the centralbody. Ile wall is thin and composedof a single layer and the wall surfaceis granulate. No regular form of openingis apparent. Remarks: This speciesis very similar in morphologyto Actinodissussp. I but differs in having broader,more blunt processesand a broadercentral body. GenusActinophasis Loeblich & Wicander 1976. Type species:Actinophasis complurikua Loeblich & Wicander 1976. Genericdescription: Loeblich & Wicander 1976,p. 5-6. Remarks: This genusis similar to the genusMultiplicisphaeridium. Specieswithin it are distinguished by the presencean ornamentof radially arrangedstriations on the centralbody centredabout the baseof the processes.The genusStelliferidiwn has a very similar ornamentationon the centralbody but can be distinguishedby the presenceof a pylome. Actinophasis cf. complurilata Loeblich & Wicander 1976. Plate 120, figs. 1-4. Holotype: Loeblich & Wicander 1976, pl. 1, fig. 3. Age: LAte Gedinnian. Remarks: comparewith Actinophasiscomplurilata Loeblich & Wicander 1976, p. 6, pl. 1, figs. 1-3. Specimensincluded here strongly resemblethe type material. However, the processesare slightly shorterand the centralbody is slightly more roundedin the specimensrecorded here. 45 GenusAmmonlNum Lister 1970. Type species:Ammonidium microcladum (DOwnie) Lister 1970. Genericdescription: Lister 1970,p. 48-48. Remarks: The genusAmmonidium encompasses acanthomorphic acritarch species with processesthat are equifurcateat the distal terminations. The wall may be smoothor sculptured. Multiplicisphaeridiumdiffers by having heteromorphicprocesses that branchin a more elaborate manner. Ammonidium?alloiteauii (Deunfo Deunff 1976. Plate 149, fig. 1; pl. 153, figs. I&2; pl. 163, fig. 1; pl. 172, fig. 1; pl. 180, figs. I&2. Description: Deunff 1955,p. 148, pl. 4, fig. 3. Holotype: Deunff 1955,pl. 4, fig. 3. Age: Middle Devonian. Remarks: This speciesis a moderatelythick walled form and commonlyappears dark in coloration in palynologicalpreparations. Ammonidium sp. 1 (herein)is morphologicallyvery similar. However, this older form, recordedhere from Wenlock agedsediments, has broader,more stout processes. Multiplicisphaeridiumraspum (Cramer) Eisenack, Cramer & Diez 1973has longer processesthan A? alloileauii that furcatein a lessordered manner. Ammonidiumgrosjeanii (Stockmans& Williere) Martin 1981. Plate 172, figs. 2-6; pl. 180, fig. 3. Description: Stockmans& Williere 1962,p. 87-88, pl. 2, fig. 17, text-fig.6. Holotype: Stockmans& Williere 1962,pl. 2, fig. 17. Age: Frasnian. Remarks: This specieshas a similar morphologyto A. microcladum,however it has processeswhich are more robust, having thicker shaftsand thicker distal pinnae. 46 Ammonidium microcladum (Downie) Doming 1981. Plato 57, figs. 2 & 3; pl. 72, fig. 1; pl. 8 1, figs. 1,2 & 3. Description: Downie 1963, p. 645, pl. 91, fig. 3; pl. 92, fig. 6, text-fig. 3g. Holotype: Downie 1963, pl. 92, fig. 6. Age: Wenlock. Remarks: The intraspecificvariation widiin A. microcladwnreported by Le Herrise,(1989, p. 83) indicatesthat A. waldronense(Tappan & Loeblich) Doming 1981 may be a junior synonymof this species. Salopidiumgranuliferum (Downie) Doming 1981has a similar grossmorphology to A. microcladumbut differs in having simple as opposedto equifurcateprocess tips. f Ammonidium cf. ludloviense Lister 1970 ex Doming 1981. Plate57, figs. 1&4. Holotype: Lister 1970,pl. 1, fig. 14. Age: Wenlock-Ludlow. Remarks: Comparewith Lister 1970,p. 50, pl. 1, figs.6,12-14. The two specimensrecorded here haveprocesses with expandedbases that mergewith the centralbody, as in A. ludloviensis. 7be central vesicleis faintly granulate.The specimensobserved have capitate process terminations which differs from the combinationof capitateand minutely furcateprocess terminations of the holotype. Specimens here are also slightly larger than the type material, the centralbody measuringupto 50um.in diameter. Ammonidiwnlisteri Smelror 1986also has expandedprocess bases but possessesa greaternumber of processes. Ammonidium sp. 1. Plate 78, figs. 1-4. Description: Acanthomorphicacritarchs which havea rigid sphericalcentral body measuringbetween 32-38urnin maximumdiameter. 7bere are more than 50 short evenly distributed processespresent. They measurebetween 3-7um in length andupto 4um wide at the base. They taper distally and possess a combinationof capitate,equifurcate bifid and\or equifurcatetrifid tips. The processto body ratio is approximately1: 8. The wall is composedof a single layer and is smooth. The processesappear to communicatefreely with the centralbody. Openingof the vesicle is by medium split. 47 Remarks: This species is morphologically similar to Ammonidium? sp. I sensu Hill 1974 (Ph. D. thesis), 1974 and 1984. Specimensrecorded in the present study have a slightly thicker, more robust wall. Ammonldiwn? sp. 1 Hill sensu Le Herisse 1989 (p. 84, pl. 5, fig. 6) is also very similar in morphology to Anunonidium sp. 1. Of the formally publishedspecies, A? alloiteauii is the most comparable.Ammonidium? alloiteauil, describedfrom the Devonianof North America, differs in possessingmore straight sidedand longer processes. Anunonidiumsp. 2. Plate 104, figs. 1-5; pl. 114, figs. I&4. Description: Acanthomorphicacritarchs which havea subsphericalcentral body measuringbetween 40-50umin maximumdiameter. 7bere are more than 50 slenderevenly distributedprocesses present. 7bey measureapproximately 8um in length and are 1-2umwide at the base. 7bey tapervery slightly distally and possessa combinationof capitate,equifurcate bifid and equifurcatetrifid tips. Ile process to body ratio is approximately1: 6. The wall is composedof a single layer which under high magnificationappears to be vacuolatewith many hundredsof small (lum in diameter)subspherical vacuoles. Openingof the vesicleis by mediumsplit. Remarks: 7be thin processesand the distinctive vacuolatewall structuredistinguish this taxon. Ammonidiummicrocladum is a comparableform by way of the form of the processes.However, A. microcladumhas a more densedistribution of processes,the processesalso being longer relative to the diameterof the centralbody. GenusArbusculidium Deunff 1968. Type species:Arbusculidium destombesii Deunff 1968. Genericdescription: Deunff 1968a,p. 101-102. Remarks: Arbusculidiumis comparableto the genusDicrodiacrodium. Both generainclude species with filamentousprocesses at one pole of the elongatedvesicle. However, the oppositepole to that possessingthe filamentouselements in Dicrodiacrodium speciespossesses a single processwith a in farcatedistal termination contrastwith the severalsimple processes at the oppositepole in Arbusculidiumspecies. 48 Arbusculidiumfilwnentosum(Vavrdova) Vavrdova 1972. Plate 14, figs. 8,9 & 10. Description: Vavrdova 1965,p. 335-336,pl. 4, fig. I. Holotype: Vavrdova 1965,pl. 4, fig. 1. Age: Arenig. Remarks: Specimensrecorded here closely resemblethe type specimensdescribed by Vavrdova. GenusBallisphaeridium Eisenack 1958 ex Eisenack 1959 emend. Eisenack 1969. Type species: Baldsphaeridiumlongispinosum (Eisenack ex 0. Wetzel) Eisenack1959. Genericdescription: Eisenack1969, p. 249. Remarks: Baltisphaeridiumis distinguishedfrom Micrhystridium by having the communication betweenvesicle and processesblocked proximally. The processescommunicate freely with the vesicle in Micrhystridium. The genusBaltisphaerosum Turner 1984differs from Baltisphaeridiumin the methodby which the vesicleopens. In the former, openingis by mediumsplit and in the latter by meansof a pylome. Baltisphaeridiumanfractum Playford 1977. Plate 137, fig. 1; pl. 153, fig. 3; pl. 163, fig. 2,3 & 5. Description: Playford 1977,p. 11, pl. 1, figs. 1-8. Holotype: Playford 1977,pl. 1, fig. 1. Age: Emsian. Remarks: This speciesis characterisedby the relatively small central body (17-35um)and the very long (30-60um),flexible, slenderprocesses. 49 Baltisphaeridium archaicum Cramer & Diez 1972. Plate58, fig. 1; pl. 72, fig. 2. Description: Cramr&Diezl972, p. 148, pl. 3l, figs.3&4. Holotype: Cramer& Diez 1972,pl. 31, figs.3 & 4. Age: Early Llanclovery. Baltisphaeridiwncf. cantabricwnCramer 1964. Plate 81, fig. 5. Holotype: Cramer 1964,pl. 4, fig. 15. Age: Ludlow-Siegenian. Remarks: Comparewith Cramer 1964,p. 290-291,pl. 4, figs. 15-16. Specimensincluded here have the sameoverall dimensions,the sameprocess number and distribution, and the samecentral body to processratio as the holotype. However, the inner body is noticeablythicker in the specimensobserved here. Baltisphaeridiumdistentum Playford 1977. Plate 163, figs.4 & 6. Description: Playford 1977, p. 12-13, pl. 1, figs. 13 & 14; pl. 2, figs. 1-5. Holotype: Playford 1977,pl. 2, fig. 1. Age: Emsian. Baltisphaeridiumhirsutoides (Eisenack) Eisenack 1959. Plate3, figs. 1,2 & 3; pl. 14, fig. 7. Description: Eisenack1951, p. 189-190,pl. 3, fig. 8. Holotype: Eisenack193 1, pl. 5, fig. 19. Neotype: Eisenack1951, pl. 3, fig. 8. Age: Late Ordovician. 50 Bakisphaeridiumklabavense (Vavrdova) Kjellstrom 1971. Plate 3 1, figs.2,3 & 6. Description: Vavrdova 1965,p. 353, pl. 2, fig. 1, text-fig. 1. Holotype: Vavrdova 1965,pl. 2, fig. 1. Age: Arenig. Remarks: Deunff 1977recorded this taxon from the Llanvim agedTachilla shalesfrom Morocco. Baltisphaeridiumlongispinosum subsp. delicatum Tumer 1984. Plate 14, figs. 11 & 12. Description: Turner 1984,p. 99-100, pl. 6, figs. 1&7. Holotype: Tumer 1984, pl. 6, fig. 7. Age: Caradoc. Remarks: Theseforms with rather delicateprocesses commonly show evidenceof mechanicaldamage in the poorly preservedmaterial observed. Baltisphaeridiumsp. I Plate 40, fig. 1. Description: Acanthomorphicacritarchs which havea rigid sphericalcentral body measuringbetween 29-32umin maximumdiameter. There are approximately15 evenly distributed, simpleprocesses which are 15-20umin length, upto 3um wide at the baseand taperdistally to accuminatetips. The processto body ratio is approximately1: I. S. 'ne wall is composedof a single layer. 'ne centralbody is relatively thick walled and has a granulateornamentation. The processesare smooth. No regular form of openingis apparent. Remarks: Baltisphaerldiumbulbosum Kjellstrorn 1971is larger in size, has a smoothcentral body and has broaderbased processes. 51 Baltisphaeridiumsp. 2. Plate 40, fig. 2. Description: Acanthomorphicacritarchs with a rigid sphericalcentral body measuringbetween 20- 23um in maximumdiameter. There are approximately15 evenly distributed simple processes.They are upto 30um in length, upto 3um wide at the baseand they taperdistally to accuminatetips. 7he processto body ratio is approximately1.5: 1. Ile wall is composedof a single layer and is smoothor very finely granulate. No regular form of openingis apparent. Remarks: Baltisphaeridiumsp. I differs in the Processeslength to centralbody ratio. Processesare longer and the centralbody is smallerin Baltisphaeridiumsp. 2. Baltisphaeridium?sp. 3. Plate 58, figs.2 & 3. Description: Acanthomorphicacritarchs with a rigid sphericalcentral body measuringbetween 35- 50um.in maximumdiameter. 17hereare approximately7-15 evenly distributed simple processes.The processesare upto 45um in length, upto 4um wide at the baseand they taperdistally to accuminatetips. The processto body ratio is approximately1.2: 1. The wall appearsto be composedof two wall layers. Ile layersare closely appressedover the centralbody, the outer layer forming the processes.Ilie centralbody has a granulateor rugulateornament and the processesare smooth. No regular form of openingis apparent. Remarks: This taxon is distinguishedby the relatively dark coloured, thick walled centralbody. The wall structureis similar to that of someof the Cymbosphaeridiwnspecies recorded at the same stratigraphiclevel in this study. However, specimensincluded here have simple processterminations in contrastto the denticulateterminations of Cýmbosphaeridiumspecies. Baltisphaeridium?sp. 5. Plate 180, figs.4-7. Description: Acanthomorphicacritarchs which havea rigid subsphericalcentral body measuring between16-30um in maximumdiameter. 7bere are approximately10-20 evenly distributed simple in processes.The processesare upto l5um length, upto 3um wide at the baseand they taper distally to 7be body is accuminatetips. processto ratio approximately1: 1.2.7be wall appearsto be composed 52 of two wall layers. 7be layers are closely appreuod over the central body and the ban of the procatsm, the outer layer forming the process shaft and tip. 7be vesicle wall of the central body and the processesis smooth. 7he opening of the vesicle is by *double pylome* which forms by the loss of two subcircular portions of the vesicle wall which lie adjacent to each other prior to pylome formation. Each pylome is surmounted by a single process. Remarks: The distinctive 'double pylomeeexcystment mechanism Is the most diagnosticfeature of this taxon. Assignmentto the genusBaWsphaeridium is questioneddue to the presenceof this unique form of opening. BabitphatridiumlBakisphaermumsp. Plate3 1, rig. 12. Remarks: This large form of Bahisphaeridiumor Bahisphaerosum(central body 72um in diamettf) has plugged, granulateprocesses that measureat least35um in length (the processesam all broken). Ile single specimenobserved closely resemblesBakisphaerosum dispar Turner 1994, however the central body is markedlysmaller in B. dispar and the diagnostictnedium split style of opening is not discen2ible. GenusBalt4phatrosum Turner 1994. Type species: Bakisphaemum diristoferi (Kjcllamm) Tumer 1994. Geneticdescription: Turner 1984,p. 101-102. Remarks: Babisphaeroswn Turner 1994 is distinguisW from BaUrphaeridium by having a medium split style of opening. Species of BaUrphaeridiurn open by means of a pylome Crurner 1984, p. 102). Baltisphaerasumonniewe Tumer 1994. Plate 31. figs.2.3 &- 6. Description: Tumer 1984,p. 104-105.pl. 5, figs.2 & S. Holotype: Turner 1984,pl. 5, fig. 5. Age: Caradoc. 53 GenusBuafingisphaeridium Schaarschmidt 1963 emend. Lister 1970. Type species: Buedingisphaeridiumpennicum Schaarschmidt1963. Genericdescription: Lister 1970,p. 59-61. Remarks: The genusLophosphaeridium has an ornamentof solid tuberclesin contrastto the hollow tubercularelements of Beudingisphaeridium.Trichosphaeridiwn has an ornamentof fine hair-like echinae. Tylotopalla may haveshort stumpyelements similar to thosein Beudingisphaeridiumbut it differs in having additionalornament in the viscinity of the elements. Buedingisphaeridiwnlunatum Le Herisse 1989. Plate 58, fig. 7; pl. 81, fig. 4. Description: Le Herisse1989, p. 87-88, pl. 5, figs. 14-15. Holotype: Le Herisse 1989, pl. 5, fig. 14. Age: Liandovery. Bue,dingisphaeridium sp. 1. Plate 58, fig. 6. Description: Subsphericalacritarchs with numerousshort pyramidal outgrowths. The maximum diameterof the body rangesbetween 26-35um. Ile hollow conical processesare closely spacedand numberapproximately 100. They are 3-4um high and 3-Sumwide at the bases. The processto body ratio is approximately1: 9. The wall is composedof a single layer, the processescommunicate freely with the centralbody. The wall is smoothto scabrateand no regular form of openingis apparent. Remarks: 7ýlotqpallapyramidale (Lister) Doming 1981appears morphologically identical from the descriptionand illustration of the holotypegiven by Lister (1970, p. 61). However, re-examinationof the holotype by Doming (1981) revealedthat the processesof the holotype are ornamentedwith echinae which justifies his transferof this speciesto Tylotopalla. 7y1otopalladeerlijAlanum(Martin) Le Herisse1989 has striateornamentation at the baseof the processes. 54 Genus Caldariola Molyneux 1988. Type species: Caldariola glabra (Martin) Molyneux 1988. Genericdescription: Molyneux 1988,p. 57. Remarks: In their erectionof the genusCaldariola, Molyneux & Rushton(1988, p. 56-57) discussin considerabledetail the complexof Lower Ordoviciangenera with large polar openingsor pylomes, namely Cymatiogalea,Priscogalae, Stelliferidium and Caldariola. 7be presentauthor follows their interpretationof thesegenera (p. 57,4th paragraph). Caldariola glabra (Martin) Molyneux 1988. Plate 3, fig. 12. Description: Martin 1972,p. 22, pl. 4, fig. S; pl. 5, fig. 17. Holotype: Martin 1972,pl. 5, fig. 17. Age: Tremadoc. Remarks. lle two specimensrecorded here accord well with the descriptionof the type material. Genus Candelasphaer0umDeunff 1978. Type species: Candelasphaeridiwninsolitum Deunff 1978. Genericdescription: Deunff 1978,p. 115. Candelasphaeridiumcf. insolitum Deunff 1978. Plate 128, fig. 6?; pl. 149, figs. 3-6. Holotype: Deunff 1978, pl. 1, fig. 11. Age: Early Gedinnian. Remarks: Comparewith Deunff 1978,p. 115, pl. 1, figs. 8-14. Ile poorly preservedspecimens of C. cf. insolitum that havebeen recorded in the presentstudy have fewer processesthan the type specimens. The original descriptionstates that 12-25processes are presentin this species,upto 10 processesare presenton specimensrecorded here. 55 Genus ComasphaerWumStaplin Jansonius & Pocock 1965. Type species: Comasphaeridiumcometes (Valeasi) StaplinJansonius & Pocock 1965. Genericdescription: Staplin, Jansonius& Pocock 1965,p. 192. Remarks: This genusis distinguishedby the high densityof solid processeson the centralbody. Comasphaeridiumdenseprocessum Cramer & Diez 1977. Plate 15, fig. 11. Description: Cramer& Diez 1977a,p. 346, pl. 2, figs. 10 &11. Holotype: Cramer& Diez 1977a,pl. 2, fig. 11. Age: Early Arenig. Remarks: 7be processesof this form are lessin numberand are broaderthan thoseof C pratulum Cramer& Diez 1977and C. tonsumCramer & Diez 1977. ComasphaeridiumcE denseprocessumCramer & Diez 1977. Plate 3 1, figs. 10 & 11. Holotype: Cramer& Diez 1977,pl. 2, fig. 11. Age: Early Arenig. Remarks: Comparewith Cramer& Diez 1977,p. 346, pl. 2, figs. 10 & 11. Processesare diimer and more numerousin the specimensobserved here than in the type materialof C. denseprocessum. Comasphaeridiumpratulum Cramer& Diez 1977has thinner and more numerousprocesses than C. cf. denseprocessum. Comasphaeridiumhirtum Le Herine 1989. Plate58, figs. 8&9. Description: Le Herisse1989, p. 89, pl. 6, figs. 8-10. 56 Holotype: Le Herisse 1989, pl. 6, fig. 10. Age: Aeronian, Liandovery. Remarks: Comasphaeridiumcaesariatum Wicander 1974, describedfrom the Upper Devonianof Ohio, USA has longer procmw thanL. hirtum. Filisphaeridium brevispinosumLister 1970is a comparablespecies in termsof the morphologyof the processesand the centralbody. It differs in the numberand densityof processespresent, processes being fewer and more sparselydistributed. Genus Coryphidium Vavrdova 1972. Type species: Coryphidiumbohemicum Vavrdova 1972. Genericdescription: Vavrdova 1972. Coryphidiumabnohadillum? Cramer & Diez 1976. Plate 15, fig. 7. Description: Cramer& Diez 1976b,p. 204, pl. 23, figs. 8& 11. Holotype: Cramer& Diez 1976b,pl. 23, fig. 8. Age: Late Arenig. Remarks: This striate form has short accuminate,spines. Preservationis rather poor and there is some questionas to the primary form of the spines. Cramer& Diez 1976billustrated and comparedthe 9 speciesof Coryphidiumpublished to that date. Similar specieswith surfacestriations are C. elegansCramer et al. 1974, C. miladum Cramer& Diez 1976and C bohemicumVavrdova 1972. Coryphidiumelegans differs by having longer processes,C. miladum hasprocesses with wide basesand capitatetips and C bohemicumhas short, stout, branching processes. Coryphidiumelegans Cramer et al. 1974. Plate 3 1, figs.4 & S. Description: Craxneret al. 1974,p. 184, pI. 27, figs 12-19. 57 Holotype: Crameret al. 1974,pl. 27, fig. 16. Age: Late Arenig-Early Lianvim. Remarks: Similar specieswith surfacestriations are C abnohadilla Cramer& Diez 1976, C. miladum Cramer& Diez 1976and C bohemicumVavrdova 1972. The former two specieshave shortermore stout processesand the latter hasprocesses with wide basesand capitatetips. Coryphidiumrarniferum? Cmmer & Diez 1976. Plate 15, fig. 8. Description: Cramer& Diez 1976,p. 206, pl. 23, figs. 16 & 24. Holotype: Cramer & Diez 1976, pl. 23, fig. 16. Age: Early Arenig. Remarks: The poorly preservedspecimens recorded bere are questionablyassigned to this species. Co?yphidium cf. tadlum Cramer& Diez 1976. Plate 15, figs. 1-6. Holotype: Cramer & Diez 1976b, pl. 23, fig. 4. Age: Late Arenig. Remarks: Comparewith Cramer& Diez 1976b,p. 206, pl. 23, figs.3,4,15,18 & 19. Specimens observedhere differ slightly from C radlum in the natureof the processterminations. Processtips here tend to be accuminaterather than club-like as in the type material. Coryphidiumelegans has a similar body shapeand processshape but has striationson the centralbody. Genus CmssiangulinaJardine et al. 1972. Type species: Crassiangulinatesselita Jardine et al. 1972. Genericdescription: Jardineet al. 1972,p. 295. Remarks: The genuscrassiangulina is, to date, monospecific,the single species,C tesselita,having a rather broad rangeof morphology. 58 Crassiangulinatesselita Jardine et al. 1972. Plate 180, fig. 9; pl. 187, figs. l. &2; pl. 191, fig. l. Description: Jardineef al. 1972,p. 295-296,pl. 1, figs. I&2. Holotype: Jardineet al. 1972,pl. 1, figs. 1. Age: Late Devonian. Remarks: This specieshas a simplebut distinctive morphology. It has a polygonal vesiclewith betweenthree and upto as many as eight 'reinforced' angles. The anglesare reinforcedby thickenings of the vesiclewall. Genus CraterisphaerkliumDeunff 1981. Type species: Craterisphaeridiumsprucegrovense (Staplin) emend.Turner 1986. Genericdescription: Deunff 1981,p. 67. Remarks: Crateyisphaerldiuminuncans Deunff 1981was statedas the type speciesfor the genusby Deunff (1981). However, this speciesis consideredto be ajunior synonymof C sprucegrovense which is now the correctname for the type. Speciesassigned to this genusare acanthomorphicforms with branchedprocesses. These forms have craterspresent in the wall of the centralbody forming a foveolateornamentation. A very similar genus morphologicallyis HapsidiopallaPlayford 1977emend. Wicander & Wood 1981which differs in possessinga reticulate, as opposed to a foveolate, ornamentation on the vesicle wall. Craterisphaeridiwnsprucegrovense (Staplin) emend.Tumer 1986. Plate 153, figs.4-7; pl. 163, figs.7,8 & 9; pl. 164, fig. 1; pl. 172, figs.7-10; pl. 187, figs.4 & 5; pl. 191, figs.2-5 Description: Turner 1986,p. 602-606. Holotype: Staplin 1961,pl. 49, fig. 6. Age: Late Devonian. Remarks: The de-scretepitting of the vesiclewall is only apparentunder high magnificationwhen light 7his observedusing microscopy. speciesis closely similar to somespecies of Hapsidiopalla, e.g. 59 H. chelaWicander & Wood 1981and H. invenustaWicander & Wood 1981but differs in the presence of a foveolaterather than reticulatevesicle wall. GenusCrystalUnium Vanguestaine 1978 ex Fensorneel al. 1990. Type species: Oystallinium oWlknse(Cramer & Diez) Fensomeet al. 1990. Genericdescription: Vanguestaine,1978, p. 270. Remarks: Fensomeet al. (1990)validated the genusby designatinga validly publishedspecies as the type. By designatingthe invalid speciesDicryotidium cambrienseas the type speciesof the genus Crystallinium, Vanguestainehad not fulfilled this obligation. CrystalliniumoWlIense (Cramer & Diez) Fensomeet al. 1990. Plate 3, figs.4,5 & 6. Description: Cramer& Diez 1972a,p. 44, pl. 2, figs.4,7 & 10. Holotype: Cramer& Diez 1972a,pl. 2, fig. 4. Age: Middle Cambrian. Genus CymatiogakaDeunff 1961 emend. Deunff 1964. Type species: Cymatiogaleamargaritata Deunff 1961. Genericdescription: Deunff 1961 a, p. 41-42; Deunff 1964a,p. 121. Remarks: The interpretationof this genusby Molyneux & Rushton(1988, p. 56-57) is acceptedhere. Cymatiogaleadeunffii Jardineet al. 1974. plate 3, figs.7-10; pl. 16, fig. 4? Description: Jardineet al. 1974,p. 123, pl. 1, figs.7 & 8; for an English translationsee Eisenack, Cramer& Diez 1979,p. 97. 60 Holotype: Jardineet al. 1974,pl. 1, fig. 7. Age: Arenig. Cymatiogaleacf. deuniffliJardine et al. 1974. plate 3, fig. 11. Remarks: Comparewith Jardineet al. 1974,p. 123, pl. 1, figs.7 & 8. Specimensincluded here have granaand echinaeornamenting the membranousouter wall layer. The specimensobserved differ from C deunffii in having minor sculpturalelements developed on the outer wall layer. CymatiogaleacE margaritata Deunff 1961. Plate4, figs. I&2. Holotype: Deunff 1961a,p. 42, pl. 1, fig. l. Age: Tremadoc. Remarks: Compared with Deunff 1961a, p. 42, pl. 1, fig. 1. Ile specimens observed here have slightly thinner and slightly longer processesthan the holotype. Cymatiogaka bellicosaDeunff 1961has thicker, more sturdy processeswhich are fewer in number than in C. cf. margaritata. Cymatiogalea messaoudii Jardine et al. 1974. Description: Jardineet aL 1974,p. 123, pl. 2, figs.5&6; for an English translationsee Eisenack, Cramer& Diez 1979,p. 105. Holotype: Jardineet al. 1974,pl. 2, fig. 5. Age: Tremadoc. Remarks: Within this species,two morphologicalvarieties have been Tecognised: 61 Cymatiogaleamessaoudii var. A. Plate4, figs.3 & 4; pl. 15, figs. 12 & 13. Remarks: Includedhere are atypical forms with very elaborateand denselypacked processes with fenestrateterminations. Cymatiogaleamessaoudil var. B. Plate4, figs.5-8. Remarks: Includedhere are forms closely resemblingthe holotype of the specieswith fewer and relatively simple processescompared to var. A. Cymatiogakamultarea (Deunff) Eisenack,Cramer & Diez 1973. Plate 16, fig. 1. Description: Deunff 1961a,p. 41, pl. 1, fig. 5; for an English translationsee Eisenack, Cramer& Diez 1973,p. 229. HoloqW: Deunff 1961a,pl. 1, fig. 5. Age: Tremadoc. Cymatiogaleavelifera (Downie) Martin 1969. Plate 16, figs.2 & 3. Description: Downie 1958, p. 340, pl. 17, fig. 2; Martin 1969 p. 133. Holotype: Downie 1958,pl. 17, fig. 2. Age: Treraadoc. Remarks: Only sevenspecimens are recordedhere, all are poorly preserved. However, they do appear to have the characteristicbifurcating and trifurcating processtips and the vela betweenprocesses that are characteristicof this species. 62 Cymatiogaleasp. 1. plate 4, figs. 9-13. Synonomy: 1988, Cymatiogakamessaoudii, Molyneux & Rushton,pl. 5, fig. c. 1989, Cymatiogakamessaoudii, Mette, pl. 3, figs. 13-16. Description: Polygonalacritarchs with a complexdouble wall layeredstructure. 7be inner body is subsphericalin shape,relatively thick walled and smooth.It has a maximumdiameter of 28-35um. 7lie outer wall layer is relatively thin and is 'pinchedup' into elaboratelyornamented linear crests. 7be crestsare 7-10umin height and haveshort furcating processesat their apices,these being an additional 2-7um in height. 7be crestsare arrangedinto polygonsdividing the vesicle into fields. 7be intracrest areasare smooth.7be vesicleopens by meansof a pylome. Remarks: This speciesshows minor variation in the height of the crestsand the processesornamenting the crests. The variation is consideredinsufficient tojustify the proposalof any varietieswithin this species. Comparablespecies include C messaoudiiand C gorkaeRaucher 1974. The former has a similar structureto the outer wall layer but the field boundariesare definedby prominentprocesses composed of the outer wall with low crestsdraped between them. In contrast,Cýmatiogalea sp. I has fields definedby crestswith minor processesornamenting the crestapices. Cymadogaleagorkae appears to have delicateprocesses ornamenting the field boundariesas in Cýmatiogaleasp. 1 but differs in that the processessupport an outer membranousnetwork. Cymatiogalea?sp. Plate 16, figs. 5-8. Remarks: Five specimensof this taxon havebeen recorded from sampleDW 294. Specimensare small (lessthan 35um in centralbody diameter),possess the characteristicpylome of Cymatiogaleaspecies and have slenderprocesses with branchedterminations. The processesare approximately10um long, lum wide and branchdistally upto the secondorder. ornamentationof the centralbody is not apparenton the dark specimensrecorded, hence their questionedassignment to the genusCymatiogalea. Lighter coloured.specimens may reveal & Stelliferidium type ornamentation.Unfortunately no material for further oxidation of sampleDW 294 remains. 63 Genus CymbosphaeridiumLister 1970. Type species: Cymbosphaeridiumbikidiwn Lister 1970. Genericdescription: Lister 1970,p. 63. Remarks: This genusincludes acanthomorphic acritarch species with two wall layers. The wall layers are closely appressedon the centralbody, giving it a relatively dark coloration. The outer layer form the hollow tubiform processeswhich are relatively light in colour. 7be processterminations are denticulate. A commonfeature is the presenceof a pylome, the operculumof which possessesa single or severalprocess. Cýmbosphaeridiwnbikidium Lister 1970. Plate 81, figs. 8-12. Description: Lister 1970,p. 64-65, pl. 6, figs. 1-9, text-figs.lga-c, f, k, 21. Holotype: Lister 1970, pl. 6, fig. 1. Age: Ludlow. Remarks: The centralbody of this speciesis smooth. Cyrnbosphaeridiumpilar var. pilar Cramer 1964 has a coarselygranular body with the granaadjacent to eachother. Cyinbosphaeridiwnpilar var. scabrawn Cramer 1970also has a granularbody, the granabeing more widely spacedin this variety of the species. Cymbosphaeridiumpilar var. 1 (herein)has a faintly granularbody and is larger in size than CymbosphaeridiumbiAldium. Cymbosphaeridium cariniosum (Cramer) Jardine et al. 1972. Plate 82, figs. 1-5. Description: Cramer 1964,p. 284, pl. 1, fig. 13, text-fig. 14, nos.7 & 8. Holotype: Cmmer 1964,pl. 1, fig. 13. Age: Ludlow. is includedin Remarks: This species the genusCymbosphaeridiwn here on the basisof its wall having double layer, structure,the species a wall the outer layer forming the processes,and also becauseit The is distinct from possessesa pylome. species other speciesin the genusin possessinga 64 greaternumber of processes.The processesare also much shorter than in the other C5vnbosphaeridium species. Cymbosphaeridiumpilar Cmmer 1964. Description: Cramer 1964, p. 286, pl. 1, figs. I&2, text-fig. 14, no. 1. Holotype: Cramer 1964, pl. 1, fig. 1. Age: Ludlow. Remarks: Cýmbosphaeridiwngueltaense Jardine et al. 1974is describedas being almostidentical to C. pilar, differing only in lacking a pylome, a diagnosticcharacteristic of C. pilar. Jardineet al. (1974) had probably observedunexcysted specimens of C pilar which they describedas C gueltaense. Cymbosphaeridiwngueltaense is probably thereforea junior synonymof C pilar. Two publishedvarieties of C pilar havebeen recorded in the presentstudy. Cymbosphaerldiumpilar var. pilar Cramer 1964. Plate 114, fig. 2; pl. 120, figs. 5,6 & 7; pl. 121, figs. 1-4; pl. 128. fig. 3?, 4&5; pl. 137, figs. 2-5 & 7; pl. 149, fig. 2. Description: Cramer 1964, p. 286, pl. 1, figs. 1&2, text-fig. 14, no. 1. Holotype: Cramer 1964, pl. 1, fig. 1. Age: Ludlow. Remarks: This variety of C. pilar is distinguishedby the presenceof coarse,closely spacedor adjacent granaon the centralvesicle. Cymbosphaeridiumpilar var. scabratumhas more widely spacedgrana. Cymbosphaeridiumbikidium has a smoothcentral body. C"ymbosphaeridiumpilar var. scabratwnCramer 1970. Plate 82, fig. 6; pl. 104, figs. 6? & 7?; pl. 128, fig. 2? Description: Cramer 1970,p. 167, pl. 18, fig. 252-255, text-fig.52L Holotype: Cramer 1970,pl. 18, fig. 252. Age: Silurian. 65 Remarks: This variety of C. pilar is distinguishedby the presenceof widely spacedgrana on the centralbody. Cymbosphaeridiumpilar var. pilar has closely spaced,coarse grana. Cymbosphaeridium bikidium has a smoothcentral body. Cymbosphaeridiumpilar var. 1. Plate 82, figs.7 & 8. Remarks: This variety of Cymbosphaeridiwnpilar is distinguishedby its large size, centralbody less than 45um in diameter,and the faintly granularbody wall. Cymbosphaeridiumcf. raVUMis similarly large in sizebut differs by having a coarselyscabrate central body wall. Cýmbosphaeridium cf. ravum (Downie) Doming 1981. Plate 59, figs. 1,3 & 5. Holotype: Downie 1963,pl. 91, fig. 6. Age: Wenlock. Remarks: Comparewith Downie 1963,p. 643, pl. 91, fig. 6, text-fig.3c. Specimensobserved here fall within the upperpart of the sizerange given for the speciesby Downie. The textureof the wall of the centralbody appearsto be more coarselyscabrate in the specimensobserved here than on the holotype. This could be due to the poor preservationof the presentmaterial. Cýmbosphaeridiumsp. 1. Plate 104, figs. 8-11. Description: Acanthomorphicacritarchs which havea sphericalcentral body measuringbetween 34- 45um in maximumdiameter. Ilere are approximately40 evenly distributedprocesses, measuring 8- Bum in length and upto 5um wide at the base,which branchdistally in a ramusculoseman er. The processlength to body diameterratio is approximately1: 4. The wall is composedof two layers that are closely appressedover the centralbody which gives the centralbody a relatively dark coloration. The processesare composedof the outer wall layer only and are consequentlyrelatively light in colour. The centralbody wall is thick (> lum) and has a granulateornamentation. The processesare smooth. opening of the vesicleis by a pylome. 66 Remarks: Specimensincluded here have the samewall structure,the samenumber and distribution of processesand are of similar dimensionsto C cariniosum. However, the processesshafts are thicker and the processterminations branch in a more complexmanner in the specimensincluded here. Dispite the poor preservation,surface ornament is apparenton somespecimens which appearsto be granulate. GenusDactylofusa Brito & Santos 1965b emend. Cramer 1970. Type species: Dactylqfusa maranhensis Brito & Santos 1965b. Genericdescription: Brito & Santos1965b, p. 12 & 20; Cramer 1970,p. 79 & 80. Remarks: EupoiWofusa Cramer 1970 is considered to be a junior synonym of Dactylojiua, for argumentssee Fensome el aL 1990,p. 179,213 & 214. Dactylqfusa ctenista (Loeblich & Tappan) Fensome et al. 1990. Plate41, figs.5 & 6. Synonomy: 1988,EupoiAllofiisa striata, Elaouad-Debbaj,pl. 2, figs. 1-6. Description: Loeblich & Tappan1978, p. 1263,pl. 8, figs. 8-9. Holotype: LA)eblich& Tappan1978, pl. 8, figs. 8-9. Age: Ashgill. Remarks: Specimens recorded here are slightly smaller (132-17lum in length) than in the type material (170-193um). The species is distinguished by the slender fusiform vesicle with accuminate poles and the longitudinal ribs that are restricted to the central region of the vesicle. Comparable species include D. anolata (Loeblich & Tappan) Fensome et al. 1990, which has a more dense ornamentation, D. platynetrella (Loeblich & Tappan) Fensome et al. 1990 which has a broader central vesicle, D. squaina (Deunfo Fensome et al. 1990 which has very feint longitudinal ridges and A striata (Staplin, Jansonius & Pocock) Fensome et al. 1990 which has a more squat vesicle shape with less pointed poles. Dactylofusastriatirera (Cramer)Fensome et al. 1990. Plate121, fig 5? Description: Cramer 1964,p. 35-36, pl. 2, figs.9 & 13. 67 Holotype: Cramer 1964, pl. 2, fig. 9. Age: Early Gedinnian. Remarks: Poorly preservedspecimens of D. striatifera are includedhere. Dactylqfusastriatifera var. striatifera (Cmmer)Fensome et al. 1990. Plate 85, figs.9,10 & 11; pl. 128, figs. 8&9. Description: Crmner 1964, p. 35-36, pl. 2, figs-9 & 13. Holotype: Cramer 1964,pl. 2, fig. 9. Age: Early Gedinnian. Remarks: Dactylqfwa stfiatifera var. stericula (Cramer& Diez) Fensomeet al. 1990differs from D. striatifera var. striatifera in having a broaderfusiform vesiclewith a greaternumber of longitudinal striations. GenusDaUlydium Stockmans & Williere 1969. Type species:Daillydium pentaster(Staplin) Playford in Playford & Dring 198 1. Genericdescription: Stockmans& Williere 1969,p. 33. Remarks: The type speciesfor the genusdesignated by Stockmans& Williere (1969), A quadradactylites,is consideredto be a junior synonymof D. pentaster(according to Playford in Playford.& Dring 1981). For this reason,D. pentasteris now the correct namefor the type speciesof Daillydium. However, the nomenclaturaltype of the genusremains the holotype of D. quadradactylites. DallWium pentaster(Staplin) Playford in Playford & Dring 1981. Plate 173, figs.2 & 3; pl. 180, figs. 10 & 13; pl. 191, fig. 6. Description: Staplin 1961,p. 416, pl. 49, fig. 18. Holotype: Staplin 1961, pl. 49, fig. 18. Age: Late Devonian. 68 Remarks: As mentionedabove, D. quadradactylitesis consideredto be a junior synonymof D. pentaster. The only other speciesof Daillydium publishedto-date, D. foveolatum Deunff 1981, differs in possessingan ornamentfoveolae on the wall of the inner body. GenusDaisypUula Loeblich & Wicander1976. Type species:DaLs)pilula compactaLoeblich & Wicander 1976. Genericdescription: Loeblich & Wicander 1976,p. 26. Remarks: This genus is distinguished by the presence of a subspherical central body with a cover of differs in matted solid processesof varying length. A similar genus is Caminella Cramer 1968 which possessinga cylindrical outer membrane which encloses the processes. Dais)pilula compactaLoeblich & Wicander 1976. Plate 137, fig. 11. Description: Loeblich & Wicjmder 1976,p. 10, pl. 3, fig. 1. Holotype: Loeblich & Wicander 1976,pl. 3, fig. 1. Age: lAte Gedinnian. Remarks: The only other speciesdescribed in the genusDaisypilula to-date,D. storeaWicander & Loeblich 1977, differs in having a much smallervesicle diameter and mat width and having a much thhmervesicle wall. GenusDateriocradus Tappan & Loeblich 1971. Type species:Dateriocradus monterossae (Cmmer) Pothe de Baldis 1981. Genericdescription: Tappan& Loeblich 1971,p. 394. Remarks: Dateriocraduspot4actylus Tappan& LA)eblich1971 was initially statedas the type species for the genus. However, this speciesis consideredto be a junior synonymof D. monterossae(see Eisenack,Cramer & Diez 1976,p. 185). Thus, A monterossaeis the correct namefor the type species of Datefiocradusbut the nomenclaturaltype of the genusremains the holotype of D. Powacrylus, i. e. Tappan& Loeblich 1971, pl. 5, fig. 1. 69 The genusDaterlocradus includes species with a threesided, slightly inflated central body with processesat the apices. lle processesbranch distally to a minimum of the secondorder and commonly in a ramusculosefashion. The genusFrankea has a similar shapeto the central body and the same distribution of processesbut differs in that the processesbranch in a palmatemanner. Oppilatala differs by having a rounded-subroundedcentral body. Dateriocraduslindus (Cramer& Diez) comb. nov. Plate 128, figs.7,10 & 11. Synonomy: 1976,Mukiplicisphaeridiwn lindum, Cmmer& Diez, p. 85, pl. 1, figs.4,6 & 8, not 1-3, pl. 2, fig. 11. Description: Cramer &Diez 1976, p. 85, pl. 1, figs. 4,6 & 8, not 1-3, pl. 2, fig. 11. Holotype: Cramer& Diez 1976,pl. 1, fig. 6. Age: Emsian. Remarks: 7be illustrations of the type specimensgiven by Cramer& Diez (1976) showstwo morphotyrpeswithin their taxon. 7be holotypeand threeof the additional specimensillustrated ( pl. 1, figs. 4,6 & 8, pl. 2, fig. 11) havea three-sidedvesicle with threeprocesses present positioned at the apicesof the vesicle. A fourth processmay be present. The distal terminationsof the processesare ramusculose.The other group (pl. 1, figs. 1-3) havea subsphericalcentral body with more numerous processes. 7be former group of morphotypes, which include the holotype, are better accommodated in the genus Dateriocradus than Multiplicisphaeridium due to the morphology of the vesicle and the distribution of processes. Dateriocradusmonterossae (Cramer) Pothe de Baldis 1981. Plate72, figs.6&7. Description: Cramer 1969,p. 490, pl. 70, figs.5-7, text-fig. 10f. Holotype: Cramer 1969,pl. 70, fig. 5. Age: Late Uandovery. Remarks: Dateriocraduspot4acrylus Tappan& Loeblich 1971is consideredto be a junior synonym (EisenackCramer of D. monterossae & Diez 1976,p. 185). Morphologically similar speciesin terms form Oppikaala of wall structureand process are eoplanktonica(Eisenack) Doming 1981 and 0. 70 (Deflandre)Doming 198 They rwnusculosa 1. both differ from D. monterossaein the distribution of processes.Processes are positionedat the apicesof the subtriangularcentral body in D. monterossaein contrastwith the more randomdistribution of processesin the OPPilatalaspecies. A useful pictorial comparisonof D. monterossaeand somemorphologically similar speciesis given by Cramer 1970, p. 125, text-fig. 39. Dateriocradustenuatum (Burmann) has more polygonal centralbody thanA monterossae. Dateyiocradustenuatum (Burmann) Comb. nov. Plate 32, fig. 1. Synonomy: 1970, Vogilandiatenuatum, Burmann p. 293, pl. 3, fig. 3; pl. 4, fig. 2.1976, Multiplicisphaeridiumtenuatum, Eisenack, Cmmer & Diez, p. 485-486. Description: Burmann1970, p. 293, pl. 3, fig. 3; pl. 4, fig. 2; for an English translationsee Eisenack, Cramer& Diez 1976,p. 285-286. Holotype: Burmann1970, pl. 3, fig. 3. Age: Ute Arenig- Early Llanvirn. Remarks: This speciesis transferredto the GenusDateriocradus as it possessesa three sidedcentral body and hasprocesses positioned at the apicesof the body which branchdistally in a ramusculose manner. This species is similar in body shape and process distribution to species of Frankea. However, species of Frankea differs by having palmate pinnae at the process terminations, Dateriocradus monterossae has deeper furcation of the distal part of the processes. GenusDeflandrostrum Combaz 1962. Type species: Deflandrastrum millepiedi Combaz 1962. Genericdescription: Combaz1962, p. 1977. included Remarks: The species hereare forms composedof four cells that are positionedabout a circular or quadratecentral lumen. Eachelongated triangular cell is joined to two adjacentcells at the basalapices. This acritarchgenus is comparablewith the chlorophytegenus Pediastrum, however it differs in the numberand arrangementof cells. 71 Deflandrastrummillepiedi? Combaz1962. Plate 82, fig. 9. Description: Combaz 1962, p. 1977-1978, fig. 1. Holotype: Combaz 1962, fig. 1. Age: Silurian. Remarks: The single specimen recorded is poorly preserved. Ile radial spines are damaged, hence the questioned assignation to the species. Deflandrastrumauthierae Combaz 1962 has a more elongateform to the triangular cells thanD. millepiedi. Deflandrastrwnspeciosum Deflandre 1967has a much larger central lumen than the other speciesin the genus. GenusDemorhethium Loeblich & Wicander 1974. Type species: Demorhethium lappaceum Loeblich & Wicander 1974. Genericdescription: Loeblich & Wicander 1974,p. 708. Remarks: This genus is quite distinct from any other by way of the short, distally open processeswith denticulate terminations. Demorhethium is, at present, a monospecific genus. Demorhethiumcf. lappacewnLoeblich & Wicander 1974. Plate 137, figs.6,8 & 11. Holotype: Loeblich & Wicander 1974, fig. 2. Age: Late Gedinnian. Remarks: Comparewith Loeblich & Wicander 1974,p. 708-711, figs. 1-6. Specimensrecorded here are closely similar to the illustrations of the type materialgiven by Loeblich & Wicander 1974. However, thereare more than the stipulatednumber of processesfor the speciespresent on the specimenshere. Processesnumber eight or more herecompared to five to sevenprocesses on the type specimens.In addition, the ornamentof baculaeis lessprominent on the presentspecimens. 72 GenusDicrodiacrodium Burmann 1968. Type species: Dicrodiacradiumancorifonne Burmann 1968 Genericdescription: Burmann1968, p. 643; for English translationsee Eisenack Cramer & Diez 1979, p. 203. Remarks: The genusArbusculidium is comparableto Dicrodiacrodium. Both generainclude species with filamentousprocesses at one pole of the elongatedvesicle. However, the oppositepole to that possessingthe filamentouselements in Dicrodiacrodiwn speciespossesses a single processwith a furcatedistal terminationin contrastwith the severalsimple processes at the oppositepole in Arbusculidiumspecies. Dicrodiacrodiumancoriforyne var. minutumBurmann 1968. Plate 16, figs. 11 & 12; pl. 32, fig. 2. Description: Burmann1968, p. 644, pl. 5, fig. 5; for an English translationsee Eisenack Cramer & Diez 1979,p. 207. Holotype: Burmann1968, pl. 5, fig. S. Age: Late Llanvim. Remarks: This form is distinguishedby the relatively broad, ribbed centralbody, the single 'apical' process,the flattened'antapex' with the fine anastomosingmesh and its relatively small size. 7be papical'process is broken in all the specimensobserved. Of the five speciesof Dicrodiacrodiumpublished to date, two havea single lapical' process,namely D. ancoriformeand D. normak Burmann1968. From the original descriptionsand illustrations of these two species,they would appearto be synonymous. GenusDictyotidium Eisenack 1955 emend. Staplin 1961. Type species:Dictyotidium dlayotum (Eisenack)Eisenack 1955. Genericdescription: Eisenack1955, p. 179; Staplin 1961, p. 417. Remarks: The prasinophytegenus Cymatiosphaera Wetzel 1933cr Deflandre 1954differs from in Dictyotidium possessingmembranous outgrowths from the vesicle that divide it into polygonal 73 fields. In Diaptidium the field dividers are non-membranous ridges. Alveosphaera Kiryanov 1978 differs from Diayoddium by having a very thick, double wall layered vesicle with very small polygonal fields. Diaptidiwn cf. arctum Kiryanov 1978. Plate59, fig. 6. Holotype: Kiryanov 1978,pl. 4, fig. 7. Age: lAte Llandovery. Remarks: Comparewith Kiryanov 1978,p. 39, pl. 4, figs.6,7 & 9. Specimensassigned here differ from the type materialof this speciesin sizeonly. The specimensobserved are 39-40umin diameter, the type materialranges between 18-30um in diameter. Diciyotidium dicryotumdiffers in having a diameterof 60-100um. Dicryotidiumstenodictyum Eisenack 1965 is also larger in size and has a greaternumber of small fields on the vesicle. Dictyotidium coarclatum(Kiryanov) Colbath 1983. Plate60, fig. 4; pl. 72, figs.4&5; pl. 82, figs. 10&11; pl. 105, figs. 1,2&3; pl. 137, fig-10. Description: Kiryanov 1978,p. 24-25, pl. 7, figs. I&4; emend.Colbath 1983,p. 257-258. Holotype: Kiryanov 1978,pl. 7, figs.4. Age: Late Silurian. Remarks: Colbath'semended description of the speciesbroadened the size dimensionsfrom 58-64urn (Kiryanov 1978,p. 24) to 25-70um(Colbath 1983,p. 257). A broad rangeof specimensin termsof size has consequentlybeen accommodated in this species. The fields on the vesiclein the speciesD. arclum, D. dictyotumand D. stenodicryumEisenack 1965 are broaderthan on D. coarctatum. Dictyotidium dictyotum(Eisenack) Eisenack 1955. Plate59, figs.2&4; pl. 83, figs.2&4; pl. 105, figs.4&6; pl. 114, fig. 3; pi. 138, fig. 2? Description: Eisenack1938, p. 27-28, pl. 3, figs. 8a-c. Holotype: Eisenack1938, pl. 3, fig-8a (lost accordingto Kiryanov [1978, p. 40-411and Eisenack, Cramer& Diez [1979, p. 162]). Age: Silurian. 74 Specimens Remarks: assignedaccord well with the descriptionand illustration of the type material. Dictyotidium stenodictyumEisenack 1965 Plate60, figs.3 & 6; pl. 72, fig. 8; pl. 121, fig. 8. Description: Eisenack1965, p. 264, pl. 22, figs.2-3. Holotype: Eisenack1965, pl. 22, fig. 2. Age: Llandovery. Remarks: Tbe fields on the vesicleof D. stenodictyumare smallerthan on D. dicryota andA arclum. 7be greaternumbers of ridgesdividing the fields gives the vesiclea rigid structure. 7bere are thickeningsof the wall at the triple junctions of the ridges. Dicryoddium sp. 1. Plate 60, figs. 1,5 & 7. Description: A speciesof Dictyotidium with a thick vesiclewall. The vesiclemeasures 55-80um in maximumdiameter and the wall is 4-9um,wide. The vesiclesurface is reticulatewith the vesicle surfacedivided into many hundredsof polygonal fields. The fields measurebetween 2-5um. across. The ridges dividing the fields are lessthan Im high and lessthan Im wide. The thick vesiclewall makesfor a rigid structure,however, broad thick fold are present. No regular form of openingis apparent. Remarks: This specieshas similarly small fields on the vesicleto A coarctatumbut can be distinguishedby the thick vesiclewall. Alveosphaeralocellata Kiryanov 1978has a similarly thick vesiclewall and a similar vesiclediameter to Dicryotidium sp. I but differs in possessingbroader, more rigid muri dividing more regularpolygonal fields on the vesicle. Dictyotidiwn sp. 2. Plate 60, fig. 2; pl. 83, figs. l. & 3; pl. 105, fig. 8; PI-114, fig. 5; pl. 138, fig. l. Description: A Dictyotidium speciesof with a thick vesiclewall. 7be vesicle measures100-160um in diameter the is maximum and wall approximatelylum thick. 7be vesicle surfaceis reticulatewith the 75 divided into fields. The fields vesicle surface polygonal measurebetween 8-18um across. 'me ridges dividing fields less the are than 2um high and lessthan 2um wide. The wall may be markedly thickenedat the triple junctions of the ridges. No regular form of openingis apparent. Remarks: This taxon differs from D. dictyotwn in the diameterof the vesicle. Specimensincluded here are between100-160um in maximumdiameter which is greaterthan the sizesgiven in the dictyotum diagnosisof D. (60-100um)by Eisenack. Gonal thickeningsof the vesiclewall are another notablefeature of Dictytidium sp. 2. GenusDiexaUophasis Loeblich 1970. Type species:Dierallophasis denticulata (Stockmans & Williere) Loeblich 1970. Genericdescription: Loeblich 1970,1970a,p. 714. Remarks: Ile contentionthat the type species,A denticulata, is a junior synonymof D. remotum (Deunff) Playford 1977, (Playford 1977,p. 19; upheldby Fensomeet al. 1990,p. 197-198) is rejected here as the polygonal shapeof the centralbody of the latter is distinguishablefrom the more rounded centralbody of the former. This group of acritarchsrepresents a good exampleof a morphologicalcontinuum of forms. The morphologicalcontinuity, in processlength and branching,sphericity of the centralbody and the degreeof ornamentationhas resultedin a complexof speciesand subspecies,of essentiallythe same morphotypebeing published. In the interestof practicability, the presentauthor considersthere to be two dominantspecies in the genusDiexallophasis; D. denticulatain which the centralbody is rounded to subroundedand D. reinota in which the centralbody is polygonal. Variationswithin thesespecies are consideredto be at the subspeciesor variety rank. The genusEvittia includesvery similar morphotypesin termsof generaloutline, processshape and ornamentation,but differs by including forms with flattenedveryhachid type bodiesrather than the centralbody being inflated. I'his differentiationis ratherunsatisfactory as compressioncan be very misleading. Speciesof Evittia are very similar in form to the speciesDiexallophasis remota. The genusEstiastra includesspecies in which the processesare coneshaped, the processesmerging proximally, as in the genusGoniosphaeridium. Adjacent processes merge to form sharpangles betweeneach other and no distinct centralbody apparent. 76 Dlexallophasisdenticulata (Stockmans & Williere) Loeblich 1970. Plate 61, figs. 4-7; pl. 72, fig. 9; pl. 83, fig. 5; pl. 84, fig. 1; pl. 105, figs. 5,7 & 9; pl. 121, figs. 9 & 10; pl. 129, figs. 1 & 2; pl. 138, figs. 3 & 5-9; pl. 149, figs. 7 & 8; pl. 153, figs. 8 & 107 Synonomy: 1963, Ve?Aachium denticulata,Stockmans & Williere, p. 458, pl. 1, fig. 4, text- fig. 13. 1973,Mukiplicisphaeridium denticulatwn, EisenackCramer & Diez, p. 587-591. Description: Stockmans& Williere 1963,p. 458, pl. 1, fig. 4, text-fig. 13. Holotype: Stockmans & Williere 1963, pl. 1, fig. 4- Age: Silurian. Remarks: Includedhere are specimensof Diewallophasiswith a roundedcentral body. Specimensnot assignedto a variety of this speciesare either too poorly preservedor of too few numbersto warrant subdivisionat the subspecieslevel. Dierallophasisdenticulata var. gotlandica (Cramer)Comb. nov. Plate40, figs. II& 12. Synonomy: 1970,Diexallophasisgotlandica, Cramer, p. 138-140,pl. 10, fig. 151, pl. 20, fig. 302; text-fig.43b. Description: Cramer 1970,p. 138-140,pl. 10, fig. 151, pl. 20, fig. 302; text-fig.43b. Holotype: Cramer 1970,pl. 19, fig. 151. Age: Silurian. Remarks: This variety is characterisedby the sphericalcentral body, the relatively simple processes with shallow furcationsand a relatively low denticulateornament. Diexallophasisdenticulata var. granulatispinosa(Downie) Comb. nov. Plate 6 1, figs. 1,2 & 3. Synonomy: 1963,Baltisphaeridium granulatispinoswn, Downie, p. 640-641, pl. 91, figs.I&7, text-fig.3c. 1970,EWttia granulatispinosa,Lister, p. 67. 77 1973,Multiplicisphaeridium granulatispinosum, Eisenack Cramer & Diez, p. 643. Description: Downie 1963, p. 640-641, pl. 91, figs. 1 & 7, text-fig. 3c. Holotype: Downie 1963,pl. 91, figs. I. Age: Wenlock. Remarks: This new combinationis proposedto accommodatea variety of A denticulataspecimens that appearto be restrictedstratigraphically to the late Liandovery-earlyWenlock in the samples studied. Ile specimensobserved are almostidentical in morphologyto the holotype of this taxon. Die-zallophasis denticulata var. figida (Cramer) Comb. nov. Plate 83, fig. 6. Synonomy: 1966,Dicrallophasis remotaforma rigida, Cramer,p. 36-37, pl. 3, figs.6-8. Description: Cramer 1966,p. 36-37, pl. 3, figs.6-8. Holotype: Cramer 1966, pl. 3, fig. 7. Age: Silurian. Remarks: This variety of D. denticulatais distinguishedby its large size (upto 150umincluding the processes)and the long rigid processes. Diexallophasisdenticulata var. A. Plate 106, figs. 1-6; pl. 114, figs.6,7 & 8. Remarks: Specimensincluded here have the samebroad rangeof processmorphology as Diexallophasisdenticulata var. denticulata(Stockmans & Williere) Loeblich 1970. However, A denticulatavar. A hasa thicker wall (ca. 2um) and a more deSCreteechinate ornamentation on the centralbody and on the processes. Multiplicisphaeridium amphitrite Deunff, Lefort & Paris 1971, describedfrom the late Ludlow of France,is of very similar morphologyto this variety of Diexallophasisdenticulata and could possibly be synonymous. 78 Diemallophasisremota (Deunff) Playford 1977. Plate 84, fig. 5; pl. 107, figs.3 & 4; pl. 122, fig-5; pl. 164, figs.2,5 & 6; pl. 173, figs. I&5; pl. 180, figs. II& 12. Description: Deunff 1955,p. 146, pl. 4, fig. 8. Holotype: Deunff 1955,pl. 4, fig. 8. Age: Wenlock-Givetian. Remarks: Includedhere are specimensof Diexallophasiswith a polygonal centralbody. Specimens not assignedto a variety of this speciesare either too poorly preservedor of too few numbersto wan-antsubdivision at the subspecieslevel. Diemallophasisremota var. remota(Deunff) Fensomeet al. 1990. Plate 84, figs. 3 & 4; pl. 107, figs. I&2; pl. 115, figs. 1,2 & 3; pl. 139, figs. 2 & 4; pl. 149, figs. 9 & 10; pl. 164, pl. 3 &4 Description: Deunff 1955,p. 146, pl. 4, fig. 8. Holotype: Deunff 1955,pl-4, fig. S. Age: Wenlock-Givetian. Remarks: The specimensof D. remotavar. remotarecorded here measure upto I 10umin total diameter. This variety has four-six processes,four of which are positionedat the apicesof the flattened polygonal centralbody. Ile processesare echinateand striateand the processterminations are denticulatewith shallow ( The specimensobserved strongly resemblethe holotype. Also comparableare specimensrecorded by Deunff (1966) as Veryhachiwnremotum from the Devonianof Tunisia. Diexallophasisremota var. rabiosum(Cmmer) comb. nov. Plate 129, fig. 3; pl. 139, figs.3 & 6; pl. 149, figs. 11 & 12; pl. 153, fig. 9? Synonomy: 1964, Ve?yhachium rabiosum, Cramer, p. 299, pl. 5, fig. 7; pl. 6, figs. 3 & 8, pl. 7, figs.5,8 & 9, text-fig-21b. 1967,EWttia rabiosa, Brito, p. 477 1970,Baltisphaeridium rabiosum, Cramer, p. 182-183. 79 1973, Multiplicisphaeridiwn rabloswn, Eisenack, Cramer & Diez, p. 747-749. Description: Cramer 1964, p. 299, pl. 5, fig. 7, pl. 6, figs. 3 & g, pl. 7, figs. 5,8 & 9, text-fig. 21b. Holotype: Cramer1964, pl. 5, fig. 7. Age: Siegenian-Emsian. Remarks: This form is combinedwith D. remotaas it possessesa flattenedvesicle and hasprocesses which havea granulateor echinateornamentation and denticulatedistal terminations. This particular variety has a large, quadratecentral body and six processes,four of which are positionedat the apices of the vesicle. The processesare rather broad. Diexallophasisremota var. remotahas an identical arrangementof the processesbut differs in having thinner, more slenderprocesses. 7be latter variety is also generallysmaller in size. Diexallophasisreinota var. thyrae (Cramer)comb. nov. Plate 173, fig. 1; pl. 180,8,11 & 12? Synonomy: 1964, Ve?yhachium thyrae, Cramer,p. 316-317,pl. 12, figs. 10 & 13. 1973,Multiplicisphaeridium thyrea, Eisenack,Cramer & Diez, p. 809-810. 1984,Exochoderma cleopatra, Martin, p. 55, pl. III, figs. 1-6,8 & 9. Description: Cramer 1964,p. 316-317,pl. 12, figs. 10 & 13. Holotype: Cmmer 1964,pl. 12, figs. 10. Age: Ludlow. Remarks: This form is recombined here with D. remota due to the similarity of morphological features such as i. central body shape, ii. process terminations and iii. ornamentation with that species. The speciesD. thyrae is denoted to variety status within D. remota due to the broadening of the speciesD. remota, see p. 76 and p. 79. Ditmallophasis remota var. A. Plate 115, figs.4,5 & 6. Remarks: This large variety of A reinota, upto 150umin total diameter,has four to six broad processeswith a strongly polygonalcentral body. Ile processesare coarselydenticulate at the terminationsand branchin the distal halfi Ile wall is thick (> lum) and sparselyornamented with echinae. 80 Diexallophasiscf. sanpetrensis(Cmmer) Doming 1981. Plate78, figs.7 & 10 Holotype: Cramer1964, pl. 3, fig. 16. Age: Ludlow. Remarks: Comparewith Cramer1964, p. 293-294,pl. 3, figs. 15-16, text-fli. 18. This small form of Diexallophasis,measuring between 18-38um in diameteracross the centralbody, is recordedhere from samplesfrom the ludensis(graptolite) Zone, latestLlandovery only. Specimenshave a similar process to centralbody ratio and a similar degreeof denticulationto D. sanpetrensis.Specimens here are smaller and havea slightly more polygonalaspect than the holotype. Diexallophasis?sp. 1. Plate40, figs. 8&9. Remarks: Acanthornorphicacritarchs with a four-sided, slightly inflated centralbody. From the two poorly preservedspecimens recovered, it appearsprobable that therewould havebeen four short stout processesat the apicesof centralbody (eachspecimen observed has only two fully preserved). The centralbody is 41-42umwide. The processesare 14-18umlong, approximately8um wide at the base and 4-5urnwide distally. The distal tips havevery shallow furcationsless than 3urn deep. The wall is composedof a single layer and the processescommunicate freely with the centralbody. The body and processesare ornamentedwith granaand minute echinae. A morphologicallysimilar speciesis Evittia sommeriBrito 1967which has deeperfurcations in the distal extremitiesof the processes. GenusDuvernaysphaera Staplin 1961. Type species: Duvernaysphaera tenuicingulata Staplin 1961. Genericdescription: Staplin 1961,p. 414-415. Remarks: The author agreeswith Cramer& Diez 1972(p. 162) and Playford 1977 (p.21) that Helios Cramer 1974is a junior synonymof Duvernaysphaera. 81 Duvernaysphaera gothica Martin 1967. Plate62, figs. 1&2; pl. 85, figs. I&2. Description: Martin 1967,p. 323, pl. 1, figs.6 & 15. Holotype: Martin 1967,pl. 1, fig. 15. Age: Silurian. Remarks: Duvernaysphaeraaranaides (Cramer) Cramer & Diez 1972has a similar discoid vesicle shape,size, and approximatelythe samenumber of processesas A gothica. It differs in the position of the processes.Duwmaysphaera gothica hasa circle of processesradiating from the equatorof the discoid centralbody, whereasthe circle of processesof D. aranaidesradiate from a position between the pole and the equatorof the vesicle. Duvernaysphaeraradiata Brito 1967. Plate 185, figs.4 & 5. Description: Brito 1967, p.477, pl. 1, figs. I&2. Holotype: Brito 1967,pl. 1, fig. 2. Age: ?Middle Devonian. Duvernaysphaerasp. Plate 78, figs. 5 & 6. Remarks: Ile two specimensincluded here have a similar structureto D. aranaides. It differs in possessinga greaternumber of processes,approximately 50, supportingthe velum. Duvernaysphaera aranaidespossesses approximately 10 processes. GenusEphelopalla Wicander 1974 emend. Martin 1981. Type species:Ephelopalla elongata Wicander 1974. Genericdescription: Wicander 1974,p. 22, emend.Martin 1981, p. 20-21. 82 Ephelopalla gorkae Martin 198 1. Plate 181, figs. 1-6; pl. 187, fig. 3; pl. 191, figs.7,8 & 9. Description: Martin 1981,p. 22-23, pl. 2, figs. 1-3 & 5-7. Holotype: Martin 1981,pl. 2, figs. 1. Age: Late Devonian. Remarks: The well preservedspecimens recorded in the presentstudy accordwell with the description and illustrations of the type materialfrom Belgium. GenusFlorisphaerldium Lister 1970. Type species: Florisphaeridiumcastellum Lister 1970. Genericdescription: Lister 1970,p. 74. Remarks: This genusis distinguishedfrom Multiplicisphaeridiumby having floreate, as opposedto ramusculose,distal terminationsof the processes. Florisphaeridiumtoyetae (Cramer) Cramer & Diez 1976. Plate 150, fig. 1. Description: Cramer 1964, p. 302, pl. 1, figs. 14 & 15. Holotype: Cramer 1964,pl. 1, fig. 15. Age: Middle Siegenian-Emsian. Remarks: Specimensrecorded here have processes that are shorterthan on the holotype. However, specimensassigned to this speciesby Cramer& Diez in 1976when they transferredthe speciesto the genusFlorisphaeridium are almostidentical to thoseobserved here. 83 Florisphaeridium sp. Plate 129, fig. 4; pl. 165, fig. 2. Remarks: The single folded specimenincluded here has approximatelyeight processeswith floreate distal terminations. The centralbody is approximately40um in diameterand processesare upto Bum in length. GenusFrankea Bunnann 1970. Type species: Frankeahamata Bumiann 1970. Genericdescription: Burmann1970, p. 290; for an English translationsee Eisenack, Cramer & Diez 1979, p. 295. Frankeasaribernardensis (Martin) Colbath 1986. Plate 16, fig. 13; pl. 32, figs.3-6. Description: Martin 1966b,p. 434-435,text-figs. 11-13. Holothm: Martin 1966b,text-figs. 12-13. Age: Arenig. Remarks: The combinationF. sartbernardensiswas not validlY publishedin Burmann1970 (p. 291) as the author did not fully reference the basionym. Frankeahamata Burmann 1970 is very similar in morphologybut differs in having only two pinnaeat the distal terminationsof the processes,F. sanbernardensismay havethree or four. Frankeahamulata Burmann1970 has threeor more short stub4ike pinnae. GenusGoniosphaeridium Eisenack 1969 emend. Turner 1994. Type species: Goniosphaeridiumpolygonale (Eisenack ax Eisenack)Eisenack 1969. Genericdescription: Eisemck 1969a,p. 256; Turner 1984,p. I 11-112. 84 Remarks: As discussedby Turner (1984, p. 112), the morphological limits of the genus Goniosphaeridium are rather vague. Forms included here are smooth walled and have conical processeswhose bases merge to form the poorly definedcentral body (i. e. the shapeof the centralbody is dictatedby the shapeof the processbases). Forms included in the genusPolygoniwn havea polygonal, well definedcentral body with simpleprocesses. Forms included in Micrhystridium havea round-ovatecentral body with simpleprocesses. Stellichinitwn and Uncinisphaeraboth havean ornamentof echinae. Goniosphaeridium cf. conneawn Kjellstrom 1971. Plate5, figs. 1.2 & 3. Holotype: Kjellstrom 1971a,pl. 3, fig. 5. Age: Middle Ordovician. Remarks: Comparewith Kjellstrom 1971a,p. 4445, pl. 3, fig. 5. Specimensassigned here are smaller (centralbody diameter25-40um as opposedto 40-45um)and havemore processes(15-20 rather than 'about 10*) than the materialdescribed by Kjellstrom. The illustration of the holotype by Kjellstrom (1971, pl. 3, fig. 5) is rather feint. 7he presentauthor hasbeen influenced in to comparingthe specimensassigned here to G. connectumby the illustration of the speciesgiven in Eisenack,Cramer & Diez 1979, p. 483. Goniosphaeridiumpolygonale subsp. pellucidum (Timofeevex Tynni) Fensomeei aL 1990. Plate 5, fig. 8. Description: Timofeev 1959b,p. 40, pl. 3, fig. 37. Holotype: Timofeev 1959b,pl. 3, fig. 37. Age: Early Ordovician. Remarks: Specimensobserved here have folded, rather flexible processesin contrastto the relatively rigid processesof the holotypeas illustratedby Timofeev. Goniosphaerldiumpolygonale subsp. polygonale (Eisenack)Fensome et aL 1990. Plate 17, figs. 1-4; pl. 32, figs.7 & 8. Synonomy: 1977, Veryhachiumsplendens, Paris & Deunff, pl. 1, fig. 4. 85 Description: Eisenack1931, p. 113, pl. 4, figs. 16-20;pl. 5, fig. 18. For further morphological information seeEisenack, Cramer & Diez 1979,p. 499. Holotype: Eisenack193 1, pl. 4, fig. 19; lost accordingto Eisenack(1959a, p. 199. Age: Silurian (the type materialwas takenfrom an erratic). Goniosphaeridiumpolygonale var. A. Plate5, fig. 9; pl. 17, figs.6,7 & 9. Remarks: Acanthornorphicacritarchs which havea strongly polygonalcentral body rangingbetween 3 lum, and 42um,in maximumdiameter. The processeshave broad bases(upto, 7um wide) that taper rapidly in the proximal half of the shaft and tapermore graduallydistally. Processesare 15-19umin length and haveaccuminate tips. The processlength to centralbody diameterratio is approximately 3: 5. The wall is composedof a single layer and the processescommunicate freely with the central body. The wall is smoothand no regular form of openingis apparent. Remarks: This form is morphologicallymost similar to G. polygonalesubsp. polygonale. The size and shapeof the centralbody are almostidentical, as is the processto centralbody size ratio. However, G. polygonalevar. A hasprocesses that are thinner distally and more numerous. Goniosphaeridiumpolygonale subsp. pellucidum has longer processesrelative to the centralbody and the centralbody is markedlysmaller. Kote- Goniosphaeridiumsp. 1 to sp.3 describedbelow can be consideredas a complexof Goniosphaeridiwnspecies which havea similar two-tier, galaeateprocesses. The three species describedshow variation in the numberand dimensionsof the processes. Goniosphaeridium sp. 1. Plate 5, fig. 4 Description: Acanthomorphicacritarchs which havea strongly polygonal centralbody. The central body rangesbetween 20um and 25um in maximumdiameter. There are approximately20 processes that am galaeatein form. They havebroad, inflated, bulbousbases (upto 10umwide) that taper rapidly to approximatelyhalf way up the shaft. The distal half of the shaft tapersmore gradually to commonlytruncated or to accuminatetips. Processare 10-14umin total length and the processto 86 centralbody ratio is approximately1: 2.7be wall is composedof a single layer and the processes communicatefreely with the centralbody. 7be wall is smoothand no regular form of openingis apparent. Remarks: The speciesis distinguishedfrom thosepreviously publishedby the galaeateprocesses. Goniosphaeridiumsp. 2 has fewer more conical shapedprocesses. Goniosphaeridium sp. 3 hasa greaternumber of processesand is larger in size. Goniosphaeridiumsp. 2. Plate5; fig. 5. Description: Acanthomorphic acritarchs which have a strongly polygonal central body. The central body ranges between 25um and 30um in maximum diameter. There are about 8-15 processesthat are galaeate,in form. 7bey havebroad conical bases(upto l5um wide) that taperrapidly to approximately half way up the shaft. The distal half of the shaft tapersmore gradually to commonlytruncated or to accuminate,tips. Processare upto,Hum in total length and the processto centralbody ratio is approximately1: 2. The wall is composedof a single layer and the processescommunicate freely with the centralbody. Ile wall is smoothand no regular form of openingis apparent. Remarks: This speciesdiffers from Goniosphaeridiumsp. I by having fewer processeswhich are more conical as opposedto bulbousat their bases. A morphologicallysimilar publishedspecies is Stellinium ocioaster(Staplin) Jardineet al. 1974which hasa similar vesicle form and numberof processes.This Late Devonianspecies, however, has crestedprocesses. Goniosphaeridiumsp. 3. Plate5, fig. 6. Description: Acanthomorphicacritarchs; having a strongly polygonal centralbody which ranges between35um and 40um in maximumdiameter. 71ere are approximately20-30 processesthat are galaeatein form. They havebroad conical bases(upto 8um wide) that taperrapidly to approximately half way up the shaft. The distal half of the shaft tapersmore gradually to truncatedor to rare accuminatetips. Processare upto l5um in total length and the processto centralbody ratio is approximately2: 5. The wall is composedof a single layer and the processescommunicate freely with the centralbody. The wall is smoothand no regular form of openingis apparent. 87 Remarks: Goniosphaeridiumsp. I is smallerin sizeand has fewer processeswith more bulbousbases than this taxon. GenusGorgonisphaerifium Staplin, jansonius & Pocock 1%S. Type species: Gorgonisphaeridiwnwinslowiae Staplin, Jansonius& Pocock 1965. Genericdescription: Staplin, Jansonius& Pocock 1965. Remarks: An English translationof the restrictedgeneric description proposed by Kiryanov (1978) is not availableto the author. For this reason,the parametersof the genusutilised hereare thosestated in the original descriptionby Staplin, Jansonius& Pocock(1965). Of the 43 speciesof Gorgonisphaeridiumconsidered to be valid at the presenttime (Fensomeet al. 1990), 26 are describedfrom the Middle to Late Devonian. It is apparentfrom personalobservation of the illustrations of the holotypesof theseMid-Late Devonianspecies that theserelatively simple, thick walled, acantho-morphotypeshave been over-split. Ile thick, generallydark-coloured vesicle wall makessubdivision of theseforms on the detail of the wall sculpturesomewhat impractical. The group has, therefore,been subdivided into complexesof speciesin the interestsof practicality for future usage of thesemorphotypes. Gorgonisphaeridiumohioense Complex. Plate 181, figs. 8,9 & 10; pl. 187, figs.6 & 7; pl. 192, figs. 1-4 Remarks: Includedhere are forms with relatively long processes,i. e. with processto centralbody ratio greaterthan 6: 1, and with simpleprocess terminations. Ile centralbody is greaterthan 30um in maximumdiameter. The speciesG. ohioense(Winslow) Wicander1974, G. crinegerumDeunff 1981, G. elongatum Wicander 1974and G. solidumJardine et al. 1974are includedin this complex. Transitional morphotypes,falling morphologicallybetween these formally describedspecies, are commonin the material studied. It is for this reasonthat theseforms are difficult to split practically and have, therefore,been grouped. The G. winslowiaecomplex differs in possessingfurcate process terminations. 88 Gorgonisphaeridiumspicatum Complex. Plate 182, figs. 1,2 & 3; pl. 187, fig. 10; pl. 192, fig. 6. Remarks: Includedhere are forms with relatively short processes,i. e. the processto centralbody ratio is lessthan 6: 1. The processtermination are simple. The centralbody measuresmore than 30um in maximumdiameter. The speciesincluded in this complexare G. spicatwn (Staplin) Staplin el al. 1965, G. absilum Wicander 1974, G. disparatumPlayford 1977, G. evexispinoswnWicander 1974, G. granatum Playford.1977 and G. pleurispinwn Wicander1974. Although the descriptionsand illustrations of the type specimensof thesespecies suggest that theseforms are easily recognisable,practical applicationof them was found to be very difficult due to the commonoccurrence of transitionalmorphotypes. The use of this group of speciesas the G. spicatumcomplex is thought to be of more practical value for f4ture work. A comparablespecies with this complexis G. seperatumWicander 1974which also has relatively short processes.This form, however,possesses bifid processes.Gorgonisphaeridium telum Wicander& Playford 1985also has simpleprocess terminations but is a much smaller species,measuring between 14-24umin vesiclediameter. Gorgonisphaeridiumtelum Wicander& Playford 1985. Plate 154, figs. 1,2 & 3; pl. 165, figs.3 & 4; pl. 192, figs-9 & 12. Description: Wicander & Playford 1985, p. 106-108, pl. 3, figs. 4 & 5. Holotype: Wicander& Playford 1985,pl. 3, figs.4. Age: Fmsnian. Remarks: This speciesis distinguishedby the simpleprocess terminations and the small sizeof the centralvesicle which measuresbetween l4urn and 24um. 89 Gorgonisphaeridiumwinslowiae Complex. Plate 192, fig. 5. Remarks: Includedhere are forms with relatively long processes,i. e. the processto centralbody ratio is greaterthan 1:6, with bifurcate and rarely trifurcate processterminations. The centralbody is greaterthan 30urnin maximumdiameter. Speciesincluded here are G. winslowiaeStaplin et al. 1965and G. furcillatum Wicanderand Playford 1985.7be G. ohioensecomplex differs in possessingsimple as opposedto furcateprocesses. Gorgonisphaeridium?sp. 2. Plate 187, figs. 8 & 9; pi. 191, figs.9,11 & 12. Remarks: Includedhere are acanthomorphicacritarchs with a sphericalcentral body measuring between2545um in maximumdiameter. The processesare simple and solid and measureupto 15umin length. The processto centralbody ratio is generallyabout 1:2. The vesiclewall is coarselyreticulate. No regular form of openingis apparent. This form may be easily distinguishedby the reticulum on the vesiclewall. The inclusion of such strongly reticulateforms in the genusGorgonisphaeridium is questioned. Gorgonisphaerldium?sp. 3. Plate 187, figs. 11 & 12. Remarks: This taxon includesacanthomorphic acritarchs with a sphericalcentral body measuring between35-55um in maximumdiameter. 7be processesare simple and solid and measureupto 20um in length. The processto centralbody ratio is generallyabout 1:2. The vesiclewall is vermiculate. No regular form of openingis apparent. This form can be distinguishedby the sinuousridges or vermiculaeornamenting the vesiclewall. The inclusion of suchornamented forms in the genusGorgonisphaeridium is questioned. 90 GenusHapsidopaUa Playford 1977 emend. Wicander & Wood 1981. Type species: Hapsidopallasannemannil (Deunff) Playford 1977. Genericdescription: Playford 1977,pl. 25 emend.Wicander & Wood 1981, p. 42-43. Remarks: Hapsidopallais differentiatedfrom the genusCraterisphaeridium by the presenceof a reticulate, as opposedto a foveolate,ornamentation on the vesiclewall. HapsidopallacL sannemanni(Deunft) Playford 1977. Plate 107, figs. 5,6,8 & 9; pl. 139, figs. 10,11 & 12. Holotype: Deunff 1957,pl. 13, fig. 1. Age: Middle Devonian. Remarks: Comparewith Deunff 1957,p. 6, pl. 13, fig. 1. Specimensrecorded here have shorter and more slenderprocesses than the type specimen. GenusHeliosphaerMum Lister 1970. Type species: Heliosphaerldium claWspinulasum Lister 1970. Genericdescription: Lister 1970,p. 76. Remarks: The low ornamentation of the wall of these spheromorphs is expanded at the distal. part of the element. Lophosphaeridium differs in possessingan ornament of solid tubercles. Buedingisphaeridiumhas conical tuberclesthat communicatefreely with the vesiclecavity. Heliosphaeridiumcf. citrinipeltatum (Cramer& Diez) Doming 1981. Plate62, figs.3,4,7 & 8. Holotype: Cramer& Diez 1972,pl. 35, fig. 58. Age: Early Llandovery. Remarks: Comparewith Cramer& Diez 1972,p. 166-167,pl. 35, figs.58-59. Specimensrecorded have lower holotype, slightly ornamentthan that of the of H. citrinipekatwn. 7be specimensobserved 91 have closely spaced'donut-like' elementsornamenting the wall. The vesicle measuresbetween 38um- 50um in diameter. Heliosphaeridiummalwwnsls Doming 1981,H. claWspinosumLister 1970and H. pseudodictywn Lister 1970all differ by possessingsolid processeswith blunt distal tips. GenusImpluWeulus Imblich & Tappan 1%9 onend. Martin 1975. Type species: Impluviculusmilonii (Deunff) Loeblich & Tappan. The vesicleis 38um-50umin diameter. Genericdescription: Loeblich & Tappan1969, p. 48; Martin 1975, p. 15. Impluviculus?sp. Platepl. 5, fig. 7. Remarks: Specimensare questionablyassigned to the genusImpluviculus as the characteristiclid-like openingis not discerniblein this dark colouredmaterial. GenusLelofusa Eisenack 1938 emend. Combaz et al. 1967. Type species:Ldofitsafusiformis Eisenack1934 ex Eisenack1938 Genericdescription: Eisenack1938a, p. 28; Combazet al. 1967,p. 297. Leiofitsa cf. bernesgae Cramer 1964. Plate62, fig. 5. Holotype: Cmmer 1964Cmmer 1964,pl. 2, fig. 10. Age: Gedinnian. Remarks: Comparewith Cramer 1964,p. 37, pl. 2, fig. 10. Specimensincluded herehave a fusiform holotype, however, vesicle closely resemblingthe the processesare shorter in the specimensobserved. Downie 1959has Leiofusatumida a slightly more roundedcentral body and longer processes. 92 Leiofiisa estrechaCramer 1964. Plate 78, figs. 12?& 13?; pl. 85, figs.4,5 & 6; pl. 107, fig. 7; pl. 129, fig. 6; pl. 139, figs.5 & 13; pl. 154, fig. 10? Description: Cramer 1964,p. 36, figs. 8 & 11. Holotype: Cramer 1964, fig. 11. Age: Early Gedi 'an. Remarks: Specimensof this large leiofusid species(upto 270umin length) are commonlybroken in the material observed. LeiofusafusifonnisEisenack 1934 ex Eisenack1938. Plate42, fig. 4. Description: Eisenack1934, p. 65-66, pl. 4, fig. 19. Holotype: Eisenack1934, pl. 4, fig. 19. Age: Silurian. Remarks: Specimens included here are 110-150mm in length. Leiofusa simplex (Combaz) Martin 1975 would appear to have an almost identical morphology (by comparison of the photographic illustrations of the holotype) and is probably a junior synonym. Leiofusacf. pittauae ex Pittau 1985; Fensomeet al. 1990. Plate 6, fig. 1. Holotype: Pittau 1985,pl. 9, fig. 12. Age: Late Tremadoc-EarlyArenig. Remarks: Comparewith Pittau 1985,p. 188-189,pl. 9, figs.9 & 12. Only the size dimensionsof specimensobserved here differ from the type material. The specimenshere are 85-96umlong here comparedto 40-47um.long in the type material. The specieswith the most similar vesicle form to L. cf. pittauae is Dactylqfwa squama(Deunfo Rauscher1973. T'his speciesis also of similar sizebut differs in possessingstriae on the vesiclewall. 93 Leiofitsa tumida Downie 1959. Plate62, fig. 5. Description: Downie 1959,p. 65, pl. 11, fig. 5. Holotype: Downie 1959,pl. 11, fig. 5. Age: Wenlock. Remarks: Leiofitsa granulacutusLoeblich 1970has a similar shapedvesicle and processform, and is a similar size to L. tumida, however,the former hasa granulateornamentation on the wall. GenusLeiosphaeridia Eisenack 1958 emend. Turner 1985. Type species: Leiosphaeridiabaltica Eisenack1958. Genericdescription: Eisenack1958a, p. 2-5; Turner 1985, p. 116. Leiosphaeridiamicrocystis Eisenack 1938 ex Eisenack1958. Plate 62, figs. 9,10 & 11. Descriotion: Eisenack1958, p. 8-9, pl. 2, fig. 6. Holotype: Eisenack1958, pl. 2, fig. 2. Age: Silurian. Remarks: This speciesof Leiosphaeridiais distinguishedby its size, 50-100umin diameter,and thick wall, 2-3um.wide. LeiosphaefidiaWenlockia Downie 1959has a thinner wall and has a diameterof 20-50um. Leiosphaeridiawenlockia Downie 1959. Plate 73, fig. S. Description: Downie 1959,p. 65, pl. 12, figs.24. HoloqW: Downie 1959,pl. 12, fig. 2. Age: Wenlock. 94 Remarks: Specimensincluded here are smooththin walled spheromorphacritarchs with a maximum diameterof 20-50um. Leiosphaeridiasp. 1. Plate62, fig. 9; pl. 122, fig. 1. Description: Spheromorphicacritarchs which havea thin (< lum thick), smoothwall. The diameter of the vesicle rangesbetween 100-180um. No regular form of openingis apparent. Remarks: This speciesis larger in size and hasa thinner wall thanL. microcystis. Leiosphaeridiaspp. Plate 5, figs. 10,11 & 12; pl. 18, fig. 1; pl. 41, figs. I&2; pl. 84, fig. 6; pl. 122, figs.2 & 4. Remarks: Specimensassigned here are thin, smoothwalled leiospheresthat are commonlyfolded in an irregular manner. Openingof the vesiclemay be by mediumsplit or by irregular rupturing of the wall. GenusLeiovalia Eisenack 1965 ex Gorka 1969 ernend. Type species:Leiovalia ovalls (Eiseuck) Corka 1969. Emendeddescription: Spheromorphicacritarchs which havean ovatecentral body. The wall is composedof a single layer and is smoothor ornamentedwith featuresof low relief (< 2um,high). Remarks: The descriptionhas been emended to include the many speciespublished in this genusthat possessornament (e. g. L. scaberulaLoeblich & Tappan1978). Eisenack1965 (p. 139) describedthe genusas one that includedsmooth walled species.Mosphaeridia is spherical-subsphericalwith a smoothwall. Lophosphaeridiumis spherical-subsphericalwith an ornamentedwall. NaWfusais elongateellipsoidal or cylindrical with roundedpoles and has a smoothor ornamentedwall. Lelofusa is elongateellipsoidal, smoothwalled and has accuminatepoles. 95 Leiovalia sp. 1. Plate 41; fig. 7. Description: Spheromorphicacritarchs which havean ovatevesicle measuringbetween 59-64um in length and 32-Slum in width. The length to width ratio is approximately1.5: 1. The wall is single layeredand is ornamentedwith grana(< lum in diameter). No regular form of openingis apparent. Remarks: Leiovalia scaberulais slightly larger and has a scabrate,ornamentation composed of fine dimples and minute irregular elevations. GenusLophosphaer0um Timofeev 1959 ex Downie 1963 emend. Type species: Lophosphaeridium rarum Timofeev 1959 ex Downie 1963. Emendeddescription: Spheromorphicacritarchs which havea sphericalto subsphericalvesicle. Ile wall is composedof a single layer and is ornamentedwith featuresof low relief (< 2um high). Remarks: Lister 1970,p. 61 gavean emendeddiagnosis of the genusthat restrictedit to include forms with solid tubercularomament. The genusis broadenedhere to incorporatespheromorphs ornamented with any form of low relief ornamentation. Lophosphaeridiumcitrinum Downie 1963. Plate63, fig. 1. Description: Downie 1963,p. 630-631,pl. 92, fig. 3. Holotype: Downie 1963,pl. 92, fig. 3. Age: Wenlock. Remarks: The transfer of this species to the genus Baltisphaeridium by Stockmans & Williere (1974, p. 12) is rejected here. The short spines on the vesicle are largely solid in this species which is a characteristic of species included in Lophosphaeridiun. 96 Lophosphaeridiumsp. Plate41, figs.3,8 & 9. Description: Spheromorphicacritarchs which havea subspherical.vesicle measuringbetween 81-90um in maximum.diameter. 7be wall is single layered,thin and commonly folded. The wall is ornamented with subpolygonalclusters of granaand baculae. Ile clustersare 2-4um.in diameterand the elements within the clustersare approximatelylum in height. The non-ornamentedboundaries between clusters are < lum wide. No regular form of openingis apparent. Remarks: The ornamentof subpolygonalclusters of elementsdistinguish this species. Lophosphaeridiwnkptomolgion Loeblich & Tappan1978 is also a strongly ornamentedspecies, howeverthe ornamentationis of variably spacedgrana and verrucaein that form. Lophosphaeridiwnsp. 2. Plate42, fig. 12; pl. 108, figs. 1,2 & 3. Description: Spheromorphicacritarchs which havea subsphericalvesicle measuringbetween 85-9 lum in maximumdiameter. The wall is single layered,thin and commonlyfolded. The wall is scabrate, ornamentedwith minute granulateelements (< lum high) and fine fovea (< lum deepand < lum in diameter).No regular form of openingis apparent. Remarks: This specieshas a very similar ornamentationto Movalia scaberulaLoeblich & Tappan 1978but differs in the shapeof the vesicle. Lophosphaeridiumsp. 3. Plate42, fig. 3. Description: Spheromorphicacritarchs which havea subsphericalvesicle measuringbetween 30-55um in maximumdiameter. The wall is single layered,thick and occasionallyfolded. The wall is coarsely scabrateand ornamentedwith what appearto be a combinationof grana,baculae and pila (all < 2um high). No regular form of openingis apparent. Remarks: The elementsare not easyto distinguishbecause of the Poor preservation. Tle pila makethe wall surfaceappear 'hairy' in somespecimens. 97 Lophosphaeridium sp. 4. Plate73, fig. 2. Description: Spheromorphicacritarchs which havea sphericalvesicle measuringbetween 65-75um in maximumdiameter. The wall is single layered,thick (approximatelylum) and occasionallyfolded. The wall is ornamentedwith granaand baculae which are closely spaced(< 2m betweenelements). The elementsare approximately2um in height and 2um in diameter. No regular form of openingis apparent. Remarks: This specieshas a similar morphologyto Visbysphaeramicrospinosa. However, the wall is thinner and the elementsare more denselydistributed on the vesiclethan in V. microspinosa. Lophosphaeridiumsp. 5. Plate 63, figs. 2 & 3. Description: Spheromorphicacritarchs which havea sphericalvesicle measuring between 25-30um in maximumdiameter. The wall is single layeredand ornamentedwith coarsebaculae. The baculaeare evenly spacedwith approximately2-3um betweenthe elements. The baculaeare 1-3umin height and approximately3-4um in diameter. No regular form of openingis apparent. Remarks: This speciesis distinguishedby its small size and the coarsebaculate ornament on the vesicle. Lophosphaeridiumsp. 6. Plate 63, figs. 4&6. Description: Spheromorphicacritarchs which havea sphericalvesicle measuring between 37-45um in maximumdiameter. The wall is single layered,moderately thick (approximatelylum) and occasionally folded. The wall is ornamentedwith evenly spacedgrana (<2um betweenelements) that are < lum in height and < 2um in diameter. No regular form of openingis apparent. Remarks: This speciesis distinguishedby the evenly distributed, descretegrana and the rather rigid vesicle. 98 Lophosphaeridiumsp. 7. Plate78, figs. 8 & 9; pl. 85, figs. 3,7 & 8; pl. 108, fig. 4. Description: Spheromorphicacritarchs which havea sphericalvesicle measuringbetween 23-45um in maximum diameter. 7be wall is single layered,moderately thick, approximatelylum, and is commonly folded. 7he wall is ornamentedwith closely spaced,evenly distributed (< lum between elements)grana that are < lum in height and < lum in diameter. No regular form of openingis apparent. Remarks: This speciesis distinguishedby the dense,even distribution of granaand the small size of the vesicle. Lophosphaeridiumsp. S. Plate 86, fig. 8. Description: Spheromorphicacritarchs which havea sphericalvesicle measuring approximately 35um in maximumdiameter (two specimensmeasured). 7be wall is thick (> lum) and single layered. It is ornamentedwith evenly distributedverrucae (> 4um betweenthe elements)that are > 2um in height and > 2um in diameter. No regular form of openingis apparent. Remarks: The specimensincluded here strongly resembleTapajonites roxol Sommer& Van Boekel 1963which was describedfrom the Middle Devonianof Brazil. However, T raxoi is approximately 140umin diametercompared to the diameterof approximately35um of Lophosphaeridiumsp. 8. The genusTapajonites has sizelimits of 100-200um.for the speciesincluded within it, hence,specimens recordedhere are assignedto the genusLophosphaeridium. Lophosphaeridium?sp. 9. Plate5 1, figs.3,5 & 8. Description: Spheromorphicacritarchs which havea sphericalvesicle measuring 75-105um in maximumdiameter. The wall is very thick (approximately2um) and single layered. The wall has an unusual 'sponge-like' texturegiving the vesiclesurface a coarselyscabrate appearance. No regular form of openingis apparent. 99 is Remarks:Lophosphaeridium? sp. 9 only recordedfrom sampleDJ 10. 'Mese morphotypesare questionablyincluded in the genusLophosphaerldium as it is debatableweather or not the coarsely scabratesurface of the wall shouldbe consideredas *ornamentationof low relief", the presenceof which is a diagnosticfeature of Lophosphaeridiumspecies. GenusMamnhiles Brito 1965. Type species: Maranhitesbrasiliensis Brito 1965. Genericdescription: Brito 1965,p. 1-2. Maranhitesbritoi Stockmans& Williere 1969. Plate,173, figs.4 & 6; pl. 188, fig. 1; pl. 193, fig. 1. Description: Stockmans& Williere 1969,p. 44-45, pl. 2, figs.4 & 7. Holotype: Stockmans & Williere 1969, pl. 2, fig. 4. Age: Early Famennian. Remarks: This rather elaborateform of Maranhiteshas tabularextensions protruding from the lateral margin of the vesicle. The cells or podsare enclosedby a thin wall layer which are positionedbetween the tabularextensions from the vesicle. Maranhitesperpkxus Wicander& Playford 1985has a similar morphologybut is describedas being consistentlysmaller in size than M. britoi. Maranhitescf. britoi Stockmans& Williere 1969. Plate 173, fig. 7; pl. 174, fig. 2. Holotype: Stockmans & Williere 1969, pl. 2, fig. 4. Age: Early Famennian. Remarks: Comparewith Stockmans& Williere 1969,p. 44-45, pl. 2, figs.4 & 7.7bese forms have thicker, more robust tabularextensions from the centralbody supportingthe membranouspods than do specimensassigned to M. britoi. 100 Maranhites mosessii (Sommer) Brito 1967. Plate 182, fig. 8; pl. 193, fig. 2. Description: Sommer1956, p. 458-461,figs. 5-8. Holotype: Sommer1956, p. 458-461,figs. 5,7 & 8. Remarks: This speciesof Maranhiteshas a smooth,circular outer margin of the vesiclewith large subcircularpods positionedon the inner wall. Morphologically similar speciesare A brasifiensis Brito 1965and A stocknansii Martin 1981emend. Martin 1984.7bese speciesalso havea circular outline but differ in possessingsmaller cells which are restrictedto the outer margin of the vesicle. Maranhilesperplexus Wicander & Playford 1985. Plate 193, fig. 6. Description: Wicander& Playford 1985,p. 110, pl. 3, figs. 1la-b & 12. Holotype: Wicander& Playford 1985,pl. 3, figs. I la-b. Remarks: This specieshas a similar morphologyto M. britoi but can be distinguishedby the larger size of the vesicle. Maranhitesstocknansil Martin 1981emend. Martin 1984. Plate 174, fig. 1; pl. 182, fig. 6. Description: Martin 1984,p. 25, pl. 7, figs. 1,3,4-7 & 10. Holotype: Martin 1981,pl. 4, fig. 10. Age: Early Famennian. Remarks: This speciesis distinguishedby the circular outline of the vesicle and the presenceof minute podswhich are restrictedto lateral margin. 101 Maranhitescfi stockmansliMartin 1981emend. Martin 1984. Plate 174, figs. 3&4. Holotype: Martin 1991,pl. 4, fig. 10. Age: Early Famennian. Remarks: Comparewith Martin 1984,p. 25, pl. 7, figs. 1,3,4-7 & 10. The pods of this form are restrictedto the lateral margin of the vesicleas in M stock?nansii, however, the pods are noticeably larger and more obtrusivein M. cf. stoclanansii. Maranhitessp. 1. Plate 193, figs. 3,4 & 5. Description: A speciesof Maranhiteswith a subcircularcentral body measuringbetween 65-IODum in maximumdiameter. Tle centralbody is moderatelythick walled and is ornamentedwith a reticulum. Ile pods are positionedon the peripheryof the centralbody and are ovatein shape. Ilere is a thickening of the wall at the outer margin of the centralbody marking a boundarybetween it and the pods. There is little or no lateral extensionof the centralbody betweenthe pods. Ile pods are positionedclosely adjacentto eachother giving a gently undulatingoutline to this species. Remarks: Ile reticulateornamentation and the thickeningof the wall at the outer margin of the central body distinguishesthis speciesfrom the closely comparableM. britoi. Maranhitessp. 2. Plate 182, figs.4 & 7. Description: A speciesof Maranhiteswith a subcircularcentral body measuringbetween 75-95um, in maximumdiameter. The centralbody is very thick walled and appearsblack in the materialobserved. The pods are positionedon the peripheryof the centralbody and are subsphericalto ovatein shape. There is little or no lateral extensionof the centralbody betweenthe pods. Remarks: Ile absenceof the lateral extensionsof the centralbody betweenthe pods is the major differencebetween this form andMaranhites britoi. This givesMaranhites sp. 2a distinctly undulatingouter margin in contrastwith the smootherouter margin of M. britoi. 102 GenusMarrocanium Crwner et al. 1974. Type species: Marrocaniumsimplex Cmmer et al. 1974. Genericdescription: Crameret al. 1974b,p. 59. Remuics: Speciesincluded here have a four-sidedveryhachid-shaped vesicle with a thin membrane extendingbetween the processes. Marrocaniumsimplix Crameret al. 1974. Plate 18, figs.3-8; pl. 33, figs. 1& 2. Description: Crameret al. 1974,p. 59, pl. 26, figs. 1-9. Holotype: Crameret al. 1974,pl. 26, figs. 1&2. Age: We Arenig-Early Llanvirn. Remarks: Ile diin transparentmembrane or web extendingbetween processes is poorly preservedin the specimensobserved. Marrocanium sp. Plate 18, figs.9 & 10. Remarks: Two specimensare recordedhere. Iley havea rectangularshaped vesicle measuring approximately35urn in length and 28urnwide. Ilere are four processesat the apicesof the vesicle measuringupto, l7urn in length. A poorly preservedmembrane is presentin the viscinity of the processes.The wall is ornamentedwith grana. These forms can be distinguished from Marrocanium simplex by the presence of the granulate ornamentationon the wall of the centralbody and the processes. GenusMicrhystridium Deflandre 1937 anend. Sarjeant 1%7. Type species:Micrhystridium inconspicuum(Deflandre) Deflandre 1937. Genericdescription: Deflandre 1937b,p. 79-80; Sadeant1967, p. 204. 103 Remarks: Micrhystridium here encompassesspecies with well defined, round to ovatecentral bodies, simple processesthat communi freely with the centralbody and that have a smoothor scabratewall. Gonlosphaeridiumhas conicalprocesses whose bases merge to form a poorly definedcentral body, i. e. the shapeof the centralbody is dictatedby the shapeof the processbases. Speciesincluded in the genusPolygonium have a polygonal, well definedcentral body with simpleprocesses. Stellichinitum and Uncinisphaeraboth havean ornamentationof echinae. Micrhystridiwn are?wrecanium (Paris & Deunff) Fensomeet al. 1990. Plate6, figs.2 & 3. Description: Paris & Deunff 1970,p. 32, pl. 2, fig. 20; for English translationsee Eisenack, Cramer & Diez 1979, p-445. Holotype: Paris & Deunff 1970,pl. 2, fig. 20. Age: Llanvirn. MicrhystýWiwnhenryii Paris & Deunff 1970. Plate 18, figs. 13 & 14. Description: Paris & Deunff 1970,p. 3 1, pl. 2, figs.2,10,14-15, IS. Holotype: Paris& Deunff 1970,pl. 2, fig. 14. Age: Llanvirn. Micrhystridium inaffectilumium?Loeblich 1970. Plate 18, figs. 11 & 12. Description: Loeblich 1970,p. 728, figs.21E-D. Holotype: Loeblich 1970, fig. 21D. Age: Middle Silurian. Remarks: Processesof the specimensobserved here are slightly shorter than in the type material describedfrom the Middle Silurian MaplewoodShale, New York, USA. 104 Micrhystridiumstellatum Deflandre 1945. Plate 86, fig. 4; pl. 140, fig. 1; pl. 174, fig. 7. Description: Deflandre 1945,p. 65, pl. 3, figs. 16-19. Holotype: Deflandre 1945,pl. 3, fig. 16. Age: Silurian. GenusMultiplicisphaer0um Staplin MI emend. Turner 1984. Type species: Multiplicisphaeridiumramispinosum Staplin 1961. Generic description: Staplin 1961, p. 410; Turner 1984, p. 120. Remarks: The genusPiliferosphaera has the samegeneral morphology as Multiplicisphaeridium but differs in possessingan ornamentof short spine-likepila on the centralbody. Ammonidiumdiffers by having equifurcateprocesses. The generaBaltisphaeridium, Micrhystridium and Salopidiumdiffer by having simple processes. Multiplicisphaeridiumbifurcatum Staplin, jansonius& poa)ck 1965. Plate42, figs.5 & 6. Description: Staplin, Jansonius& Pocock 1965,p. 182, pl. 18, fig. 13. Holotype: Staplin, Jansonius& Pocock1965, pl. 18, fig. 13. Age: Middle Ordovician. Remarks: The delicatedistal furcationsare commonlydamaged in the materialobserved. This taxon is very similar in morphologyto speciesof Ordovicidiumwhich havebeen recorded at the same stratigraphiclevel from which the presentspecimens have been recovered. Multiplicisphaeridium bifurcalwn differs from thesespecies by having slightly deeperand more elaboratedistal process furcation. 105 Multiplicisphaeridiumconsolator Cramer & Diez 1977. Plate 19, figs. I&2. Description: Cramer& Diez 1977a,p. 347, pl. 3, fig. 17. Holotype: Cramer& Diez 1977a,pl. 3, fig. 17. Age: Early Arenig. Remarks: Multiplicisphaeridiummuldradiale (Burmann)Eisenack, Cramer & Diez 1976differs in possessingmore elaboratedistal processterminations. Multiplicisphaeridiumcrispum (Vavrdova) Comb. nov. Plate 19, figs.3-6; pl. 33, fig. 3. synonomy: 1990,Kladothecidum crispum, Vavrdova, p. 247-248,pl. IV, fig. 3; text-fig. 8. Description: Vavrdova 1990,p. 247-248,pl-IV, fig. 3; text-fig-8. Descriptionof the materialobserved here: Acanthomorphicacritarchs which havea well defined subsphericalcentral body measuringbetween 30-35um in maximumdiameter. There are approximately 10-15slender processes present which are upto 25um in length. The processbases are upto 5um wide and the shaftstaper distally to brancheddistal terminations. Branchingis restrictedto the distal extremitiesof the processeswhere the pinnaefurcate in a palmatemanner upto the 3rd order. The processto centralbody ratio is approximately4: 5. The wall is composedof a single layer and the processescommuni freely with the centralbody. The wall is smoothto slightly granuloseon the surface. No regular form of openingis apparent. Remarks: Inclusion of this speciesin the genusKladothecidum by Vavrdova 1986is rather puzzling. Not only is the morphologythat of a Multiplicisphaeridiumspecies but thereare also, what would appearto bea numberof closely relatedspecies of Multiplicisphaeridiumpublished from this stratigraphiclevel. Someof theseclosely relatedmorphotypes have been observed in the presentstudy. Theseinclude M. consolatorCramer & Diez 1977which has a lesswell defined, more polygonal centralbody with shorterprocesses and M. firmum (Burmann)Fensome et al. 1990which has a more polygonal centralbody and stout processes. 106 Multiplicisphaeridiumfirinum (Burmann) Fensome et al. 1990. Plate 19, figs.7-1 1; pl. 33, figs.4,5 & 6? Description: Burmann1970, p. 295, pl. 5, figs. 3&4. Holotype: Burmann1970, pl. 5, fig. 4. Age: lAte Arenig-Early Llanvim. Remarks: The transferof this speciesfrom Adorfla to Mulliplicisphaeridium by Cramer& Diez . made (1979, p. 43) was legitimisedby Fensomeet al. (1990). 7be polygonalbody and the short, stout processeswith elaborateterminations distinguish this species. A similar speciesis A consolator Cramer& Diez 1977which was describedfrom the Late Arenig of Morocco. Processesare broader and lesselaborate at the distal terminationsin M. consolator. Multiplicisphaeridium multipugiunculatwnCramer & Diez 1977is also similar but it has many more processesthan A firmum. Multiplicisphaeridiwnfisheri (Cramer)Lister 1970. Plate63, figs.7 & 8; pl. 86, fig. 7. Description: Cramer 1968,p. 65, pl. 1, fig. 1. Holotype: Cmmer 1968,pl. 1, fig. 1. Age: Late Llandovery. Remarks: Leptobrachion arbusculiferum (Downie) Staplin, Jansonius & Pocock 1965 is of a similar size and has a similar process distribution to M. fisheri but has deeper and more complex furcation of the processes.Mulliplicisphaeridium ramispinosumhas slightly shorterprocesses and a more rounded centralbody. The more irregular body shapein M. fisheri is a reflection of the relatively thin wall of this species. Multiplicisphaeridiuminconstans Cramer & Diez 1977. Plate 19, fig. 13; pl. 33, figs.7,8 & 9. Synonomy: 1977,EWttiaflosmaris, Deunff, p. 143, pl. 1, fig. 18, pl. 2, figs.7,9,11 & 14. Description: Cramer& Diez 1977a,p. 347, pl. 4, figs.5 & S. 107 Holotype: Cramer & Diez 1977a, pl. 4, fig. 8. Age: Early Arenig. Remarks: Evittiaflosmaris Deunff 1977,described from the Llanvirn of the Anti Atlas region of Morocco appearsto havean identical morphologyto M. inconstansand is here consideredto be a synonym. Multiplicisphaeridiumrayii Cramer& Diez 1977has a similar processmorphology but differs by having a lesswell definedcentral body and by being much larger in size. Multiplicisphaeridiumcf. inconstansCramer & Diez 1977. Plate 19, fig. 12. Holotype: Cramer& Diez 1977a,pl. 4, fig. 8. Age: Early Arenig. Remarks: Comparewith Cramer& Diez 1977. Specimensincluded here have a thicker and more robust wall thanM. inconstans. The branchingof the processesis to the secondorder. Multiplicisphaeridiumlobeznum (Cramer) Eisenack, Cramer & Diez 1973. Plate 130, figs. I&2; pl. 140, fig. 2; pl. 150, fig. 3 Description: Cramer 1964, p. 296, pl. 2, fig. 15, pl. 7, fig. 3, text-fig. 19, no. 6. Holotype: Cramer 1964,pl. 2, fig. 15. Middle Siegenian-Emsian. Remarks: The contention of Colbath (1979, p. 20-21), upheld by Fensome et al. (1990, p. 348) that this species is a junior synonym of M. cladum Downie 1963 is rejected here. The photographic illustration and the line diagram of the holotype of M. lobanum given by Cramer show a completely different style of process shaft and distal branching when compared to the holotype of M. cladum. Multiplicisphaeridium lobeznum is distinguished by the relatively small, spherical vesicle and the very complex, densely branched distal process terminations. Multiplicisphaeridium ramispinosum has less complex and less dense distal branching of the processes. 108 Multiplicisphaeridiumramispinosum Staplin 1961. Plate 130, figs.4 & 5; pl. 165, figs.6,8 & 9; pl. 174, figs.5 & 6; pl. 182, fig. 5; pl. 188, fig. 3; pl. 193, figs.7,8 & 9. Description: Staplin 1961,p. 411, pl. 48, fig. 24. Holotype: Staplin 1961, pl. 48, fig. 24. Age: lAte Devonian. Remarks: This ratherbroad taxon hasa sphericalto subsphericalvesicle with relatively sparsely distributed processesthat branchdistally in a ramusculose,fashion. Multiplicisphaeridiumlobanum has a smallervesicle with more complexand more denselyramusculose distal terminationsto the processes.Mukiplicisphaeridiumfisheri hasa lessregular vesicleshape which reflectsthe thinner vesicle wall of that species. Multiplicisphaeridium cf. ramispinosum Staplin 1961. Plate42, figs.4,7,8 & 9. Holotype: Staplin 1961, pl. 48, fig. 24. Age: lAte Devonian. Remarks: Comparewith Staplin 1961,p. 411, pl. 48, fig. 24. Tle poorly preservedspecimens included herehave lesscomplex distal terminationsthan the holotype of M. ramispinosum. Multiplicisphaeridiumraspum (Cramer) Eisenack, Cramer & Diez 1973. Plate 130, fig. 3; P1.140, figs. 3 & 4; pl. 150, fig. 2; pi. 154, fig. 4; pi. 165, fig. S. Description: Cramer 1964,p. 301, pl. 4, figs. 1-6 & 11. Holotype: Cmmer 1964,pl. 4, fig. 1. Age: Middle Siegenian-Emsian. Remarks: This speciesrather convenientlyaccommodates forms which havea morphology that is transitionalbetween Ammonidium? alloiteauii, which has shorter, lesscomplex processes, and Mulliplicisphaeridiwn ramispinosum,which haslonger, more complexprocesses. The morphological M. is variation observedhere within raspum almostidentical to that representedby Cramer(1964) of the specimensfrom the type locality. 109 Multiplicisphaeridiumnuticum? Martin 1973. Plate42, figs. 10,11 & 12. Description: Martin 1973,p. 11-12,pl. 1, figs.28,29,32; pl. 4, fig. 131; pl. 5, figs-150-153,156,163, 166,169 & 170. Holotype: Martin 1973,pl. 5, figs. 150,156 & 166. Age: Early Uandovery. Remarks: The specimensassigned here are ratherpoorly preserved. Mukiplicisphaeridiumvariabik (Lister) Doming 198 1. Plate 108, figs.6-9; pl. 116, figs. 1,2 & 3. Description: Lister 1970,p. 87-88, pl. 11, figs.4-7,9 & 10, text-figs.25d & 26c. Holotype: Lister 1970,pl. 11, fig. 10. Age: Ludlow. Remarks: Specimensincluded here have a small centralvesicle (16-24um in diameter)with processes that branchin a ramusculosemanner. Branchingoccurs in the distal half of the process,upto the fourth order. Mulliplicisphaeridiwn cfi saharicumLister 1970. Plate 86, figs.5 & 6; pl. 108, fig. 5. Holotype: Lister 1970, pl. 12, fig. 4. Age: Ludlow. Remarks: Comparewith Lister 1970,p. 94, pl. 12, figs.2,3 & 4. Specimensrecorded here have a thicker wall (ca. 2um thick) than in the type materialwhich was describedby Lister from the Welsh Borderlands. Cymbosphaeridium T'hisspecies appears superficially similar to carinioswn.However, the two species by C. differ wayof theirwall structures, cariniosumhaving two wall layers,Muhiplicisphaeridium cf. saharicumhaving a singlethick layer. Multiplicisphaeridiumraspwn (Cramer) Eisenack, Cramer & 110 Diez 1973 is also morphologicallysimilar but differs in the processesbeing of greaterlength and being greaterin number. Mulliplicisphaeridium sp. 1. Plate 108, figs. 10,11 & 12. Synonomy: 1971, Multiplicisphaeridiwn arbusculiferum,De-unff, Lefort & Paris, p. 11. Description: Acanthomorphicacritarchs which havea subsphericalcentral body measuringbetween 3545UM in maximumdiameter. There are approximately10-15 slender processes which are upto, 35um in length. The processbases are upto,7um wide and the shaftstaper distally to brancheddistal terminations. Branchingoccurs in the distal two thirds of the processes.Branching is ramusculose, upto the 4th order. The processto centralbody ratio is approximately3: 4. The wall is composedof a single layer and the processescommunicate freely with the centralbody. The wall is smoothto slightly granuloseon the surface. No regular form of openingis apparent. Remarks: This form appearsto be identical to the specimensdescribed as Multiplicisphaeridiwn arbusculiferum(Downie) by Deunff, Lefort & Paris 1971, from the late Ludlow of France. Comparison with the holotype of M. arbusculiferum (now Leptobrachion arbusculiferum [Downie] Doming 1981) shows that Deunff, Paris & Lefort (1971) incorrectly assigned the specimens they illustrated to this species, in the opinion of the present author. Multiplicisphaeridium?sp. 2. Plate 165, figs.7,10,11 & 12. Description: Acanthomorphicacritarchs which havea polygonalcentral body measuringbetween 23- 35um in maximumdiameter. There are approximately10-20 slender processes which are upto 20um in length. The processbases are upto 4um wide and the shaftstaper distally to brancheddistal terminations. Branchingoccurs in the distal half of the processes.Branching is ramusculose,upto, the 4th order. The processto centralbody ratio is approximately4: 5. The wall appearsto be composedof a single layer but the natureof communicationbetween the processesand the centralbody is not clear from the specimensobserved. The wall is smoothon the surface. No regular form of openingis apparent. form Remarks: This acanthomorphic with a polygonal centralbody is not typical of forms included in hence the genusMultiplicisphaer0um, the questionedassignation. The wall relationshipbetween the III processes and the central body is not clear in the thermally altered specimens observed, some specimens appear to have solid processesand some don't. This form appears to be comparable to Dateriocradus sp. B of Playford 1977 which he described from the Devonian of Ontario. GenusMuraticavia Wicander 1974. Type species: MuraticaWaenteichia Wicander 1974. Generic description: Wicander 1974, p. 14. Remarks: MuraticaWadiffers from PolyedrYxiumin lacking serratededges and projectionsfrom the vesicle. MuraticaWasp. 1. Plate 185, figs.7-1 1; pl. 188, fig. 9; pl. 196, figs.2 & 3. Description: Acritarchswith an apparentlydisc or flattenedstar shapedcentral body reinforcedwith thickenedribs that radiatefrom the polesof the vesicleto the equator. The ribs numberbetween six and ten and commonlyextend beyond the equatorto supporta membranousfringe. The total diameter of the vesicle rangesbetween 39-53um. No regular form of openingis apparent. Remarks: Thesemorphologically distinct palynomorphsshow a considerablerange of morphology. Study of larger populationsmay justify the proposalof severalspecies within the rangeof morphology illustrated here. Other speciesin the genusfrom the Middle to Late Devonianinclude the type species M. enteichiaWicander 1974and M. munifica Wicander& Wood 1981. Both of thesespecies have a more sphericaloutline to the vesiclewhich is divided into pentagonalfields as opposedto the pseudo- triangular fields of MuraticaWa sp. 1. GenusNav(fusa Combaz el al. 1967 ex Eisenack 1976. Type species: NaWfiaa naWs(Eisenack) Eisenack 1976. Generic description: Combaz et al. 1967, p. 293. Remarks: Includedhere are fusiform acritarchspecies with roundedpoles. The genusLeiofiua has accuminatetips at eachpole of the vesicle. 112 Navifusabacilla (Deunff) Playford 1977. Plate 154, fig. 9; pl. 166, figs.6 & 7. Description: Deunff 1955,p. 148, pl. 4, fig. 2. Holotype: Deunff 1955,pl-4, fig. 2. Age: Middle Devonian. Remarks: Includedhere are cigar-shapedacritarchs with a smoothvesicle wall. This specieshas a more elongatevesicle form than N. minuta. NaWfusaminuta (Deunff) Eisenack,Cramer & Diez 1979. Plate 154, figs.5 & 7; pl. 183, fig. 3. Description: Deunff 1955, p. 148, pl. 4, fig. 5. Holotype: Deunff 1955,pl. 4, fig. 5. Age: Middle Devonian. Remarks: Specimenshere are fusiform in shapewith roundedpoles. They differ from N. bacilla in having a broader, more squatvesicle shape. GenusNeoveryhachium Cramer 1970. Type species: Neoveryhachiumcanninae (Cramer) Cramer 1970. Generic description: Cramer l970, p. 110-112. Remarks: Neoveqhachiumis distinguishedfrom the genusVeqhachium by the presenceof rectangular striationson the vesicle. Speciesof Veryhachiumhave a smoothvesicle wall. 113 Neovwyhachiumcaminae (Cramer)Cramer 1970. Plate 96, fig. 8. I Description: Cramer 1964, p-307,309, pl. 14, fig. 16, pl. 16, figs. 1-3, text-fig. 28, no. l. Holotype: Cramer 1964,pl. 16, fig. 1. Age: Ludlow-early Gedinnian. Remarks: Neow?yhachium carminae is a relatively small speciesof Neoveryhachiumwith four processespositioned at the apicesof the quadratevesicle. A fifth processmay be present. Neovvyhachiummayhilknse Doming 1981is larger in size. GenusOnondageHa Crwner 1966 Type species: Onon-dagellaarymmetfica (Deunff) Cramer 1966. Genericdescription: Cramer 1966,p. 86-87. Remarks: Ile genusOnondagella is distinguishedfrom Veryhachiumby possessingthree sturdy - processes,one of which is commonlybroader. This broaderprocess houses the openingto the vesicle which is by meansof an epibystra. The genusTriangulina differs by having a doublelayered wall with a cavationbetween the wall layersat the apicesof the threesided vesicle. Onondagellaasymmetrica (Deunff " Deunfo Cramer 1966. Plate 154, fig. 11; pl. 155, figs. I&2; pl. 166, figs.3,5 & 8. I)mription: Deunff 1961,p-217. Holotype: Deunff 1954, fig. 15. Age: Devonian. Remarks: Onondagellaasymmetrica is distinguishedby the pointed distal terminationsof the processes.Specimens included here are almostidentical to thoserecorded from the La Vid Shales (Emsian-lowerCouvinian) of Leon, Spainby Cramer& Diez (1976). 114 Onondagelladeunffli Cramer 1966 78, fig. figs. Plate 11; pl. 86, 9,10 & 11; pl. 87, figs. 1 & 2; PI-109, figs-I & 2; pl. 122, fig. 7; pl. 130, figs. 8& 12; pl. 140, fig. 5. Description: Cramer 1966,p. 87-88, pl. 2, figs. 12 & 13, text-fig.2 (16). Holotype: Cramer 1966,pl. 2,13. Age: ?Ludlow-? Gedinnian. Remarks: Onondagellaarymmetrica differs from 0. deuqffii by possessingsharp, as opposedto blunt, processtips. Onondagellasp. 1. Plate 140, figs.6-9. synonomy: 1986,Pulvenosphaeridium sp., Al-Ameri, pl. 1, fig. 6. Description: A speciesof Onon-dagellawith a rounded-triangularshaped vesicle. The vesiclehas a maximumdiameter of between60-85um. Oneof the apicesof the vesiclehouses an epibystrawhich forms the openingto the vesicle. Ile other two apiceshave a roundedmorphology. The wall of the vesicle is thick (> lum) and appearsto be smooth. Remarks: This speciesof Onondagellacan be differentiatedfrom other speciesin the genusby the much reducedapices not housingthe epibystra. Both 0. deuniffliand 0. asymmetricaposses processes at thesepositions. An identical morphotypeto Onondagellasp. 1, recoveredfrom the Lower Devonianof North Africa, was assignedto the genusPuMnosphaeridium by Al-Ameri 1986. The presenceof an epibystra suggeststhat this form is better accommodatedin Onondagella. GenusOppilatala Loeblich & Wicander 1976. Type species: Oppilatala vulgaris Loeblich & Wicander 1976. Genericdescription: Loeblich & Wicander 1976,p. 19. 115 Remarks: The genus Multiplicisphaerldium differs from Oppilatala in lacking proximal plugs at the base of the processes. 7be genus Cymbosphaeridium opens by means of a pylorne which differs from the simple rupture style of opening in Oppilatala. 7be genus Dateriocradus differs from Oppilatala in possessing a three sided central body. Oppilatala eoplanlaonica(Eisenack) Doming 1981. Plate 87, figs. 3&6. Description: Eisenack1955, p. 178-179,pl. 4, fig. 14. Holotype: Eisenack1955, pl. 4, fig. 14. Age: Late Ludlow. Remarks: Oppilatala ramusculosa(Deflandre) Doming 1981has a higher centralbody diameterto processlength ratio and a greaterdepth of furcation of the processesthan 0. eoplan1donica. Dateriocradusmonterossae differs by having a threesided central body. Useful comparative illustrations of thesemorphologically similar speciesis given by Cramer 1970,p. 125, text-fig.39. Oppilatala insolita (Cramer& Diez) Doming 1981appears to be of identical morphologyto 0. eoplanktonicaand may well be a junior synonym. OppiWala eoplaniaonica-ramusculosa Complex. Plate73, figs.3,4 & 6. Remarks: Specimensassigned here are poorly preservedforms with the samegeneral morphology as the 0. eoplanktonica-0.ramosculosa complex of morphotypes(see Cramer 1970, p. 125, text-fig. 39a & b). Specimensare too poorly preservedto be assignedto one of thesetwo species. Oppilatal0frondis (Cramer& Diez) Doming 1981. Plate64, figs.2,3,5 & 7. Description: Cramer& Diez 1972,p. 152, pl. 32, figs. IS & 19. Holotype: Cmmer& Diez 1972,pl. 32, fig. 19. 116 Remarks: Priewalder(1987, p. 47) questionedthe assignmentof this speciesto the genusOppilatala. In the presentmaterial, the presenceor absenceof plugs at the baseof the processes,this being the featurethat distinguishesOppilatala speciesfrom Multiplicisphaeridium species,is questionable. Oppilatala eoplanA:tonica and 0. ramusculosaboth havelonger and fewer processesthan 091firondis. Multiplicisphaeridium cladum(Downie) Eisenack1969 differs by possessingprocesses with broad basesthat taperdistally. GenusOrdovicidium Tappan & IA)eblich 1971. Type species: Ordoviddium ekgantulumTappan & Loeblich 1971. Genericdescription: Loeblich & Tappan1971, p. 398. Remarks: The genusPeteinosphaeridium differs by having vela ornamentingthe processshafts. Multiplicisphaeridium differs by having processesthat communicatefreely with the centralbody. OrdoWcidium cf. heteromorphicum (Kjellstrom) LAxblich & Tappan 1978. Plate20, figs. 1,2 & 3. Holotype: Kjellstrom 1971a,pl. 4, fig. 2. Age: Middle Ordovician. Remarks:Compare with Kjellstrom 1971a,p. 53, pl. 4, fig. 2. Specimensobserved here are smallerthan 0. heteromorphicum(central body 25-40umcompared to 67-76umin the type material). GenusOtygmahapsis Colbath 1987. Type species: Orygmahapsisfistulosa(Colbath) Colbath 1987. Generic description: Colbath 1987, p. 66. Remarks: Orygmahapsisdiffers from the generaDictyoddium, Melikeriopalla andAlveosphaera in possessinga pseudoporein the centreof eachfield. 117 Orygmahapsisfistulosa(Colbath) Colbath 1987. Plate 109, figs. 6,7 & 8; pl. 116, fig. 4. Dewription: Colbath 1983,p. 259, figs.34-36. HoloqW: Colbath 1983, figs.35 & 36. Age: Silurian. Remarks. O?ygmahqpsisjUtuIosa has a considerablygreater number of fields than the only other speciesin the genusat the presenttime, 0. magnata. GenusOzolobrachion Loeblich & Drugg 1968. Type species: Ozotobrachionpalidodigitatus (Cramer)Playford 1977. Genericdescription: Loeblich & Drugg 1968,p. 130. Remarks: This genusdiffers from Ve?yhachiwn in having processesthat do not communicatewith the centralbody. 7be processesin speciesof Ozotobrachionare tabular in form and may be opendistally. The genusTriangulina hasprocesses that taperdistally to a simple tip. Ozotobrachionfurcillatus(Deunfo Playford 1977. Plate 140, figs. 10,11 & 12; pl. 155, fig. 3; pl. 166, figs. 1&2. Description: Deunff 1955,p. 146, fig. 18. Holotype: Deunff 1955, fig. 18. Age: Middle Devonian. Remarks: Ozotobrachionpalidodigitatus (Cramer)Playford 1977differs in possessinga triangular shapedvesicle with fewer and broaderprocesses than 0. furcillatus. Ozotobrachionpalidodigitatus (Cramer)Playford 1977. Plate 109, fig. 3?; pl. 130, fig. 6; pl. 141, figs. I&2; pl. 150, fig. 4. Description: Cramer 1966,p. 247, pl. 1, fig. 8, text-fig. 3, no.5. 118 Holotype: Cramer 1966,pl. 1, fig. 8. Age: Gedinnian-Emsian. Remarks: Ozotobrachiondactylos Loeblich & Drugg 1968, describedfrom the Late Gedinnianof Oklahoma,USA is consideredto be a junior synonymof 0. palidodigitatus (Fensomeet aL 1990). Ozotobrachiondicros Loeblich & Drugg 1968has longer and more slenderprocesses than 0. palidodigitatus that taperto closeddistal terminations. GenusPalacanthus Wicander 1974. Type species: Palacanthus aculus Wicander 1974. Generic description: Wicander 1974, p. 30. Palacanthustripus Martin 1984. Plate 175, fig. 7; pl. 183, fig. 1. Description: Martin 1984b,p. 27, pl. 5, figs.6,7 & 9. Holotype: Martin 1984b,pl. 5, figs.6. Age: Early Famennian. Remarks: A comparablespecies is VeryhachiumtrispininjUtum Cramer1964 which has a similar vesicle shape. Palacanthustripus howeverdiffers in possessinga microechinateornamentation. GenusPeteinosphaeridium Staplin, Jansonius& Pocock 1965 emend. Eisenack 1969. Type species: Peteinosphaeridium trifurcatum Staplin, lansonius & Pocock 1965. Remarks: The genusPeteinosphaeridiwn is differentiatedfrom the genusOrdovicidium by the presence of vela on the processshafts. 119 Peteinosphaeridiumcruzianum Vavrdova 1990. Plate20, figs.4 & 5. Description: Vavrdova 1990,p. 246-247,pl. IV, fig. 6; text-fig.7. Holotype: Vayrdova 1990,pl. IV, fig. 6. Age: Late Arenig. Remarks: Specimensrecorded here are fragmentarybut the distinctive short vellate processespresent enablethe assignmentto this species. Peteinosphaeridiumsp. Plate20, figs.6-1 1; pl. 43, fig. 2. Remarks: Eight poorly preservedspecimens of this taxon havebeen recorded. Specimenshave a subsphericalcentral body of approximately40-50um. The processesare upto 18umin length with brancheddistal terminations. Vela are presenton the shaftsof the processes,which are approximately 2um wide and runs the entire length of processshaft. GenusPirea Vavrdova 1972. Type species: Pirea dubia Vavrdova 1972. Genericdescription: Vavrdova 1972,p. 82. Pirea colliformis complex. Plate2 1, figs. I&2. Remarks: Burmann.(1970) describednine speciesin the genusDeunffia which have subsequentlybeen transferredto the genusPirea by Eisenack,Cramer & Diez 1976. This group of morphotypesappear to havebeen 'over-split' at specieslevel resulting in therebeing considerablescope for synonomy. Ilere are four easily recognisablemorphological groups of the publishedspecies within the genusthat are as follows: 120 1. Pirea colliformis complex. This complexincludes forms with a more or less smoothwall and a prominent horn (or process)with a blunt termination. T'hehorn occupiesgreater than 1\5 the length of the body. The publishedspecies included in this complexare Pirea colliformis (Burmann)Eisenack, Cramer & Diez 1976, P. lagenaria (Burmann)Eisenack, Cramer & Diez 1976,P. inflata (Burmann)Eisenack, Cramer& Diez 1976and P. transitoria (Burmann)Eisenack, Cramer & Diez 1976. 2. Pirea capitata complex. This complexincludes forms with a more or less smoothwall and a short, stubby apical horn that occupiesless than 1\5 the length of the body. The publishedspecies included in this complexare Pirea capitata (Burmann)Eisenack, Cramer & Diez 1976 and P. capitulifera (Burmann)Eisenack, Cramer & Diez 1976. 3. Pirea ornata (Burmann)Eisenack, Cramer & Diez 1976. This speciesincludes forms with an spiculateomament. 4. Pirea nervata (Bunnann)Eisenack, Cramer & Diez 1976. This specieshas a horn of moderate length (approximately1\5 the length the centralbody) with fine parallel ribs orientedlongitudinally at the baseof the process. Burmann(1970) illustratedP. inflwa as having ribs at the baseof the neck but they are not mentionedin the description(p. 321). GenusPolyedryxium Deunff 19S4onend. Deunff 1971. Type species: PoWryxium deflandreiDeunff 1954ex Deunff 1971. Genericdescription: Deunff 1971, p. 17. Polyedryxiumevolutum Deunff 1955. Plate 155, figs-5,8 & 11; pl. 167, figs. 1,2 & 3. DescriPtiOn: Deunff 1955,p. 147, pl. 4, fig. 7. Holovipe: Deunff 1955,pl. 4, fig. 7. Age: Middle Devonian. Remarks: This distinctive speciesof PolyedrYxiwnis distinguishedby the numerous,short, denticulate processes. 121 Polye,dryxiumftagulosum Playford 1977. Plate 155, fig. 4; pl. 175, figs. 1,2 & 3. Description: Playford 1977,p. 34, pl. 16, figs. 8-14. Holotype: Playford 1977,pl. 16, figs. 8. Age: Emsian. Remarks: This speciesof PoWryxiwn can be distinguishedby the three sidedoutline of the vesicle. Polye,dryxium pharoane Deunff 1954ex Deunff 1961. Plate 155, fig. 7&9; pl. 167, figs.4&5; pl. 175, fig. 3; pl. 194, figs. 1,2&4. Description: Deunff 1961,p. 217. Holotype: Deunff 1954, fig. 13. Age: Couvinian(Devonian). Renlarks: Eisenackidiummartensianum Stockmans & Williere 1969and Senziellaincurvata Stockmans & Williere 1969are consideredto bejunior synonYmsof this species(Lu Lichang & Wicander 1988). GenusPolygonium Vavrdova 1966. Type species: Polygoniumgracile Vavrdova 1966. Genericdescription: Vavrdova 1966b,p. 412-413. Remarks: Speciesincluded in the genusPolygonium have a polygonal, well definedcentral body, simple processesand a smoothor scabratewall. Micrhystridium encompassesforms with a well defined, round to ovatecentral body. Goniosphaeridiumhas conical processeswhose bases merge to form a poorly definedcentral body (i. e. the shapeof the centralbody is dictatedby the shapeof the processbases). Stellichinitumand Uncinisphaeraboth havean ornamentof echinae. 122 Poýygoniumgracile Vavrdova 1966. Plate 6, figs. 8,9,10 - 13; pl. 21, figs. 3-13; pl. 32, fig. 10. Description: Vavrdova 1966b, p. 413-414, pl. 1, fig. 3; pl. 3, fig. 1, text-figs. 3b & 4b. Holotype: Vavrdova 1966b,pl. 1, fig. 3, text fig. 3b (non pl. 2, fig. 3). Age: Arenig. Remarks: There is considerablevariety in the morphologyof the specimensthat can be assignedto this rather broad species. Poor preservationof the specimensobserved here prohibit the legitimatesplitting of this speciesat the subspecieslevel. Polygoniumsp. 1. Plate 6, figs.4 & 5. Description: Acanthomorphicacritarchs which havea large subpolygonalcentral body. The body has a maximum diameterranging between 57-65um. The processesare slenderand rather flexible. The width at the process basesis approximately 2um tapering distally to accuminate tips. Process length ranges between 15-20um and the process length to Central body diameter is approximately 1:3. The wall is relatively thick and black in colour in the material observed. No ornament is discernible on the vesicle and no regular form of opening is apparent. Remarks: This speciesis conspicuousby its large size, flexible processesand subpolygonal.central body. Polygonium?sp. 2. Plate 6, figs.6 & 7. Description: Acanthomorphicacritarchs which havea polygonal-subpolygonalcentral body. The body has a maximumdiameter ranging between 18-25um. There are approximately60 processespresent flexible. The bases which are slenderand rather width at the process varies between2-5um and they taperdistally to swollen, roundedtips of upto 2um in diameter.The processlength rangesbetween 6- 1lum and the processlength to centralbody diameteris approximately1: 3. The wall is relatively thick. No ornamentis discernibleon the vesicleand no regular form of openinghas beenobserved. 123 Remarks: The swollen tips of the processesare the most diagnosticfeature of this Won. It is questionablyassigned to the genusPolygoniwn as the centralbody of someof the specimensare only slightly polygonal. A morphologically similar form is the unpublished"Archaeohistrichosphaeridiwn sp. A* Rasul 1971 (unpublishedPh. D. thesis,University of Sheffield)which was describedfrom the Tremadocof Shropshire,England. BaltisphaeridiumclaWcinctum W. Wetzel 1967,B. flagellicum Kjellstrom 1971 and B. perpaucispinumKjellst rom 1971all havesimilarly swollen processtips. However, the wall relationship is different in theseforms which is reflectedby the more roundedcentral body of these species. GenusPratulasphaern Wicander & Playford 1985. Type species: Pratulasphaeranovacula Wicander & Playford 1985. Genericdescription: Wicander&Playfordl985, p. 114-115. Pratulasphaeranovacula Wicander & Playford 1985. Plate 176, figs. I&2. Description: Wicander& Playford 1985,p. 115, pl. 5, figs. 8-13. Holotype: Wicander& Playford 1985,pl. 5, figs. 8. Age: Fmsnian. Remarks: The blade-likeprocesses protruding from the sphericalcentral body are the distinguishing feature.of this species. GenusQuadn? dftum Cramer 1964. Type species: Quaraditwnfantasticum Cmmer 1964. Genericdescription: Cramr 1964,p. 333. Remarks: This genusincludes species with a flattened,quadrate inner body enclosedby an outer inner body. 7be membranewhich is attachedat the apicesof the outer membraneis rarely fully 124 preserved. The genusDuvemaysphaera differs from Quadraditumin having a discoid, as opposedto a quadrate,central body. QuadraditwnfantasticumCramer 1964. Plate 87, fig. 8; pl. 130, figs.7,9,10 & 11; pl. 141, fig. 8. Synonomy: 1976,Duwrnaysphaera oa, Loeblich & Wicander, p. 28, pl. 9, figs. 10 & 11. Description: Cramer 1964,p. 334, pl. 14, figs.3 & 4, text-fig. 37, nos.1-3. Holotype: Cramer 1964, pl. 14, fig-3. Age: Ludlow-early Gedinnian. Remarks: Duvernaysphaeraoa Loeblich & Wicander1976 appears to be identical to Q. fantasticum from the descriptionsand illustrations given by the respectiveauthors. Quadraditumfantasticumis the nameused here as it is the senior. Quaraditum inciswn Cramer1964 has an X-shapedcentral body as opposedto the quadrangular central body of A fantasticum. Quadraditumscutifemm Deunff 1966has shorterand broader processesat the apicesof the centralbody. Quadraditumscutiferum Deunff 1966. Plate 109, fig. 9; pl. 122, figs.3 & 6. Description: Deunff 1966, p.24, fig. 3. Holotype: Deunff 1966, fig. 3,. Age: Devonian. This of Quadraditumhas capitate process terminations surmounted by 'umbrella- Re,Marks: species shaped'vela. GenusQuadtispodles Henelly 1958, onend. Potonie& Lele M. Genericdescription: Potonie& Lele 1961,p. 33. 125 Quadrisporitescf. acanthiferCramer & Diez 1976. Plate 184, fig. 9. Holotype: Cramer& Diez 1976,pl. 7, fig. 77. Age: Emsian. Remarks: Comparewith Cramer& Diez 1976,p. 92, pl. 7, fig. 77. The single specimenrecorded in the presentstudy is larger in sizethan Q. acanthifer(20-30um) Measuring 47um in maximumlength. The specimenobserved here is otherwiseidentical in morphologyto Q. acanthifer. Genus QuisquffliesWilson & Urban 1963, emendWilson & Urban 1971. Type species: Quisquilitesbuckhomensis Wilson & Urban 1963. Genericdescription: Wilson & Urban 1971,p. 240.. Renjarks: The genusNaWfiua differs in having a linear long axis to the vesicleas opposedto the bean shapedvesicle of Quisquilites. The genusPseudolunulida differs in possessinga sculpturedvesicle wall. Quisquilitesbuckhomensis Wilson & Urban 1963. Plate 175, fig. 1. Synonomy: 1967,NaWfusa bacilla forma cresentis,Combaz et al, p. 299, pl. 1, figs.G & M, text-fig. 1. Dwription: Wilson & Urban 1963,18 & 19, pl. 1, figs. 1-12. Holotype: Wilson & Urban 1963,18 & 19, pl. 1, fig. 1. Age: Late Devonian. Remarks' The single specimenof this taxon recordedhere has a strongly curvedvesicle. pseudulunulidaimperatrizensis Brito & Santos1965 has a similarly shapedvesicle but differs in possessinga sculpturesvesicle wall - 126 GenusSalopidium Doming 1981. Type species: Salopidiumgranuliferwn (Downie) Doming 1981. Genericdescription: Doming 1981,p. 198. includedin Remarks: The species Salopidiumhave a subspherical,foveolate central body and simple processesthat communicatefreely with the centralvesicle. The generaMultiplicisphaeridium, Ammonidiumand Percultisphaeradiffer from Salopidiumby possessingbranched processes. BaltisphaerOwn differs by possessingproximal plugs to the processesand Micrhystridium differs in having a smoothcentral body. cf. Salopidiumwoolhopensis Doming 1981. Plate 64, figs. 4 & 6. Holotype: Doming 1981, pl. 1, fig. 14. Age: Wenlock. Remarks: Comparewith Doming 1981,P. 199, Pl. 1, fig. 14.7lie poorly preservedspecimens included aimensions, herehave the same numberof processesand processdistribution as the holotype but evidenceof the sculpturaldetail on the centralbody is lacking. Genus SoUsphaeriftm Staplin, jansonjus & Pocock 1%5 anend. Sarjeant 1968. Type species: Solisphaeridiumsimuliferwn (Deflandre)Pocock 1972. Genericdescription: Staplin, Jansonius& Pocock 1965,p. 183-184;Sadeant 1968, p.222. Solisphaeridiumsolidispinosum Cramer & Diez 1977. Plate22, fig. 1. Description: Cramer& Diez 1977a,p. 352, pl. 2, figs. 15,17-19. Holotype: Cramer& Diez 1977a,pl. 2, fig. 15. Age: Early Arenig. 127 Remarks: From the description and illustrations of Cramer & Diez (1977), it would appear that the morphology of S. solidispinosum grades into that of S. solare Cramer & Diez 1977, the former having shorter and broader processes. Specimensobserved here have processesthat are at the larger end of the sprocess;length spectrum' for the speciesS. sohdispinoswn. Solisphaerldiumsp. 1. Plate 7, figs. I&2; pl. 22, figs.2 & 3. Description: Acanthomorphicacritarchs which havea spherical-subpolygonalcentral body. The body has a very thin wall (< lum) and measuresbetween 26-33um in maximumdiameter. Processesare solid and slender,tapering gradually to accuminatedistal tips. They measure1-2um wide at the base and 9-13um.in length. The processto centralbody ratio is approximately1: 3.7be processesare solid and the surfaceof the wall is smooth. No regular form of openingis apparent. Remarks: Other speciesof Solisphaeridiumdescribed from the Ordovicianinclude the following: S. solidispinoswnCramer & Diez 1977which has shorter,broader processes; S. solare Cramer& Diez 1977which has processesof similar length that are broader,and S. lucidum (Deunfo Turner 1985 which has a very similar processmorphology but they are markedlyfewer in number. Solisphaeridiwn nanum (Deflandre)Turner 1985described from the Silurian is also similar but has slightly shorter processeswhich are describedas being not completelysolid. Solisphaeridiumsp. 2 has fewer and shorterprocesses and is noticeablysmaller in size. Solisphaerldiumsp. 2. Plate 7, figs.3&4. Description: Acanthomorphicacritarchs which havea sphericalcentral body. 7be body has a very thin in wall (< jum) and measuresbetween 22-25um maximumdiameter. Processesare solid and relatively in base rigid. 7bey memure2-3um width at the and taperdistally to accuminatetips. 7be length body rangesbetween 8-10um. The processto central ratio is approximately1: 2.5.7be processesare is solid and the surfaceof the wall smooth. No regular form of openingis apparent. Remarks: Solisphaeridiumsp. I has longer and a greaternumber of processesand is noticeablylarger in size. Solisphaeridiumnanun (Deflandre)Turner 1984is the most comparablespecies. Process length, sizeand distribution is very similar but the processesof S. nanumare describedas having a degreeof cavationin contrastto the solid processesof Solisphaeridiwnsp. 2. 128 GenusSteUechinatum Turner 1984. Type species: Stellechinawn cekstwn (Martin) Turner 1984. Genericdescription: Turner 1984,p. 137. Remarks: Comparablegenera include UncinisphaeraWicander 1974and Polygoniwn. The former has a similar echinate,ornamentation of the wall as Stellichinatumbut differs in possessinga more rounded central body. Polygoniumdoes possess a similarly shapedvesicle, however, this genusdiffers in having a smoothor granulatevesicle wall in contrastwith the echinatewall of Stellichinatwn. Stellechinatumhelosum Tumer 1984. Plate22, figs.4,5 & 6. Description: Turner 1984, p. 139, pl. 14, figs. 5 & 8. Holotype: Tumer 1984, pl. 14, fig. 5. Age: Camdoc. Remarks: Specimensrecorded in the presentstudy accordwell with the descriptionand illustration of the type material. Stelkchinatum sp. 1. Plate7, figs.5 & 6. Description: Acanthomorphicacritarchs with a polygonal-subpolygonalcentral body which measures 3745um maximumdiameter. The processesare of moderatelength and are slendermeasuring upto 15umlong and 4um.wide at the base. Ile processterminations are simple. The ratio of processlength to body width is approximately1: 3. The wall is composedof a single wall layer and the processes freely body. The is appearto communicate with the central wall of the processes ornamentedwith short (< 3um), fine, hair-like echinae.There appearsto be no ornamentationon the centralbody and no regular form of openingis apparent. Remarks: Stellichinitwn helosumhas longer processesand coarserornamentation than SIellichinatwn has sp. 1. Stellichinatumsp. 2 also a more coarseornamentation than this species. 129 Stellechinatwn sp. 2. Plate7, figs.7 & 8. Description: Acanthomorphicacritarchs with a subpolygonalcentral body which measures39-47um maximum diameter. The processesare of moderatelength, ca. 15um, slenderand have simple distal terminations. The ratio of processlength to body width is approximately1: 3. The wall is composedof a single wall layer and the processescommunicate freely with the centralbody. Ile wall is ornamented with evenly spacedgrana (ca. lum diameter)and rare echinae. The ornamentappears to be most prominent on the processstems and at the processbases. No regular openingis apparent. Remarks: This form hasan ornamentationof the wall dominatedby granawith occasionalechinae present. This contrastswith the dominanceof the hair4ike echinateornamentation of Stellichinatum sp. 1 and Stellichinatumsp. 3 describedherein. Stellechinatumsp. 3. Plate7, fig. 9. Description: Acanthomorphic;acritarchs which havea strongly polygonal centralbody of 26-37um. maximumdiameter. The processesare long and slendermeasuring upto, 18um long and 4um,wide at the baseand they havesimple terminations. ilie processto centralbody ratio is approximately2: 3. The wall is composedof a single layer and the processesappear to communicatefreely with the central body. The wall of the processesis ornamentedwith short (< 3um long) hair-like echinaebut there body. appearsto be no ornamenton the central No regular form of openingis apparent. Remarks: Stellichinatwnsp. 3 has longer processesrelative to the width of the centralbody than Stellichinatumsp. 1. In addition, the former differs in lacking ornamentationon the centralbody. GenusStefflferOum Deunff, Gorka & Rauscher 1974. Type species: Stelliferidiumstriatulum (Vavrdova)Deunff, Gorka & Rauscher1974. Genericdescription: Deunff, Gorka & Rauscher1974, p. 13. Remarks: The author follows the intexpretationof Molyneux & Rushton 1988Of this genus(p. 57,4th paragraph). 130 Stelliferidium corlinulum (Deunff) Deunff, Gorka & Rauscher1974. Plate 8, figs.4,7,8 & 9; pl. 22, fig. 7. Synonomy: 1988, Stelliferidiumbarbarum, Elaouad-Debbaj. Description: Deunff 1961a,p. 41, pl. 1, figs. 8 & 10; Deunff, Gorka & Rauscher1974, p. 14. Holotype: Deunff 1961, pl. 1, fig. 8. Age: Tremadoc. Remarks: This speciesof Stelliferidiumis characterisedby the relatively broad processeswith multifurcate terminations. Stelliferidiwn pseudoomatumPittau 1985. Plate 9, figs. 1,2 & 3. Description: Pittau 1985,p. 195-196,pl. 8, figs. 11-12, text-fig.24. Holotype: Pittau 1985,pl. 8, fig. 11. Age: Tremadoc-LateArenig. Remarks: The contentionof Tongiorgi in Bagnoli, Stouge& Tongiorgi 1988(P. 201), upheldby Fensomeet al. 1990 (p.460) that this speciesis a junior synonymof Caldariola (then Priscogalae) Rushton1988 is here. The illustrations description glabra (Martin) Molyneux & rejected and of the type materialclearly indicatesornamentation at the baseof the processeson the vesicle. 71e processes, in C with the associatedradial ornamentation,are absent glabra. Stelliferidiumsimpkx (Deunff) Deunff, Gorka & Rauscher1974. Plate 8, fig. 3. Description: Deunff 1961a,p. 41, pl. 1, fig-9. HoloqW: Deunff1961a, pl. 1, fig-9. Age: Tremadoc. 131 Remarks: Includedhere are forms with short processes(< 5um in length) with accuminateand capitate distal terminations. Stelliferidiwn cf. simpkx (Deunff) Deunff, Gorka & Rauscher1974. Plate 8, fig. 5. Holotype: Deunff 1961a,pl. 1, fig. 9. Age: Tremadoc. Remarks: Comparewith Deunff 1961a,p. 41, pl. 1, fig. g. Specimenshere have longer processes(8- loum) than in the type material(ca. 5um). Includedhere are forms with processesgreater than 5um in length with accuminateand capitatedistal terminations. Stelliferidiumstriatulum (Vavrdova)Deunff, Gorka & Raucher1974. Plate 8, figs. 1&2; pl. 22, fig. 8. Description: Vavrdova 1966b,p. 411-412,pl. 1, fig. 2; pl. 2, fig. 3, text-fig. 3a. Holotfpe: Vavrdova 1966b,pl. 2, fig. 3. Age: Arenig. Remarks: Processesin this speciesare multifurcate,at the distal terminationsas in S. cortinulum but the shaftsare markedlythinner and generallyshorter. Stelliferidium trifidum (Rasul) Fensome et al. 1990. Plate 7, figs. 10-13; pl. 22, figs. 9,10 &II? Synonomy: 1988,Stelliferidium distincta, Elaouad-Debbaj. De-scriptiOn:Rasul 1974,p. 60, pl. 5, fig, 7. Holotype: Rasul 1974,pl. 5, fig. 7. Age: Tremadoc. is Remarks: Stelliferidiwn trifidum morphologically similar to S. timofeeWi (Deunfo Fensome et al. both by 1990. Illustrations and description of species these authors shows distinct similarity in shape of 132 the central body and the size, numberand distribution of processes.However, the processterminations are the critical feature. Rasul(1974, p. 60) distinguisheshis speciesby having trifid processtips in contrastto Deunff (1961a,p. 39) who describedhis speciesas having simple or grooved (bifid) processes. GenusStelUnium Jardine el al. 1972. Type species: Stellinim oaoaster (Staplin)Jardine et al. 1972. Genericdescription: Jardineet al. 1972,p. 298. Remarks: These forms have a star-shapedoutline Composedof triangular expansions positioned in at least two planes. Ile expansionsare commonlycrested. Stellinium comptwnWicander & Loeblich 1977. Plate 176, figs.7 & 8; pl. 183, fig. 7; pl. 188, fig. 5; pl. 194, fig. 9. Description: Wicander& Loeblich 1977,p. 151, pl. 9, figs. 1-6. Holotype: Wicander& Loeblich 1977,pl. 9, figs. 1-4. Age: Late Devonian. Remarks: This speciesis distinguishedby having a quadrate,more or lesssquare, vesicle outline. Stellinium ocloaster(Staplin) Jardine et al. 1972. plate 155, fig. 10; pl. 167, figs.6 & 8; pl. 176, figs.5 & 6; pl. 183, fig. 8; pl. 188, fig. 7; pl. 194, figs.3,6,7 & 8. Dmription: Staplin 1961, p. 413-414, pl. 49, figs. 3 & 4. Holotype: Staplin 1961,pl. 49, fig. 3. Age: Late Devonian. Remarks: Stellinium micropolygonale(Stockmans & Williere) Playford 1977 is consideredto be a junior synonymof this species(Fensome et al. 1990). Stellinium octoasterincorporates forms with in (i. in more than four processes one plane e. outline) when compressedon a palynological slide. Slellinium Complumhas only four processesforming the outline. 133 GenusStriatotheca Burmann 1970. Type species: Striatothecaprincipalis Burmann1970. Genericdescription: Burmann1970, p. 299-300; for an English translationsee Eisenack, Cramer & Diez 1979, p-755. Striatothecaprincipalis Bunnann 1970. Plate23, figs. 1,2 & 3; pl. 34, fig. 1; pl. 43, figs.4 & S. Description: Burmann1970, p. 300, pl. 11, fig. 1. Holotype: Burmann 1970, pl. 11, fig. 1. Age: IAte Arenig-Early Llanvim. Remarks: Specimensassigned here have relatively fine striationson the centralbody that extendonto the processshafts. Striatothecaprincipalis var. parva Burmann1970. Plate34, figs.2 & 3. Description: Burmann1970, p. 300, pl. 8, fig. 6. Holotype: Burmann 1970,pl. 8, fig. 6. Age: Late Arenig-Early Llanvim. Remarks: This variety has thin processeswith relatively few, coarsestriations on the centralbody that do not extendonto the processshafts. Striatothecaquieta (Martin) Rauscher1973. Plate 34, fig. 4. Description: Martin 1969,p. 100, pl-5, fig. 226; pI. 6, fig. 290; for an English translationsee Eisenack, Cramr & Diez 1979, p. 773-774. 134 Holotype: Martin 1969,pl. 6, fig. 290. Age: Middle-Early Ludlow, seeremarks. Remarks: The type materialdescribed from Belgium outcrop is believedto be reworked from the Ordovician (Eisenack,Cramer & Diez 1979,p. 773). This specieshas shorterprocesses at the apicesof the vesicle than S. principalls. Genus Tetraporina (Namnova ex Bolkhovitina) Kar & Bose 1976 Synonomy: 1972,Horologinella, Jardineet al, p. 296. Type species: Tetraporinapelludda Naumovaex Bolkovitina 1953. (Lectotypedesipated by janwnius & Hills 1981,card 3197. Genericdescription: Kar & Bose 1976,p. 79. Remarks: The type species of the genus Horologinella Cookson & Eisenack 1962 is a dinoflagellate cyst. This genus should therefore be restricted to accommodatepalynomorphs of that group. Acritarchs with a superficially similar morphology to Horologinella are best accommodated in the genusTetraporina. Tetraporinahorologia Staplin 1960. Plate 194, fig. 12. Synonomy: 1972,Horologinella horologia, Jardineet al., p. 296. Description: Staplin 1960,p. 6, pl. 1, figs.4 & 6. Holotype: Staplin 1960, pl. 1, fig. 4. Age: Carboniferous. Remarks: This specieshas broad, descretelobes at the apicesof the four-sidedvesicle. Tetraporina quadrispinahas a more angularaspect to the vesiclewith longer expansionsat the apices. 135 Tetraporinaquadrispina (Jardine et al. ) comb nov. Plate 194, figs. 10 & 11. Synonomy: 1972, Horologinella quadrispina,jardine et al., p. 296, pl. 1, figs.5 & 6. Description: Jardineet al. 1972,p. 296, pl. 1, figs. 5&6. Holotype: Jardineet al. 1972,pl. 1, figs 5. Age: Upper Devonian,probably Famennian. Remarks: This speciesis recombinedwith the genusTetraporina as Horologinella is a dinoflagellate cyst genus. lie speciesis distinguishedby the extendedlobes at the apicesof the four sidedvesicle. The inter-lobe areasare highly concave. GenusAysanoprobolus Loeblich & Tappan 1970. Type species: 7hysanoproboluspolyhon Loeblich &Tappan 1970. Genericdescription: Loeblich &Tappan 1970,p. 26 1. 7hysanoproboluspolykion Loeblich & Tappan1970. Plate 109, figs. 10 & 11; pl. 141, fig. 3. Synonomy: 1970 Multiplicisphaeridiwn bonitum Cramer,p. 150-152,pl. 15, figs.207-209 & 213, text-fig.55a. Description: Loeblich &Tappan 1970,p. 262-266, figs. 1-12. Holotype: Loeblich &Tappan 1970, figs. 10-12. Age: Early Gedinnian. Remarks: From the descriptionsand illustrationsof the type material,MUNPH&Phaeridiwn bonitum & Diez Cramer 1970ex Eisenack,Cramer 1973,described from the late Silurian-earlyDevonian of NW Spain, appearsto be synonymouswith T polyhon. 136 GenusTongzla Li Jun 1987. Type Species: Tongdameitana Li Jun 1987. Genericdescription: Li Jun 1987,p. 626. Tongziameitana Li Jun 1987. Plate9, figs. 12 & 13; pl-23, figs.4,8,9 & 10. Description: 11 Jun 1987, p. 626,628, pl. 69, figs. 1-3. Holotype: Li Jun 1987,pl. 69, fig. 1. Age: Arenig. Remarks: Specimensrecorded here are generallypoorly preserved. 'Me speciesis distinguishedby its sphericalcentral body and the palmate,first order branchingof the distal terminationsof the hollow processes. Vavrdova (1990) recordedthis speciesfrom the Late Arenig of Czechoslovsdda. Genus TrematophoraEisenack 1965. Type species: Trematophoraradiata Eisenack1965. Genericdescription: Eisenack1965, p. 270. Remarks: In his erectionof the speciesT radiata, Eisenack(1965, P-270)neglected to diagnosethe new genus,Trematophora, into which he had placedhis new species. As the genusis, to the present authorsknowledge, monospecific, the diagnosisgiven for the speciesT radiata also standsas the genericdiagnosis. Tremarophoraradiata Eisenack1965. Plate79, figs. 1,2 & 3; pl. 87, fig. 4. Description:Eisenack 1965, p. 270, pl. 23, figs.4 & S. 137 Holotype: Eisenack1965, pl. 23, figs.4. Age: Wenlock. Remarks: Specimensrecorded here are the samesize and havethe samegeneral morphology as the holotype. GenusManguHna Cramer 1964. Type species: Triangulina alargada Cramer1964. Genericdescription: Cramer 1964,p. 334. Remarks: Thesetriangular verybachid-shaped forms are distinguishedby having a two-layeredwall structurein which thereare cavationspresent between the wall layersat the apicesof the vesicle. Plangulina sanpetrensis(Cmmer) Fensome et aL 1990. Plate 110, fig. l?; pi. 116, fig. 5?; pi. 123, fig. 1; pl. 156, fig. l? Description: Cramer 1966,p. 88, pl. 2, figs. 14 & 15, text-fig.2, no. 14. Holotype: Cramer 1966,pl. 2, fig. 14. Age: Ludlow- Early Gedinnian? Remarks: Triangulina alargada Cramer 1964has a very similar morphologyto T sanpetrensis.It differs in the shapeof the centralbody, the former having a rounded-triangularshape, the latter having a triangular shapewith a more angularaspect. Triangulina alargada Cmmer 1964. Plate 141, figs.4,7 & 10; pl. 150, figs.6 & 8. Description: Cramer 1964,p. 334-335,pl. 6, figs. 1 & 4, text-fig.39. Holotype: Cramer 1964,pl. 6, fig. 4. Age: Emsian. Remarks:This speciesis distinguishedby therounded inner body. Formstransitional between T. alargadaand T. Sanpetrensishave been recorded in thepresent study. 138 GenusTrichosphaeriNum Timofeev 1966. Type species: Trichosphaeridiumannolovaense Timofeev 1966. Genericdescription: Timofeev 1966,p. 37. Trichosphaeridiumannolovaense Timofeev 1966. Description: Timofeev 1966,p. 37-38, pl. 8, fig. 5. Holotype: Timofeev 1966, pl. 8, fig. 5. Age: Middle Cambrian. Remarks: Two varietiesof this relatively simplemorphotype are recordedhere. The varietiesof this speciesare distinguishedon the sizeof the centralbody and minor differencesin the thicknessof the wall. Trichosphaeridiumannolovaense var. A. Plate9, figs.4 & 8. Remarks: Includedhere are relatively small forms (50-70umin maximumdiameter) with a moderately thick wall. Trichosphaeridiumannolovaense var. B. Plate9, figs.7. Remarks: Theseare relatively large forms (70-100umin maximumdiameter) with a thin wall. Genus TunisphaeridiumDeunff & Evitt 1968. Type species: Tunisphaeridiumlentaculiferum (Martin) Cramer 1970. Genericdescription: Deunff & Evitt 1968,p. 2. 139 Remarks: Speciesincluded in this genushave a sphericalcentral body with thin, solid processes supportinga thin outer membrane. Tunisphaeridiumtentaculiferum (Martin) Cramer 1970. Plate 116, fig. 6. Description: Martin 1967,p. 312, pl. 1, fig. 23, text-fig. 3. Holotype: Martin 1967,pl. 1, fig. 23. Age: Silurian. Remarks: A single damagedspecimen is recordedhere. However, the sphericalcentral body, the slendercapitate processes and the membraneare all discernibleon the specimen. Tunisphaeridium parvum Deunff & Evitt 1968has shorterprocesses than 0. tentaculaferum. cf. Tunisphaeridiumsp. Plate 156, fig. 4; pl. 167, figs.7 & 9. Remarks: Specimensincluded here have an identical centralbody and processshaft morphologyto T tentaculiferwn. However, thesespecimens have a pad shapeddistal terminationto the processesand they lack the outer membranouswall layer that characterisesspecies of the genusTunisphaeridium. The lack of outer wall layer may be a function of the preservation. Genus TylolopaUaLoeblich 1970. Type species: 7ýlotopalla digitifera Loeblich 1970. Genericdescription: Loeblich 1970. Tylotopallaastfifera Kiryanov 1978. Plate74, figs. I&2. Description: Kiryanov 1978,p. 86, pl. 13, figs.5a-b. 140 Holotype: Kiryanov 1978,pl. 13, figs.Sa-b. Age: Wenlock. Remarks: A morphologicallysimilar speciesis T. deerlyAlanum(Martin) Le Herisse,1989 which also possessesstriate ornamentationthat is bestdeveloped at the processbases. This speciesdiffers from A. astrifera in having a lower densityof processeson the centralbody. Specimensrecorded here are 59- 64um in diameterwhich is towardsthe larger end of the ratherbroad size rangefor the species(39- 72um) given by Kiryanov. 7ýlotopalla cf. deerlykianum(Martin) Le Herisse1989. Plate 64, fig. 1. Holotype: Martin 1973,pl-5, fig. 167. Age: Ashgill-Early Llandovery. Remarks: Comparewith Martin 1973,p. 23, pl. 5, figs. 167,173. The poorly preservedspecimens observedshow the samemorphology and densityof processeson the centralbody as the type material. The size of the specimenshere, 100-11lum in diameter,is markedlygreater. IýIotqpalla cL wenlockiaDoming 1981. Plate74, figs.3,4 & 7. Holot)W: Doming 1981,pl. 2, fig. 4. Age: Wenlock. Remarks: Comparewith Doming 1981,p. 200, pl. 2, fig. 4. The poorly preservedspecimens recorded herehave approximately the samenumber and distribution of processesas the holotypebut differs in the processesbeing of a shorterlength. Genus UmbehasphaerWumJardine et at. 1972. Type species: Umbellasphaeridiumsaharicum Jardine et al. 1972. Genericdescription: Jardineet al. 1972,p. 302-303. Remarks:Species in this genuspossess processes that have open and flared distal terminations. 141 Umbellasphaeridiumdeflandrei Moreau-Benoit 1967 ex Jardineet al. 1972. Plate 176, figs.3 & 4; P1.183,figs. 6,9,10 & 11; PI-195, figs.4 & 5. Description: Moreau-Benoit1967, p. 203, pl. 1, figs.22-23. Holotype: Moreau-Benoit1967, pl. 1, figs.22-23. Age: Emsian. Remarks: This speciesis distinguishedfrom U. saharicumby the greaternumber of processespresent on the vesicle, more than 10, which are shorterin length. Umbellasphaeridimsaharicum Jardine et al. 1972. Plate 193, fig. 9; fig. 195, figs. 1&2. Desr,ription: Jardine et al., p. 303, pl. 2, figs. II& 12, pl. 3, fig. 1. Holotype: Jardineet al. 1972,pl. 2, fig. 12: Age: Famennian. Remarks: This specieshas relatively few, betweenfour and 10 in number, trumpet-shapedprocesses. Umbellasphaeridiwndeflandrei has shorterand a greaternumber of processes(more than 10) that are generallyshorter in length. Genus UncinisphaeraWicander 1974. Type speciesUncinisphaera lappa wicander 1974. Remarks: The genusStellichinitum differs from Uncinisphaerain having a polygonal aspectto the centralbody. Uncinisphaera?sp. 1. Plate23, figs. 11,12 & 13; pi. 34, fig. 10. Description: Acanthomorphicacritarchs with a sphericalcentral body of 35-40ummaximum diameter. Ibe processesare long and slender(upto 22um long and 2-3um wide at the base)and have simple distal 142 terminations.The ratio of processlength to body width is approximately2: 3.7be wall is ornamented with short (< 2um) hair-like echinae and no regular form of opening is apparent. Remarks: This taxon is questionably assigned to the genus Uncinisphaera as the communication betweenprocesses and centralbody is not discerniblein the carbonisedspecimens observed. The only formally describedspecies in this genusfrom the Ordovicianis U. protea Playford & Wicander 1988. This specieswould appearto be better placedin the genusStellechinatum as it possessesa polygonal centralbody. Molyneux,(1997) published six forms that were questionably assignedto Uncinisphaerain opennomenclature from the Arenig of SouthWales. Uncinisphaera?sp. I describedin the presentstudy has longer processesthan any of thoseforms describedby Molyneux. GenusVeliferites Brito 1967a. Type species: Veliferitestunuimarginatus Brito 1967a. Remarks: Speciesincluded in this genushave a four, five or six sidedflattened veryhachid-type is by vesicle. Ilere is a thin transparentmembrane at the equatorof the vesiclewhich supported short differs by discoid-shaped processesat the apices. Ile genusDuvernaysphaera possessinga central body. Veliferites?sp. Plate 65, figs. I&2. Remarks: Specimensincluded here have a five-sidedflatteBed central body, 32-37umin diameter,with is fully in five short processes(4-7um long) at the apices. The membraneor velum not preserved the however, the in the the specimensobserved, remnantsof membraneare evident viscinity of processes. Genus VeryhachiumDeunff emend. Turner 1984. Deunff 1951 Deunff 1959. Type species: Veryhachiumtrisulcwn ex Genericdescription: Turner 1984,p. 139-140. 143 Remarks: The emendationof the genusby Turner 1984states that the wall may be smoothor ornamentedwith grana. Forms with short sPV ines or echinaeare included in the genus Illosacapsula Loeblich & Tappan1976. Ve?yhachiwn cf. arcarium Wicander& Loeblich 1977. Plate 156, fig. 7; pl. 168, fig. 1-4. Holotype: Wicander& Loeblich 1977,pl. 10, figs. I&2. Age: IAte Devonian. Remarks: Comparewith Wicander& Loeblich 1977,p. 154, pl. 10, figs. I&2. The specimens included herehave a larger centralbody and longer, more slenderprocesses than V. arcarium. The specimenshere are almostidentical in morphologyto the thesistaxon V polyaster subsp.acutum Deunff 1966which is nomennudum. The speciesV pentasterStaplin 1961has more concavevesicle sidesdmn V. cf. arcarium. Veryhachiumcf. cymosumWicander & Loebfich 1977. Plate 168, figs.6 & 7. Holotype: Wicander& Loeblich 1977,pl. 10, figs.7 & 8. Age: Late Devonian. Remarks: Comparewith Wicander& Loeblich 1977,P-155, pl-10, figs.5-10. The specimensincluded here have the samearrangement of processesand the samesize dimensions as V. CYMOsUMbut differ distal in slightly in the natureof the terminationsof the processes.7be terminations this taxon are more blunt with roundedtips than the sharplyaccuminate tips of the processesof the type specimens. veqhachium europaeumStockmans & Williere 1960has a similar processnumber and arrangementas V. cf. cymosumbut has more slenderprocesses with sharplyaccuminate tips. Veryhachiumdowniei Stockmans& Williere 1962. Plate 150, fig. 7; pl. 195, fig. 9? Stockmans& Williere 1962a,p. 47-48, pl. 2, figs.20-22, text-fig.2; for English D,escription: an translationsee Eisenack, Cramer & Diez 1979,p. 394. Holotype: Stockmans& Williere 1962a,pl. 2, fig. 21. Age: Devonian. 144 Remarks: Specimensincluded here are generallypoorly preserved. Veryhachiumdowniel var. downiei Stockmans& Williere 1962. Plate 177, fig. 1; pl. 184, fig. 1; pl. 188, fig. 8; pl. 195, figs.6,7 & 8. Description: Stockmans & Williere 1962a, p. 47-48, pl. 2, figs. 20-22, text-fig. 2; for an English translation see Eisenack, Cramer & Diez 1979, p. 394. Holotype: Stockmans& Williere 1962a,pl. 2, fig. 21. Age: Devonian. Remarks: Specimensincluded here are thoseclosely resemblingthe holotype of the species. Ve?yhachium europaeum Stockmans & Williere 1960. Plate 131, fig. 2; pl. 168, fig. 5; pl. 177, fig. 2. Description: Stockmans& Williere 1960,p. 3, pl. 2, fig. 25. Holotype: Stockmans& Williere 1960,pl. 2, fig. 25. Age: Frasnian. Remarks: This relatively simple speciesof Ve?Aachium has four processes,three at the apicesof the three sidedvesicle and one protruding from the interapicalregion. 7be vesiclewall is smooth. VeryhachiumcL europaeumStockmans & Williere 1960. Plate 87, figs.9 & 10; pl. 123, fig. 2. HoloVipe: Stockmans& Williere 1960,pl. 2, fig. 25. Age: Fmsnian. Remarks: Comparewith Stockmans& Williere 1960,p. 3, pl. 2, fig. 25. Specimensassigned here have the samearrangement of the four processesthat are presentas in the type specimenbut differ in having a more convexvesicle. Specimensassigned to V. europaeumby Cramer 1964are very similar in morphologyto the specimensassigned here. 145 Veryhachiumlairdii Deflandre 1946ex Loeblich 1970. Plate9, fig. 9; pl. 34, fig. 6; pl. 116, fig7. Description: Deunff 1959,p. 28, pl. 8, figs. 75-79. Holotype: Deunff 1959,pl. 8, fig. 75. Age: Middle Silurian. Remarks: Veryhachiumlairdii was consideredto be a junior synonymof V. valienteCramer 1964by Martin 1969,p. 95, Turner 1984,p. 141-142and Fensomeet al. 1990,p. 517. However, Cramer (1964) statesin his remarks(under the sub-heading'Similar forms, p. 311) that V valientediffers by having a more straightsided vesicle between the processes.This morphologicaldifferentiation is retainedhere as the specimensobserved are more similar to the holotype V. lairdii with concavesides than that of V. valientewhich is more straight sided. VeD*achium longispinosum? Jardine et al. 1974. Plate24, fig. 6; pl. 51, figs.4,6 & 7. Description: Jardineet al. 1974,p. 116, pl. 1, fig. 1; for an English translationsee Eisenack, Cramer & Diez, 1979,P-449. Holotype: Jardineet al. 1974,pl. 1, fig. 1. Age: Late Ordovician. Remarks: Specimensare questionablyassigned to V longispinosumbecause the processesof the specimensrecovered are broken. The centralbody and proximal parts of the processesare morphologicallyidentical to the holotype. Veryhachiumminutwn Downie 1958emend. Plate 141, fig. 6; pl. 51, figs. 4,6 & 7. Holo*w: Downie 1958,pl. 17, fig. 4. Age: Tremadoc. Description: Downie 1958,p. 344, pl. 17. fig. 4. Emendeddescription: A small speciesof Veryhachiumwith betweenfour and six processes.Four proce&sesare positionedat the apicesof the equidimensionalto slightly elongatecentral body, minor 146 be between accessory processesmay present the apical processes. The flattened central body has sides that are straight to slightly concave and it measures 10-30um in length and 10-25um in width. Ile processes are simple with accuminate distal terminations and they have a rather rigid, firm appearance. 7be processesmeasure between 8-30um in length. The wall of the vesicle is sMDOthor may have a scabrate surface. Opening of the vesicle is by epityche. Remarks: Ile original descriptiongiven by Downie (1958) statessize dimensionsfor the vesicleof 3- l5um. The speciesis broadenedhere to include larger forms of upto 30um vesiclewidth. veryhachiwn lairdii Deflandre 1946ex Loeblich is larger and has more concavesides. Veryhachium valiente Cramer 1964has a similarly straight sidedvesicle but is also larger in size. From the specimensobserved, three morphologicalvarieties of this speciescan be recognisedbased on the length and numberof the processes: Ve?yhachium minutwn var. A. Plate 24, fig. 11; pl. 43, figs. 7 & 8. Remarks: Specimenshere have processes that are shorterthan the vesicle length. This variety is relatively common. Veryhachiumminutum var. B. Plate 24, fig. 10; pl. 43, fig. 9. Remarks: Specimenshere have processes that are longer than the vesiclelength. This variety is relatively rare. Ve?yhachium minutum var. C. Plate43, figs. 10 & 11. Remarks: Specimenshere have a fifth and occasionallysixth processpresent which alters the simple four-sidedoutline of the vesicle. This variety is relatively rare. 147 Veryhachiwnreductum (Deunff) Downie & Sadeant1965. Plate 12, fig. 1; PI-35, figs. 4 & 5; pl. 44, figs. 1,5 & 6; pi. 52, figs. 2,4 & 6; pl. 65, fig. 4. Description: Deunff 1959,p. 27-28, pl. 1, figs. 1,3,8,10-12,14,16-17,22-23. Holotype: Deunff 1959,pl. 1, fig. 10. Age: Caradoc. Remarks: The intraspecificvariety illustratedby Deunff (1959, pl. 1) is a good reflection of forms observedhere. The centralbody has a maximumdiameter ranging between 20-40um and the process length rangesbetween 10-30um. Veryhachiumtrisulcum Deunff 1951ex Deunff 1959has longer processes. IrIllosacapsulasetosapellicula (Loeblich) Loeblich & Tappan1976 has a similar body shape,spine length and overall size dimensionsto V. reductumbut differs in possessingan ornamentof short spinesor echinae. Veryhachiumsubglobosum Jardine et al. 1974. Plate44, figs. 8,10,11 & 12; pl. 52, figs. 1,3 & 5. Description: Jardineet al. 1974,p. 115-116,pl. 1, fig. 2. Holotype: Jardineet al. 1974,pl. 1, fig. 2. Age: Late Ordovician. Remarks: This relatively large speciesof Veryhachium(central body 40-60umin maximumdiameter; is by body long processes30-100um in length) characterised the globosecentral and slenderprocesses. Specimensrecorded here have processes at the lower end of the size spectrumfor the speciesthat was diagnosis. Processes here 30-35umin given in the original of the specimensobserved are commonly length. Breakageis commondue to poor preservation. is V. Deunff 1959, but form has A morphOlOgicallYsimilar form trisulcumvar. venutum this a more angularcentral body. Ve?yhachium trapezionarion Loeblich 1970. Plate 87, fig. 7. Description: Loeblich 1970,p. 743 & 744, figs.38A-C. 148 Holotype: Loeblich 1970, fig 38B. Age: Middle Silurian. Remarks: Veryhachiumrhomboidium Downie 1959is smallerin size and has a thinner wall than V trVezionarion. The contentionmade by Turner (1984, p. 145) that the former is a senior synonymof the latter is rejectedhere. Ver)*achiumvaliente has fewer and shorterprocesses and is generally smaller in size than V. trapezionarion. Veryhachiumpertonense Doming 1981is similar in termsof shape,size and numberand distribution of processesbut differs in having a granularas opposedto a smoothwall. Ve?Aachium cf. trapezionarionLoeblich 1970. Plate 73, fig. S. Holotype: Loeblich 1970, fig 38B. Age: Middle Silurian. Remarks: Comparewith Loeblich 1970,p. 743 & 744, figs.38A-C. 7be four specimensincluded here have the samenumber and distribution of processesand the samegeneral shape as V. trapezionarionbut differ in the processto centralbody ratio. The ratio is approximately1: 1 in V. trapezionarionin in contrastwith a ratio of approximately2: 1 V. cf. trapezionarion. Veryhachiwntrisulcum Deunff 1951ex Deunff 1951. Dwription: Deunff 1959,p. 27-28, pl. 1, figs. 1-4,8,10,12-14,16,17,20,22 & 23. HoloqW: Deunff 1959, pl. 1, fig. 4. Age: Middle Ordovician. Renwks: Two varietiesof this specieshave been recorded in the presentstudy. Veryhachiumtrisulcum var. trisulcum (Deunff) Fensomeet al. 1990. Plate24, figs.2 & 3. Description: Deunff 1959,p. 27-28, pl. 1, fig. 4. Holotype: Deunff 1959,pl. 1, fig. 4. Age: Middle Ordovician. 149 Remarks: 7be specimensobserved here are ratherpoorly preserved. 7be small central body distinguishesthis variety from V. trisulcumvar. venutumDeunff 1959. Veryhachiumtrisulcwn var. venutumDeunff 1959. Plate43, fig. 12; pl. 44, fig. 2. Description: Deunff 1959,p. 27-28, pl. 1, figs.2 & 20. Holotype: Deunff 1959,pl. 1, fig. 2. Age: Ordovician. Remarks: Veryhachiumsubgloboswn Jardine et al. 1974differs by having a more globosecentral body. Veryhachiumvaliente Cramer 1964. Plate 87, fig. 5. D,escription: Cramer 1964,p. 311, pl. 12, figs.3,4&6. Holotype: Cramer 1964, pl. 12, fig. 3. Age: Late Ludlow-Emsian. Remarks: Veryhachiwnlairdii differs from V valientein having concaveas opposedstraight sided inter-apicaloutline. Veryhachiwnwenlockanum (Downie cc Wall & Downie) Downie & Sadeant1965. Plate65, fig. 3; pl. 110, figs.2,3,5&6; pl. 116, figs. 8&9; pl. 131, fig. 1; pl. 141, fig. 5. Description: Downie 1959,pl. 12, figs.9 &11. Holotype: Downie 1959,pl. 12, fig. 9. Age: Wenlock. Remarks: This speciesis distinguishedby the small three-sidedcentral body and the three long needle- broken in like processes.The processesare commonly the materialobserved. 150 Veryhachiwnsp. 1. Plate45, fig. I&2. I)escription: A speciesof VerAachiumwith threeprocesses and a concaveor straight sidedcentral body, rarely with slightly convexsides. The centralbody measuresbetween 30-4lum in maximum diameter. Processesare simple and measureupto l8um in length and are commonlybroken. Remarks: The angularity of the centralbody distinguishesthis speciesfrom other tri-processedforms describedfrom the Ordovician. Veryhachiumreductwn (Deunff) Downie & Saýeant1965 is of similar size and processmorphology but has a more convexcentral body. Veryhachiumsp. 3. Plate45, fig. 3. Description: A three sidedspecies of Veqhachiumwith threeshort ( Remarks: Villosacapsulaentrichos (Loeblich) comb nov. has a similar centralbody and processshape but differs by being coveredin short conical spinesof upto 2um in length. Veryhachium sp. 4. Plate 44, figs. 3,4,7 & 9. Description: A speciesof Veryhachiumwith threesides and three short (<5um in length) truncated processesat the apicesof the centralbody. 7be centralbody has convexsides and has a maximum diameterof 30-40um. 7be wall is relatively thick, 1-2um, and hasa smoothdistinctive porcelain-like texture. 7be truncatedtips of the processesbare slight thickeningsof the wall in somespecimens. Remarks: This speciesis distinguishedby the short truncatedprocesses, the convexcentral body and the thick porcelain-likewall. 151 Veryhachiumsp. 5. Plate45, fig. 5. Ikscription: A speciesof Veryhachiumwith threesides and threeshort (<5um in length) truncated processesat the apicesof the centralbody. The centralbody hasconcave-straight sides and hasa maximum diameterof 28-37um. The wall is relatively thick, 1-2um, has a porcelain-liketextured and is smooth. The truncatedtips of the processesbare slight thickeningsof the wall in somespecimens. Remarks: This speciesis distinguishedby its short truncatedprocesses, coneave-straight sided central body and thick 'porcelain-like' texturedwall. This form is distinguishedfrom Veqhachiumsp. 4 by the,straight sidedas opposedto convexsided vesicle. Veryhachiumsp. 7. Plate 10, figs. 1-4. Description: A speciesof Veryhachiumwith four sidesand four processespositioned at the apicesof the central body. 7be centralbody is squareto slightly rectangularin outline and has slightly convex sides. lie maximumdiameter of the vesiclemeasures between 30-35um. Ile processesare broad at the bases(< lum) and taperdistally to truncatedtips. 7beir length varies between5-15um. 7le wall of the vesicleis very thick (> lum) and no ornamentationis visible. Openingof the vesicleis by epityche. Remarks: This speciesis distinguishedby its truncatedprocesses and thick walled robustvesicle. Veryhachiumsp. S. Plate 9, fig. 10. Description: A speciesof Veqhachiumwith four sidesand four long slenderprocesses at the apicesof the centralbody. ne centralbody is rectangularin outline and measuresbetween 28-32um in length and 18-2lum in width. The processesare 3-4um wide at the basesand taper distally to accurninatetips. processlength rangesbetween 20-29um. At thejunctions of the processesand the centralbody the in wall is puncturedwith poresof approximatelylum diameter. Openingof the vesicle is by epityche. 152 Remarks This speciesis distinguishedby the rectangularcentral body, the long slenderprocesses and the puncturedvesicle wall. Veryhachium?sp. 9. Plate65, figs.7,8 & 9. Description: A veryhachid-shapedspecies with threesides and threeprocesses positioned at the apices of the vesicle. 7be centralbody hasconvex sides and is 40-65umin miximum diameter. 7be processesare pluggedat the basesand hollow distally. 17heprocesses on all the specimensrecorded here are broken. The vesiclewall is thick (ca. lum), smoothand dark in colour which contrastswith the lighter colouredhollow processes. Remarks: The distal terminationsof the processeshave not beenobserved due to the poor preservation of specimens,hence the questionedassignment of theseforms to the genusVe? Aachium. Ve?Aachium checkleyensisDoming 1981has a similarly thick vesiclewall and thinner walled processes,however, Veryhachiumsp. 9 has a larger centralvesicle. Poor preservationof specimensrecorded does not permit comparisonof the processesbetween them two species. Ve?Aachium? sp. 10. Plate65, figs. 10 & 11. Description: A veryhachid-shaped specieswith three sides and three processesat the apices of the in vesicle. The central body has slightly convex sides and measuresbetween 32-38urn maximum diameter. The processesare pluggedat the basesand are hollow distally. Tlie processeson all the is has specimensrecorded here are broken. I'lie vesiclewall very thick (ca. 2um) and a granulate ornament. The processesare thin walled and smooth. Remarks: The distal terminations of the processeshave not been observed due to the poor preservation forms Veryhachiwn. of specimens, hence the questioned assignment of these to the genus Veryhachium? sp. 10 has similar morphology to Veryhachium? sp. 9 (herein) but differs in having a thicker, granular wall. 153 Genus Wksacapsula Loeblich & Tappan 1976. Type species: Villosacapsulasetosapellicula (Loeblich) Loeblich & Tappan1976. Genericdescription: Loeblich & Tappan1976, p. 307-308. Remarks: Veryhachidforms with short spinesor echinaeare includedhere. Villosacapsulafakinan(Martin) comb. nov. Plate24, fig. 9? Synonomy: 1968, Vey3*achiumf4hrum,Martin, p. 93-94, pl. 2, figs. 109 & 110; pl. 6, fig-256, text-figs. 42 & 43. Description: Martin 1968,p. 93-94, pl. 2, figs. 109 & 110; pl. 6, fig. 256, text-figs. 42 & 43. Holotype: Martin 1968, text-fig. 42. Age: Ordovician-Silurian. Ile holotype is believedto be reworked from the Ordovician(Eisenack, Cramer & Diez 1979,p. 411). Remarks: The morphologicallimits of Ve?yhachiwn and Villosacapsulaoutlined in the genericremarks abovenecessitate the transferof VeryhachiwnfaAlrumMartin 1968to the genusVillosacapsula. The few poorly preservedspecimens of V.fahrum observedhave a scabrate,wall with rare echinae. Ile lack of echinaeis believedto be the result of the poor preservation. Villosacapsulahorridum (Paris & Deunff) comb. nov. Plate45, fig. 5. SynonomY: 1970, Veryhachiumhorridwn, Paris & Deunff, p. 27, pl. 1, fig. 8; pl. 3, fig. 3. Description: Paris & Deunff 1970,p. 27, pl. 1, fig. 8; pl. 3, fig. 3. Holotype: Paris & Deunff 1970,pl. 1, fig. 8. Age: Llanvirn. 154 Remarks: Ile limits Veryhachium morphological of and Villosacapsulaoutlined in the genericremarks abovenecessitates the transferof Veryhachiwnhorridwn Paris & Deunff 1970 to the genus Villosacapsula. Villosacapsulasetosapellicula (L: )eblich)Loeblich & Tappan1976. Plate 45, figs. 7,8,10-12. Description: Loeblich 1970,p. 743, figs. 36A-B, 37A-B. Holotype: Loeblich 1970, fig. 36A. Age: Ashgill. Remarks: In the poorly preservedmaterial observed here, the echinaeare commonlyabraded giving a granular appearanceto the vesiclewall. Villosacapsulasp. 2. Plate 66, figs. I&2. Remarks: Included here are two poorly preserved specimens, both with a four-sided central body and with four processespositioned at the apices. Ile sides of the central body are straight to slightly convex. The central body is approximately 25um in diameter and the processesvary between 10-28um in length. The vesicle and processesare ornamented with echinae. Villosacapsulafakirum has a larger central body than Villosacapsula sp. 2. Genus WirgalasporliesCombaz 1967. Type species: Virgalasporitesrudil Combaz1967. Genericdescription: Combaz1967a, p. 14. Remarks: AbacumFombella 1978is ajunior synonymof this genus(Fensome et al. 1990, p. 23). 155 Virgatasporites rudii Combaz 1967. Plate 10, figs.5 & 6. Description: Combaz1967a, p. 12, pl. 1, figs.27 & 28. Holotype: Combaz1967a, pl. 1, fig. 27. Age: Tremadoc. Genus VlubysphaeraLister 1970. Type species: Vubysphaeradilatispinosa (Downie) lister 1970. Genericdescription: Lister 1970,p. 98. Vishysphaeramicrospinosa (Eisenack) Lister 1970. Plate 88, fig. 2; pl. 141, fig. 9. Dewription: Eisenack1954,209-210, pl. 1, fig. 8. Holo*W: Eisenack1954, pl-1, fig. 8. Age: Wenlock. Remarks: The intraspecificvariation within this taxon recordedby Le Herisse(1989) is similar to that havebeen here, dim observedhere. Within this spectraof morphotypesthat observed consistent defined follows: varietiescan be recognisedwhich are as Vishysphaeramicrospinosa var. A. Plate 66, figs. 5 & 6; pl. 74, figs. 5,6,8 & 9; pl. 81, fig. 1 Remarks: The specimenrecorded here have short (<2um) broad (1-2um) conateor baculateprocesses. density The elementsare of relatively low spatial on the centralbody with > 2um betweeneach. 7be diameterof the vesiclevaries considerablyin this form, measuringbetween 35-70um. Lophosphaeridiumbut This variety closely resemblessome species of can be distinguishedby the thick vesicleWall. 156 Visbysphaeramicrospinosa? var. B. Plate 123, fig. 7 & S. Remarks: Specimensincluded here have short (<3um long) broad (approximately2um, wide) baculate processes.The elementsare denselyspaced on the centralbody with <2urn betweeneach. Ile diameterof the vesiclemeasures between 45-60um. This variety is questionablyincluded in this speciesas the wall is relatively thin in comparisonwith the other varieties. Visbysphaeramicrospinosa var. C. Plate 110, figs.7-10; pl. 116, figs. 10 & 11; pl. 123, figs.4 & 5. Remarks: Specimensincluded here have short (< 3um) echinateprocesses. The elementsare densely spacedon the centralbody with < 2um betweeneach. The diameterof the vesicle measuresbetween 42-60um. Vishysphaeracf. oligofurcatum(Eisenack) Lister 1970. Plate 110, fig. 4; pl. 123, fig. 3. Holotype: Eisenack1954, pl. 1, fig. 8. Age: Late Llandovery. Remarks: Comparewith Eisenack1954, p. 209-210,pl. 1, fig. 8. Specimenshere have processes which havea more sparsedistribution on the centralbody than V. oligofurcatum. Visbysphaerapirifera (Eisenack)Kiryanov 1978. Plate66, fig. 4. Dmription: Eisenack1954, p. 206-207,pl. 1, figs. la-b; text-fig. 1. Holo*W: Eisenack1954, pl. 1, figs. la-b. Age: Late Liandovery. Remarks: A morphologicallycomparable species is V dilatispinosa (Downie) Lister 1970. Both V. balloon-shaped Pirifera and v. dikuispinosahave thin processesprotruding from the thick-walled, 157 sphericalcentral body. However, the processeson V. dilatispinosumare ornamentedwith echinaein contrastwith the smoothprocesses of V pirifera. Visbysphaerasp. 1. Plate66, figs.7-1 1. Description: Acanthomorphicacritarchs which havea robust, thick-walled, sphericalcentral body ranging between21-25um in maximumdiameter. T'heprocesses are conical or clavatein shape. 71ke processeslength rangesin size from 5-9um in length and the processesnumber approximately 15-25 on eachspecimen. The processlength to maximumbody width ratio is approximately1: 4. The wall of the centralbody is composedof two wall layersgiving it a relatively dark appearance.The wall of the processesis composedof a single layer and consequentlyappears relatively light in colour. The wall of the central body and the processesis smooth. No regular openingis apparent. Remarks: This speciesof Visbysphaerais distinguishedby the small, robust centralbody and the is prominentprocesses. 7be variability in the natureof the processeswhich hasbeen observed here form probably a function of poor preservation. 7be authorwould expectthe clavateprocess to predominatein better preservedmaterial. Visbysphaerapilifera hasa very similar morphologyto Vubysphaerasp. 1 in termsof body and larger processform. However, they differ in size, the former being approximatelythree times than the latter, ind also in the degreeof inflation of the processes.Visbysphaera piriferum has more distinctly is club-shapedprocesses. Vubysphaera dilatispinosa also larger in size and hasan echinate ornamentationon the processes. Visbysphaerasp. 3. Plate 67, fig. 1. Remarks: The single specimensrecorded here has a centralbody diameterof 85um. T'heprocesses are The is short (< Joum) and haveaccurninate terminations. specimenobserved rather poorly preserved damaged. Visbysphaeraofigo fu rcatumhas a smallercentral body d and the processesare commonly . an longer processesrelative to the centralbody diameterthan Wsbysphaerasp. 1. Visbysphaera in having (< 5urn long) Microspinosadiffers very short processes.. 158 Genus VogdandlaBurmann 1970. Type species: Vogtlandiaramifurcata Burmann 1970. Genericdescription: Bunnann 1970,p. 292. Remarks: Ile genusVulcanisphaera differs from Vogtlandiain possessingclusters of processesthat radiateout from the samepoints on the centralbody. Vogtlandiasp. 1. Plate 10, figs.7-11. Synonomy: 1988, Vogdandiacoalita, Molyneux & Rushton,fig. 7d, e&f. 1989, Vogdandiacoalita, Cooper& Molyneux, fig. 4e. Description: Acanthomorphicacritarchs which havea polygonalcentral body rangingbetween 25-42um in maximumdiameter. The processesshafts are conical or cylindrical in shapeand haveramusculose distal terminations. 7be terminationsmay branchupto the 4th order. 7be processeslength rangesin size from 25-30umin length and they numberbetween 15-20 on eachspecimen. The processlength to maximumbody width ratio is approximately1: 1. In somespecimens, there appears to be a groupingof processesat eachpole with a girdle present. The wall is composedof a single wall layer and the processescommunicate fieely with the centralbody. 7be wall is smoothand no regular form of openingis apparent. Remarks: Molyneux & Rushton(1988, fig. 7d, e, f) and Cooper& Molyneux (1989, fig. 4e) illustrate the samespecies as describedhere. They assignedit to Vogtiandiacoalita Martin in Martin & Dean 1978. However, V. coalita is not a legitimatename as it was placedinto synonomywith V flosmaris (Deunff) Molyneux 1987by Martin in the paperin which it was described,this was doneas an addendumto that paper(Martin 1978,p. 19). VogtlandiaCoalita is thereforeconsidered to be a junior synonymof V.flosmaris. Specimensobserved here have far more complexdistal processterminations than the holotype of V flosmaris and are thereforeinformally assignedto a new species. Genus VulcanisphaeraDeunff 1961 emend. Rasul 1976. Type species: Vulcanisphaeraafricana Deunff 1961. Description: Rasul 1976,p. 479. 159 Vulcanisphaeranebulosa Deunff 1961. Plate 11, figs. I&2. synonomy: 1988, Vulcanisphaeraafricana, Elaouad-Debbaj,pl. 4, figs.9,10,11,13 & 14; pl. 6, fig. 2. Description: Deunff 1961a,p. 42, pl. 2, fig. 3 Holotype: Deunff 1961a, pl. 2, fig. 3. Age: Tremadoc. Remarks: A morphologicallysimilar speciesis V africana Deunff 1961but this form has less elaborateprocesses than V nebulosa. Vulcanisphaerasimplex Jardine et al. 1974. Plate24, fig. 6. Description:Jardine et al. 1974,p. 119, pl. 2, fig. 7. Holotype: Jardineet al. 1974,pl. 2, fig. 7. Age: Lower Tremadoc. Remarks: This species is distinguished from others in the genus Vulcanisphaera by having an almost 7bis is due broadening base polygonal central body. to of the vesicle at the of the processes. This by having furcations species is also distinguished relatively simple at the distal ends of the processes. Genus WinwaloeusiaDeunff 1977. Type species: Winwaloeusiadistracta (Deunff) Deunff 1977. Genericdescription: Deunff 1977b,p. 466. Remarks: This genusis superficially similar to Veryhachium.It differs in the presenceof crestson the vesiclewall forming a *pseudo-triletemark". The vesicle opensby splitting into two parts which quite distinct from the epitychestyle of openingin Veryhachiumspecies. 160 Winwaloeusiadistracta (Deunff) Deunff 1977. Plate 150, fig. 5; pl. 177, fig. 5. Description: Deunff 1966,p. 22, fig. 2. Holotype: Deunff 1966, fig-2. Age: Middle-late Devonian. Remarks: Winwaloeusiaranulaeforma Martin 1984has an identical vesicle shapeto W. distracta but differs in having an vesicleornamented with grana. Winwaloeusiatwnida Deunff 1977has processes which havemore constrictedproximal terminationsthan the processesof W. distracra. Thesethree speciesare closely similar in morphology. Acritarch Form A. Plate 11, figs.6,7,9 & 10. Remarks: Acanthomorphicacritarchs which havea sphericalto subsphericalcentral body measuring 30-37um.in diameter. The processesare short, 5-7M in length, with slightly taperingshafts in a distal direction. The ramusculosedistal branchingof the processesis to the 2nd or 3rd order. 7be central body to processratio is approximately5: 1. Ile wall is composedof a single layer and the natureof the communicationbetween the processesand the centralbody is not discerniblein the specimens observed. No regular form of openingis apparent. Speciesof the genusTimofeeWa differs by having the centralbody divided into fields. Vulcanisphaera specieshave clusters of processessprouting from the samepoint on the centralbody. Vogtlandia speciesdiffer in possessinga polygonalcentral body. Acritarch Form B. Plate 11, figs.3,4 & 5. Remarks: Acanthomorphicacritarchs which havea polygonal centralbody. Ile centralbody has a maximumdiameter ranging between 25-32um (two specimensmeasured). There are approximately15- 2-3urn base 20 processeswhich are wide at the and tapergradually to accuminatetips. They supporta fine tmbeculumrunning along the shaft. The processesare 13-15umin length. The centralbody to 161 processratio is approximately2: 1. Tbe natureof the wall structureis indeterminatefrom the dark specimensobserved. No regular form of openingis apparent. This speciesis distinguishedby the Polygonium-typecentral body, the processarrangement and the trabeculaerunning along the shaftsof the processes.Only two specimenshave been recorded. Acritarch Form C. Plate45, fig. 6. Remarks: Acanthomorphicacritarchs which havea subsphericalto ovatecentral body. The body is 25-34urnin length and 21-24umwide. The processesare rigid, they have solid 'pin-like' shaftsand bifurcating or trifurcating pinnaeat the distal extremities. They rangebetween 10-15um in length, distributed. is numberapproximately 50 and are evenly The processto centralbody ratio is layer. is approximately1: 2. The wall thin, smoothand appearsto be composedof a single Opening by meansof a pylome. The wall of this fom is very thin andhas a very distinct hyaline appearance.The bifurcating pin-like broken in processesare also diagnosticbut they are commonly this poorly preservedmaterial. Acritarch Form D. Plate25, figs. 1-5. Remarks: Acanthomorphicacritarchs which havea rigid sphericalcentral body measuringbetween 39- 48um in diameter. The processesappear to havehollow tubular shaftswith fine branchingpinnae The 100-150in sprouting from the distal ends. processesare closely spacedand are approximately between9-13um in length, 2-4um base flare distally. The number. ney measure wide at the and they is 1:4. Ile be two layers, processto centralbody ratio approximately wall appearsto composedof the There is between outer layer forming the processes. no communication the processesand the central body. The occasionalopenings that havebeen observed are pylomes. Tbeseforms occur in high numbersin sampleJW 5. Superficially they appearsimilar to Lua I-eiming 1988,however is having erduapuzianaMartin & Yin this species reportedas an apical tabular here. In extensionwith a circular openingwhich was not evident addition, the processesare generally distally. shorterand more robust 162 Acritarch Form E. Plate67, figs.2 & 4. Renuuts: Spheromorphicacritarchs measuring between 60-92um in maximumdiameter. Ile wall is composedof two layersthat show variabledegrees of separation. Ile vesicle is ornamentedwith low irregular verrucaeand rugulae. The only methodof openingobserved is by mediumsplit. Speciesof Dia)wtidim show a more regularly orderedpolygonal pattern of ornamntation on the vesicle. Acritarch Form F. Plate 81, figs. 1&4. Remarks: Acanthomorphicacritarchs which havea rigid, sphericalcentral body meamringbetween 4048um in maximumdiameter. The processesappear to havehollow tubular shaftswith capitateor bifid distal terminations. The processesare closely spacedand are approximately100 in number. They measurebetween 10-20um in length and 24um in width. The processto centralbody ratio is approximately1: 3.5. The wall is thin and is composedof a single layer. No regular form of opening is appamt. Four specimensof this form are recordedfrom the Late Telychian (Uandovery) samplesanalysed here. The relationshipbetween the processesand the centralbody, and the detail of the morphologyof the processtips is not discerniblefrom the specimensobserved. Acritarch Form G. Plate 88, figs.4,5,7 & 8; Pl. 110, figs. II& 12; pl. 117, fig. 1; pl. 123, figs.6 & 9; pl. 141, fig. 11. Remarks: Forms includedhere are single walled acritarchsthat when compressedhave a circular (i. outline. The outer margin of the circular vesicle e. the outermostquarter of the radius of the vesicle) is is alwaysfolded. The centralpart of the vesicle generallynot folded. The surfaceof the vesiclemay be smoothor ornamentedwith ridges. No regular form of openingis apparent. The regularity in the arrangementand distribution of the folds distinguishesAcritarch Form G from the Saharidia has genusLeiosphaeridia. The genus a similar tendencyto possessperipheral folds but can be distinguishedby having & smoothor finely granulatesurface with a central pylome present. 163 Acritarch Form H. Plate 88, fig. 6. Remarks: The single well preservedspecimen included here is a spheromorphicacritarch with a subsphericalvesicle of 45um in maximumdiameter. Ile wall is single layeredand thin. 7bere appearsto be a pore or pylome presentfrom which an ornamentof linear striationsradiate. 7be striationsextend approximately half way aroundthe subsphericalvesicle. 7be other half of the vesicle iS SMDDth. Acritarch Form 1. Plate 88, fig. 3; fig. 117, fig. 6. Remarks: Includedhem are spheromorphacritarchs measuring between 35-45urn in diameter. The wall of the vesicleis thin, lessthan lum, and ornamentedwith an open reticulum. The elementsare closely spaced(< Imm &part)vermiculae and rugulae.The ornamentis lessthan lum in height. No regular form of openingis apparent. speciesof Lophosphaeridiumdiffer from Form I in possessingequidimensional omamental elements. Acritarch Form J. Plate 117,2-5. Remarks: Four specimensof this form are recordedfrom the Monograptusuniforinis (graptolite) Zone (Gedinnian)in the presentstudy. 17heyare flattenedor pad-shapedacritarchs with four or five sides. The maximumdiameter of the vesicleranges between 55-65um. A slight thickeningat the peripheral In irregular margin of the vesicleis apparent. addition, thickeningsof the wall on the upper and lower facesof the vesicleare present. No regular form of openinghas been observed in the specimens studied. 164 Acritarch Form K. Plate53, fig. 1,2 & 3? Remarks: Five specimensof this form havebeen recorded from a single sample,DJ 10, of Ashgill age. 7bey are acanthomorphicacritarchs with a subsphericalcentral body which measuresbetween 60-75um in diameter. 7be processesare between25-35urn in length but are commonlydamaged in the material less 5um observed. 7he processesare narrow, than wide, and are of a consistentwidth along the entire length of the shaft. The processterminations furcate upto the first order at the distal extremity. 7be wall appearsto be composedof two wall layers, the outer wall layer forming the very thin transparent is The is processes.The centralbody thick walled relative to the wall of the processes. wall No form is in onmunentedwith granaand echinae. regular of opening apparent the specimens observed. Iliese thin processedacanthomorphs are comparablewith Actipilion druggii Loeblich 1970which was The feature also describedfrom LAte Ordoviciansediments. thin walled processesare a characteristic druggil has in branching of this species. However,A simpleprocesses contrastto the processesof Acritarch Form K. Acritarch Form L. Plate 67, figs.3-7; pl-88, figs-9,10 & 11; pl. 111, fig. 1; pi. 117, fig. 9; pl. 123, fig. 14. Remarks: Includedhere are very large acanthomorphicacritarchs with a sphericalcentral body and 7be body between130-200urn in sturdy, evenly distributedprocesses. central measures maximum diameter. The processeshave simple distal terminationsand appearto solid. 7bey measureupto 90um in length. in the materialstudied, this form commonlyoccurs as fragmentarypieces. No regular form of openingis apparent. by its large This gmthomorphic form is conspicuous very size. Acritarch Form M. plate 11. figs. 8& 11. Remarks:Acanthomorphic acritarchs which havea spherical-subsphericalcentral body measuring between3242um in diameter. The processeshave narrow (2-3urnwide) straight sidedshafts of between12-20um in length. Ile processterminations branch in a ramusculosemanner. Processesmay 165 branch upto the 5th order, the higher order branchesforming a fine meshof pinnae. The centralbody to processratio is approximately2: 1. The natureof the wall structureis indeterminatefrom the dark specimensobserved. No ornamentis evidenton the centralbody and no regular form of openingis apparent. Acritarch Form N. Plate25, figs.6-9; pl. 35, fig. 1 Remarks: Acanthomorphicacritarchs; which havea rigid, sphericalcentral body measuringbetween - 45-56urnin maximumdiameter.. 71le processes appear to havehollow tubular shaftswith simple open distal terminations. The processesare closely spacedand are approximately100-150 in number. They is measurebetween 18-25urn in length and 2-4um wide at the base. 71e processto centralbody ratio be forming approximately1: 2.5. The wall appearsto composedof two layers, the outer layer the between body. No form processes.nere is no communication the processesand the central regular of opening is apparent. Acritarch Form D, describedabove, differs by having branchingpinnae at the distal terminationsof the body processes.It also has a smallercentral and the processesare. shorter. Acritarch Form P. Plate 184, figs.2-8. Remarks: Includedhere are acanthomorphicforms with a subsphericalcentral body and short, hollow, distally openprocesses. Ile centralbody is thick walled and measuresbetween 30-65um in mAximum diameter. ne processesvary considerablyin numberand size in the populationstudied. 11ey number between10 and 60 and measureupto 10urnin length. The width of the processesis also variable base. The distally, however measuringupto 12urnwide at the processescommonly taper specimens The distally. No form with straight sidedprocesses also occur. processesare alwaysopen regular of openingis apparent. includesforms A comparablegenus is Dilatisphaera which also with open endedprocesses, however have body have longer speciesincluded in Dikuisphaera a thinner walled central generally processes. 166 Acritarch Form R. Plate 184, fig. 10. Remarks: Ile single specimenincluded here is a coenobialform composedof four cylindro-conical shapedcells radiating from a centralpoint. Eachcell measuresapproximately 30um in length and has an open distal terminationwhich is circular in outline. Acritarch Form S. Plate 184, fig. 11. Remarks: The single specimenincluded here is triangular in outline and measures47um in maximum diameter. The apicesof the vesicleare echinatewith spinesless than 2um in length. 71e interapical areasare smoothand their outline is concave. No openingis apparent. Acritarch Form T. Plate I 11, figs. 2,3 & 4. Remarks The two specimensincluded here are sphericalin shapeand measure55um and 59um in diameter. Ile vesicleis divided into numerouspolygonal fields by low ridges, as in speciesof Dictyotidium. Within eachfield, what appearto be pores, 3-6 in number, are present. The poresare field. arrangedin a regular mannerwithin each This form is of similar morphologyto specieswithin the genusOrygmahapsis. Orygmahapsis species differ by havingjust a single pore at the centreof eachfield. Acritarch Form U. Plate 123, figs. 10,11 - Remarks: Includedhere are thick walled (approximately2um thick) sPheromOrPhicacritarchs with a The is coarselyscabrate or rugulateornamentation. vesicle sphericaland measuresbetween 40-65um in form is maximumdiameter. No regular of opening apparent. 167 This form was recordedin large numbersin graptolite datedsamples of late Siegenianage. Acanthomorphicacritarchs indet. Remarks: This categoryincludes acanthomorphic acritarchs which are Poorly preservedand which can not be allocatedto a publishedgenus. Spheromorphicacritarchs indet. Remarks: Includedhere are sphericalor subsphericalforms which are too poorly preservedto be assignedto a genus. 168 Chapter 5. The Prasinophyta Round 1971. introduction. The Prasinophytaare a division of the greenalgae. There appearsto be no definition of the group in the literature that is satisfactoryfor useby palynologistswho are concernedonly with the fossilised phycomastage of the life cycle. However, Tappan(1980, p. 818) provided the following definition: -Motile stagewith ultramicroscopicbody scales,and two to four scaly flagella arising from the apical. pit that is surroundedby four apical projections;large axial plastid; may havecolonial, coccoid, palmelloid, or branchingstage; cysts or phycomaenlarge vegetatively. Planktonicand benthic; marine and freshwater;Platymonas may be symbioticwith the marineworm Convoluta.Precambrian to Holocene." lie prasinophytefossil record is not fully representativeof the geologicalhistory of the group as only a small proportion of the group producea fossilisablephycoma as part of their life cycle (Tappan 1980). However, fossil prasinophytescommonly form significant proportionsof palynological assemblagesthroughout the Phanerozoic.They appearto be 'disasterspecies' (Tappan 1980) surviving and flourishing, in the middle and late Palaeozoicfor example,when other phytoplanktongroups underwentdecline. Fossil IRmsinophytemorp-hology. In the literature, it is commonto seethe sameset of morphologicaldescriptors used to describethe fossilisedprasinophytes as thoseused to describethe acritarchs. This is all well and good for the descriptionof the detail of morphology,e. g. the ornamentation,however, confusioncould arise from the use of termswhich have functionalconnertations. This problem was addressedby Colbath(1983) who warnedagainst the use of the term 'cyst' when describingthe fossilisedbody of prasinophytes."The term 'cyst'" he said, "is bestused to describethe but because bodies formed by resting stageof an organism, the acid resistant are prasinophyceans during a stageof active growth and division, they are better referredto by the term 'phycoma' (plural: phyr,omata). " In the presentstudy, termsused for the detailedornamentation are thoseused for the acritarchs. However, it is necessaryto define the following termswhich are particularly applicableto the pmsinophytes. Ala: Flangelike extensionfrom the equatorof the centralbody. Central body: 7be phycoma,minus the ala or membranousoutgrowths. 169 Crest: Flangelike, membranousoutgrowth from the centralbody. phycoma: The fossilisedorganic body of the prasinopbyteas a whole. Phycomadevoloment in the Prasing2hyta. Our Knowledgeof the prasinophyceanlife cycle is basedon numerousfield and laboratory investigationsof modemday species(Ostenfeld 1910; Parke& Hartog-Adams1965; Parke 1966;Parke ef aL 1978). A brief summaryof the life cycle of the modemday prasinophytePterospenna is given in fig. 12. -Ibe stagesthat are potentially fossilisableare thosefrom the beginningof the phycomaphase, phase 3 on the diagram,through to phase8, which showsthe empty phycomahaving releasedthe inner wall containingthe motile cells. The phycomataproduced by modem speciesare closely comparablewith someof the organicwalled microfossilsrecorded from palynologicalpreparations from rocks. It is basedon thesecomparisons that severalfossil microplanktongenera have been classified under the prasinophyta. For a comprehensivereview of the biology of the Prasinophyta,a subjectwhich falls outsidethe realmsof the presentstudy, the readeris referredto Tappan19 80, p. 806-812. Classificationof the Prasinop-hyta. The classificationof the Divison Prasinophytawas addressedby Tappan(1980) who proposeda system inc,orporating both presentday and fossil forms. Severalpalynomorph genera included in the Prasinophytaby Tappanshow only superficialsimilarity to the phycomataof modemday species. For example,Leiosphaeridia, which showssuperficial by day Halosphaerahas been demonstrated have similarity to the phycomataproduced the modem to a dissimilar wall ultrastructure(Jux 1969). There is also the distinct possibility that the greatvariety of Leiosphaeridiaspecies recorded in the literature are multi-sourced,possibly by animal and plant. For it this reason,it is dangerousto include this genus,as is presentlydiagnosed, in the Prasinophyta. In the presentstudy, only the generawhich are now indisputablyconsidered to be prasinophytes (Fensomeet al. 1990)are includedin this division. Theseare TasmanitesNewton 1875, which is day by Pachysphaera Ostenfeld,herospertnella is by producedat the present pelagica which produced pterospermamoebij (Jorgensen)Ostenfeld, and Cymatiosphaerawhich is producedby Pterospe?7na marginatumGaarder. The supragenericscheme of Tappan(1980, Table 10.1) is hereused in part. The position of the LeiosphaeridiaceaeTimofeev 1956in the PrasinoPhytais rejecteduntil further evidenceis available 170 Figure 12. The life cycle of herospenna. 4' N Life cycle of Pterosperma. 1. Motile phase, a scale-co%eredcell Mth ewentric nucleus, large saucer- shaped plastid lyýing against the convex side of the bod%, and starch-enclosed pyrenoid; four long inserted scale- and hair-covered flagella. Nl'otile phase may independently excentricallyýv reproduce and repeatediv fission. 2. Dividing motde ceUs. 3. Beginning of phycoma phase as motile cell loses flagella, rounds off, and develops thickened wall and a flangelike ala. Phycoma increases rapidlý in %olume, plastid divides into many smaller ones that surround a central lipid globule; size increase from continues to maturity, requiring two %%eeksto three-and-a-half months in culture. 4,5. Maiure ph comata of varied size, vvith thickened inner wall, just prior to dhision of cell contents. 6. Phýconia '% in edge view. 7. Thickened inner wall of ph.ýcorria and contained cell material has escaped through the release suture, a slit in the outer phyconia wad]; after escape, the former inner %vaflenlarges to clouhle the pre%ious diameter and the contents di%ideinto mo, four, or eight uninucleate masses that de%elop flagella. 8. Empty phycoma, shov%ing release suture compare fossil prasinophytes of Figure 10.17 part I and Figure 10.5), peripheral ala, and ring of alaband pores, as vveil as other scattered pores. 9. Phycoma inner wall, each of the early 8 quadriflageUate ceus ha%ing divided vt%iceto produce increases in diarneter 32 niotile ceUs; inner %vafl up to 16 times that prior to release from outer wall, in accompanied by decrease wall thickness and continued dhision of motile cells that finaliv burst the data from %%alland escape. Based on various species, Parke et al., 1978.1, x 1000; others, x 150. 171 regarding their prasinophycean affinity. Ile families TasminaceaeSommer 1956, Cymatiosphaeraceae Madler 1963 and PterospermellaceaeEisenack 1972 are utilised to accommodate the genera Tasmanites, Prerospermella C)mxiosphaera and respectively. However, the inclusion of other palynomorph genera in these families by Tappan (see Table 10.1) is rejected, again pending further evidence. Rmsinogbyle systematics. lie synonomyof the tax&in this sectionfollows that of Fensomeet al 1990unless otherwise stated. Division Prasinophyta Round 1971. Order PterospermatalesSchiller 1925 Family CymatiosphaeraceaeMadler 1963. Genus Cymadosphaem0. Wetzel 1933 ex Deflandre 1954 emend. Denandre & Cookson 1955. Type species: C5mwiosphaeraradiata 0. Wetzel 1933. Genericdescription: Deflandreand Cookson1955, p. 288. Remarks: The genusis includedin the division Prasinophytaas phycomataof identical morphologyare producedby the modemday prasinophytespecies Pterosperma marginatum. The acritarchgenus Dicfyotidiwn differs from Cymatiosphaerain possessinglow solid ridges defining the boundaries betweenthe fields on the vesicleas opposedto the membranoussepta in speciesof Cymatiosphaera. Cymatiosphaeracanninae Cmmer 1964. Plate 156, figs.2,3 & 5; pl. 168, figs 8&9. Description: Cramer 1964,p. 325-326,pl. 6, fig. 9, pl. 14, fig. 10. Holotype: Cramer 1964,pl. 14, fig. 10. Age: Emsian. Remmis: This distinctive speciesof Cymatiosphaerahas striationspresent on the outer membranous Cramer 1964has wall layer. Cymatiosphaerapeligrosa a similar over-all shapeto C. carminaebut 172 lacks the striationson the outer wall. A pictorial comparisonof thesetwo speciesis given by Cramer 1964, p. 325. Cymatiosphaeragorstia Doming 1981. Plate74, fig. 10. Description: Doming 1981, p. 185, pl. 2, fig. 7. Holotype: Doming 1981,pl. 2, fig. 7. Age: Ludlow. Remarks: Cymatiosphaeraoctoplana Downie 1959is smaller, has fewer fields and hashigher flanges. CymatiosphaeraKi? yanoWi (Kiryanov) Fensomeet al. 1990. Plate68, figs.6 & 7. Description: Kiryanov 1978,p. 32-33, pl. 7, fig. 6. Holotype: Kiryanov 1978, pl. 7, fig. 6. Age: Late Silurian. Remarks: Colbath(1983) observedthis taxon in his study of the microfloras from the Silurian BainbridgeFormation, Missouri, USA. As a consequencehe transferredthis species,then named Cymatiosphaeropsisreticulosa, to the genusCymatiosphaera. In doing so, Colbathcreated a jumor homonymof Cymatiosphaerareticulosa Takahashi 1964. Fensomeet al. 1990 subsequentlyproposed the presentname. '17hespecies is distinguishedby the thick vesiclewall (4-8um thick) and a two-tier reticulum. The first- order reticulum,is broad, fields commonlybetween 10-15um, wide, with a secondorder microreticulum within thesefields. 173 Qonxiosphaeracf. ledburicaDoming 1981. Plate 89, figs. 1,2 & 3. Holotype: Doming 1981,pl. 2, figs. 13 & 14. Age: Ludlow. Remarks: Comparewith Doming 1981,p. 185, pl. 2, figs. 13-14. Specimenshere have a similarly thick, smoothwall, and a similar numberof fields on the vesicle as the holotype. Iley are also of a similar size. The type materialdiffers in possessinghigher flanges. Cymatiosphaeraleonensis Cmmer & Diez 1976. Plate 185, figs. 1,2 & 3; pl. 196, fig. 1. Description: Cramer& Diez 1976,p. 80, pl. 4, fig. 35. Holotype: Cramer& Diez 1976,pl. 4, fig. 35. Age: Late Emsian. Remarks: Specimensrecorded appear to be identical to the type materialdescribed by Cramerand Diez (1976) from Iberia. Cymatiosphaeranebulosa (Deunff) Deflandre 1954. Plate 142, figs.3,4 & 5; pl. 177, figs.8&9. Description: Deunff 1954,p. 214, fig. 8. Holotype: Deunff 1954, fig. 8. Age: Devonian. Remarks: This relatively small speciesof Cymatiosphaerais characterisedby the thick walled, dark colouredcentral body. 174 Cymatiosphaeraoctoplana? Downie 1959. Plate79, figs.7,8 & 9. Description: Downie 1959,p. 63, pl. 11, fig. 2. Holotype: Downie 1959, pl. 11, fig. 2. Age: Wenlock. Remarks: The proposedsynonomy of C wenlockiaDownie 1959with C. octoplanaby Doming (1981, p. 186) allows for greatervariation in the numberof fields presenton the vesiclewithin this species. The specimenshere, which are questionablyassigned to the species,show variation in the numberof fields present. Tbe high flangesdividing the fields are commonlydamaged due to poor preservation. Cýmatiosphaerapeligrosa Cramer 1964. Plate 168, fig. 10. Description: Cramer 1964, p. 326, pl. 17, figs. 4-8. Holotype: Cmmer 1964,pl-17, fig. 6. Age: Emsian. Remarks: This speciesis morphologicallysimilar to C. nebulosabut differs in possessingshort spines at the distal extremitiesof the crestiunctions. Cymatiosphaeracarminae differs in possessingstriations on the crestsof the outer wall layer. Cymatiosphaerasp. 1. Plate I 11, figs.5,6 & 7; pl. 117, figs.7 & 8; pl. 131, pl. 5; pl. 142, fig. 1. Description: A speciesof Cymatiosphaerawith a subspherical,transparent, thin walled centralbody which memres between28-35um in diameter. Ile centralbody is divided into approximately10-15 indistinct fields by tall (upto 12umhigh) membranoussepta which are composedof the outer wall layer. The septaare smooth. Deunff 1966,described RenuAs: Cymatiosphaeravelata from the Devonian of Canadahas similarly diameter body. tall septarelative to the of the central However, this speciesis considerablysmaller in size, the centralbody measuringbetween 11-15um, than Cymatiosphaerasp. l. Cymadosphaera 175 pterophora (Deflandre & Courteville) Downie & Sadeant 1965, which was described from the Cretaceous of France has almost identical flange morphology to Cymatiosphaera sp. I but differs in having a thicker, granulate central body. Family PterospermellaceaeEisenack 1972. GenusPlerospemeUa Eisenack 1972. Type species: Plerospemella aureolata(Cookson & Eisenack)Eisenack- 1972. Genericdescription: Eisenack1972, p. 597. Remarks: The genusPlerospemella is includedin the Prasinophytaas phycomaof identical morphologyhave been observed to be producedby the modem day speciesPterospema moebii. Pierospermellacircunutriata (Combazet aL) Eisenack,Cramer & Diez 1973. Plate 142, figs.6,7,8? & 9. Description: Combaz et aL 1972, p. 304, pl. 3, figs. 13 & 14a-b. Holotype: Combazet aL 1972,pl. 3, figs. 14a-b. Age: Emsian. Remarks: This speciescan be distinguishedby the presenceof concentricstriations on the centralbody of the phycoma. 176 Pterosper7nellaeruplio Martin 1984. Plate 185, fig. 12; pl. 196, fig 5?. Description: Martin 1984,p. 29-30, pl. 9, figs.5,7,11 & 12. Holotfpe: Martin 1984,p. 29-30, pl. 9, figs. 12. Age: Early Famennian Remarks: This speciesis morphologicallysimilar to P. onondagaensis(Deunff) Eisenack,Cramer & Diez 1973but differs in having a broader,more rigid ala. Pterospermellaonondagaensis (Deunff) Eisenack,Cramer & Diez 1973. Plate 131, figs.6,7 & 8; pl. 142, fig. 10; pl. 150, fig. 11? Description: Deunff 1955,p. 148, text-fig.27. Holotype: Deunff 1955, text-fig.27. Age: Middle Devonian. Renuuics: A closely comparablespecies is 0. eruptio Martin 1984,which was describedfrom the early Farnmenianof Belgium. This speciesis here takento differs from 0. onondagaensisin possessing more ribs supportingthe ala which is relatively broad. Family TasmamtaceaeSommer 1956 ex Tappan 1980. Genus TasmanilesNewton 1875. Type species: Tasmanitespundatus Newton 1875. Genericdescription: Newton 1875,p. 341. Remarks: phycomataof identical morphologyto Tasmanitesare producedby the modem day It is for fossil Tasmanitesis included in prasinophytepachysphaera. this reasonthat the genus the division PrasinOPhYta- 177 Tasmanitesmariinssonii Eisenack 1958. Plate 34, figs.9 & 12; pl. 43, figs. 3 & 6. Description: Eisenack1958a, p. 6, pl. 1, figs. 10-13. Holotype: Eisenack1958a, pl. 1, fig. 10. Age: Ordovician(based on material from an erratic). Tasmanitesmedius Eisenack 193 1. Plate68, figs.2,3 & 5. Description: Eisenack 1931, p. 109, pl. 5, fig. 1. Holotype: Eisenack193 1, pl. 5, fig. 1. Age: Silurian. Neotype: Eisenack1955, pI. 5, fig. 13. Age: Silurian. Remarks:Specimens observed here are smallerin size than the type material, measuring35-62um in diametercompared to 120umof the type specimen,the neotypeis 114umin diameter. As discussed above, the phycomaof the prasinophytegrows during ontogeny,therefor size is maturity dependantas opposedto speciesdependant. For this reasonthe small forms of this morphotype,falling outsidethe stated'sizemeasurements for the species,are included. 178 Chapter 6. The Chitinozoa Eisenack 1931. introduction. The term chitmozoa was introduced by Eisenack (193 1) for the pseudochitinous, capsulate, acid resistant fossils that he recorded from the Baltic Silurian. In that publication (p. 80) he defined the group as follows: "Axially symmetrical animals of small rod, club, flask or bubble shape, structureless, chitinous cuticle which is always open at the oral end and the aboral end is probably closed or at best furnished with a very narrow opening. In the majority of cases this end is indented. Size from 70um- 1500um. Often the test bearscharacteristic spines. (etc. ne open oral end becomesoriented downwardsin the genusDesmochitina). 0 Sincethe early recordsof the chitinozoa,which relied primarily on the shapeof the blackenedoutline of the vesicle for their recognition, chitinozoanstudies have progressed greatly, notably with the introduction of scanningelectron microscopy, to provide refined biostratigraphicresolution in lower Ordovician-Devoniansequences. Chitinozoanmomhology. The morphologicalterms used for the chitinozoain this study are mainly thosepublished by Combazet al. 1967. Subsequentto this publication severalcontributions to the dictionary of morphologicalterms for this group havebeen made, notably thoseof Cramer 1967, Taugourdeau.et al. 1967, Jansonius 1970, Jenkins 1970,Eisenack 1968b, 1972a& 1972b,Legault 1972a,& 1972b,Laufeld 1974, Wrona 1980and Paris 1981. A glossaryof alphabeticallyordered descriptive terms is given below which is largely after IAufeld 1974 (p.37) with someminor alterationsand additionsmade. A pictorial representationof someof the termsused is presented(fig. 13). Aboral: The closedpart of the vesicleopposite to the aperture. Aboral scar: Thin walled, centralpart of the base. Synonymouswith the basalscar. Aperture: The main openingby which the vesiclecommunicates with the exterior. 179 Figure 13. Chitinozoan Illorphol(TY. A APERTURE COLLAR N ORAL PLUG SCAR APERTURE OPERCULUNI FOLLAL FEXURE _ýOF SHOULDER FLANGE uj L) F LA%K 0. BASALL "Iiý PORE SA, BASA!. EOC..- BASAL"' BASAL BASE Ic S SCAR I-*-- I-*-- W W A-,-pr 1 1-4 A --Ol iI A- Width (diameter) of apertu, p APERTURE C- Length of the chamber L- Tota! length of the ves:c; e PR CESSE3 N' - Minimum width of neck M3ximum v6dth of the vesý,cle SCULPTURE A+pr - Joint width of the aperture and the length of the neck processes APPENOIX W+ap - Joint width of the vesicle % and the length of the -appendices Lap - Length of the appendices w W+ap 180 Processes from the basal Iley be , 4ppendages: extending edge. may reduced, elongated, simple, branching, coalescent or rhizoid, see Combaz et al. 1967, fig. 4. Basal callus: The thickenedcentral part of the base. Basal edge: Ile convexpart of the vesicleconstituting the transition from the chamberto the base. Basalprocess: A processprotruding aborally from the central part of the base. Base: The part of the chamberaborally of the basaledge. Body: Synonymouswith chamber,sometimes referred to as the body chamber. Carina: A flange or membranepositioned at the basaledge of the chamber. It may be reduced, extended,perforate, reticulate or digitate, seeCombaz et al. 1967, fig. 4. Chain: Tbree or morevesicles connected along their longitudinal axis. Chamber. The part of the vesiclebetween the baseand the flexure, or where the latter is lacking, the collar or lip. Collar. The subeylindricalor orally widenedpart of the vesiclebetween the apertureand the chamber in forms lacking a neck. Distal: In an outward direction from the longitudinal axis. Flank: The part of the chamberbetween the shoulderand the basaledge. Fkxure: The concavepart of the vesicleconstituting the transition betweenthe chamberand the neck. Longitudinal axis: 7be geometricalaxis that runs from the aboralpole through the centreof the of the "rture. Mucron: The small teat or thickeningthat extendsfrom the aboralpole, synonymouswith basalcallus. jVeck. 7be part of the vesiclebetween the flexure and the lip, or where the latter is lacking, the sq)erture. 181 operculum: A thin disc closing the vesicle. This is positioned between the chamber and the collar, or where the latter is lacking, the aperture. Oral: The part of the vesiclewhere the apertureis located. ornamentation: External morphologicalelements and sculptureof the vesicle wall. 7be following descriptiveterm am usedhere: scabrate,granulate, echinate (slender simple elements Prosome: A thick plug-like elementclosing the vesicle. This is Positionedbetween the chamberand the collar, or where the latter is lacking, the aperture. praximal: In an inward direction towardsthe longitudinal axis. Shoulder. The convexpart of the chamberpositioned aborally of the flexure in forms with subcylindricalflanks. T,vin: Two specimensconnected along their longitudinal axis. Yesick: The organic test as a whole. vesick shape: The termsused to describethe vesicleshape are: cylindrical, cylindro-spheroidal, spheroidal,conical, cylindro-conical,ovoidal or discoidal, seeCombaz et al. 1967, fig. 2. Vesiclewall: Ile organicwall of the test enclosingthe centralcavity and consistingof one or more layers. The interior and exterior part of the vesiclewall may be smoothor ornamented. ne biological affinity of the chitinozoa: A bTiefTeview. Ile biological affinity of the chitinozoahas been a point of much debatesince the group was given its is is nameby Eisenack(1931). 7be one, and probably only, aspectof their affinity that agreedupon their placementin the animal kingdom (Eisenack193 1; Laufeld 1974). The problemsof understandingthe group biologically are much enhancedby the absenceof modem day leads lack knowledge representatives.This, subsequently, to a of of the other stagesof their life cycle. However, severalspeculative ideas have been made as to their affinity basedupon observationof the life is morphologyof the fossilisedstage of the cycle which what we observein palynological detail in preparations. Observationsof the morphologytook a major step foreword with the introduction of scanningelecton microscopy. The availability of such detail has brought about a surge in interestin solving the chitinozoanaffinity problem. 182 The mode of occurrence,as individuals, chainsor cocoons,and their spatial distribution, chitinozoans having only beenrecovered from sedimentaryrocks depositedin the marine realm, is additional information availableto us. Ile group is also apparentlystratigraphically restricted to the early ordovician through late Devonianwith recordsof chitinozoanlike microfossils reportedfrom the earlier Precambrianand Cambrian(Bloeser et al. 1977,Bokhari 1980)and the later Mississippian (Wilson & Clarke 1960). Initial observations using light microscopy by Eisenack (193 1) led to the suggestion that they may be fact related to testaceanrhizopods (Rhyzopodae=protozoans with root like pseudopodia). 7be that testaceanrhizopods are fresh water dwellers, coupledwith their susceptibilityto dissolutionwhen subjectedto palynologicaloxidation agents,e. g. KOH, indicatesthat they are not relatedto this group (Eisenack1931; Jansonius 1970 & Jenkins1978). A number of theoriesconcerning chitinozoan affinity are in debateat the presenttime. The suggestion that they were somekind of ciliate protists was first suggestedby Eisenack(1932) and has received subsequentsupport from Deflandre(1942) and Reid & John (1981). The contentionthat the chitinozoa (1955) may be relatedto the allogromfid foraminiferawas first proposedby Collinson & Schwalb and has beenrecently reintroduced,amongst considerable controversy, by Cashman(1991). Cashman (1990; 1991)observed microstructures, including micropores,a laminatedwall structureand what he interpretsto be juvenile chitinozoanspositioned on the adult vesiclewall, which has led him to He proposedthat the chitinozoanswere a monophyleticgroup of rhizopods. also proposesan foraminifera. evolutionarypathway along which the chitinozoaevolved into the allogromfid A commoninterpretation of the chitinozoantest hasbeen that it servesthe purposeof an egg case. Various groupsof fossilshave been considered for the sourceof the eggs,the groupsproposed having a The similar spatialdistribution and stratigraphicoccurrence as that of the chitinozoa. groups include (Kozlowsky consideredto be potentialproducers of the eggs metimans of unknown affinity 1963), graptolites(Jenkins 1970), scolecodontsand gastropods(Laufeld 1974, Paris 1981). Recent by Jaglin & Paris (1992) led to study of Late Silurian teratologicchitinozoan morphotypes them to concludethat it is far more likely that the chitinozoawhere eggsof marine organismsas opposed a vegetative reproductive organ. Other less favourableinterpretations include that of Obut (1973) who proposedthe chitinozoacould be Loquin (1981) fungal Finally, is relatedto the dinoflagellatesand who proposeda affinity. there the form (Bockelie option that the chitinozoamay an entirely unknown group of organisms 1981)with no fossil or modem day representatives. 183 The broad nature of the presentstudy doesnot allow time for detailedSEM analysisof the chitinozoa assemblages.It is primarily for this reason,coupled with the generalpoor stateof preservationof the assemblagesthat no further light can be shedon the chitinozoanaffinity debatefrom this research. Chitinozoanclassification. lie chitinozoaareconsidered undoubtedly to belongto the animal kingdom (Laufeld 1974). For this reason,their classificationis subjectto the rules of the InternationalCode of Zoological Nomenclature (ICZN). 7be earlier publicationsregarding the supragenericclassification of the chitinozoaare largely based upon the original supragenericstructure proposed by Eisenack(1931). 7be three families proposedby Eisenack(1931) were the Lagenochitinidae,containing flask shapedforms, the Conochitinidae, including forms with a conical shapedvesicle and the Desmochitinidaewhich includesspecies with a more globular vesiclewhich commonlyform chainsof individuals. Over the following 35 years, these families were emendedand supplementedwith additionalfamilies (Van Oyen & Calandra1963; Wilson & Dolly 1964;Jansonius 1964; Taugourdeau 1966; Tappan 1966) as researchersfelt the needfor a more extensivesuprageneric structure to copewith the, by then, rapidly expanding'pool' of chitinozoantaxa. The only diversion from this trend was by the Frenchschool (Taugourdeau 1965; Combazed. 1965) who proposedan elaboratekey to generabased on the presenceor absenceand the generalnature of the copula, which they consideredto be a critical featureof the chitinozoa. Descriptiveterms rather than formal family nameswere utilised initially, however,Taugourdeau. (1966) replacedhis earlier descriptiveterms by emendingthe original families of Eisenack(193 1) and he, in addition, introduced the family Ancyrochitinidae. Eisenack (1968b) divided the chitinozoans into two groups above the family level which he called the former operculida and the prosomida, the possessingan operculum, the latter a prosome. In 1972 he renamed the groups the Operculatifera and the prosomatifera. In his Ph.D. thesis,Paris (1981)produced a comprehensivesuprageneric scheme based on the broad frameworkintroducedby Eisenack(1931). Aphylogenetic model for the chitinozoa(fig. 67) is also his ideas. provided which lendsconsiderable weight to The schemeutilises the two groupingsof Eisenack(1968; 1972), the Operculatiferaand the ProsOm2tiferaat the order level, and the three families of Eisenack(1931); the Desmochitinidae,which is emended;the COnOchitinidaewhich is restricted;and the Lagenochitinidaeat the family level. Twelve subfamilieswere also introducedwith generalisted alphabeticallywithin them. In the II yearssince. its publication, the schemehas commonlybeen adopted by chitinozoanworkers dispite the prior warningsof JAufeld (1974) and Bockolie (1978). 184 Laufeld (1974, p-37) gives two substantialreasons for discardingany supragenericscheme for the chitinozoa,both of which are still significant at the presenttime. He statedthat a systematicscheme at the family level of a group of extinct fossilsof uncertainaffinity is far from convincing. His second criticism, which follows on from the first, is the potentialof difficulty of accessto a particular taxon positionedin an outdatedscheme for future workers. Bockolie (1978) observedspecimens of Lagenochitinafrom the Arenig of Spitsburgenwhich show the presenceof an operculumand a prosomein a single specimen. Ile fact that both an operculumand a prosome,can occur in the samespecimen raises doubts as to the groupingsof he chitinozoainto the operculatifers,and the Prosomatifera. For the reasonsof i. the questionablefeatures Of chitinOzOanmorphology (Bockolie 1978), ii. the inherentinstability of any supragenericscheme involving biota of unknownbiological affinity and iii. the easeof accessto taxa for future workers, the chitinozoaare listed here in alphabeticalorder. 185 Chitinozoan systematics. Chitinozoan taxa are listed in alphabetical order for the reasons given in the previous chapter. All m,easurements given are based on five specimensunless stated otherwise. Synonomyfor the chitinozoahere largely follows that of Paris 1981. A synonymylist is provided where the presentauthor is in disagreementwith Paris (1981) or where the taxon was publishedpost 1981. The agesstated here for the holotypesof the speciesare thosesited by their authors. GenusAncyrochidna Eisenack 1955. Type species: Ancyrochitina ancyrea Eisenack 1931. Generic description: Eisenack 1955, p. 163. Ancyrochitinaancyrea (Eisenack) Eisenack 1955. Plate 46, figs. 1,2 & 3; pl. 90, figs. 1,3 & 5; pl. 124, figs. I&2? Description: Eisenack1931, p. 88-89, pl. 2, fig. 8-11, pl. 4, fig. 4. Holotype: Eisenack1931, pl. 4, fig. 4. Age: Indeterminate,holotype recoveredfrom drift sediments. Remarks: The morphologicallimits of A. ancyreaas outlined by IAufeld 1974, p. 39 are adheredto here. The most diagnosticfeature of this taxon are the appendagesarising from the basaledge of the vesicle that branchin an antler-like fashion. Ancyrochitinaprimativa Eisenack1964 and A. pachydermaLaufeld 1974both possesssimple appendages.Ancyrochitina merga Jenkins 1970 differs in possessinga greaternumber of appendagesthat are generallyshorter in their length than thoseon A. ancyrea. Ancyrochitinaftagilis Eisenack1955 has slender,more fragile appendages. 186 Ancyrochitinaancyrea? var. A. Plate 157, figs. 1-4; pl. 169, fig. 1. Remarks: Specimensincluded here are questionablyassigned to the speciesA. ancyreadue to the thick ShaftsOf the appendagesand the limited branchingof the appendagedistal extremities. However, this variety is characterisedby this appendagemorphology and by the spinoseornamentation on the vesicle neck. Comparableforms areA. ftankeli Wright 1976and A. morzadecisensu Boumenjel ef al 1988. lie former differs in possessinglarger and more prominentornamentation on the neck. Ile latter has the samestyle and distribution of ornamentationon the vesicleas but differs from A ancyrea?var. A. in possessingshorter appendages. Ancyrochitinaftagilis Eisenack1955. Plate92, figs.5,6 & 7. Description: Eisenack1955, p. 175, pl. 2, figs. 1-6. Holotype: Eisenack1955, pl. 2, fig-1. Age: Silurian. Remarks: Ancyrochitinafragifis differs from A. ancyreain possessinglonger and more slender appendagesthat generallybranch in a lesscomplex manner. Severalvarieties of this specieshave been recordedin the presentstudy. Ancyrochitinaftagilis var. brevisTaugourdeau & Jekhowsky1960. Plate 90, figs. 2,4 & 6. Description: Taugourdeau& Jekhowsky1960, p. 1219,pl. 1, figs. 12 & 13. Holotype: Taugourdeau& Jekhowsky1960, pl. 1, fig. 12. Age: Gothlandien-LowerDevonian. Renvuics: This variety is distinguishedby the presenceof slenderappendages that furcateat the distal The furcating distal quarterof the appendagelengtli. spinesreunite at the extremity of the appendage to give a hollow, subsphericalstructure. 187 Ancyrochitinaftagilis var. regularls Taugourdeau& Jekhowsky1960. Plate9 1, figs. I&3. Description: Taugourdeau& Jekhowsky1960, p. 1219,pl. 1, figs. 15. Holo": Taugourdeau & Jekhowsky 1960, pl. 1, fig. 15. Age: Lower Devonian. Remarks: This variety has simpleappendages and a much shorterneck than the holotype,of the species. Ancyrochitinaftagilis var. A Plate 91, figs.2,4 &5; pl. 92, figs. 1-4; pl. 124, figs.4&5. Remarks: This variety of A. firagilis has relatively long and slenderappendages protruding from the basaledge of the vesicle. The appendagesfurcate in the distal half of the process,usually in the distal third, to form flexible slenderpinnae. Branchingof the appendagesis upto the third order. 7be slendernature of the appendagesand the branchingpinnae at the appendageterminations distinguish this varietY. Ancyrochitinapachyderma Laufeld 1974. Plate93, figs. 1-5. Description: Laufeld 1974,p. 45-46, fig-IOA-F. Holotype: Laufeld 1974, fig. IOF. Age: Silurian. Remarks: Ancyrochitinapachyder7na closely resemblesA. primativa Eisenack1964 in possessing simple appendages.However, A. pachydema has appendageswhich are generallylonger with much broaderbases. 188 Ancyrochitinapilosa Taugourdeau& Jekhowsky1960. Plate94, figs. 1,2 & 3. Description: Taugourdeau& Jekhowsky1960, p. 1220,pl. 11,figs. 23 & 24. Holotype: Taugourdeau& Jekhowsky1960, pl. II, figs.23. Age: Silurian. Ancyrochitinaprimativa Eisenack1964. Plate 69, figs. 1& 2; pl. 75, fig. 1-5. Description: Eisenack1964, p. 323-324,pl. 27, figs. 1-6 & 8-14, pl. 28, figs. 1-5. Holotype: Eisenack1964. Age: Silurian. Remarks. All specimensrecorded here are from Telychian(upper Llandovery) to Sheinwoodian(lower Wenlock) agedsediments. The speciesis characterisedby relatively short, simple appendages. Ancyrochitinapacft)de? 7na generally has longer simpleappendages that havebroader bases. Ancyrochitinator7nentosa Taugourdeau & Jekhowsky1960. Plate 143,1?; pl. 124, figs.6&7? Description: Taugourdeau& Jekhowsky1960, p. 1220-1221,pl. 11,figs. 27,28 & 27. Holotype: Taugourdeau& Jekhowsky1960, pl. 11,fig. 27. Age: Gothlandian. Remarks: This speciesis characterisedby the presenceof short, sturdy appendagesarising from the basaledge that start branchingadjacent to the vesicle. Spinesare also apparenton the neck of the vesiclein this taxon, in contrastwith the otherwisesimilar speciesAncyrochitina asterigis Paris 1981 which has a smoothneck. 189 Ancyrochitinatumida Taugourdeau & Jekhowsky1960. Plate 124, fig. 8; pl. 143, fig. 2. Description: Taugourdeau& Jekhowsky1960, p. 1221,pl. 11,fig. 30 & 31. Holotipe: Taugourdeau& Jekhowsky1960, pl. 11,fig. 30. Age: Lower Devonian. Remarks: Ibis specieshas a similarly shapedbody chamberand form of basaledge appendages as A. ancyreabut differs in possessinga much shorterneck. Ancyrochitinatomentosa has more robust appendagesthat start to branchadjacent to the vesicle. Ancyrochitinasp. 1. Plate53, figs.4,5 & 6; pl. 54, figs. 1-4. Dewription: A speciesof Ancyrochitinawith a cylindro-conicalshaped vesicle. The length of the vesicle rangesbetween 135-175um. The chamberwidth rangesbetween 70-85um and the width of the neck is between30-40um. The neck is slightly flaring towardsthe oral opening. Ile chamber occupiesbetween 1/2 to 3/4 the total length of the vesicle. Long slenderappendages protrude from the basaledge. 7be appendagesare upto 40um.in total length and lessthan 7um wide. They branchupto the secondorder in the distal half of their length. The appendagesappear to havea rbyzoid (sponge- like) texture. T'hewall of the vesiclehas a scabratesurface. Remarks: This speciesis distinguishedby the cylindro-conicalshaped vesicle and the rhyzoid textured, slenderbranching processes. A closely comparablespecies, which was recordedfrom a similar stratigraphiclevel, is McWhochitina spongiosa(Achab 1977)which hasa similar vesicleshape and rhyzoid texturedappendages. The appendagesof this species,however, join distally to form a trabeculum. Ancyrochitinamerga Jenkins 1970 possesses a greaternumber of appendagesthat are shorterin their length than thoseof Ancyrochitinasp. Specimensrecorded here are commonlywithout appendagesdue to mechanicalbreakage. However, the proximal stubsof the broken appendagesare apparentwhen observedunder high magnification. 190 Ancyrochitina sp. 2. Plate70, figs. I&2. Remarks: The six poorly preservedspecimens included here are all fmgmented. For this reasona full descriptionof this taxon is not possible. However, thereare severalfeatures apparent that may enable this form to be identified by future workers. 7lie chamberis ovoidal in shapeand surmountedby a cylindrical neck of moderatelength (necklength is approximatelyequal to chamberlength). The entire vesicle length is approximately150-200m (4 specimensmeasured). The surfaceof the vesicle is scabrateor micro-echinate. Severalappendages protrude from the basaledge, the numberand morphology of which is not clear from thesefractured specimens. A diagnosticfeature is the rhyzoid texture of the appendages. Ancyrochitina sp. 2 is only recordedfrom TelychianOate Uandovery) sedimentsin the pre-sentstudy. GenusAngochidna Eisenack 1931. Type species:Angochitina echinataEisenack 193 1. Genericdescription: Eisenack1931, p. 82. Angochitinaceratophora? Eisenack 1964. Plate 125, figs. 1&2. Description: Eisenack1964, p. 320-321,pl. 30, figs.7-9. Holotype: Eisenack1964, pl. 30, fig. 7. Age: Silurian. Remarks: Three poorly preservedspecimens are questionablyassigned to this taxon. Thesespecimens by body indicating am distinguishedfrom Ancyrochitinaspecies the subspherical chamber the absence of a basaledge. 191 Angochitinachlupachi Paris & Laufeld 1981. Plate 132, figs.2,3 & 6. Description: Paxis&lAufeldl981, p. 14, pl. 3, figs.9,10,13,14,16,18,20&22. Holotype: Paris & lAufeld 1981,pl. 3, figs.9. Age: Lochkovian. Remarks: This specieshas a more ovoidal shapedbody chamberand lessdense ornamentation than A. echinataEisenack 1931. Angochitinacrassispina Eisenack 1964. Pl. 118, fig. 1,2,3 & 4? Description: Eisenack1974, p. 320, pl. 30, figs.3 & 4. Holotype: Eisenack1974, pl. 30, fig. 3. Age: Silurian. Remarks: This specieshas a very sparseOrnament Of Prominentspines. Angochitinaechinata Eisenack 1931has a more denseornamentation. Angochitina chlupachi has a more elongate,ovoidal shaped vesicle. Angochitinaechinata Eisenack 1931. Plate94, figs.4,5 & 6. Description: Eisenack,p. 82, pl. 1, figs.6 & 7. Holotype: Eisenack193 1, pl. 1, fig. 7. Age: Silurian. Remarks: A complexof Angochitina speciesof similar morphologyOccur in the Silurian samples studiedhere. lAufeld (1974) reporteda similar rangeof morphotypesfrom the Silurian of Gotland and it is essentiallyhis parametersfor the speciesthat havebeen utilised here. Angochitinaechinata has a more globosebody chamberthan both A. elongataEisenack 1931 and A. longicollis Eisenack1959.7bese threespecies all PO'Iesssimple Ornamental.spines. Angochitina 192 dewnica Eisenack1955 has longer, robust, furcating spinesand a shorterneck than the three species mentionedabove. Angochitinaelongata Eisenwk 1931. Plate95, figs. I&2. Description: Eisenack193 1, p. 82, pl. 1, figs. 8&9. Holotype: Eisenack1931, pl-1, fig. 8. Age: Silurian. Remarks: Angochitina echinatahas a more globosebody chamberand A. longicollis has a longer neck than A. elongata. Angochitinamilanese Collinson & Scott 1958. Plate 169, fig. 5. Description: Collinson & Scott 1958,p. 11-13,pl. 1, figs. 1-5,7,8,19 & 26. Holotype: Collinson Y Scott 1958,pl. 1, fig. 2. Age: Middle Devonian. Angochitinaphilippoti Complex. Plate 157, figs. 5 & 6; pl. 158, figs. 1-5; pl. 169, figs. 3 & 4. Remarks: Includedhere are a rangeof morphotypesfrom the Lower and Middle Devonianthat without the use of scanningelectron microscopy are not practically distinguishable. Ile vesicle shapeis branching body cylidro-spheroidaland is ornamentedwith numerous processespositioned on the darkened here, distribution chamberand on the neck. In the materialstudied the of processes,be it in in horizontal in Alpenachitina vertical rows as in Gothlandochitina,or rows as or randomly distributed light as in Angochitina, is not apparentusing the microscope. At the presenttime, this group of forms biostratigraphybecause are of little value for high resolution of the numerousmisidentifications of thesemorphotypes in the literature (Paris 1988). As a result of both the observationtechnique used in the presentstudy (light microscopyonly) and the stateof preservation,this situation can not be improvedupon here. 193 Species included in this complex of forms are Angochitina philippoti Paris 1976, A. caeciliae Paris 1976, A. devonica Eisenack 1955, Gothlandochitinajouannensis Paris 1976, G. illiziensis Boumenjel 1985, G. marettensis Paris 1981, G. racheboej?Paris 1981 and Gothlandochitina sp. A Paris 1985. Angochitina?cE seurad Paris 1988. Plate 70, figs. 4,5 & 6. Holotype: Paris 1988,pl. 12, fig. 2. Age: Rhuddanian(early 11andovery). Remarks: Comparewith Paris 1988,p. 77-78, pl. 12, figs. la-b, 2&3. The four specimensassigned to this taxon, all recordedfrom TelychianOate Llandovery) aged sediments, have the sameslender shaped vesicle asA. Seurati. 11esespecimens also havea pilose ornamentationwhich is a diagnosticfeature of A. seurati, the detail of which is not apparentfrom the light microscopyanalysis undertaken. It appearsthat the specimensobserved in the presentstudy have shorterpila than thoseof the type specimens.This brings aboutthe questionableassignation of this species(i. e. cf. seuran) to the genus Angochitina. It may be arguedthat this speciesbe bestaccommodated in the genusSphaerochitina Eisenack1955 because of the presenceof shorterornamental spines. Angochitinasp. 1. Plate76, figs. 1-7. Description: A speciesof Angochitinawith a cylindro-sphericalshaped vesicle. The vesicle is relatively small ranging in length from 90-110um. The chamberwidth rangesbetween 65-80um and the width of the neck is between25-30um. The neck flares towardsthe oral opening. The chamber occupiesapproximately 1/2 of the total length of the vesicle. Short slenderappendages are presenton the chamberand on the neck. They tend to be better developedon the body chambertowards the bifurcate distal aboral surfacewhere they commonly at the extremity. Ile appendagesare upto Sumin total length and are no more than 3um wide at their base. Ile wall of the vesiclehas a smoothor scabmte. Remarks. Appendagesare commonlybroken in the poorly preservedassemblage observed here. However, this speciesis distinct by way of its vesicleshape and its delicatebifid spines. Angochitina devonicahas & similar shapedvesicle but differs in possessingmore robust appendages. 194 GenusArmoricochitina Paris 1981. Type species: Armoricochilina ceneratiensis(Paris) Paris 1981. Genericdescription: Paris 1981, p. 175-176. Armoricochitinanigerica (Bouche)Molyneux & Paris 1985. Plate55, figs. 1-5. Description: Rouche 1965, p. 157-158, pl. 2, figs. 8,12 & 13. Holotype: Bouche1965, pl. 2, fig. 8. Age: Upper Ordovician. Remarks: Ile specimensrecorded here show a considerablevariation in the overall size of the vesicle. GenusBelonechidna Jansonius 1964. Type species:Belonechitina micracantha (Eisenack) Paris 1981. Genericdescription: Jansonius1964, p-906. Belonechitinacapitata (Eisenack)Paris 1981. Plate 47, figs. 1-4; pl. 56, fig. 4 & 5. Description: Eisenack1962, p. 310-311, pl. 15, figs.6-8. Holotype: Eisenack1962, pl. 15, fig. 6. Age: Indeterminateas the holotype was recoveredfrom drift sediments. Remarks. This speciesof Belonechitinahas a low apiculateornamentation and a rather bulbousaboral margin. 195 Belonechitinamicracantha (Eisenack 1931) Plate 35, figs.6 & 9; pl. 47, fig. 5; pl. 48, fig. I&6. Dewription: Eisenack1931, p. 84-85, pl. 1, figs. 19-21,pl. 2, figs.20-22, pl. 4, fig. 15. Holotype: Eisenack193 1, pl. 1, fig. 19. Age: Ordovician. Remarks: Specimensincluded here are generallytoo poorly preservedto be assignedto a subspeciesof B. Micracantha. Belonechitinarobardeti Paris 1981has a more sparsedistribution of spinesover the vesicle than B. micracantha. Belonechitinamicracantha subsp. micracantha (Eisenack 1959). Plate26, figs.2 & 3; pl. 35, figs.7 & 8; pl. 47, figs.6,7 & 8. Description: Eisenack1959, pl. 1, fig. 5, pl. 3, fig. 12. Holotype: Eisenack1959, pl. 1, fig. 5. Age: Remarks: This subspeciesis distinguishedby the short ornamentalspines and the angularnature of the vesiclebetween the aboralmargin and the side of the body chamber. Belonechitinamicracantha subsp. pellifera (Eisenack1959). Plate 36, figs. 1,4 & 5. Description: Eisenack1959, pl-1, fig. 5-7. Holotype: Eisenack1959, pl. 1, fig. 7. Age: Remarks: This subspeciesis distinguishedby the relatively long spinesand the convexaboral vesicle margin. 196 Belonechitinamicracantha subsp. robusta (Eisenack1959). Plate26, pl. 1; pl. 36, figs.2 & 3. Description: Eisenack1959, pl. 1, fig. 5, pl. 3, fig. 12. Holotype: Eisenack1959, pl. 1, fig. 5. Age: Remarks: This subspeciesis distinguishedby the relatively long and rigid ornamentalspines. It differs from B. micracanthasubsp. pellifera in the shapeof the aboral margin. The junction betweenthe aboralmargin and the side of the body chamberis noticeablymore angularin B. micracanthasubsp. robusta than in the subsp.pellifera. GenusBursachidna Taugourdeau 1966. Type species: Bursachitinabursa (raugourdeau& Jekhowsky)Taugourdeau 1966. Genericdescription: Taugourdeau1966, p. 34. Bursachitinabursa (Taugourdeau& Jekhowsky)Taugourdeau 1966. Plate 159, figs 3&4; pl. 169, fig. 6 Description: Taugourdeau& lekhowsky 1960,p. 1225,pl-VII, figs. 89 & 90. Holotype: Taugourdeau& Jekhowsky1960, pl. Vll, figs. 89. Age: Lower Devonian. Remarks: A similar speciesmorphologically is Butbochitinabulbosa Paris 1981which differs in possessinga narrower apertureand a more inflated aboralpart of the chamber. Genus Calpichidna Wilson & Hedlund 1964. Type Wcies: Calpichitina scabiosaWilson & Hedlund 1964. Genericdescription: Wilson & Hedlund 1964. 197 Calpichitina knticularis (Bouche) Paris 1981. Plate 56, figs. I&2. Description: Bouche1965, p. 160, pl. 2, figs. 14 & 15. Holotype: Bouche,1965, pl. 2, fig. 14. Age: Silurian. Remarks: Specimensobserved here are almostidentical in morphology to thoserecorded from the Ashgill of the Anti Atlas by Elaouad-Debbaj(1984a). Calpichitina sphaerica(raugourdeau & lekhowsky) Paris 1981. Plate 132, figs.4 & 5; pl. 144, fig. 1. Description: Taugourdeau& Jekhowsky1960, p. 1227,pl. 7, fig. 103. Holotype: Taugourdeau& Jekhowsky1960, pl. 7, fig. 103. Remarks: Specimensrecorded here are of closely comparablemorphology with thoseillustrated by Paris 1981from the Gedinnianof Armorica. Calpichitina sp. 1. Plate 100, fig. I. Description: Vesicle subsphericalwith a thickenedrim bordering the sphericalaperture. Ile vesicleis ornamentedwith denselypacked echinae of < 3um,in height. The diameterof the vesicle ranges between50-75um (two specimensmeasured). Remarks: Only two specimensof this taxon havebeen recorded in the presentstudy. It can be distinguishedby the presenceof fine echinaeon the chamberwall. 198 Calpichitina sp. 2. Plate 80, figs.8&9; pl. 100, fig. 2; pl. 134, figs. 3,5&6. Vesicle Description: subsphericalwith a thickenedrim bordering the r, pherical aperture. The v esic I e is onwnented with denselypacked grana < 2um in height and < 2um in diameter. 7be diameterof the vesicle rangesbetween 60-75um. Remarks: This speciesof Calpichilina is distinguishedby the Presenceof granaon the vesiclewall. Calpichilina sp. I differs in possessingan echinateornamentation. Genus Cingulochitina Paris 1981. Type species: Cingulochitinacingulata Eisenack1937. Genericdescription: Paris 1981,p. 164-165. Remarks: The author hasendeavoured to use the speciesin this genusthat were utilised by Paris 1981, (p. 165) to maximisethe comparabilityof the assemblagesstudied here with thosefrom south-west Europe Cingulochitinaconvew (Laufeld) Paris 1981 Plate95, fig. 3 & 6; pl. 133, figs. 1,2 & 3; pl. 144, fig. 5. Description: lAufeld 1974,p. 97, fig. 58. Holotype: Laufeld 1974, fig-58D. Remarks: Specimens recorded here accord well with the type material. Cingulochitinacf. convexa(Laufeld) Paris 1981 figs. figs-5 Plate 95, figs.4 & 5; pl. 96, 1-7; pl. 112, & 6; pl. 125, figs.3-7; pl. 133, figs.4-8; pl. 144, figs.2 & 3. Holotype: IAufeld 1974, fig. 58D. 199 Remarks: Compare with IAufeld 1974, p. 97, fig. 58. Cingulochitina cf. conve-w here has a more elongatevesicle than type specimensof the species.Laufeld describedthe type material as having uncommontwins and chainswhich also differs from the presentmaterial as many chainsof specimens have beenrecorded. Cingulochitinacf. convexais synonymouswith C. sp. aff. conve-wof Paris 1981, p. 165. Cingulochitinaervensis (Paris) Paris 1981. Plate 144, figs.7,8 & 9; pl. 112, figs.3 & 4?; pl. 118, fig. 6. Description: Paris 1979, p. 59-61, pl. 1, fig. 1-8. Holotype: Paris 1979,pl. 1, fig. 1. Age: Emsian. Remarks: The interpretationof this speciesby Paris 1981(p. 167, text-fig.78) is followed here. Cingulochitinaplusquelled Paris 198 1. Plate 144, fig. 6. Description: Paris 1981,p. 171-174,pl. 32, figs. 1-5,10 & 21, text-fig.78. Holotype: Paris 1981,pl. 32, figs.3. Age: Gedinnian. Remarks: The interpretationof this speciesby Paris 1981(p. 167, text-fig.78) is followed here. Cingulochitina serrata (raugourdeau & Jekhowsky) Paris 1981. plate 96, fig. 1-7; pl. 112, fig. 2; pl. 126, fig. 1; pl. 134, fig. 1; pl. 144, fig. 5; pl. 151, figs.4&5. Description: Taugourdeau& Jekhowsky1960, p. 1226,pl. 6, figs.76-79 & 81 (not 8o, [paris, 19811). Holotype: Taugourdeau& Jekhowsky1960, pl. 6, fig. 76. Age Gotlandian. 200 Remarks: Cingulochitinaserrata hasa short neck and an almostequidimensional, vesicle (i. e. the length is equal or slightly greaterthan the width). This speciesis shorter in length than the other "cies of Cingulochitina recordedin the presentstudy. Cingulochitinacf. serrata Craugourdeau& Jekhowsky)Paris 1981. Plate 97, figs. 8,9 & 10; pl. 126, figs.2,3,4 & 6; pl. 134, figs.4 & 7. Holovipe: Taugourdeau& Jekhowsky1960, pl. 6, fig. 76. Age Godandian. Remarks: Comparewith Taugourdeau&Jekhowsky 1960,p. 1226, pl. 6, figs.76-79 & 81 (not go, paris, 1981]). Specimensincluded here are essentiallytransitional forms betweenC. semataand Cingulochitina sp. A (herein). Specimensare slightly longer than they are broad, in a similar manner to c. serrata,but they are rather larger in size (> 100urnin length). Cingulochitina sp. I is a more C. slender form than cf. serrata. Cingulochitinasp. 1. Plate 79, figs. 10 & 11; pl. 98, figs. 1-8; pl. 126, figs.5 & 7. Description: A speciesof Cingulochitinawith an almoststraight sided, conical vesicle. The length of the,vesicle rangesbetween 115-145um. The vesiclewidth rangesbetween 50-65um at the aboral towardsthe The the between nuygin and tapers oral opening. vesiclewidth at oral margin range's 27- 45um- The vesicle flares orally from the position of the prosome. A reducedcarina is presentat the is basaledge. The vesiclewall smooth. The shapeof the specimensincluded in Cingulochitinasp. I are comparablewith the Re'marks: by IAufeld 1974, fig. 57D, but illustration of C. dngulata they tend to be slightly more elongated. An differenceis that Cingulochitinasp. I encompassesforms broad Sational with and narrow carina. is This taxon includesthis variation as it commonlynot possibleto decipherthe carina.width using I is larger light microscopy. Cingulochitinasp. also than C dnguWa, having a vesicle length greater forms in Ongulachitina than n5um. 17hese are very similar shapeand size to sp. A of Paris 1981 (p. 174, fig. 78). broad hasbeen from An unusualvariety of this rather taxon recorded Ludlow agedsediments. 201 Cingulochitinasp. I var. A. Plate99, figs. 1,2 & 3. Remarks: This variety is only recordedftom latestGorstian (Ludlow) agedsediments in this study. It is distinguishedby the presenceof striationsrunning perpendicularto the longitudinal axis of the vesicle. GenusConochidna Eisenack 1931 ernend. Nris 1981. Type species: ConochitinaclaWformis Eisenack 193 1. c;eneric description: Paris 1981,p. 178. Conochitinaannilata Taugourdeau& Jekhowsky1960. Plate 80, fig. 3. Description: Taugourdeau& Jekhowsky1960, p. 1222,pl. 3, figs.44,45 & 46. Holotype: Taugourdeau& Jekhowsky1960, pl. 3, fig. 44. Age: Silurian. Conochitinabrevis Taugourdeau & Jekhowsky1960. Plate 12, figs. 1-8; pl. 26, figs. 4,5 & 6; pl. 70, fig. 3; pl. 80, fig. 2. DescriPtiOn: Taugourdeau& Jekhowsky1960, p. 1222,pl. 3, figs.47,48 & 49. Holotype: Taugourdeau& Jokhowsky1960, pl. 3, fig. 47. Age: Silurian. Conochitinachydaea Jenkins 1967. Plate 37, fig. 4-7. Description: Jenkins1967, p. 453, pl. 70, figs.4-8. 202 Holotype: Jenkins1967, pl. 70, fig. 4. Age: Llanvirn. Remarks: Conochitinasimplex Eisenack 1931 has a broader chamberthan C. chydaea. Conochitina intemw,dia Eisenack1955 has a simple conical chamber. ConochitinacL chydaeaJenldns 1967. Plate 37, figs.2 & 3. Holotype: Jenbw 1967,pl-70, fig. 4. Age: Llanvim. Remarks: Comparewith Jenkins1967, p. 453, pl. 70, figs. 4-8. Specimensincluded here have a more doesC. The in roundedaboral margin than chydaea. sidesof the vesicle are also more parallel these forms comparedto the orally taperingsides of the type specimens. A comparableform is one described in opennomenclature by Paris 1981. His Conochitinasp. D (p. 189, pl. 9, fig. 4) is almost identical to the specimensincluded in C. cf. chydaeahere. Conochitinacf. kpida Jenkins 1967. Plate 26, fig. 9; pl. 48, fig. 5. Holotype: Jenkins1967, pl-70, fig. 2. Age: Caradoc. Remarks: Comparewith Jenkins1967, p. 452-453, pl. 70, figs.2 & 3. Specimensincluded herehave a lesspronounced flexure betweenthe body chamberand the neck of the vesicle than in the type material. Genus CyathochitinaEisenack 1955 emend. Paris 1981. Type species: Cýathochltinacampanulaefonnis (Eisenack) Eisenack 1955. Genericdescription: Paris 1981, p.287. 203 CýalhochitlnacalLx (Eisenack) Eisenack 1958. Plate 37, fig. 1. Description: Eisenack1931, p. 87, pl. 2, fig. 3, pl. 4, fig. 14, text-fig. l. Holotype: Eisenack1931, pl. 2, fig. 3. Age: Indeterminateas the holotype was recoveredfrom Baltic drift sediments. Remarks: CyathochitinacampanuWormis (Eisenack)Eisenack 1955 has a broader and more stout test 'The than C. CajLx. former also differs in possessinga conical chamberthat tapersrapidly orally. Cyathochitinacampanulaeformis (Eisenack) Eisenack 1955. Plate27, fig. 1; pl. 36, fig. 6; pl. 49, figs.2 & 5; pl. 74, fig. 4. Description: Eisenack1931, p. 86, pl. 2, figs. 1 & 2, pl. 4, figs. 1 & 11-13. Holotype: Eisenack193 1, pl. 2, fig. 2. Age: Indeterminateas the holotype was recoveredfrom Baltic drift sediments. Remarks: Cyathochitinakuckersiana (Eisenack) Eisenack 1962 and C calLxsire morphologically similar to C campanuWormis. T'heformer has a wide, membranousskirt-like carina,compared with the more narrow and rigid carinaof C campanulaefonnis.Cýathochitina calix has a barrel-shaped body chamberas opposedto the orally taperingconical shapedchamber of C cwnpanulaeformis. Cyathochitinadispar Benoit & Taugourdeau1961. Plate48, fig. 7; pl. 49, fig. 1. Description: Benoit & Taugourdeau1961, pl. 3, figs.22-28. Holotype: Benoit & Taugourdeau1961, pl. 3, figs.28. Age: Ordovician. Remarks: Specimensincluded here are almostidentical to the type specimen. 204 Cyathochitinacf. elenitae Cramer 1964. Plate77, figs. 1,2 & 3. Holotype: Cramer 1964, pl. XUH, fig. 9. Age: Ludlow. Remarks: Comparewith Cramer 1964,p. 345, pl. XXIII, figs.9 & 10.7be three specimensincluded here have a similar shapedvesicle to the type specimensof C. elenitae. However, specimenshere have a greaterconstriction of the neck in the viscinity of the prosomewhich is positioned further from the oral openingthan in the type material. Cyathochitinacf. fistulosa Taugourdeau& Jekhowsky 1960. Plate 27, fig. 2. Holotype: Taugourdeau& Jekhowsky1960, p. 1224pl. V, fig. 67. Age: Ordovician. Remarks: Comparewith Taugourdeau& Jekhowsky1960, p. 1224, pl. V, figs.67 & 68. The three specimensrecorded here have the characteristicstraight sidedvesicle of this species,however they have a more stout vesicle than the tyrpespecimens. Cyathochitinasp. 1. Plate7 1, figs. 1,2 & 3. Description: A speciesof Cyathochilinawith a long cylindrical neck and a conical body chamber. 7be length of the vesicle rangesbetween 140-190um. 7be chamberwidth rangesbetween 76-90um and the width of the neck is between25-33um. 7be chamberoccupies between 113 and 1\2 the length of the vesicle. A reducedCarina is presentat the basaledge. 7be vesiclewall is coveredwith a granulateand Inicroechinateornamentation. Remarks: The distinctive cylindro-conicalvesicle shape, the reducedcarina and the ornamentation distinguish this speciesof Cýathochitina. Cyathochitinakuckersiana has the samegeneral vesicle shape but this specieshas an extendedcarina and a smoothvesicle wall. Fungochifina specieshave the same vesicle shapeand they also possessornamentation. However, the presenceof a reducedcarina distinguishesCYathOchitina 9P. I from theseforms. 205 GenusDesmochidna Eisenack 1931 onend. Eisenack 1962. Type species: Desmochitinanodosa Eisenack 193 1. Generic description: Eisenack1931, p. 91-92. Desmochitinaminor Eisenack193 1. Plate 13, fig. 4?; pl. 26, fig. 8; pl. 38, figs.3 & 4; pl. 49, fig. 4. Description: Eisenack1931, p. 93, pl. 3, figs.9-11. Holotype: Eisenack 1931, pl. 3, fig. 9. Age: Ordovician. Remarks: Eisenack(1962) united the four previously namedspecies of Desmochitina,A minor Eisenack193 1, D. erinaceaEisenack 193 1, D. coccaEisenack 193 1, andA wnphoreaEisenack 1931 under the nameD. minor. The variation that is apparentis now consideredto be intraspecific. Several of the original speciesnames are presentlyin use asforma nameswithin the speciesD. minor. Desmochitina minor forma cocca Eisenack 193 1. Plate26, fig. 7; pl. 38, figs.2 & 5; pl. 49, fig. 3. Description: Eisenack1931, p. 94, pl. 3, figs. 14 & 15. Holotype: Eisenack1931, pl. 3, fig. 14. Age: Ordovician. Remarks: This forma has a subsphericalshaped vesicle. A pictorial comparisonwith someof the other forma forma is published,formae (e. g. typica, ovulum)within the speciesD. minor given by Paris 1981, p. 119, fig. 68. Desmochitinapiriformis Laufeld 1967. Plate 38, fig. 1; pl. 49, fig. 6. DescriptiOn: Laufeld 1967,p. 332-333,fig. 27A-E. 206 Holotype: Laufeld 1967, fig. 27A. Age: Caradoc. Remarks: This speciesis distinguishedby having the widest part of the body chamberpositioned towardsthe oral opening,as opposedto the widest part being mid-way betweenthe aboral and oral poles of the chamber,as in D. minor. GenusEisenackitina Jansonius 1964. Type species: Eisenackitinacastor Jansonius 1964. description: Jansonius1964, 912 . Generic p. Eisenaddtinacastor Jansonius 1964. Plate 159, fig. 6. Description: Jansonius1964, p. 912-913,pl. 2, figs. 15-17. Holotype: Jansonius 1964, pl. 2, figs. 16. Age: Givetian. Eisenackitinaraucheri Paris 1976. Plate 145, fig. 8. Description: Paris 1976,p. 103, pl. 17, figs. 13,14,19&23; pl. 18, fig. 18&22; pl. 21, figs.6, S& 14. Holotype: Paris 1976,pl. 76, fig. 17. Age: Lochkovian. Eisenackitinataugourdeaui (Rauscher & Doubinger) Paris 198 1. Plate 145, figs. 1,2,4 & S. Description: Rauscher& Doubinger 1967,p. 319-320,pl. 4, fig. 6. Holotype: Rauscher& Doubinger 1967,pl. 4, fig. 6. Age: Devonian. 207 GenusEremochidna Taugourdeau & Jekhowsky 1960. Type species: Eremochitinabaculata Taugourdeau & Jekhowsky1960. Genericdescription: Taugourdeau& Jekhowsky1960, p. 122. EremochitinacE baculataTaugourdeau & Jekhowsky1960. Plate 28, figs. I&2. Holotype: Taugourdeau& Jekhowsky1960, pl. VIII, fig. 107. Remarks: Comparewith Taugourdeau& Jekhowsky1960, p. 1229, pl. VllI, figs. 107 & 108. Forms included here are transitionalmorphotypes between the speciesE. bacuWa and Eremochitinabrevis (Benoit & Taugourdeau)Paris 1990. EremochitinabreWs (Benoit & Taugourdeau)Paris 1990. Plate27, figs.3,4 & 5; pl. 28, fig. 5 & 6. Description: Benoit & Taugourdeau 1961, p. 1410, pl. 4, figs. 44-46. Holotype: Benoit & Taugourdeau1961, pl. 4, fig. 44. Age: Ordovician. Remarks: Eremochitinabaculata has a longer and more slendervesicle. GenusFungochilina Taugourdeau 1966. Type species: Fungochitinafungiformis(Eisenack) Taugourdeau 1966. Genericdescription: Taugourdeau1966. 208 Fungochitinapistilliformis (Eisenack)Taugourdeau 1966. Plate 169, fig. 2? Description: Eisenwk 1931,p. 88, p. 88, pl. 2, figs.6 & 7, pl. 4, figs.2 & 3. Holotype: Eisenack1931, pl. 4, fig. 2. Age: Silurian. Remarks: Two varietiesof this specieshave been recorded in the presentstudy. Fungochitinapistillifonnis var. lata (raugourdeau& Jekhowsky)Taugourdeau 1966. Plate 127, fig. 4; 145, figs.3,6 & 7. Description: Taugourdeau& Jekhowsky1960, p. 1232,pl. Xl, figs. 156 & 157. Holotype: Taugourdeau& Jekhowsky1960, pl. XI, figs. 156. Age: Lower Devonian. Remarks: This variety possessesa relatively denseornament of conesand short spines. Fungochitinapistilliformis var. A Plate 127, figs. 1&2. Remarks: Only two specimensof this taxon havebeen recorded in the presentstudy. This variety has lata a relatively sparsedistribution of ornamentationcompared to Fungochitinapistilliformis var. based, which are in the form of broad rather rigid spines. GenusGollandochitina Laufeld 1974. Type species: Gotlandochitinamartinssoni Laufeld 1974. Genericdescription: Laufeld 1974,p. 83. 209 Gotlandochitinalabdata Diez & Cramer 1978. Plate 99, fig. 4. Description: Diez & Cramr 1978,p. 207, pl. 1, figs.37-39,41 & 42. Holotype: Diez & Cramer 1978,pl. 1, fig. 39. Age: Lower Devonian. Remarks: Ibe single specimenrecorded here showsthe diagnostictrabeculate ornamentation of this species. GenusHoegisphaera Staplin M. Type species: Hoegisphaeraglabra Staplin 1961. Genericdescription: Staplin 1961,p. 419. Hoegisphaeracf. glabra Staplin 1961. Plate 80, fig. 4; pl-99, figs.5 & 6; pl. 113, fig. 7; pl. I 18, fig. 7; pl. 134, fig. 2; pl. 154, fig. 5. Holotype: Staplin 1961, pl. 50, fig. 5. Age: Upper Devonian. Remarks: Comparewith Staplin 1961,p. 419-420,pl. 50, figs.5-7. SpecimensIncluded here are identical to the type specimensin all respectsapart from size. The type specimenshave a size rangeof 110-130umin contrastwith a diameterof 60-90umin the presentmaterial. GenusJenkinochitina T%ris198 1. Type species:Jenkinochitina oelandica (Eisenack) Paris 1981. Genericdescription: Paris 1981, p. 190. 210 JenAlnochitinavulgaris Complex. Plate 38, fig. 6; pl. 49, figs. 8 & 9. Remarks: The stateof preservationof the materialobserved and the fact that time only permits the use of light microscopyand not SEM analysisin the presentstudy makesit impractical to split this complex of morphotypes. Speciesincluded in this complexare Jenkinochilina vulgaris, J. actonica (Jenkins) Paris 1981,J. communis(raugourdeau) Paris 1981and J. traWlIensis(Paris) Paris 1981. GenusLagenochidna Eisenack 1931. Type species: Lagenochitinabaltica Eisenack1931 aeneric description: Eisenack193 1, p. 80-81. Lagenochitinabaltica Eisenack193 1. Plate29, figs. l. & 2; pl. 38, fig. 8. Description: Eisenack1931, p-80-81, pl-1, figs. 1-3. Holotype: Eisenack193 1, pl. 1, fig. 1. Age: Ordovician. Remarks: Lagenochitinacapax Jenkins 1967 has a greaterdegree of flexure betweenthe neck and the body chamberthan L baltica. Lagenochitina Jenkins1967. 0 capax Plate 38, fig. 7. Description: Jenkins1967, p. 465, pl. 73, figs.2-3. (Fig. 2 is in fact a specimenof L. deunfii). Holotfpe: Jenkins1967, pl. 73, fig. 3. Age: Camdoc. Remarks: Lagenochitinadeunfli Paris 1974is smallerthan L. capaxand L. baltica differs from the former in having a lesserdegree of flexure betweenthe body chamberand neck. 211 Lagenochitina?destombesi Elaouad-Debbaj 1988. Plate 13, figs. I&2. Description: Elaouad-Debbaj1988, p. 91-92, pl. 7, fig. 1,4-6,10-12,15,17 & 20. Holotype: Elaouad-Debbaj1988, pl. 7, fig. 6. Age: Tremadoc. Remarks: Ile assignmentof this speciesto the genusLagenochitina is questionedas the flexure betweenbody chamberand neck is not at all clear on the illustrations of the type specimensby Elaouad- Debbaj- Lagenochilinadeunffi Paris 1974. Plate50, figs. 1,2,5 & 6; pl. 100, fig. 3. Description: Paris 1974,322-323,pl. 1, figs. 1-3, pl. 3, figs. 1,2 & 4, pl. 4, figs.7 & 10. Holotype: Paris 1974,pl-3, fig. 1. Age: Lower Caradoc. Remarks: Lagenochitinacapax Jenkins 1967 is consideredto be a larger speciesthan L. deun!ffi. Two specimensof L. capar are illustratedby Jenkins(pl. 73, figs.2 & 3) with the holotype, fig. 3, measuring 209UMin length. This contrastswith the vesiclelength rangefor the speciesL. deunffl of 73-140um. Interestingly, given the rangeof the length of the vesiclein L. deuniffl,the other specimenillustrated by Jenkins, fig. 2, falls within this range,and is thereforea specimenof L. deunffl. Lagenochitinacf. deunffi Paris 1974. Plate49, figs.7 & 8. Holotype: Paris 1974,pl. 3, fig. 1. Age: Lower Caradoc. Remarks:Compare with Paris 1974,322-323,pl. 1, figs. 1-3, pl. 3, figs. 1,2 & 4, pl. 4, figs. 7 & 10. Specimensincluded here have a similarly narrow apertureand are of a similar size to L. deunffi. However, theseforms havea more elongatedvesicle. 212 Lagenochitinacf. naWculaTaugourdeau & Jekhowsky1960. Plate 135, fig. 1. Holotype: Taugourdeau& Jekhowsky1960, pl. IX, fig. 119. Age: Silurian. Remarks: Comparewith Taugourdeau& Jekhowsky1960, p. 1229-1230,pl. IX, figs. 119 & 120. Specimensobserved here have the samevesicle shape as Lagenochitina naWcula but do not show evidenceof the searon the vesiclewall which occursas a result of the unusualmethod of chain fonnation in this species. No chainsof this taxon were observed. Lagenochitinaventriosa (Achab) Elaouad-Debbaj 1988. Plate 13, fig. 3. Description: Achab 1980,p. 232, pl. IV, figs.5-7. Holotype: Achab 1980,pl. IV, figs.5. Age: Arenig. Remarks: Specimensrecorded here are closely comparableto the type specimens. GenusMargachilina Eisenack 1968 Type species: Margachitina margaritana (Eisenack)Eisenack 1968. Genericdescription: Eisenack1968, p. 182. Margachitina catenariacatenaria Obut 1973. Plate 151, fig. 7? Description: Obut 1973, p. pl. 15, fig. II Holotype: Obut 1973, pl. 15, fig-11. 213 Margachitina catenariacrassipes Paris 1981. Plate 146, figs.2? & 3? Description: Paris 1981, p. 143-145,pl. 25, figs. 13-16. Holotype: Paris 1981,pl. 25, fig. 16. Age: Lochkovian. Margachitina catenariatenuipes Paris 1981. Plate 146, fig. S. Description: Paris 1981, p. 145-147,pl. 32, fig. 13?; pl. 33, figs. 12,16 & 18; pl. 34, figs.4 & 6; pl. 37, figs. 13,14 & 16. Holotype: Paris 1981,pl. 34, fig. 4. Age: Pragian. GenusMuscochidna Paris 1981. Type species: Muscochitinamuscosa Paris 198 1. Generic description: Paris 1981, p. 268. Muscochitinamuscosa Paris 198 1. Plate 113, figs. 2? & 3?; pl. 146, figs. 6,7 & 8. DescriPtiOn: Paris 1981,p. 269-270,pl. 30, figs.7,8,13-15 & 17-20; pl. 41, figs. 13 & 14. HolotYPe: Paris 1981,p. 269-270,pl. 30, fig. 17. Age: Gedinnian. 214 GenusPkciochifina Croner 1964. Type species: Pkaochitina canninaeCramer 1964. Generic description: Cramer 1964,p. 346. Pkctochitina carminae?Cnuner 1964. Plate 100, figs.5-8; pl. 101, figs. 1-4. Description: Cramer 1964, p. 346-347, pl. XX, figs. 19 & 21, text-fig. 49. Holotype: Cramer 1964,pl. XX, fig. 21. Age: Ludlow. Remarks: Ile specimensrecorded here are poorly preserved,hence the elaborateand delicate appendagesof this speciesare commonlybroken. For this reason,the specimensrecorded are questionablyassigned to P. carminae. The rhizoid (sponge-like)texture of the appendagesof the specimensrecovered here appearsidentical to that of the appendageson the type specimens.P. carminae?is recordedonly from the Saetograptusincipiens graptolite zone (latestGorstian, lower Ludlow) in the presentstudy. Plectochitinasp. 1. Plate 113, figs. 1,4,5 & 6. Remarks: Only one reasonablywell preservedspecimen and severaldamaged specimens have been in recorded. The vesicleis cylindro-spheroidal shapeand approximately150um in length. There are trabeculateaboral, appendages arising from the basaledge measuring upto approximately40um in length. The appendagesbranch distally to join up with adjacentappendages. They appeartobe solid in The and are commonlybroken the materialobserved. wall of the chamberand the neck appearsto be smDoth. This form of Pkctochitina is recordedfrom the Monograptustransgrediens graptolite zone Oatest Pridoli) in the presentstudy. 215 GenusPogonochifina Taugourdeau 1961. Type species: Pogonochitinasimplex Taugourdeau 196 1. Genericdescription: Taugourdeaul961,p. 147-148. PogOnochitina?secunda (Schallreuter) Paris 1981. Plate 39, fig. 4. Description: Schallreuter 1963, p. 394, pl. 1, fig. 1. Holotype: Schallreuter1963, pl. 1, fig. 1. Age: Middle Ordovician. Remarks: Pogonochitinagrandis Taugourdeau196 1, P. simpkx Taugourdeau1961 and A spinifera Taugourdeau1961 all possessa more conical test than P?.secunda. Pogonochitina?secunda has a distinct flexure betweenthe body chamberand the neck. GenusPseudoclathrochidna Cramer 1%7. Type species: Pseudoclathrochitinacamenchuae (Cramer) Cramer 1967. Genericdescription: Cramer 1967,p. 46. Pseudoclxhrochitinacf. carmenchuae(Cramer) Cramer 1967. Plate 71, figs. 6-9. Holotype: Cramer 1964,pl. XXIV, fig. IS. Age: Lower Devonian. Remarks: Comparewith Cramer1964, p. 346, pl. XXII, figs. 8,9 & 10, pl. XXIV, fig-18. The have dimensions specimensrecorded here the samegeneral vesicle shape and as p. carmenchuae. However the ornamentationis more elaboratein the presentmaterial. Of the three specimensrecorded, This from only one is very well preserved. specimenshows appendages protruding the vesicle which branchin an anastomosingfashion distally to form a densemesh. The two lesswell preserved be in illustrations. specimenshave a damagedmesh as can seen the plate Pseudockuhrochitinacf. 216 carmenchuaeis recordedfrom the Telychian(late Llandovery) agedsediments here, contrasting with the Upper Ludlow-Lower Gedinnianstratigraphic records of P. carmenchuaeby Cramer (1964). Another specieswith a closely comparablemorphology to P. cf. carmenchuaeis Acanthochitina? rashidi Jenkins 1970,a form probablybetter placedin the genusPseudoclWhrochifina. This species, describedfrom the late Ordovicianof Oklahoma,has a similarly structuredornamentation which tends to be better developedon the flanks of the vesiclein the type specimens.Pseudoclxhrochitina cf. carmenchuaehas ornamentation better developedat the aboralmargin. GenusPlerochidna Eisenack 1955. Type species: Pterochitinaperivelata (Eisenack)Eisenack 1955. Genericdescription: Eisenack1955, p. 177. herochitina pefivelata (Eisenack)Eisenack 1955. Plate 127, fig. 6; pl. 134, fig. 8; pl. 135, fig. 2; pl. 147, figs. 1,2 & 3. DescriptiOn: Eisenack1937, p. 229-230,pl. 16, fig. 4, text-fig.7. Holotype: Eisenack1937, pl. 16, fig. 4. Age: Silurian GenusRhabdochitina Eisenack 1931. Type rpecies: Rhabdochitinamagna Eisenack 193 1. Genericdescription: Eisenack1931, p. 90-91. Rhabdochitinamagna Complex. Plate 29, figs.3 & 7; pl. 56, fig. 3; pl. 71, fig. 5; pl. 77, fig. 5; pl. 102, figs. 6 &7 Remarks: This complexof forms havebeen commonly recorded in the literature from Ordovician and Silurian sediments,e. g. Eisenack1931,1939, Jenkins1967, Benoit & Taugourdeau1961, lister & Downie 1967. The speciesof Rhabdochilinaincluded in the complex are of very similar morphology discerniblefrom in and are not practically the poorly preservedmaterial observedhere. For this 217 reason,these species have been grouped into the R.. magnaComplex. They are Rhabdochitinamagna Eisenack193 1. R.. concephalaEisenack 1934, R.. truncataTaugourdeau 1961 & R.. Wrgata Taugourdeau1961. GenusSagenachidna Jenkins 1970. Type species: Sagenachitinaoblonga (Benoit & Taugourdeau)Jenkins 1970. Genericdescription: Jenkins1970, p. 270. Sagenachitinaoblonga (Benoit & Taugourdeau)Jenkins 1970. Plate 30, fig. 5; pl. 39, fig. 1. Description: Benoit & Taugourdeau196 1. p. 1406,pl. 1, figs. 1-6. Holotype: Benoit& Taugourdeau1961, pl. 1, figs. 1& 2. Age: Arenig. Remarks: Sagenachitinaretifera Craugourdeau& Jekhowsky)Jenkins 1970 has a longer neck relative to the body chamberthan S. oblonga. The former has the more slendertest of the two species. Ile mesh-workcarinas of the specimensobserved are generallypoorly preserved. Sagenachitinacf. retifera (Taugourdeau& Jekhowsky)Jenkins 1970. Plate 30, figs. 1-4. Holotype: Taugourdeau& Jekhowsky1960, pl. 2, fig. 25. Age: Arenig. Remarks: Comparewith Taugourdeau& Jekhowsky1960, p. 1222,pl. 2, figs.25 & 26. lie specimens recordedhere have constricted necks as opposedto the parallel-sidednecks of the type specimens. Specimensobserved have an almostidentical test form to specimensassigned to S. cf. retifera by Paris 1981 (p.303, pl. 10, fig-18). 218 GenusSphaerochitina Eisenack 1955. Type species: Sphaerochitinasphaerocephala (Eisenack) Eisenack 1955. Genericdescription: Eisenack1955, p. 162. Sphaerochitinapilosa Collinson & Scott 1958. Plate 178, figs. 1-4; pl. 196, fig. 6. Synonomy: 1985,Fungochitinapilosa, Paris et aL, pl. 28, figs. 3-6 & 10. 1988,Fungochitinapilosa, Paris in Streelet aL Description: Collinson & Scott 1958,p-21-22, pl. 3, figs. 1-5. Holotype: Collinson & Scott 1958,pl. 3, fig. 2- Age: Middle Devonian. Remarks: The transferof this speciesto the genusFungochilina by Paris (1981) is rejectedon the basis of the spheroidalbody chamberof this species,as illustratedby Collinson & Scott (1958, text-fig. 10, pl. 3, figs. 1-5). Specimensrecorded here have a very similar morphology to the type specimens. Sphaerochitinasphaerocephala (Eisenack) Eisenack 1955. Plate 50, figs.3,4 & 7; pl. 102, fig. l?; pl. 135, figs.3,4 & 5; pl. 151, fig. 8?; pl. 178, fig. 5. Description: Eisenack1932, p. 271-272,pl. 12, figs. 14 & 15. Holotype: Eisenack1932, pl. 12, fig. 15. Age: Silurian. Remarks: Sphaerochitinaimpia Laufeld 1974has a similar morphologybut is smaller in size than S. from sphaerocephala,ranging in length 80-105m. Specimenswith this relatively simple morphology that have a vesicle length greaterthan 105mare includedin S. sphaerocephala. 219 Genus Urnochitina Paris 1981. Type species: Urnochitina urna (Eisenack)Paris 1981. Generic description: Paris 1981,p. 153. Urnochitinaurna (Eisenack)Paris 1981. Plate 136, figs. I&2. Description: Eisenack 1934, p. 69, pl. 5, figs. 7-13, text-fig. 34. Holotype: Eisenack1934, pl. 5, fig. 7. Age: Silurian. Genus VelatachitinaPomnot 1968. Type species:Velatachitina nebulosa Poumot 1968. Genericdescription: Poumot 1968,p. 49-51. Remarks: Two generato comparewith Vekitachitinaare Eremochitinaand Siphonochitinawhich both differ from the former in the structureof the aboralpole. The differencein thesestructures is well iflustratedby Paris 1981, p. 23 1, fig. 100. Velatachitinanebulosa Poumot 1968. Plate29, fig. 4. Description: Poumot 1968,p. 52, pl. 1, figs.9 & 10. Holotype: Poumot 1968,pl. I fig-9. Age: Llandeilo. has Remarks: Velatachitinaveligera a more elongatetest and a shorteraboral velurn than v nebulosa. 220 Velatachitinaveligera Poumot 1968. Plate39, figs.5,6 & 7. Description: Poumot 1968,p. 50-51, pl. 1, figs.7 & 8. Holotype: Poumot 1968pl. 1, fig. 7. Age: Arenig. Renwks: Velatachitinanebulosa has a shorter, more stout test and a longer aboral velum than V. veligera. Velatachitinasp. Plate29, figs.5? & 6?; pl. 39. fig. 3. Remarks: The specimensrecorded here have a similar test shapeto that of V. CopuWaPournot 1968. However, the specimensobserved have a much shorteraboral velum(< 1/3 the total vesiclelength) than in V. copulata. Chitinozoan Form A. Plate50, figs. 8&9. Remarks: FourteenPoorly Preservedspecimens, which are all recordedfrom Caradocaged sediments, featureis is are assignedto this taxon. The diagnostic the oral apertureof the vesiclewhich composed in of a mesh-worktype of wall structure. This type of structureis apparent the speciesSphaerochitina fenestrata Taugourdeau& Jekhowsky1960 which was describedfrom the Devonianof the Sahara. Analysis of the vesicle shapeis not reliable if basedon the poorly preservedspecimens observed here. lie variation in vesicle form can be seenin the photographicillustrations. 221 Chapter 7. Stratigraphic palynology. 'Me primary aim of the present study was to produce a complete palYnological zonation for the Ordovician to Devonian interval of the Anti Atlas. However, it was evident from very early in the study that this would not be possible due to the limited number and stratigraphic spread of the samples made available and also due to the non productive nature of palynological preparations from certain intervals (e. g. the Uandeilo). As a consequence,the palynostratigraphy of the present study is presented in the form of a series of described palynological associations with stratigraphic gaps between, as seen in the accompanying figures. The assemblagesare consideredin threesections; the first dealswith the assemblagesrecorded from the Ordovician field samples,the secondwith the assemblagesrecovered from the Silurian to Lower J>evonian.field samplesand the third dealswith the assemblagesrecorded from the exploration well Oum Doul-1. Within eachsection, the assemblages,many of which are macrofossildated, are describedand comparedwith palynomorphassemblages of a similar agethat have beenreported in the literature. A notable limitation of the presentstudy is the difficulty in stratigraphicallyrelating field samples collected from a single formation to eachother. The field samplesprovided for the study were largely collectedas single samplesfrom roadsideexposures. Although it has beenpossible to allocateall the samplesutilised in the study to a particular formation, it is often not possibleto say how samplesfrom a single formation relateto eachother in termsof their relative stratigraphicposition. An alternativemethod of ordering the samplesis to havethem in chronostratigraphicorder by utilising the macrofossilspresent. This was found to solve the problem in part. Having the benefit of the abundantgraptolitic faunasrecorded from the Silurian-LowerDevonian field samplesdoes allow these samplesto be placedin a chronostratigraphicorder. However, the Ordovician field samples,in which the shelly macrofossilbiostratigraphic resolution is ratherlimited, this methodof ordering samples within formationswas not alwaysfound to be possible. Where severalassemblages are recordedfrom sampleswithin a formation whoserelative agesare not known from the macrofossilinformation, e.g. from the Fezouata(shale) Formation and from the Ktaoua(sandstone and shale)Formation, attemptshave been made to placethe samplesin chronostratigraphicorder using the palynomorphassemblages. This has beenattempted by comparing the presentassemblages with previouspalynological studies. Where severalassemblages have been recordedfrom sampleswithin a formationwhich cannotbe placedin relative stratigraphicorder, these assemblagesare only describedand illustratedas having beenreported from that particular formation. 222 In describing the assemblages,the terms rare, occasional, common and abundant are used when referring to the proportions of taxa recorded in an assemblage. 7bese terms refer to the following percentages of taxa recorded: Lessthan I%- RARE 2-5% - OCCASIONAL 6-14% - COMMON More than 15%- A13UNDANT The assemblagecompositions are illustratedon the enclosedTilia graphswith the proportions of the major palynomorphgroupings illustrated towards the right hand side of the graphs. The palynomorph groupingsutilised are the acritarchs,the prasinophytes,the chitinozoaand the spores. As statedin the earlier chapterregarding the classPrasinophyceae, only the microplanktonindisputably assignableto this classare includedin this grouping. Within the acritarchs,a three fold subdivision of the group has beenmade, namely the 'acanthomorphicacritarchs', the 'spheromorphicacritarchs' and the 'other acritarchs'(i.e. non acanthomorphicand non spheromorphicacritarchs). Mie morphologicalscope of eachof thesethree subdivisions of the Acritarcha,is as definedby Cramer& Diez 1979, p. 23-29.7be acritarchshave been subdivided in sucha mannerin order to apply the environmentalmodel of Dorning (1987) which relatesthe palaeoenvironmentof depositionof the host sedimentsto the broad morphotypic compositionof the acritarchassemblage. The term 'association' is used here as a characteristic assemblageor group of similar assemblagesthat by future possessa taxa composition and/or taxa abundancesthat are practically recognisable workers for biostratigraphical purposes. in the vast majority of caseswhere more than one assemblageis allocated to an 'association', degree is beneficial in establishing the of similarity of the taxonomic composition of the assemblages 7lie degree is establishing the 'association'. of similarity calculated with the aid of a cluster analysis of from the assemblageswhich is run using the Tilia graph program, the results which must then be interpreted manually. Assemblagesfalling within a cluster on the Tilia graph dendrogram,which have a less total sum of squares of approximately two or is here considered to be a potential 'association' (D. W. Jolley pers. comm. 1992). However, this grouping by statistical analysis must be analysed 'association' i. it be by future manually to verify the practicability of the e. that may recognised insignificant in data, Acanthomorphic workers. For example, relatively taxonomic categories the e. g. heavily influence future acritarchs indet., may the cluster which would make recognition of an Oassociation'defined on such biostratigraphically insignificant groups impractical. Under the sections headed 'relevant literature', a brief resume of the palynOstratigtaphic studies that have been utilised for comparison with the assemblagesanalysed is given. Comparisons are primarily Gondwanan include those from Iberia (Cramer & made with northern studies which Diez 1978, Diez & Cramer 1978, Paris 1981), North Africa (Taugourdeau & Jekhowsky 1960, Poumot & Van OYen 1964, 223 from Northern Gondwana Figure 14. A comparisonof chitinozoanbiozonations published pre 1982, from Paris 198 1. Poumot BIOZONESDE Tau a Cramer AGE jeg; w. ýbgloire & al. S Diez CHITINOZOAIRES 19.67 1960 1964 1978 - 1 a. 38 AictonenAýA 8 ? 18 Emsien 37 a. aicto. S. butbasa. 36 3. butboad 17 IS a. mm.1tima Praguien- 34 G. jouann. -A. cattLUAe ? z Si eg enien Ui 33 M. catenaAia ttyuipa z 32 A. COMOAd-M. W. tZnUjpeA 1 18 16 is 0 31 C. A- 1 17 PtU44. - CeWatitMiA 3 > 7 1 30 C. 1 12 LU pt"Queuea 16 Tt"q. :9 E. A. - 6 1 Lochkovien- 28 L. tavicu& Gedi nn i en 27 E. bohemZca 26 A. 64agitiA 2S E. bohem. - A. chtu,--U 24 U. wLna 10 Pridolien H 9 P. 1 z 23 pmivetata 4 1 2.1 A. cf. echinata 6 Ludlow G 21 A.? thadeui ? -0 enlock 20 S. tycopeadoides Llandovery 19 C. ptoboscýije,%a 't-Lunc=- 3 9a 13 2+3.base Ashgill is S. azvac. - S. sp. B FI 17 C. hcmcctavijcrr,.. - 16 S. 'tobu4t, -C. Is. R.?cf. qaZlica- Caradoc 14 1. tanvitten"S deunj5i pi4SvZMSiS Llandeilo Flo L. pi4iot. s:. a.--. pi4sot. 1 piasctzna, ýs 0> 9 L. sp. aff. 0 8 Sup. C.? awoticana 0 E2 7 jojuw4a 5 Llanvirn inf. 6 C. camp. - L. esthonica S C. catix 4 C. pkotocatix S. henty.4 .3 - ) 2 Arenig 2 V. (P. vanen4i4- C. paeudowt. 1 E. bae-111atabaevi4 03 2+3 024 D1 Tabl. 40 : Essai do corrilations entra I& biotonation des Chitinozoaires propos&e icl, at I*$ zonations Itabliss par d'autres-autours (Sahara at Afrique du Nord $. I. : Taugourdeau qA Jekhowsky (1960), POumOtat Van Dy; n (1964). Xagloire (1967). Jardins at J&paudjan (1968) -, Espagne : Cramer at Diet (1 78). Diaz at Cramer (1978)]. 224 Magloire 1967, Jardine & Japaudjian 1969, Jardine et al. 1974, Paris 1990) and the Middle East (Keegan, Rasul & Shaheen1988). Many of the older publications regarding Northern Gondwanan palynostratigraphy have had their rather low resolution zonal schemescalibrated against the more comprehensive recent schemese. g. Paris 1981 (fig. 14). In the present study, there is a tendency to compare the assemblagesrecorded to the more recent zonal schemesin which the data from the older publications has been considered. Comparisons are made with the UK, Baltica and N. America where appropriate. The assemblagesrecorded from the Ordovician aged field samples. Tremadoc-earliest Arenh!. The oldest samplesanalysed for palynologyin the presentstudy were taken from the Fezouata(shale) Formation of Tremadocto earliestArenig age. Ibe five samplesinvestigated from this interval, none of which havebeen dated by macrofossils,are assignedto one of threepalynological associations describedbelow. Relevantliterature: The earliestpalynological studies of Tremadocage were carried out by Deunff (1961a& 1964a)on material from the Algerian Sahara. More recently, Jardineel al. (1974) establishedfour palynologicalzones through the Tremadocof Algeria and Elaouad-Debbaj(1988) publishedsix zonesfor the samestratigraphic interval in Morocco. Eight zonesfor the Tremadocof the UK were erectedby Rasul (1979)which were comparedto the North African schemesby Elaouad- Debbaj (1988), fig. 15. Assemblagesrecorded from the UK by Molyneux & Dorning 1989and Molyneux & Rushton1988 and by Mette 1989from SW Spainare also comparableto thoserecorded here. Generalcomposition of the Tremadoc-earliestArenig assemblages. Ile genericcomposition of the Tremadoc-earliestArenig assemblagesare dominatedby Acanthodiacrodium,Cýmatiogaka, Polygoniwn and Stelliferidiwn. Low diversity chitinozoan in latestTremadoc-earliest assemblageswere only recorded the Arenig assemblagesstudied, although, from late in chitinozoanshave been reported the early Tremadoc-earlylate Tremadoc Morocco by Elaouad-Debbaj(1988). 225 Figure 15. A comparisonof the Tremadocaged acritarch zonation of a. Rasul 1979, b. Naumova1950, c. Jardinaet al. 1974and d. Elaouad-Debbaj1988, from Elaouad-Debbaj1988. FA - - T a b c d ges ANGLETERRE BALTIQUE SAHARAALGERIEN MAROC < Arenaceous Beds (A) Shumatdia 7 pu,6itta cl Beds (A) Brachiopod Argiles 6 Beds ? d ' El 6? 5 (B) Cassi 5 Uonogtaptvs 4 A-eneti" Beds 3 (C) 2 2 ý 1 Argiles Trans. beds (T) 61 d ' El DicA,,L'yone, -na Dictyonvia Louha xili Ii otabetti0owe Beds Beds (D) xii Argilo- x gr6seux Bo Ix Beds de viii I'Oued Mya 226 Detail of the Tremadoc-earliestArenie Assemblages. AssociationI (seeTilia graph 1). Association 1, recordedfrom samplesDW 105 and DW 115 from the Fezouata.Formation, is dominatedby acanthomorphic:acritarchs with the notableabsence of chitinozoa. Stelliferldiwn spp. are abundant,notably S. cortinulwn and S. trifidum, with common\abundantPolygonium gracile and Acanthodiacrodiumspp. e.g. A. unifome, A. constrictumand A. wnplium. Other significant occurrencesinclude Irigatasporitesrudii and Tkichosphaerldiwnannolovaense. pjgcussion- The palynology of the FezouataFormation has been studied previously by Elaouad-Debbaj (1988b), however,her study is difficult to compareto the presentdue to her speciationwhich is based on observationsusing electronmicroscopy. Comparisonof stratigraphicallyimportant groups such as the Stelliferidium and Cymatiogakaspecies is difficult due to her adoptionof tax&based on minute detail which is-not apparentunder the light microscope. Despitethese problems, synonomyof the detailedSEM taxautilised by Elaouad-Debbajinto morphologicallybroader light microscopy determinabletaxa doesenable the partial applicationof her zonal scheme. 'Me presenceof abundant Stelliferidium cortinulum (= S. barbarumof Elaouad-Debbaj[1989b]) indicatesthat the associationin questionis no youngerthan her Zone 3. As mentionedby Elaouad-Debbaj(1988b), assemblagesfrom Morocco are broadly comparablewith thosereported from the UK by Rasul(1974,1979). Rasul(1979) proposedeight zoneswithin the Tremadocseries of the UK basedon 55 commonlyoccurring and relatively short ranging species. The his Zone 2 based associationunder discussionappears to resemble on the abundantoccurrence of Stelliferidium coHinulwn in associationwith presenceof S. simplexand Acanthodiacrodiwn ainplium. Priscogalae (-Stelliferidiwn in In addition, Jardineet al. (1974) recorded coriinulwn cortinulurn) their ZonesBI-B2. A tentativecomparison of the threeaffore mentionedzonal schemesis suggestedby Elaouad-Debbaj (1988b), fig. 15. This showsthat Zone 2 of Rasul(1979) and the upper pad of BI of Jardineet al. (1974) to be approximatelyequivalent in ageto Zone 2 of Elaouad-Debbaj(1988b). It would appear likely, therefore,given the presenceof abundantStelliferidium COrtinulumin associationwith S. ASSOCiation1 is Zones2 both Rasul sijnplex andAcanthodiacradiurn amplium, that assignableto of (1979) and Elaouad-Debbai(1988b) and probably the upper pad of Zone 111of Jardineet al. (1974). 227 Figure 16. A correlation of the standard graptolite zones and the Northern Gondwanan defined herein from chitinozoan zones with the palynological associations the Ordovician. U.J GRAPTOLITE N. GONDWANA 6w CHITINOZOAN PALYNOLOGICAL r- ce STAGES ZONES ASSOCIATION From Paris 1990 ZONES From Paris 1990 G. persculptus Hirnantian T. C. extraordina elongata Rawtheyan u A. merga Association12 M D. anceps V)< Cautleyan F7 oe7 D. complanatus A. nigerica /, / --g Pusgillian Ai P linearis O nni an . Actonian B rob usta U Marshbrook D. clingani . 0 Longvillian J.tanvillensis < Soudleyan u C. multidens Harnagi an L. dalbyensis Association10 z ý 7- ;7SF -- < Costonian L. deunffi Ass datio u 5; N. gracilis 0 Late L. ponceti 0 6 Ce Z 0 Early G. teretiusculus L. pissotensis L . clavata A. Late D murchisoni armoricana z . < S. formosa Early D. artus C. ralix C.-protoca protoca Iix Association 8 D. hirundo D. bulla Fennian 1.gibberulus Es.henryi Association 7 whitlandian D. nitidus D.ornensis zU. 1 Association,ýOZ Ce E. brevis 5 11 < 7 Association D. deflexus E. baculata, 4 Moridunian P.approximatus C. symmetrica A. conifundus ssociation 7ZZ 7 Late ,M Association.4Z Z:z ui 7y?;,,Mrz70 77 Z flabelliforme L. destombesi Early R. 000 'Irz I , M/711-77 - kaan Not sampled or barren 228 Association 2 (seeTilia graph 1). Association2, recordedfrom sampleDW 65 from the FezouataFormation, is composedof a low diversity acritarchassemblage dominated by Cymatiogaleamessaoudii which makesup approximately 65 % of the assemblage.Other forms presentinclude Polygoniumgracile, Gonlosphaeridiumcf. connectum,Caldariola glabra, andAcanthodiacrodium costatum. This Discussion: associationof specieswas not recordedby Elaouad-Debbaj(1988b) in her study of the MoroccanTremadoc. However, Jardineet al. (1974) recordedCýmafiogalea messaoudil from Algeria in their ZonesBI& B2. The presenceof Caldariold glabra and Goniosphaeridiumcf. conneaumwould suggestthat this associationis probablyyounger than this level if we comparethe associationwith assemblagesrecorded from the UK e.g. Molyneux & Rushton 1988. Ile absenceof chitinozoain this associationimplies an older agerelative to Association3 describedbelow. Association 3 (seeTilia graph 1). Association3, recordedfrom samplesDW 304 and DW 305 from the FezoustaFormation, incorporatesassemblages with diverseacritarchs and low numbersof primitive chitinozoans. Notable taxa presentare common\abundantAcanthodiacrodium raia, common\abundantCymaliogaka sp. 1, commonStelliferidiwn trifidwn and commonVogtlandia sp. 1. A significant occurrencein this associationis that of Cymaliogaleadeunffl. Solisphaeridiwnspp. and Stellichinitwn spp. also or-cur here. The chitinozoancomponent of the assemblagesis characterisedby low numbersof Conochitina brevis and rare Lagenochitina?destombesi and L. ventriosa. I Lscussion-Comparison with the zonal schemeof Elaouad-Debbaj1988b indicates that this association can be assignedto the youngestzone, Zone 6, of that scheme. This is basedlargely on the presenceof the chitinozoanspecies mentioned above. Species of note from this association that were recorded from Algeria by Jardine el al. (1974) are Cymatiogalea deunffl and Acanthodiacrodiwn raia (- Priscotheca raia in Jardine et al. 1974). 7be co- in occurrence of these taxa Association 3 suggeststhat it may be assignable to Zone C2 which is Arenig\Llanvirn positioned at the base of the interval in their scheme (fig. 3). However, abundant A. raia, as recorded in Association 3, are reported from Zone CI by Jardine et al. (1979) which suggests for an age of latest Tremadoe the association. More convincing comparisonsof Association3 can be madewith assemblagesrecently documented & Rushton from the UK by Molyneux (1988) and by Molyneux & Doming 1989. lie co-=uffence deunffl, Cymatiogaka (= Cýmatlogalea of Cýmatiogaka messaoudil sp. 1 pars.), Vogilandia coalita Vogtiandia 1) and Stelliferidiumtri fldum is in the UK sp. . present assemblagesand in Association3 229 herein. The ageassignation of latestTremadoc to earliestArenig for the UK assemblagesby Molyneux & Rushton(1988) and by Molyneux & Doming (1989)appears to be consistentwith the age indicated by comparisonof Association3 with the North African zonal schemes.In addition, Mette (1989) reportedsimilar assemblagesof acritarchsfrom SW Spainwhich he also datedas latest Tremadocto earliestArenig. It is also interestingto note the occurrenceof Tongziameitana in sample304. This taxon has only previously beenreported in the literature from the early Arenig of China (Li jun 1989) and from the late Arenig of Czechoslovakia(Vavrdova 1990). This implies the associationin questionis Arenig in age, however, making ageinterpretations from comparisonwith so few recordsof this relatively recently publishedtaxon may be misleading. Are"i - Thirteen samplesbelieved to be of Arenig agehave been analysed which are all assignedto the FezouataFormation. Of thesesamples, five havebeen dated using macrofossils,of which only one yielded palynomorphs. The palynomorphsrecovered from the non macrofossildated samples all indicate an Arenig age. From thesesamples, several associations can be recognisedwhich are describedbelow. Unfortunately, the relative stratigraphicpositions of theseassociations to eachother is not determinablefrom the lithostratigraphicdata available to the author. Ile relative is chronostratigraphicpositions of the samples largely indeterminatedue to a lack of data in the literature regardingthe evolution of acritarchassemblages during the Arenig. Ile chitinozoanzonation is of Paris (1990) for northernGondwana utilised were the samplesin questionyielded chitinozoansof instances, zonal value, which, in some enablesthe positioning of samplesstratigraphically relative to eachother. Relevantliterature: The acritarchsof the Arenig interval in Morocco havebeen studied previously by Crameret aL 1974a& 1974b,and Cramer& Diez 1977from subsurfacematerial from the Tadla basin from Zekkara. As is for and by Fournier-Vinas(1985) there no macrofossilage control the sections theseauthors studied, emphasis has been placed on the macrofossilconstrained chitinozoan zonal This incorporates data schemeof Paris 1990(fig. 16). zonal scheme palynological generatedfrom Arenig-Llanvirn agedsections in the Anti Atlas by Elaouad-Debbaj(1984). The zonal schemeof Jardineet al. (1974) from Algeria is of little chronostratigraphicuse through the Arenig interval as ZonesC2, D&E are all datedas Arenig/Llanvirn in age. -Me palynologyof the Arenig seriesin the UK hasbeen studied by Molyneux 1987. nese different in assemblagesare markedly their compositionto the previously recordedGondwanan 230 assemblages,notably the chitinozoan component, and they are generally poorly preserved. Both these factors makes them difficult to compare with the assemblagesfrom Morocco. GeneraA coMnsition of the Arenig assemblages. 1"beOrdovician assemblagesam characterisedby a generalincrease in abundanceof chitinozoans relative to the older assemblagesstudied. The genericcomposition is also markedly different with Eremochitinaprominent in almostall the assemblagesstudied, commonly associatedwith Belonechitina,Sagenachitina and Velatachitina. Within the acritarch component,Cor>phldium species are characteristicwith Acanthodiacrodiumspecies far lessapparent than in the older assemblages.The generaMarrocanium, Peteinosphaeridiumand Pirea, all consideredto appearin the Arenig (Downie pers. comm. 1989), are all recordedhere. Detail of the Arenig assemblages. Amdation 4 (seeTilia graph 2). Of the five macrofossildated samples, only one sample,DW 262, yielded palynomorphs. The sample is datedas Arenig, probably Lower Arenig, on the basisof the shelly macrofaunapresent (see appendix 1). Ile palynomorphassemblage is a rather impoverished,poorly preservedone with notable occurrencesof the acritarchsCoryphidium ramiferum, Frankea saribernardensis and Multiplicisphaeridium inconstans.Chitinozoans recovered include Belonechitinamicracantha micracantha,B. micracantharobusta and Eremochitina sp. Association 5 (seeTilia graph 3). This striking associationof taxa recordedfrom the Arenig agedsamples was recoveredfrom samples JW 4 and JW 5. The associationincludes the zonal chitinozoanspecies Eremochilina brevis with the baculata interesting closely relatedform E. cf. and with a very acritarchcomponent. The acritarchsare dominatedby the abundantoccurrence of Acritarch Forms D and N in conjunctionwith Coryphidium cf. tadlum, Dicrodiacrodium ancoriferumminutum, Goniosphaeridiumpolygonale pellucidum, Marrocanium simpla, Multiplicisphaeridiumconsolator. M. crispum,common Polygonium gracile, Stellichinitumhelosum and Striatothecaprincipalis. This associationcan be assignedto the E. brMs Zone of Paris (1990) basedon the presenceof E. breWs. This indicatesan ageof Whitlandianor 'middle' Arenig for this association. 231 Association 6 (seeTilia graph 4). SamplesDW 307 and DW 291 are also assignableto the E. brevis Zone on the basis of the presenceof E. brMs but thesesamples have yielded a noticeablydifferent acritarch assemblagesto those recorded in samplesJW 4 and JW 5. Multiplicisphaeridiumfirmum and Tongziameilana are presenthere, however, CoWhidium cf. tadlum, Dicrodiacrodiumancorifenon minutum and abundantPolygonium gracile are featuresof the assemblagesin commonwith thoserecorded from JW 4 and JW 5. Association 7 (seeTilia graph 5). Included here is sampleJD 29 which yielded a relatively diversechitinozoan assemblage including Cýathochjtinaaunpanulaeformis, Eremochitina cf. baculata,Lagenochitina capar, Velatachitina nebulosa,Sagenachitina cf. retifera and significantly S. oblonga. 7be presenceof the latter species indicatesthat this associationis no older than mid D. ornensisZone accordingto Paris (1990) and henceit is probably youngerthan Association5 describedfrom samplesJW 4 and JW 5. SampleDW 303 (seeTilia graph 6) yielded characteristicOrdovician palynomorphs e. g. Eremochitina cf. baculaa, Velatachitinasp., Peteinosphaeridiwnspp., Pirea colliforynis, in associationwith commonTremadoc-earliest Arenig speciessuch as Acanthodiacrodium amplium, A. constHcrum,A. raja, Cymatiogakamessaoudil, C multarea, C velifera and Cymatiogaka sp. 1. One can only is assumethat the Tremadoc-earliestArenig componentof this assemblage recycled. Ijanvirn. Two samples,DW 309 and DW 310, were studiedfrom the Tachilla Formation, both of which am datedas probableLlanvirn ageon the basisof the macrofaunalcontent, see appendix 1. Relevaunddlt-eratum*Publications regarding the palynologyof the Llanvirn agedsediments from Morocco include Fournier-Vinas1985, Crameret al. 1974,Deunff 1977and Elaouad-Debbaj1984. Paris and Deunff 1970 studiedcomparable Llanvirn ageassemblages from France. The chitinozoan, be from zonal schemeof Paris 1990can utilised to refine the ageof the samplesstudied that indicated by the macrofaunalcontent. 232 CenerAacommsition of the Llanvim assemblans. 77hepalynological assemblages are characterisedby relatively diverseacritarchs and chitinozoans. 710 genericcomposition of the acritarchcomponent is rathersimilar to that recordedfrom the Arenig assemblages,namely Coryphidium,Marrocanium, Multiplicisphaeridium and Striatotheca. Notable absenteesfrom the Llanvirn assemblagesare the generaAcanthodiacrodium and Polygonium. The chitinozoansare characterisedby an increasein diversity of speciespresent and the prominenceof the genusBelonechitina. Other generaof note that are presentinclude Jenkinochitina, Pogonochitina, sagenachidnaand Velatachitina. Detail of the Llanvim assemblages. Association 8 (seeTilia graph 7). Ile acritarchassemblages from samplesDW 309 and DW 3 10 are characterisedby a high diversity of acritarch speciesincluding Bakisphaeridiumklabavense, Comasphaeridiwn denseprocessum, Coryphidiumekgans, Frankeasartbernardensis, common Goniosphaeridium polygonak polygonale, Marrocanium simpkw, Striatothecaprincipalis and abundantVer)*achjum jairdii. The chitinozoanassemblage is dominatedby common\abundantBelonechitina micracantha with occasional/commonConochitina ch)daea, common Desmochitina minor cocoa,JenA! nochitina vulgaris, Pogonochitina?secunda, Sagenachitina oblonga and Velatachitinaveligera. RI: - Using the zonal schemeof Paris 1990, the chitinozoanspresent indicate that these _scussion. macrofossildated Llanvirn palynomorphassemblages from the Tachilla Formation are assignableto the cyathochitina protocalLxZone basedon the co-occurrenceof Belonechitinamicracantha, Sagenachitinaoblonga, Velatachitinaveligera and Jenkinochitina vulgaris. This suggestsan early Lower Llanvirn agefor the assemblages. Llan-ddilla,. Three samples,JHO 220, GAO 388 and GAO 471, datedas Llandeilo on the basisof the macrofossil contentwere processedfor palynologicalanalysis. Thesethree samplesof sandylithology were found to be barrenof palynomorphs. 233 Thirteen samplesbelieved to be of Caradocage have been analysed for their palynological content, 354, DW 361 eight of which, DW 323, DW 336, DW 337, DW 349, DW 353, DW and DW 362 have beendated using macrofossils,see Appendix I. All the samplesof Caradocage are assignableto the KtaouaFormation. As with the Arenig samples,it is not possibleto placesome of the samplesof Caradocage that have been studiedin uthostratigraphicorder. Furthermore,the broad datationof the samplesusing their in As shelly macrofossilcontent does not allow arrangement a chronostratigraphicorder. a havebeen defined, from consequence,two palynologicalassociations of the assemblages and these, suggestionsare madeas to the relative stratigraphicposition of eachassociation to the other. Relevantliterature: Caradocpalynological assemblages from Morocco have beenstudied previously by Elaouad-Debbai(1986,1988). Data generatedin her 1996publication on the chitinozoansfrom the Lower Ktaouaformation has been incorporated into the zonationof Ordovician chitinozoansof Northern Gondwanaby Paris (1990). 7bis zonationcan be applied to someof the assemblagesof Caradocage documented here. Other relevantpublications regarding Late Ordovician palynology of Northern Gondwanainclude Molyneux & Paris 1985,Molyneux 1988and Paris 1988which are all basedon subsurfacematerial from Libya. The zonationof Jardineet al. (1974) erectedon material from Algeria is of little use in the Late Ordovicianas only one zoneis defined for the Caradoc-Ashgill interval. The palynologyof the type Caradocfrom the UK hasbeen documented by Turner (1984), by Jenkins(1967) who looked at the acritarchsand who studiedthe chitinozoans. Caradoc (; eneralcomposition of the agedassemblages. The Caradocaged samples generally contain impoverished, poorly preservedacritarch assemblages dominatedby speciesof VerAachiumand Villosacapsula. Spheromorphicacritarchs referable to the Lophosphaeridium generaLejosphaeridia and are also relatively common. The chitinozoancomponents of the assemblagesare composedprimarily of the generaBelonechitina, Lagenochitina,notably L deunffi, with qathochitina, Conochitinaand Jenkinochitina also present. The chitinozoanassemblages are also poorly preserved. Caradocaged assemblages in detail, from Caradoc Two associationsof palynomorphsare apparent the agedassemblages. The five samples thesetwo of Cýaýoc agethat are not assignableto one of associationscontainedvery impoverished dominatedby indeterminate VeD*achium. palynomorphassemblages, generally speciesof 234 Aswdation 9 (seeTilia graph 8). Association9 is recordedfrom samplesDW 335, DW 336, DW 337 and DW 415. This associationis characterised.by commonLagenochitina deunffi and abundantVillosacapsula Setosapellicum. Veryhachiumspp. are abundantwith occasionancommonv. reduclumand inconsistentVeryhachium sp. 1. Belonechitinaspp. are consistentlypresent, notably B. capitata. Discussion: The presenceof commonLagenochitina deunffi indicatesthat this associationis assignable to L. deunffi Zone of Paris (1990). This suggestsa Costonian,lowest Caradocage for thesesamples which is consistentwith the Lower Caradoeage indicated by the macrofossilsrecorded from samples DW 336 and DW 337, seeappendix I. Association 10 (seeTilia graph 9). Association10 is recordedfrom samplesDW 352, DW 353, DW 354 and DW 362. This associationis characterisedby occasional-abundantY'llosacapsula setosapellicum and abundantVeryhachiwn spp. notably Veryhachiumreductum, Veryhachium sp. 1, Veryhachiumsp. 3 and Veryhachiumsp. 4. Ile chitinozoancomponent is rather impoverished. Notableoccurrences include Belonechitinacapitata and jenjUnochitinaspp. in low numberswith Lagenochitinadeunffi rare or absent. Discussion: Comparisonof this associationwith assemblagesrecorded in the literature of Caradocage from northern Gondwana and the UK appears to indicate the absenceof age diagnostic palynomorphs. However, the low numbers of Lagenochitina deuniffi are indeed significant in this LA)wer Caradoc macrofossil dated association. The macrofossilspresent in samplesDW 353, DW 354 and DW 362 enablea Lower Caradocage assignationfor this association,see appendix I. Paris (1990, p. 198) in describingthe Lagenochitina dalbyensisZone (lower Caradoc)mentions the presenceof a few L. deunlffispecimens persisting into the L. dakensis Zone from the underlyingL. deunffi Zone in which they are common. The Lower Caradoc coincidenceof the presenceof a agedmacrofossil assemblage and the rare specimensof L. deunffi in this associationsuggests that this assemblagemay be assignableto the L. "byensis Zone. This indicatesthat Association9 containingcommon L. deuniffiis older than this association. 235 A 1hei 1-1. Four samplesbelieved to be of Ashgill agehave been studied. Of these,two, 7D 17 and GAO 19 are datedusing macrofossilsbut both were found to be barrenof palynomorphs. SamplesDW 359 and DJ 10 yielded reasonablywell preservedassemblages which are comparableto Ashgill agedassemblages describedin the literature. Relevantliteratu Palynologicalassemblages of Ashgill age from Morocco have beenstudied by Elaouad-Debbai(1984,1988). Information from her 1984publication on the Ashgill chitinozoanshas beenincorporated into the zonationof Ordovicianchitinozoans of Northern Gondwanaby Paris (1990). other relevantpublications regarding Late Ordovicianpalynology of Northern Gondwanainclude Molyneux & Paris 1985,Hill & Molyneux 1988,Molyneux 1988and Paris 1988which are all based on subsurfacematerial from Libya. 7be zonationof Jardineet al. (1974) erectedon material from Algeria is of little use in the Late Ordovicianas only one zoneis defined for the Camdoc-Ashgill interval. 7be palynologyof the Ashgill from the UK, including the type areahas been documented by Whelan (1988) and Barron (pers. comm. 1992). Numerouspapers regarding the Ashgillian palynology of Anticosti and westernCanada have been published by Achab and co-workers,e. g. Achab 1981, 1984,'1987 and 1989. GeneralcoM2gsition of the Ashaill agedassemblages studied. The acritarchassemblages are dominatedby the genusVeryhachium in associationwith less frequent forms assignableto the generaLeidsphaeridia and Lophosphaeridium. The occurrences spher0morphicI-- forms, of Diexallophasis and leiofusid notably Dactylqfwa are regarded as significant. Ashgill aged assemblagesin detail. The two samplesstudied yielded quite dissimilar assemblagesin termsOf speciescomposition. A&wdation 11 (seeTilia graph 10). The assemblagerecovered from DW 359 is rather poorly preserved. Veryhachiumspecies occur V. V in abundantly,notably V. minutum, reductumand subglObOswn, associationwith Dacrylqfusa forms Diexallophasisincluding D. denticulata clenistaand primitive of Gotlandica. A sparse Belonechitina chitinozoanassemblage composed primarily of speciesand rare ancyrochitinids,notably Ancyrochitinaancyrea is also recorded. DW 359, from Upper KtaouaFormation Discussion: Sample collected the (sensuDestombes et al. I, 198s), seeappendix yielded a closely comparableassemblage to that recordedfrom the same 236 stratigraphiclevel by Elaouad-Debbýj(1988). Sherecorded a similar suite of ver3*achjum species,the netromorphDactylofiaa denista (referedto incorrectly asEuPoiA! Iqfiua striata by Elaousad-Debbaj 1988)with rare, very poorly preservedspecimens of Aremoficaniwn jy?ingosagis. Ile latter taxon was not recordedfrom DW 359, maybeas a result of the preservation. Comparisonwith the data of Elaouad-Debbaj(1984,1988) suggestsan early-'middle' Ashgill age for DW 359.71e absenceof the speciesArmoricochitina nigerica in this associationsuggests an ageof earliest Ashgill according to zonation schemeof Paris 1990. Hill and Molyneux (1988) consideredVeryhachiwn jubgjobosum and Diexallophasis denticulwa to indicate an Ashgill agein Libya, thesespecies Occur in ZonesAsI-As2 of their zonal schemefor the Libyan subsurface. Veryhachiwn subglobosum is also considered to indicate an Ashgill age in the Kingdom of Jordan (Keegan, Rasul and Shaheen 1990). Recent work on the type Ashgill of the UK (Barron pers. colnrn. 1992) suggeststhat the first appearanceof the genus Diexallophwis is in Ashgill aged sediments. Association 12 (seeTilia graph 10). The assemblagerecovered from sampleDJ 10 is reasonablywell preserved. Ile acritarchcomponent is composedof abundantVeryhachium reductum and commonV. subglobosumwith Lophosphaeridium r,pp. andDiexallophasis sp. also present. Chitinozoansoccur in high numbersin this sample(32 % of the palynornorphsum). This componentis dominatedby Ancyrochifina sp. I with Armoricochitina nigerica, Belonechitinacapitata and Calpichilina knticularis all prominent. Discussion:.Ile zonationof Paris (1990) is directly applicablehere. The abundantoccurrence of Ancyrochitina spp. within the chitinozoanpart of the assemblagein associationwith Armoricochitina is nigerica indicatesthat this sample assignableto the A. merga Zone. This indicatesan ageof ,middle' Ashgill- Whelan(1988) also reportedan increasein ancyrochitinidabundance in the late Ashgill in the UK. Ile acritarchspresent, e. g. Dituallophasis sp. and Ver)*achiwn subglobosum indicate that the assemblageis assignableto ZonesAsl-As2 of Hill and Molyneux (1988) which are of Ashgill age. 237 Assemblagesrecorded from the Silurian to Lower Devonian aged field samples. Telychians latest Liandovery. The oldest samplesanalysed from the Silurian in the presentstudy are Telychian in age. Eight graptolite datedsamples from the were processedfor palynology of which six yielded workable assemblages.17here was a major problem in the processingof thesesamples due to the presenceof abundantamorphous sapropelic kerogen. 7he adoptionof fuming Schulze'ssolution to dissagregate this materialwas found to be successful. Relevantliterature: The broadnature of the zonationsproduced by Jardineet al. (1974), Taugourdeau & jekhowsky 1960and Keegan,Rasul & Shaheen(1990) makesthem of little benefit for comparison with the assemblagesof refined biostratigraphicdates that havebeen utilised here. Ile assemblagesare mainly comparedwith materialstudied from Libya (Hill, Paris & Richardson1985, Hill & Mo lyneux ' 1988, Paris 1988,Paris 1988), from the SwedishIsland of Gotland (Le Herrise 1989, Laufeld 1974) and with the Silurian acritarchdistribution chartsof Cramer(1970) compiled from Americanand Europeandata. The zonationproposed by Jardine& Yapaudjian(1968) for the PolignacBasin of Algeria utilises nuny taxa in opennomenclature at this stratigraphiclevel which makescomparison with the presentassemblages difficult. Hill (1974) divided the type Llandovery from the UK into four gcritarch zones,which, due to the differencein the assemblagecompositions when comparedto the Moroccanassemblages (e. g. the absenceof Deunffla andDomasia speciesin the Moroccan assemblages),are not applicable. Gene -al coMagsition of the assemblages. Amorphoussapropelic kerogen is abundantin the palynologicalpreparations with palynomorph dominatedby assemblagesgenerally spheromorphicacritarchs. The genusLeiosphaeridia occurs abundantlywith Dicryotidium and the prasinophyteTasmanites also common. Of the acanthomorphs, Ammonidiumspecies and visbyspheridsare frequent. The chitinozoanassemblages are generallypoorly diversity preservedand of low species throughoutthis stratigraphicinterval. Detail of the Telychian agedassemblages. Two associationsof palynomorphswidiin the Telychianaged samples are apparent (fig. 17). 238 Northern Gondwanan Figure 17. A correlationof the standardgraptolite zones and the defined herein from the Silurian. chitinozoanzones with the palynologicalassociations S.W. EUROPEAN STANDARDGRAPTOLITE CHITINOZOAN PALYNOLOGICAL W.J WJ STAGES ZONES r- ZONES ASSOCIATION From Rickards1989 after Paris 1981 7 Gedinnian M. uniformis _; Association 23 DEV. _; tF: ------M. transgrediens 24 Association 22 M. perneri yez M. bouceki . Pridoli ýz M. lochkovensis Association 21 M. pridoliensis (- M. similis) 23 M. ultimus M. parultimus 5 M. balticus/caudatus kozlowskii N. do 0 N. inexpectatus atedas N. been Ludfordian auriculatus Ludlowhave 3: B. cornutus analaysedbut association% 0 B. praecornutus C. 8b oh ern icus 0 aversus S. leintwardinensis ...... C. hemiaversus S. incipiensor Association 20 L. invertus F.tumestens ------Gorstian L. scani,C ý to L. proge -n i r nilssoni; Association 19 $car'ic, u - N. nilssonj 22 ------G P.?ludensis =2= Association 18 z 2 Homerian G. nassa :5 ýz - C. lundgreni Ce U W 0 _j Association 17 V) z M. flexilis W zz/zz=/z=/ C. rigidus Sheirtwoodian Association 15 M. riccartonensis Fzz/z //z / C. murchisoni z 2'1 C. centrifugus z/ M. crenufata Association 14 M. griestoniensis Telychian M. crispus ------M. turriculatus Association 13 19 Ce W 77 > 0 M. convolutus 0 Aeronian P. leptotheca z D. magnus C. gregarius < M. tri ýIt J ...... C. cyphus L. Rhuddanian acinacces A. atavus P.acuminatus o0o, G. Hirnantian persculptus T. (Paris'90) o elongata larr" 239 Association 13 (seeTilia graph 11). Monograptus tuniculatus-M. aispus Zone in age. SamplesDW 246,JW 249and JW 46 wereanalysed from theMonograptus turTicu1xUS-M. Crispus zonesof whichonly DW 246yielded palynomorphs. This associationcontains an unusuallyhigh proportionof acanthomorphicacritarchs (74 %) comparedwith theother Lower Silurianaged samples studied.Important constituents of theassociation include Comasphaeridium hirium, Diciyotidiumspp., Diexallophasisdenticulata, Oppilatal0frondis, Veryhachiumspp. and Vubysphaeramicrospinosa var. A. 7be poorlypreserved chitinozoan assemblage comprises forms including Angochitina? cf. jeurata, 2, Cyathochitina Cyathochitina ,4ncyrochitina sp. cxnpanulaeformisand sp. 1. Discussion: Only one palynologicalzone, Zone L14, is defined for the Telychian ageof Libya by Hill & Molyneux (1988). The assemblagesrecovered by them are of similar speciesdiversity to those studiedhere, the speciescompositions, however, are somewhatdifferent. Taxa recordedfrom sample DW 246 in commonwith the Libyan Telychianassemblages include Diexallophasis denticulata and Visbysphaeramicrospinosa. Significantabsentees from the presentassemblage include the Domasla andDeuniffia group which are believedto be associatedwith the low latitude realm. 7bis element, Despitehaving beenrecorded in closelyproximal Libya (Hill & Molyneux 1988), is not recordedhere. The assemblagesrecorded by Le Herisse(1989) from the early-middleTelychian Nar Formationof Gotland are of considerablyhigher speciesdiversity than the presentassemblage. Many species recordedfrom thosehighly diversified assemblagesare presenthere including Comasphaeridiumhirtum and Oppilaala? ftondis. Again, a noticeabledifference in the speciescomposition is the absenceof Domasia andDeunffla speciesin the presentassemblage. Paris (1981) investigateda chitinozoanassemblage of Monograptustur? iculatus Zone age from SW Europe, his Zone 19, in which he found low speciesdiversity. Assemblageshere haveno speciesin commonwith thoseobserved by Paris (1981). Assemblagesrecorded from the similar stratigraphic level in Gotlandby IAufeld (1974) also lack speciesin commonwith the presentassemblages. We shouldbare in mind that the intenseoxidation requiredto enablethe observationof palynomorphs within this thermally mature,sapropelic rich palynofaciesmay havehad an impact on the assemblage compositionsrecovered. 240 Association 14 (seeTilia graph 11). Monograptusgriesioniensis-M. crenulata Zone in age. Four samples,DW 248 (M. griestoniensisZone in age),DW 249, DW 250 and DW 251 ( all M. CrenulataZone in age)of low speciesdiversity havebeen analysed from this interval. 7he cluster analysis(see Tilia graph 11) indicatesthe closesimilarity of the assemblagecompositions of these assemblages(TSOS less than 1). The assemblagesare dominatedby Leiosphaeridia species,notably L rnicrocystis. Lophosphaeridiumspecies are also commonas is Tasmanitesmedius. Buedingisphaeridiwnlunatum, Dictyotidiwn sp. 1, Veryhachiwn?sp. 9, Vuhysphaerasp. I and Vuhysphaerasp. 2 are all particularly diagnosticof this associationand CymatiosphaeraRryanoWi is inconsistentlypresent. The chitinozoanassemblage is highly impoverished,however, the morphologically distinctive Pseudoclathrochitinacf. carmenchuaeis of note, as is the first appearance in the presentstudy of Ancyrochitinaprimativa. Discussion: As with Association13 describedabove, comparisonwith Hill & Molyneux 1988 is of little benefit due to the relatively broadnature of their zonal schemeand the considerabledifferences betweenthe assemblagecomposition they observedcompared to thoserecorded here. The chitinozoanassemblages of Zone 7 of Paris (1988) from Ilbya, which approximatesto the Monograptusgriestoniensis-M. crenulata Zones is also quite dissimilar in compositionto the assemblagesof that agerecorded here. None of the zonal forms quotedby Paris, e.g. Prerochitina diechaii andMargachitina margaritanaare present. 7be only chitinozoanconsidered to be of potential stratigraphicsignificance recorded here is PseudoclWhrochitinacf. carmenchuae. The acritarchassemblages of Monograptuscrenulata Zone agedescribed from the Lower Visby Formation by Le Herisse(1989) havea moderatenumber of taxa in commonwith this association,e. g. Bue,dingisphaeridium lunatum, Mayotidium dictyotum,but they are of considerablyhigher species diversity than the presentassociation containing the Deunffla andDomasia speciestypical of low latitude assemblagesof Telychianage. it appearsthat the previouslyunpublished taxa e.g. Dictyxidium sp. 1, Veryhachium?sp. 9, Vuhysphaerasp. 1, Irtsbysphaerasp. 2 and Pseudoclathrochitinacf. cannenchumoccurring in conjunctionwith the high abundancetaxa (e.g. LeiosphaeridiamicrOcYstis) are possibly the best indicatorsof this interval in Morocco. Ile reasonfor the notabledifferences between these and the Libyan assemblagesof a similar agecould possiblybe associatedwith the mixing of the low latitude Deunffia-Domasiarealm with the high latitude NeoveqhachjumCarminae realm in Libya (Hill & latitude, Molyneux 1988)in contrastwith the high more provincial flora of the Morocc4knassemblages. 241 Again, it shouldalso be notedthat the severeoxidation techniqueapplied to thesesamples could possibly have an impact on the assemblagecompositions recovered. Wenlock. Ten graptolite datedsamples of Wenlock agehave been analysed, eight from the Sheinwoodian(Lower Wenlock) and two from the Homerian(Upper Wenlock). Of the eight samplesfrom the Sheinwoodian, two, both from the Cýrtogrqptusellasae Zone, were found to be barren of palynomorphs. Four palynological associationshave been recorded from the Wenlock agedsamples analysed. Significant literature: As with the Llandoveryinterval, applicationof the zonal schemesof Jardineel aL (1974), Taugourdeau& Jekhowsky(1960) and Keegan,Rasul & Shaheen(1990) are not of benefit here due to the chronostratigraphicallybroad agesof their zones. Ile recentpalynostratigraphic publicationson north-east11bya, Thusu & Owens(1985) and EI-Amauti, Owens& 7busu (1988), do not cover the mid-late Silurian interval. Comparisonof the chitinozoanassemblages is madewith Paris (1981) who analysedsome Homerian material from south-westEurope, with Laufeld (1974) from Gotland and with Doming 1981bfrom the Welsh Basin. The acritarchassemblages are comparedwith thosefrom Gotland (Le Herrise 1989)and from the type sectionsin the UK (Downie 1959,1963 and Doming 1981a). (; eneralcomosition of the Wenjock agedassemblages. The Wenlock agedassemblages are generallypoorly preserved. 7be acritarchcomponent is very much dominatedby spheromorphicforms, the vast majority of which are assignableto the genus Lejosphaeridiawith frequentLophosphaeridium spp. andDicryotidium. spp. present. The prasinophytesTasmanites and Cymatiosphaeraare also common. Of the acanthomorphicforms, the generaAmmonidium, Oppilatala, Tylotopallaand Vubysphaeraare commonlypresent. As with the I.Jandovery assemblages, the chitinozoancomponent is generallyimpoverished with the genera Angochitina andAncyrochitina are frequentlypresent throughout this interval. memblages. Four associationsof palynomorphassemblages have been recognised in thesesamples (fig. 17). 242 Association 15 (seeTilia graph 11). Mowgraptus riccartonensisZone in age. Three samples,DW 162, DW 357 and DW 358 are assignedto this association. Cluster analysisof the assemblagesgives a TSOSof lessthan 2 which indicatesthe close similarity of their composition. Lejosphaeridiamicrocystis is super-abundantcomprising between 46-62 % of the palynomorphsum. Lejosphaeridiasp. 1, Dicrptidiwn cf. coarawn and Tasmanitesmadius are also common. inconsistentlypresent forms includeDateriocradus monterossae, the Oppilwala eoplanktonica- ramusculosacomplex, Wfirondis, 41otopalla astifera, T. cf. deerlijkianum, Vubysphaera microspinosavar. A and Acritarch Form L. The chitinozoanrecovery is low in this association(less than 4% of the palynomorphsum). The only taxa of note are Ancyrochitinaprimativa and Cyathochitinacf. eUnitaewhich are both inconsistentlypresent. Discussion- Doming (1981)proposed three zonesthrough the Wenlock of the Welsh basin. His zonal taxa do not occur here, however,it is interestingto note the occurrenceof Dateriocradusmonterossae which is restrictedto the upper part of his Zone W1 and the lower part of Zone W2. This taxon is coincidentallyonly recordedfrom the Monograptusriccartonensis Zone in the presentstudy, which is of approximatelythe samechronostratigmphic position as that record of Doming. Le Herrise (1989) found this speciesto rangefrom the latestTelychian to the earliestHomerian in Gotland. The.sparse chitinozoan assemblage has only one taxon in commonwith the assemblagesdocumented by Doming (1981) from the UK and Laufeld (1974) from Gotlandwhich is the long ranging species Ancyrochitinaprimativa. Association 16 (seeTilia graph 11). MowgraPtus riccartOnensisICYrtograPtusrigidus Zonal boundaryin age. A single sample,DW 367, comprisesthis association.It is composedprimarily of Angochitina sp. I % which makesup approximately60 of the palynomorphsum. Other chitinozoansare rare and include Cingulachitina sp., Conochitinaspp. and the Rhabdochitinamagna complex. The acritarchsare of very low diversity Oessthan 10 species)with LeiOsPhaeridiaspp. dominantand occasional Vuhysphaeramicrospinosa. p,Iýussion- No previouslyrecorded age diagnostic chitinozoans or acritarchsare present in this it is interesting flood association. However, to note the of Angochitina sp. I at this stratigraphiclevel. 243 Association 17 (seeTilia graph 11). Monograptusflailis Zone in age. Assemblagesfrom samplesDW 355 and DW 356 comprisethis association. The acritarch component is dominatedby Leiosphaeridiaspp. with L. microcystisfar lessconspicuous than in Association 16. Dicryotidium coarctumand Oppilatala?ftondis are alsoprominent. The chitinozoansoccur in very few numberswith Anc3mchitinaprimativa, Angochitina sp. and Cyathochitinasp. inconsistentlypresent. Discussion: Doming (1981) recordedOppilatal0frondis from the UK as having its youngest occurrencein the middle of his ZoneW2 which would appearto approximateto the youngest stratigraphicoccurrence of this taxon in the presentstudy. However, Le Herrise recordedthis form as high as the Ludfordian (Upper Ludlow) and doesnot considerit to be reworked. Two samplesfrom the Cynograptusellesae Zone, DJ 84 and JW 9, were processedfor palynological analysisbut were found to be barrenof palynomorphs. Association 18 (seeTilia graph 11). pristiograptus? ludensisZone in age. Two samples,DW 230 and DW 231, were processedfor palynology from the Pristiograptus?ludensis Zone of which one, DW 231 yielded palynomorphs. The assemblageis relatively diversecompared to the assemblagesfrom older Wenlockiansamples and thereis a markedchange in the palynofacies. lie amorphoussapropelic material which was abundantin the Telychianand Sheinwoodianaged preparationsis rare here. The acanthomorphicacritarch abundance is markedly increasedat the expense of the spheromorphsand the chitinozoanabundance and diversity is slightly increased. The main constituentsof the acritarchcomponent are abundantAmmonidium sp. I (5o %), Cymatiosphaeraocloplana?, Dieurallophasis cf. sanpetrensis,common Leiosphaeridia spp., Lophosphaeridiumsp. 6, Lophosphaeridiumsp. 7 and Onondagelladeunffi. An interestingoccurrence in the chitinozoanassemblage is the first appearanceof Cingulachitinasp. 1. Discussion: The baseof the rangeof Onondagelladeunffi in both the UK (Doming 1981, Upper - IA) in Gotland Herisse Ludlow, ZonesL3 and and (Le 1989, Ludlow) is younger than that recorded here. it is interestingto note the coincidence the first Cingulachitina of appearanceof r, p. 1 in this 244 study comparedwith that of Cingulachitinasp. A Paris 1981 (= Cingulachitina sp. I herein) from south west Europewhich appearsin both casesin the latestWenlock, in or close to the Pristiograptus? ludensisZone. seven graptolite datedsamples of Ludlow agehave been analysed. Of these,three, JW 224, DW 34 and JW 10 me biostratigraphicallyconstrained to graptolite zonesbased on the macrofaunapresent. The remainingsamples, DW 215, DW 232, DW 234 and DW 235 are lesswell constrainedby the macrofossils,DW 215 having beendated as 'middle' Ludlow in age, the remainderare datedas Ludlow in age. The stratigraphicposition of thesefour samplesrelative to the highly constrained samples,and to eachother, is indeterminatefrom the palynology. For this reason,the general compositionof the Ludlow assemblagesis describedin somedetail. This is done in order to give a more comprehensiveoverview of the palynologyof the Ludlow interval studied. A detaileddescription of the highly constrainedassemblages follows the generaldescription. ]gelevantliterature: Jardineet al. (1974)published four zoneswithin what they term the '(Wenlock?) Ludlovien' interval of Algeria. No Pridoli interval is representedin their scheme. The somewhat vaguechronostratigraphic interpretation of the agesof the zonesis a problem with their schemeat this stratigraphiclevel. Keegan,Rasul & Shaheen(1990) publishedjust one palynological zone correspondingto the entire Ludlow seriesfrom the Kingdom of Jordan,as did Taugourdeau& jekhowsky (1960) for the Algerian Sahara.The type areafrom the UK has beenstudied by Lister (1970) and by Dorning (1981a, 1981b). The palynostratigraphyof the Silurian successionon Gotland is documentedby Le Herrise (1989)who looked at the acritarchsand Laufeld (1974) who studiedthe chitinozoans. The zonal schemeof Paris 1981covers only the lowermostpart of the Ludlow series, namely the Neodiversograplusnilisoni Zone. Generalcompgsition of the Ludlow agedassemblages. With the exceptionof the earliestLudlow assemblagesi. e. Association19 describedbelow, the Ludlow assemblagesare well preservedand of moderatelyhigh speciesdiversity. 7be,chitinozDans show a in major proliferation of species the assemblagesconsidered to be youngerthan the Lobograptus The to is inconsistentbut scanicusZone . acanthomorphic spheromorphicacritarch ratio somewhat the higher in gcanth rphs are noticeably abundancethan in the earliestLudlow and Wenlock Ludlow assemblages.The terrestrialcomponent of the agedassemblages studied makes up less than 1% of the palynomorphsum in eachof theseassemblages. lie acritarchassemblages are composedof inconsistentAmmonidiwn microcladwn, Cymbosphaaajum C bikidiwn in Gorstian spp., notably C. carinlosumand the agedsamples, common Diclyofidium spp., 245 commonDiexallophasis spp., inconsistentlycommon Leiqfusa estrecha, inconsistently abundant Multiplicisphaeridium cf. saharicum,and inconsistentOnondagella deunffi, Oppilatala eoplankonica and Acritarch Form G. Surprisingly, only one specimenof Neoveryhachiumcarminae was recorded in the entire study which was recoveredfrom a Ludlow agedsample. lie Chitinozoanassemblages are characterisedby abundantOngulachitina spp. and common Ancywhitina spp. including A. fragifis, A. primativa andA. packdffma. Calpichitina spp., Angochitina echinata,Pkaochitina carminae?and Sphaerochitinaspp. are also present. Detail of the biostratigMah&allyhighly constrainedsaMples. only three of the sevensamples of Ludlow ageare tightly constrainedbiostratigraphically by the graptolitic faunaspresent. Two associationsappear to be present,both of Gorstian age, (fig. 17) which are as follows. Association 19 (SeeTilia graph 12). Neodiversograptusnilssoni-Lobograptus scanicus Zone in age. This rather indistinct associationfrom the earliestLudlow, recordedfrom samplesJW 224 and DW 34, has many featuressimilar to thoseof the underlyingWenlock assemblages.The associationis characterisedby a high proportion of spheromorphicacritarchs and a highly impoverishedchitinozoan fauna. The commonacritarchs are Leiosphaeridia spp, and Acritarch Form L with inconsistent cymbosphaeridiwnspp. notably C bikidium, Mayotidium spp., Dituallophasis spp., Lophosphaeridiwnsp. 7 and Vubysphaeramicrospinosa var. C. The rare chitinozoansrecorded include Ancyrochitinafragilis var. A. Discussion: This rather impoverishedassociation contains few taxa of potential biostratigraphicvalue. CWnbosphaeridium bikidiwn was originally recordedfrom the BringewoodBeds of Shropshire(up pe r . Gorstian)by Lister 1970and from a similar stratigraphiclevel by Doming 1981 (Zone 2-early Zone 3). This taxon is recordedin the early Corstianhere which is lower than previousrecords from the UK. ,Ibe impoverishedchitinoman assemblageof Association19 containsno taxa in commonwith Zone 22 of paris (19gi) which occursat the samechronostratigraphic level. I'he first appearanceof Ancyrochitinafiragilis var. A in Association19 is of note. 246 Association 20 (SeeTilia graph 12). Saetograptusincipiens Zone in age. This associationis only recordedin samPleJW 10- It is composedof highly diverse acritarch and chitinozoanassemblages which contrastwith the low diversity assemblagesof Association 19. The characteristic acritarchs are common Cymbosphaeridium bikidium, C. Cariniosum, Da crylo fus a striatifera striatifera, Leiofiisa estrecha, Multiplicisphaeridiumi'uherl, Acritarch Form G and Acrit&rCh Form I. The chitinozoan assemblageis also diverse in species composition including Anc)mchitina ancyrea, A. ftagilis breWs, A. pilosa, Angochitina echinata, A. elongata, abundant Cingulochitina spp. notably C. cf. conveza and Cingulachitina sp. 1, and occasional MCIOChitina carminae? Discussiow. Severaltaxa recordedhere were reportedby Doming (1981) from the UK. He reported Ammonidiummicrocladwn, Oppilatala eoplan1donicaand Mukiplicisphaeridiumfisheri from sediments no younger than Wenlock in age. 7besetaxa are recordedin the presentassociation which is of late Gorstianage. CymbosphaeridiwnbiNdium hasa youngestoccurrence in the UK of earliestLudfordian (the lower part of Zone L3, Doming 1981)which is consistentwith the occurrenceof that taxon in the presentstudy. Both Onondagelladeunffi andLeiofiaa estrechaare reportedto havea rangebase at the baseof Zone L3 (Doming 1981)in the UK, however,these taxa are recordedin this older association in Morocco. In Gotland, the stratigraphicrange top of Ammonidiummicrocladum (Le Herrise 1989)is similar to that recordedhere. Onondagelladeunffl and Neovwqhachiumcayminae are examplesof other coincidentaltaxa from Gotlandat this stratigraphiclevel. 7be first appearanceof diverseand abundantAncyrochitina, Angochitina and Cingulochitinaspecies and the presenceof Pkaochitina carminae?are all of note at this stratigraphiclevel. Wdoli-Lower Devonian. Nine graptolite datedsamples have been analysed from this stratigraphicinterval. From the cluster analysiscarried out on Tilia graph 13, thereappears to be threeassociations present, the first including assemblagesfrom samplesDW 51, DW 52, DW 55 and DW 56, the secondincluding assemblages from DW 94, DW 57 and DW 58, and the third including assemblagesfrom DW 96 an DW 97. However, the secondcluster (DW 94, DW 57 and DW 58) is rather misleading. Analysis of the DW 94 it be different speciescomposition of sample shows to quite from samplesDW 57 & DW 58. The clusteringof the threesamples is a result of the coincidentnumbers of relatively insignificant taxa categorieson the Tilia graphplot, e.g. the Acanthomorphicacritarchs indet., Spheromorphicacritarchs indet and Lejosphaeridiaspp. For this reason,four rather than three associationsare describedfrom the Pridoli to Lower Devonianaged field samples(figs. 17 & 18). 247 Relevantliterature: 7be chitinozoansof the Silurian-Devonianboundary stratotypesin Bohemia are documentedby Paris, Laufeld & Chlupac(1981). The chitinozoanzonation of Paris (1981) also covers this interval in part. Ile chitinozoans,acritarchs and miospores;from the upper Silurian to Devonian of the Algerian Saharaare documentedby Jardine& Japaudjian(1968), Jardine et al. (1974) and Boumenjelet al. 1988.. In 1983,Wicander published a biostratigraphiccatalogue of the North American acritarchs. In addition, thereare numerousacritarch assemblages of late Silurian to Lower Devonian agereported from aroundthe globe, notably Cramer 1964, Deunff 1976,1980, Deunff & Paris 1971, Loeblich & Wicander 1976and Playford 1977.The miosporecomponent of palynological assemblagesgenerally become more significantbiostratigraphically late in the Silurian and through the Devonian. Significantpublications regarding Upper Silurian and Lower Devonian spore biostratigraphyinclude Richardson& Lister 1969,Richardson and McGregor 1986, Streelet al. 1987, Massa& Moreau-Benoit1976 and Steemans1989. Generalcomosition of the Pridoli to Lower Devonianaged assembla2es recovered from the field sampLes-. lie preservationof the assemblagesis moderatewith generallyhigh abundancesof palynomorphs recoveredand moderatespecies diversity. The dominantacritarch genera over this stratigraphic interval are Cymbosphaeridium,Dictyofidiwn, Diexallophasis,Leiosphaeridia and Vabysphaera. Biostratigraphicallyimportant generapresent are Actinophasis, Hapsidippalla, Onondagella, orygmahapsisand 7hysanoprobolus.The generaOngulachitina, Fungochitina, Muscochitinaand pkciochitina are all significant occurrenceswithin the chitinozoanassemblages. Detail of the Pridoli to Lower Devonianaged assemblages mcovered from the field samples. Association 21 (seeTilia graph 13). MonograptuslochkoWensis Zone in age. Assemblagesrecorded from samplesDW 51, DW 52, DW 55 and DW 56 are included in this includes association. The acritarchcomponent of the assemblages Ammonidiumsp. 2, cymbosphaeridiumpilar, Dkmallophasisdenticulata var. A, Multiplicisphaeridium variabile, Multiplicisphaeridiwn sp. 1, Orygmahapsisfistulosa,inconsistent Hapsidiopalla cf. sannemanni, Quadraditumfantasticumand 7hysanoproboluspoly)don, common\occasionalVisbysphaera form L. The microspinosavar. C and commonacritarch chitinozoanassemblage is relatively impoverishedwith Cingulachitinaervensis and C. cf. sematainconsistently present. Ile only miosporesrecorded in this associationare Retusotriklesspp. which consistentlymake up less than I% of the palynomorphsum. 248 Discussion- Taxa recordedhere in commonwith thoseselected by Jardine (1974) Jardine & - et at, and Yapaudjian(1968) to be of biostratigraphicallyvalue include only Cymbosphaeridiumpilar and Quadraditumfintasticum. Thesetaxa indicate a position of ZonesGS-H in the schemeof Jardine el al. and ZonesIV-Vb of Jardine& Yapaudjian. It is interestingto note that 7hysanoproboluspoly1don is here recordedin the Pridoli having previously only beenrecorded from the lowermost Devonian (e.g. Wicander 1981). Application of the chitinozoanzonal schemeof Paris (1981) to this associationis not possibledue to the impoverishedchitinozoan assemblages recorded. Association 22 (seeTilia graph 13). monograptus! ransgrediensZone in age. DW 94 is the only samplefrom which this associationwas recorded. The associationincludes abundantCy7nbosphaeridiwn sp. 1, CommonDiexallophasis denticulata var. A, Hapsidiopalla cf. sannemanni,Orygmahapsisfistulosa, Triangulina sanpetrensisand Visbysphaeramicrospinosa var. C. -Ibe chitinozoanassemblage is of moderatespecies diversity including, Angochitina echinata, Cingulachitina spp., Muscochitinamuscosa and Pkaochitina sp. 1. Discussion: The zonal schemeof Jardineet al. (1974) andJardine & Yapaudjian(1968) are not applicableto this associationdue to the lack of coincidentstratigraphically useful taxa. Paris (1981) defined a zonefrom this chronostratigraphiclevel, Zone 24, from SW Europewhich has no taxa in commonwith the associationdescribed here. Association 23 (seeTilia graph 13). Monograptus uniformis Zone in age. Assemblagesrecorded from samplesDW 57 and DW 58 are included in this association. lie include Diexallophasis significant acritarchspresent common denticulatavar. A, occasional Ammonidiumsp. 2, Cymbosphaeridiumpilar pilar andMultiplicisphaeridium variabik, Orygmahapsis ftstujosa, Riangulina sanpetrensis,Visbysphaera microspinosa var. C, Acritarch Form G and inconsistentDiexallophasis remota var. A and Acritarch Form J. The sparsechitinozoan assemblages includeAngochitina crassispina,occasional Hoegisphaera cL glabra, and occasionalCingulochitina SPP. first Discussion: It is interestingto note the occurrenceof Cýmbosphaeridiumpilarpilar s.s. as late as in Specimens Cymbosphaeridiwn the Gedinnian the presentstudy. of pilar recordedfrom the older sampleshave a lessprominent ornamentation than this variety from the Gedinnian. Ile youngest 249 Figure 18. A correlation of the standard ammonoid, conodont and graptolite zones, the Northern Gondwananchitinozoan zones and the O.R. S. continent spore zoneswith the palynologicalassociations defined herein from the Devonian. CONODONT 6W GRAPTOLITE SPORESZONE S.W. EUROPEAN AMMONOID ZONES U ZONES ZONES From Richardson CHITINOZOAN From PAILYNOLOGICAL ;5 morrowI From Cregor ZONES From House & Celdsetzer Jaeger & Nic ASSOCIATION V) 1988 From Paris 1981 1977 1988 1986 Wockumeria praesulcata Pusillites. .2 Stufe p ------ophyta z Association33 45 ------Clymenia eocpansa Stufe postera Flexuosa- z LZ Plat clymenia traehytera < SWf E r-C ------(L) marginifera I/ 0- E Association 32 M ------U- rhomboiden Cheiloceras W Stufe Torquata- crepida Association31 P.triangularis Crickitews holzapfeli gigas ------r ----- ro ------A. c: ManLicoceras triangularis Dvalis- corclatum bulliferus Pharciceras Association30 lunulicosta asymmetriums ------z Optivus- Maenioceras ------disparilus 4 triangulatus < 11 terebrawrn hermanni z it 0 z Maenioceras C-ri$-t2tU-s ------< Z -: -- oe > > molarium Lemurata. // W 7- varcus I ------maonificus 0 Cabrieroceras crispiforme ensensis ------kockelianus 01 - U-1 Pinacites -. 1 r- Association 29 0 ri jugleri Devonians- australis naumovii Anarcestes costatus o Association 28 lateseptatus ------patulus ------Sellanarcestes s; r`oJn7s Z, -I Velatus-langii wenkenbachi iversus ------38 q- M. Pacificus E --.. ------Douglastownense. Mimagoniatites gronbergi :Zý ------eurypterota 37 zorgensis clehiscens M. yukonensis z ------36 Association 27 0 Anetoceras ------Association 26 - hunsrueckianum 35 kindlei ------Po l ygOna lis. 34 M. fanicus emsiensis A! M. kayseri ------33 Uj (4 -X-11- "71 -567ci-tus- ý21 UL ___ 12 M. hercLniý_ ': ------Breconensis. --- 31 Us zavallatuis I delta- -ý7N`aeherc __ ------Association23 -j - 6ýrW- - yn icus aensis Micrormatus- hes---- erius 27 - --- M. uniformis newportensis Z st; tn Association 23 -harmemsis ------lartj 250 occurrencesof Ammonidiumsp. 2, Dituallophasis denticulatavar. A and Orygmahapsisfisfulosa are recordedat this level. Angochitinacrassispina is only recordedin this associationin the present study. Associations24 and 25. Theseassociations are describedfrom the assemblagesrecorded from Oum Doul-I and are documented later in this chapter. Association 26 (seeTilia graph 13). Monograptusyukonensis Zone in age. TUeassemblages recorded from samplesDW 96 and DW 97 comprisethis association. 7be association is dominatedby abundantCyrnbosphaerldium pilarpilar, Acritarch Form U and Cingulachitina spp., notably C. cf. conwwa,C serrata and Cingulochitinasp. 1. Other significant occurrencesinclude Triangulina Vishysphaera B C, ,4crinophasis cf. compluritala, sappetrensis, microspinosavars. and FungochitinaPistilliformis and inconsistentQuadradifum scutiferwn, Ancyrochitina tor?nentosa, A. jumida and questionableRerochitina perivelata. Discussion: As with the assemblagesfrom the Monograptusuniformis Zone, the specimensof cymbosphaeridiwnpilar are ornamentedwith relatively coarsegrana. Actinophasiscomplufilata has only previously beenrecorded from the Late Gedinnianof North America (Loeblich & Wicander 1976), the closely relatedmorphotype Actinophasis cf. complurilata is recordedhere from slightly younger sediments. Comparisonof the chitinozoanpart of the assemblagewith Paris 1981, table 39, showsmarked contradictions of the supposedchronostratigraphic ranges of someof the species recordedby that author. For example,several of the Cingulachifinaspecies supposedly restricted to the pridoli and Gedinniane. g. Cingulachitinasp. A (= Cingulachitinasp. I herein), C serrata and C. here in latest cf. serrata are recorded the Siegenianin considerablenumbers. Other notableoccurrenm Paris (198 include occurring youngerthan the recordsof 1) Ancyrochitinatormentosa, A. tumida, pterochitina perivelata?,Fungochitina pistillifomis lata. Ilese latter forms occur in far fewer numbersthan the Cingulachitinaspecies. Assemblagesrecovered from Oum Doul-1. Twenty-six core samplesfrom between1496m (Strunian) and 4215.4m of Ourn Doul-I have been describedfrom wAysed. The assemblagesare the oldest to the youngestfor reasonsof continuity with 251 the descriptionsof the Ordovician-LowerDevonian field samples. NO macrOfossildata for the well is availableto the author, hencethe datesassigned are derivedsolely from the palynological assemblages. Lower to Middle Devonian. Twenty samplesfrom this interval havebeen analysed,the assemblagesfrom which comprise five palynologicalassociations (fig. 18). Relevantliterature: The relevantpalynostratigraphic literature for this stratigraphicinterval has already beendiscussed in the sectiondescribing the Silurian to Lower Devonian aged field samples. 7be most significant comparativepapers include Paris, Laufeld & Chlupac 1981, Paris 1981, Jardine& japaudjian 1968,Jardine et al. 1974,Boumenjel et al. 1988, Wicander 1983, Cramer 1964, Diez & Cramer 1977,Deunff 1976and 1980,Deunff & Paris 1971, Loeblich & Wicander 1976, Playford 1977, Richardson& Lister 1989,Richardson & McGregor 1986, Streel et al. 1987, Massa& Moreau. ]Benoit1976 and Steenuns1989. Association 24 (seeTilia graph 14). This associationis describedfrom the four lowemostcore samplesfrom the well which are from the Lmhaifid Formationbetween 4214.5m and 4217mdepth. The assemblagesare generallyof high speciesdiversity. The acritarchsoccurring in high abundanceinclude Cymbosphaeridiumpilarpilar, C. pilar scabratum,Dierallophasis denticulata, D. reinota, D. remota rabiosumand M"Itiplicisphaeridiwn reunispinosum.Several taxa of biostratigraphicalvalue occur in lower numbers including Dateriocraduslindus, Multiplicisphaeridiumlobanum, M. raspum, Onondagelladeunffl, Ozotobrachionpalidodigitatus, Rerospermellaonondagaensis, and Quadraditumfintasticum. Ile. chitinozoanassemblages are also diversein speciescomposition with Angochitina ch1upachi, angulachitina spp, Hoegisphaeracf. glabra and Sphaerochitinasphaerocephala all prominent. The include other notableoccurrences within the chitinozoanassemblages PterochitinaPerivelata, Urnochitina urna and Calpichitina sphaerica. Ile sporesmake up approximately30 % of the This is dominatedby Retusotriletes palynomorphsum. component spp. with rare Apiculiretusotriletes spp. The presenceof Brochotrietesspp. and zonatespores (plate 136, figs.3 and 6 respectively)is significant for biostratigraphicpurposes. ]2Ls:,cussion- The previouslypublished stratigraphic ranges of many of the taxa recordedappear to indicate contradictoryages for this association.Within the chitinozoancomponent of the assemblages, biostratigraphicmarkers. Paris (1981) Pteroch seve,ral speciesare significant considered iti na pMveW a be lending and Urnochitina Urna to zonal species, their namesto his two zonesfrom the Pridoli (Paris 252 1990, table 40). The rangesof thesetwo speciesand the also presentSphaerochiti na sphae ro Cephala is illustrated by Paris (1981, table 39) as being restrictedto the Pridoli. However, the presenceof Angochitina chlupaci and Calpichitina sphaericais not consistentwith a Pridoli age for this association. The stratigraphicrange of thesespecies does not extenddown into the Pridoli but would appearto indicatea Lower Gedinnianage. Ilie acritarchassemblages appear to be dominatedby forms having previous stratigraphicrecords from the Lower Devonian. Theseinclude Ozotobrachlonpalidodigitatus (Godinnian-Emsian,Cramer 1966, Playford 1977),Dlexallophasis remota var. rabiosum(Siegenian-Emsian, Cramer 1964,1970), Multiplicisphaeridium lobeznwnand M. raspum(both Middle Siegenian-Emsian,Cramer 1964). Both C?uaraditumfantasticum and Onondagelladeunffi which occur in the late Silurian are reported to rangeinto the Gedinnian(Diez & Cramer 1977). It is interestingto note that Cymbosphaeridiumpilar pilar s.s. was recordedfrom the macrofossildated field samplesstudied here that are Gedinnianand younger in age. Within the sporeassemblages, the presenceof rare zonatespores and Brochotriletesspp. is important. Richardson& McGregor (1986) record the first appearanceof zonatemiospores within their is micrornatus-newportensisZone which of Gedinnianage. Forms with foveolateornamentation are also interpretedas having their first appearanceat this level. Considerationof the acritarchand sporeassemblages would appearto indicatea Gedinnianage for this association. The chitinozoanassemblages also possessspecies indicative of a Gedinnianage, however they do contain forms that havepreviously been reported as being restrictedto the Pridoli, e.g. pyeroýhitinaperivelata, Urnochilina urna and Sphaerochitinasphaerocephala. Ilese latter species may either be interpretedas ranging into the Gedinnianor, more likely, they are reworked. The presenceof zonatespores and Brochotriletes sPP. suggests that this associationis younger than lowermostGedinnian (Richardson & McGregor 1986)which implies that this associationis younger than Association23. A&wdation 25 (seeTilia graph 14). This associationincorporates the assemblagesrecovered from threecore samplesbetween depths 4069.Sm and 4071.5m from the Lmhaifid Formation. The diverseacritarch component of the by C)vnbosphaeridium assemblagesis dominated common pilar pilar, abundantDiexallophasis denlicuMtaand commonA remotavar. rabiosum. Biostratigraphicallysignificant taxa occurring in fewer numbersinclude Baltisphaeridiuman ifractum, Daisypilula compacta, Demor, het hi um cf. jappaceum,Diexallophasis remota var. A, Onondagelladeunffl, Onondagellasp. 1, Ozotobrachion 253 furcillatus, 0. palidodigitatus, Pterospermella circumstriata, Quadraditumfantasticum, 7hysanoprobolus polybon and Triangulina alargada. Ilie chitinozoanassemblages are of moderatelyhigh diversity but only moderateabundances of tax& recorded. The genusAncyrochitina is representedby rareA. tormentosaand A twnida. Five species of Cingulachitina are recordedincluding the biostratigraphicallysignificant form C. plusquelleci. Eisenackitinaspecies are prominentincluding commonE. taugourdeauiand rare E. raucheri. Other significant occurrencesinclude Fungochitina pistilliformis lata, Margachilina spp. notably M. Catena?ja crassipesand M. catenariatenuipes, Muscochitina muscosa and Pterochitina perivelxa. 11lespores make up lessthan 5% of the palynomorphsum in this associationwith Retusotrileresspp. donjumt and tripapilate forms common. Zonatespores also occur in low numbers. Discussion: Severalof the chitinozoanspecies recorded here were reported from south-westEuropean sectionsby Paris 1981. The co-occurrenceof Muscochitinamuscosa, Ancyrochitina tormentosa, CingulachitinaPlusquelkci, Margachitina catenariafenuipes, Eisenac)dtina raucheri, E. raugourdeaui and Fungochitinapistilliformis lata hereclearly indicatesthat this associationis assignableto Zones29 to 30 of Paris (1981, table 39). This would indicatean ageof late Gedinnianfor the association. Ile occurrenceof Rerochitina perivekita andMargachitina catenaria crassipesat this stratigraphiclevel is 39). This be interpreted ftwffier for rather anomalous(see Paris 1981,table could as evidence the reworking of Pridoli agedsediment during the Gedinnian. lie ageindicated from the acritarchassemblages is clearly consistentwith that derived from the chitinozoans. Forms suchas Daisypilula compactaOate Gedinnian, Loeblich & Wicander 1976), Demorhethiumlappaceum (late Gedinnian,Loeblich & Wicander 1974,1976; Gedinnian,Deunff 1980), Ozotobrachionfurcillatus(Late Gedinnian-MiddleDevonian, the late Gedinnianrecords include Loeblich & Drugg 1968and Loeblich & Wicander 1974), 0. palidodigitatus (Gedinnian-Enisian, Cramer 1966, Playford 1977),Plerospemella circurmtriata OateGedinnian-Emsian, Loeblich & Wicander 1976), Quadraditumfintasticum(Llandovery-latest Gedinnian, Diez & Cramer 1977; Gedinnian,Deunff 1980), 7hysanoproboluspolyhon (late Gedinnian,Loeblich & Tappan 1970, Loeblich & Wicander 1976; Gedinnian,Deunff 1980)and Triangulina alargada (Gedinnian-Givetian, Diez & Cramer 1977; Gedinnian,Deunff 1980)are all typical of Gedinnianaged assemblages. The taxon Diouallophasisremota var. A was recordedin the macrofossildated field samplesor earliest C;edinnian age and would appearto rangeupto the late Gedinnianon the evidenceof the associated Baltisphaeridium palynomorphsfound here. anfracrumappears to occur at a Youngerstratigraphic level in morocco comparedto previousrecords from North America (Wicander 1983). Onondagella biostratigraphic has sp. I is a distinctive palynomorphof potential use and previously beenreported by Al-Ameri (1986) as PuMnosphaeridiwnsp. from the Lower Devonianof North Africa. 254 The rather indistinct miospore assemblagescontain zonate forms suggesting an age younger than earliest Gedinnian (Richardson & McGregor 1986). The acritarchand chitinozoanassemblages strongly indicatean ageof late Gedinnian for this mociation. Association 27 (seeTilia graph 14). 71e assemblagesfrom two samplesfrom the AssaFormation between depths 3675m to 3677.5m are included in this association. The assemblagesare of moderatespecies diversity dominatedby the acritarchsDiexallophasis remota rabiosumand D. remotaremota. Other notableacritarchs present in lower numbersinclude Ammonidiwn?alloiteauli, Candekisphaeridiumcf insolitum, Florisphaeridium loyetae,herospermella onondagaensis,Triangulina alargada and Winwaleosiadistracta. The sparsechitinozoan assemblage includes Ongulachitina serrata, Margachitina catenaria catenaria and Sphaerochitinasphaerocephala. TUe sporesare relatively high in abundancemaking up over 40 % of the palynomorphsum within the assemblages.Biostratigraphically significant occurrencesinclude Mayotriletes emsiensis,D. richardsoni andDibolisporites variverrucatus. Discussion: There appearsto evidenceof the mixing of palynomorphsfrom two stratigraphicintervals. - The sporesDictymiktes enviensisand Dibolisporites variwmcatus were recordedby Massa& Moreau-Benoit(1976) from Ubya within their Zone 2, for which an ageof late Siegenianto earliest Emsianwas proposed. The stratigraphicrange of A entsiensison the Old Red Sandstonecontinent, Siegenianto early Emsian(Richardson & McGregor 1986), supportsthe datationof Zone 2 by Massa & Moreau-Benoit. The acritarchFlorisphaeridium toyetae is previously recordedfrom the middle Siegenian-Emsian(Cramer 1964). The co-occurrenceof D. emsiensis,D. variverrucatusand F. toyetae indicate an ageof late Siegenianto early Emsianfor this association. However, severaltaxa indicativeof a Gedinnianage are also recordedin this association. Ilese include the acritarchCandelasphaeridium cf. insolitum (Gedinnian,Deunff 1980; Steemans1989), the chitinozo&nscingulachitina serrata (Pridoli-Gedinnian,Paris 1981),Margachitina catenaria Catenaria (middle Gedinnian,Paris 1981)and Sphaerochitinasphaerocephala (Pridoli-earliest Gedinnian,Paris 1981), and the sporeDicryotriletes richardsoni (Gedinnian,Steeman 1989). This appearsto be further latestSilurian Devonian evidenceof reworking of and early sedimentsduring the Lower Devonian interval. 255 A&wdation 28 (seeTilia graph 14). The assemblagesfrom sevensamples from the N'Kheila Formation betweenthe depths3239m and 3504.2mare includedin this association. The acritarchassemblages shows a markedcontrast in compositionto theseof the underlying association. 7bere is a distinct increasein the abundanceof Ammonidium?alloiteauil and Gorgonisphaeridiumtelum with severalforms making their first up-sectionappearance including Craterisphaeridiumsprucegrovensis, Cymatiosphaera carminae, NaWfiisa bacilla, N. minuta Onondagellaaspwnetfica, Polyedryxiumevolutum, A embudum,and A pharoane. There is a notable reductionin the abundanceof Diexallophasisremota compared to the underlying association. Ile chitinozoanassemblages also show a markedchange in this association. The Angochitina phi,Uppoti complex of speciesis very conspicuoushere with the presenceof Burrachitina bursa and Eisenackitinacastor also of stratigraphicsignificance. Ancyrochitinaancyrea var. A is inconsistently presentin this association. The sporesassemblages are dominatedby large grandisporesand includesstratigraphically important speciessuch as Emphanispofites annulatus, Grandispora douglwtownense, G. gabesensisand G. protea. Diatomozonotriklessp. and Hystrichosporilesspp. are also present. A single specimenof Ancyrosporanettersheimewls was recoveredfrom the uppermostsample included in this association. piscussion: Comparisonof the sporeassemblages of this associationwith assemblagesfrom the GhadamisBasin, Tunisia (Loboziac& Streel 1989)indicates an Eifelian age. This is basedon the co- occurrenceof Emphanisporitesannulatus, Grandispora douglastownense, G. gabesensisand G. protea. Comparisonwith the zonationscheme of Richardson& McGregor (1986) showsthat the associationis douglastownense-A. probably assignableto their G. eurypterotaZone basedon the presenceof G. douglastownense,G. protea (= Calyptospofitesproteus) andAncyrospora nettersheimensis. This zone is indicatedto OCCUPYthe latestEmsian to earliestEifelian interval by the authors. Considerationof sporedata from both Northern Gondwana(Loboziac & Streel 1989)and the Old Red Sandstone indicates continent (Richardson& McGregor 1986) an ageof early Eifelian. The acritarchcomponent of the assemblagesis consistentwith a Middle Devonian age for the N. bacillum, Onondagella association. NaWfiuaminuta , asymmetricum,Polyedryxium embudum, P. in Eifelian evolutumand P. pharoaneare all typical the (Deunff 1955,1966,1971, Legault 1973, Playford 1977, Wicander 1983). The abundanceof Ammonidium?alloiteauii and the first upsection Stellinium recordsof awerisphaeridiwn sprucegrovense, octoasterand Cymatiosphaeracarminae are notable stratigraphicOCCUffences. 256 The notable featurewithin the chitinozoancomponent of the associationat this stratigraphiclevel is the marked increasein abundanceof chitinozoanswith abundant\commonforms assignableto the Angochitina philippoti complex. Bursachitinabursa and Eisenackitinacastor andAncyrochitina ancyreavar. A are the other morphologicallydistinct forms of note here but theseforms do not occur in all the assemblagesincluded in this association. A&wdation 29 (seeTilia graph 14). The assemblagesfrom four samplesfrom the N'Kheila Formationbetween the depths3130.65 and 3186.5 are included in this association. The compositionof the assemblagesis not dissimilar to thoseof the underlying association28, however there is a markedchange in abundanceof severalof the taxa present. This is confirmedby the dendrogramillustrating the clusteranalysis on Tilia graph 14. Within the acritarchcomponent, the most notablechange is the increaseabundance of Veryhachiumspecies, notably V. cf. arcarium and V. cf. cymoswn. 7be other acritarchswith a notableincrease in abundanceare Polyedryxiumpharoane and cf. Tunisphaeridiumsp. A notabledecrease in abundancefrom the underlying associationis that of Ammonidium?alloiteauii. MultipUcisphaeridium?sp. 2 is the only acritarch to makesits first upsection appearancein this association. The chitinozoansare far lessnumerous than in Association28. Forms assignableto the Angochitina philippoti complexare still prominentwith Bursachitinabursa andAncyrochitina ancyrea var. A present. The sporeassemblages are onceagain dominated by Grandisporasýp. which, due to poor preservation, were found difficult to speciate. A notableaspect of this assemblageis the increasein abundanceof Ancyrosporanettersheimensis. Discussion: The presenceof Ancyrosporanettersheimensis suggests that the associationis no younger than Eifelian in age(Loboziac & Streel 1989). This is substantiatedby the absenceof the ubiquitous speciesGe? ninospora kinurata which has a Givetian and youngerrange. Ancyrosporanettersheimensis has beenrecorded in over 50 wells from the subsurfaceof Libya with a similar trend in abundancesas that recordedin the presentstudy (P. Swire pers. comm 1992). 7be increasein abundanceas recorded in this associationis believedto occur in the late Eifelian. As the association,the acritarchsand NaWfusa N. with underlying chitinozoansrecorded e.g. minuta , bacillum, Onondagellaasymmerricum, Polyedryxium evolutum P. pharoane and Bursachitinabursa are consistentwith a Middle Devonianage (Deunff 1955,1971, Legault 1973, Wicander 1983). 257 UDger Devonian. Twenty samplesfrom this interval havebeen analysed,the assemblagesfrom which comprisefive palynological associations(fig. 18). Relevantliterature: The publicationsconcerning material from Libya and Algeria (Paris et al. 1985, Streel et al. 1988, Loboziac& Streel 1989,Boumenjel et al. 1988, Massa& Moreau-Benoit1976) and the Ardennesand Belgium (Martin 1981,1982,1984, Streelet al. 1987) for this stratigraphicinterval are most comparablewith the assemblagesrecorded in the presentstudy. Comparisonwith previous studiesin the UK and Eire (Richardson& McGregor 1986, Higgs Clayton & Keegan1988), North America (Wicander1974,1983, Wicander& Playford 1985, Wicander& Loeblich 1977,Jenkins & Legault 1977)and Brazil (Brito 1967) are also madewhere relevant. Association 30 (seeTilia graph 14). The assemblagefrom a single sample,OD 2409.65from the Anou SmairaFormation comprisesthis association. The associationis markedlydifferent in speciescomposition to the previous. This associationincludes the first appearancesof the acritarchsAmmonidium grosjeanii, DailWium pentaster,Diewallophasis reinota tyrea, Maranhitesspp. notably M. britoi andM. stoclanansil,Palacanthus tripus, Pratukisphaeranovacula, Quisquilitesbuckhornensis, Stellinium comptumand Umbellasphaeridium d&ndrel. Also prominentare abundantTasmanites spp. and Craterisphaeridiumsprucegrovense. The chitinozoanassemblage is dominatedwith the speciesSphaerochitina pilosa which makesup approximately4% of the palynomorphsum. The poorly preservedspore assemblage lacks the Grandisporaspecies that dominatedthe assemblages of Association29. DiscussianL.7be chitinozoanSphaerochitina pilosa has a strat'graPhicrange of late Emsianthrough Frasnian(Jenkins 8-' LegRult 1979, Streelet aL 1988)indicating an ageof no younger than Frasnianfor this association. The diverseacritarch assemblage suggests an ageof Famennian,probably lower Famennianbased on comparisonprimarily with materialdocumented from outcrop in Belgium (Martin 1981,1982,1984) Libya and also from the subsurfaceof (Streelet at. 1985, Paris et al. 1988, P. Swire pers. comm. 258 1992). When compared to material of Late Devonian age from Belgium, the present assemblageshave many species in common. The material studied by Martin (1981,1992,1984) is dated by shelly macrofaunas and ranges between early Frasnian and early Famennian in age. In her 1981 publication in which she documents the latest early Fammenian aged assemblages, the coincidence of taxa present with the present study is greater than those from the Frasnian. These coincident taxa include Maranhites b?*oi, M. stoclanansii, DailWium pentaster, Polyedryxium pharoane (-Eisenackidium martensianwn), Ammonidium grosjeanil, A. sprucegrovensis and Stellinium comptwn. However, it is notable that Ephelopalla gorkae, recorded in the overlying Association in the present study, is typical of the latest early Frasnian interval in Belgium and it may be concluded, therefore, that this association is older than the latest early Frasnian. In Libya, several prominent speciesobserved here and in Belgium e. g. Maranhites spp. are not recorded, however taxa such as Umbellasphaeridium deflandrei and Craterisphaeridium sprucegrovensis are recorded from the Frasnian of Libya. It is interesting to note the occurrence of a flood of tasmanitids in Libya during the early Frasnian (P. Swire pers. comm. 1992). Similarly high abundancesof Tasmanites spp. are recorded in the present association, however, one can not be over cautious in correlating such events from one sedimentary basin to another. The only previouslypublished record of Pratulasphaeranowular appearsto be from the Frasnianof Iowa, USA (Wicander& Playford 1985). This record is consistentwith the ageassignation of the presentassociation. From the chitinozoanand acritarchdata available from North Africa and Belgium, a Frasnian,probably early Frasnianage can be assignedto this association. It is interestingto note the absenceof Geininosporakmurata from the presentstudy. This taxon occurs in greatestabundance in the early\middleGivetian at which time it appearsto be almostubiquitous (Streelet aL 1987, Loboziac& Streel 1989,Loboziac pers. comm. 1992). It occursin lower numbers and is more sporadicgeographically in the Frasnian(P. Swire pers. comm. 1992). This speciesis not recordedfrom the Frasmanaged Moroccan assemblages studied here. Association 31 (seeTilia graph 14). The assemblagesfrom two samplesfrom the Draa Formationat depths1809m and 1809.3mare included in this association. The acritarchassemblages are diversein their speciescomposition with the most notablechange from the underlying associationbeing the abundantpresence of Gorgonisphaeridi= spp, notably the G. spicatumcomplex of forms. Also prominentare Baltisphaeridium?sp. 5, Cý7=josphaera konensis, 259 DailWium pentaster,Diexallophasis reinota var. tyrea, Ephelopalla gorkae, Maranhitesmosessil, M. stoclanansii, MuraticaWa sp. 1, herospemella eruptio, Stellinium Comptum, S. octoaster Umbellasphaeridium deflandrzi and Acritarch Form P. Biostratigraphically significant forms occurring in low abundancesinclude Crassiangulina tesselita and Palacanthustripus. Ammonidium grosjeanli is far lesscommon than in the underlyingassociation 30. No chitinozoansare recordedin this association. Within the sporeassemblages, the stratigraphicallyuseful speciesAuroraspora torquata and Ancyrosporafurcula are present. Discussion: T'hepresence of Aurorasporatorquata in the associationenables the applicationof the zonal schemeof Richardsonand McGregor(1986). Its presencesuggests that the presentassociation is assignableto the torquata-gracilisZone or younger,implying an ageno older than latestFrasnian. This age is refined by the acritarchassemblages when they are comparedwith thosefrom Belgium documentedby Martin (1984). The compositionof the presentassociation indicates a correlationwith her assemblagesIII to V. This is basedon the co-occurrenceof Ammonidiumgrosieanii, Daillydium pentaster,Diexallophasis remota var. tyrea, Maranhitesmosessli, M. stoclanansii,Craterisphaeridium sprucegrovense(=Ammonidium sprucegrovense), Palacanthus tripus, Polyedryxiumpharoane, Rerospermellaeruptio, Stelfiniumcomptwn and S. ocioasterhere and in Belgium. An early Faxnennianage for the associationcan thereforebe inferred. The broad natureof the publishedstudies concerning material from the subsurfaceof Libya (Streeler al. 1985, Paris ef al. 1988)and Algeria (Jardineet al. 1974)makes comparison of the present assemblagesimpractical. Association 32 (seeTilia graph 14). The assemblagesfrom two samplesfrom the Draa Formationat depths1612m and 1612.1m are included in this association. The assemblageis dominatedby the super-abundanceof Gorgonisphaeridiumspp. There is a changein the compositionof the Gorgonisphaeridiumcomponent of the assemblagesfrom the underlying associationwhich is dominatedby the Gorgonisphaeridiumspicatum complex. 7be presentassociation is dominatedby the Gorgonisphaeridiumohioense complex with the first stratigraphicoccurrence of Gorgonisphaeridiwn?sp. 2 and Gorgonisphaeridiumsp. 3 also at this level. Taxa occurring in fewer numbersinclude aassiangulina tesselita,Craterisphaeridium sprucegrovensis, Ephelopalla gorkae, 260 Muraticavia sp. 1, Polyedryxiumpharoane, Stelliniwn comptum,S. ocloaster and Veryhachiumdowniel downiei. No chitinozoansand no agediagnostic miospores are recordedin assemblagesconstituting this association. Discussion: Comparisonof this associationof acritarchswith the literature indicatesan ageof Famennianor older (Streelet al. 1985,Paris el aL 1988,Jardine el al. 1974). Recentunpublished work on the subsurfaceof 11bya(P. Swire pers. comm. 1992)indicates that Craterisphaeridium sprucegrovensishas a stratigraphictop in the early Famennianby the calibration of the occurrencesof this form with the associatedmiospore assemblages. The presenceof this form, therefore,and the stratigraphicpopition of the associationin the well (i. e. aboveAssociation 31 which is interpretedas e4rly Famennianin age)indicates an ageof early Famennian. There is evidenceof reworking at this stratigraphiclevel indicatedby the presenceof the Upper Silurian to Lower Devonianspecies Onondagella deuqffl. 7be presenceof severalother taxa within the associationas a result of reworking (e.g. Ephelopallagorkae, MuraticaWasp. 1, Polyedryxium pharoane) can not be ruled out. Association 33 (seeTilia graph 14). The assemblagefrom one sample,OD 1496from the Lefdar Formation at depth 1496min the well constitutesthis association. As with Associations32 and 33, the acritarchcomponent of this associationis dominatedby the super. abundanceof Gorgonisphaeridiumspp. with the Gorgonisphaerldiumohioense complex predominating. The Gorgonisphaeridiumspicatum complex, Gorgonisphaeridium?sp. 2 and Gorgonisphaeridiumsp. 3 are also prominent. Other stratigraphicallysignificant forms occurring in low numbersare Crassiangulinatesselita, Maranhites spp. notably Maranhiles sp. 1, Terraporinahorologia, T. quadrispinaand Umbellasphaeridiumsaharicum. Severalacritarchs; present are discussedbelow as having beenreworked e. g. aaterisphaeridium sprucegrovensis,Polyedryxiwn pharoane and A embudum. one specimenof Sphaerochitinapilosa was recoveredfrom this assemblagewhich is believedto be strong evidencefor the presenceof reworkedpalynomorphs (see discussion below). Ile diversemiospore assemblage recovered includes several age diagnostic forms including Refispora Vekitispofites kpidophyta, pusillites, Discemisporitesmicromanifestus, Spelaeotdktes granuWus and Aurorasporalorquata. 261 DiscuwionL The miosporespresent in this associationenable a refined biostratigraphicage to be assigned. Ile presenceof Redsporakpidophyta, Velatisporitespusillites, Discernisporites micromanifestusand Auroraspora torquata suggeststhat the associationcan be assignedto the pusillites-lepidophytaZone of Richardson& McGregor (1986). This indicatesan ageof early Strunian. An ageno more refined than Strunianis indicatedby the applicationof the zonal schemeof 11iggs,Clayton and Keegan(1988) in which the co-occurrenceof X kpidophyta and V. pusillites implies the presentassociation is assignableto their LL-LN Zones. Further unpublishedevidence from Ubya of an early Strunianage comes from the presenceof commonSpelaeotriletes granulatus in associationwith R. kpidophyta (P. Swirepers. comm. 1992). The acritarchsCrassiangulina lesselita, Tetraporina horologia, T quadrispinaand Umbellasphaeridiumsaharicum are all previously recordedfrom the Strunianof North Africa (Streelet al. 1985, Paris et al. 1988,Jardine et al. 1974),however, it is interestingto note that the latter three, Tetraporinahorologia, T quadrispinaand Umbellasphaeridiumjaharicum, are not recordedin the Frasnianto early Famennianassemblages here which differs from the pervious recordsin Libya (see Paris et al. 1988). There are no unequivocalrecords of Strunianaged chitinozoans in the literature to my knowledge. The species recoveredin the presentassemblage, Sphaerochitina pilosa, has a publishedstratigraphic range top in the Frasnian(Jenkins & Legault 1979, Paris et al. 1988), henceit safeto say that the occurrence of this form in Strunianaged sediments indicates the presenceof reworkedpalynomorphs. Further evidencecomes from the acritarchcomponent of the assemblagesin which the previous recordsof severalforms e.g. Polyedryxiwnembudum (Emsian-Givetian, Deunff 1966,1971, Playford 1977) indicaterecycling has occurred. It shouldbe noted, therefore,that taxa whosestratigraphic occurrence is not previously documentedfrom this level (e.g. Craterisphaeridiwnsprucegrovensis, DailWium pentaster,Polyedryxium pharoane and Pterospe?mella eruptio) could very possibly be recycled. 262 Chapter 8. Environmental palynology. Previousstudies regarding the spatialdistribution of palynomorphs(e. g. Muller 1959, Staplin 1961, Aldridge et al. 1981,Doming 1987)have revealedtrends in the gross morphologyof the constituents of palynologicalassemblages from the terrestrialrealm through the continentalshelf and out into abyssalareas. In the presentstudy, the relative abundanceof palynomorphgroupings have been calculatedin order to investigatethe palaeoenvironmentsof depositionof the samplesstudied. The environmentalmodel of Doming (1987), constructedon data from the Palaeozoic,is applied here and the resultsare consideredin conjunctionwith the sedimentalogicaldata available. The groupingsutilised am the acritarchs,which are split into 'acanthomorphs','spheromorphs' and 'other acritarchs'sensu Cramer & Diez 1979,prasinophytes, chitinozoans and spores. The proportions of thesegroups are illustratedon Tilia graphs1-14. In summary,Doming (1987) recognisedtrends in the grosscomposition of palynologicalassemblages recoveredfrom i. sedimentsdeposited in the littoral or nearshorezone, ii. sedimentsdeposited in the neritic zone(on the mid to outer shelf) and iii. sedimentsdeposited in the bathyal and abyssalzone (figs. 19 & 20.) Within the littoral zone,low diversity marinepalynofloras are dominatedby thin walled spheromorphic acritarchs. Thesesimple acritarchsmay be accompaniedby flask shapedchitinozoans without long spinese. g. Sphaerochitina(Laufeld 1974). In the late Ordovician, Silurian and Devonian(i. e. the period of primitive land plant colonisationand diversification), the marine elementis commonly associatedwith high proportionsof miosporesderived from the adjacentlandmass. Ile proportions of the allochthonousterrestrial element is obviously strongly influencedby the sedimentationrates prevailing at the time of deposition,however, the proportionsof miosporesin the assemblagescan give a generalindication of the distancefrom shorelineof the site of deposition. The abundanceof miosporespresent can be generallyinterpreted as being inverselyproportional to the distancefrom the palaeoshoreline. The mid to outer shelf areasupports a higher diversity microflora with acanthomorphicacritarchs dominant. The associatedchitinozoans include forms with complexand elaborateornamentation e. g. Ancyrochitina, Pkaochifina. Assemblagesrecovered from sedimentsdeposited in the abyssalrealm have a low diversity composition dominatedby spheromorphicacritarchs as in the littoral zone. However, spheromorphicforms recoveredfrom sedimentdeposited in deeperparts of the basin are noticeablythicker walled e.g. Lejosphaeridiamicrocystis. Prasinophyceanalgae are also commonly associatedwith suchdeposits, notably Tasmanites 263 Figure 19. Palynomorph distnbution across the continental shelf for the Ordovician (Caradoc) and the Silurian (Wenlock). Ordoy, cian: Caradoc ffl LwDi No A, *Im C) C: D )L- - 9 N '00 Des Cya Lag Anc Ordovician diagrammatic distribution Fig. 14.4 - organic palaeontology; sketch of selected palynomorph from the Caradoc carbonate shelf. L. Leiosphaeridia, N. Navifusa, P. Peteinosphaeriýium, B. Baltisphaero- Micrhystridium. Spores: Di. Chitinozoansý Des. sum, V. Veryhachium, M. Diadospora, No. Nodospora. Desmochitina, Cya. Cyathochinna, Lag. Lagenochirina, Anc. Ancyrochirina. S, jur an Wenýock - M\L Lin Con Anc Son Fig. 14.5 SJurian organic palaeontology; diagrammaticsketch of selectedpalynomorph distribution from the Wenlock carbonate shelf. L. Leiosphaeridia, P. Pterospermella,S. Salopidium, D. Diexallophasis, M. Micrhystridium, V. Veryhachium. Spores: Am. Ambitisporites, al. alete spores with thickened equatorial margin. Chitinozoans: Lin. Linochirina. Con. Conochitina,Anc. Ancyrochinna, Sph. Sphaerochinna. 264 Figure 20. Palynomorph distribution across the continental shelf for the Devonian (Givetian) and the early Carboniferous (Toumasian). Devonian: G,vet. an Re Ac Gr OX Des Anc A, g Soh Fig. 14.6 Devonian organic palaeontology; diagrammaticsketch of selected palynomorph distribution from the Givctian carbonate shelf. L. Lewsphaeridia, P. Pol yedrixiurn, M. Multiplicisphaeridium, G. Gorgon isphaeridiurn, V. Veryhachium. Spores: Re. Rewotriletes,, Ac. Acinosporites, Gr. GrandLspora. Chitinozoans: Des. Desmochitina, Anc. Ancyrochum, Ang. Angochirina, Sph. Sphaerochinna Caroorife, ous Tournais-an G4 sG ýW Fig. 14.7 - Carboniferous organic palacontology; diagrammaticsketch of selected palynomorph distribu- tion from the Tournaisian carbonate shelf. L. Leiosphaeridia,S. Stellinium, G. Gorgonisphaeridium, U. Unellium, M. Micrhystridium, V. Veryhachium,Spores: Re. Reworriletes, Sp. Spelaeorriletes. 265 spp. Ile chitinozoansrecovered from deepwater sedimentstend to be small forms, Suchas Desmochitinaspp., andlack the elaborateornamentation of thosecommonly recoveredfrom shelf deposits. An exampleof palynomorphdistribution acrossthe continentalshelf for eachof the systemsstudied here, namely the Ordovician,the Silurian and the Devonian is presentedby Doming (1987), figs. 19 & 20. Ilese, are useful for comparisonwith the palynomorphtrends observed. Doming (1987) considersrelative water depth, nutrient supply, oxygen availability and the rate of sedimentation to be the major factorscontrolling the distribution of palynomorphs;in the marine realm. His broad model is basedon observationsin the field and on the considerationof the interplay of these factors acrossa. typical teffestrial-shelf-abyssaltopography. Recentpalaeogeographic models for Northern Gondwana(e. g. Scotese& McKerrow 1990, Paris 1992, T. P. Young pers. comm. 1992)indicate that a shallow topography,relatively stablecontinental situation prevailedin Morocco throughmost of the Ordovician to Devonian interval during which an almost completesequence of sedimentswere deposited(Destombes, Hollard & Willefert 1985). The Ordovician. All the assemblagesanalysed from the Ordovicianin the presentstudy are marine in origin. In general, the preservationof palynomorphsis rather poor so caution must be expressedin nuking interpretation of the assemblagesrecovered which are probably not a full representationof the original assemblage that was deposited. Howeversome broad conclusionscan be drawn. Ile FezouataFormation. (sm Tilia mphs 1-6). The assemblagesrecorded from this formation are dominatedby acanthomorphicacritarchs which indicate depositionin a mid to outer shelf setting. 7be assemblageincluded in Association2 is the only exceptionfrom the FezouataFormation assemblages analysed. Here, the assemblageis of a much lower speciesdiversity, dominatedby one species,Cý7=iogalae messaoudii,of the 'other acritarch' group. The high abundanceof this form is at the expenseof the acanthomorphicacritarchs. This may indicate a more stressfulenvironment of deposition(e. g. high salinity, near shore)at that time. 71ere is no lithological reflection of this apparentchange in the depositionalconditions. 266 The Tachila Formation(see Tilia graph7). The assemblagesrecorded from the Tachila Formationare also dominatedby acanthomorphic acritarchs. The spheromorphspresent are relatively thick walled. The chitinozoanelement is diverse in specieswhich commonlypossess relatively elaborateonamentation for this stratigraphicinterval e.g. Belonechitinamicracantha. Ile environmentof depositionenvisaged for this associationof palynomorphsis outer shelf. The fine grainednature of the shalelithology supportsthe idea that depositionoccurred in a relatively low energyenvironment. Ibe KtaouaFormtion (seeTilia gmphs8-10). The samplesanalysed from the Caradocaged part of the KtaouaFormation yielded particularly poorly preservedassemblages. Low diversity acanthornorphicacritarchs predominate and the chitinozoans, when preserved,are generallyforms of modestor low ornamentation. Deposition of thesesediments probably took placein a mid to outer shelf setting. The assemblagesof Ashgill agefrom the KtaouaFormation contain acritarchassemblages of moderate speciesdiversity. The assemblageincluded in AssociationII possessesabundant acanthomorphic acritarchswith commonleiofusids. Poorly preservedAncyrochitina spp. are also recorded. No more than a mid to outer shelf depositionalsetting can be inferred from this association. 7be assemblageincluded in Association12, however,possesses forms indicative of outer shelf deposition. Evidencefor this comesfrom the low diversity of acritarchspecies present which, although dominatedby acanthomorphicforms, contain significant abundancesof thick walled spheromorphse. g. Lophosphaeridium?sp. 9. Further evidencecomes from the abundantpresence of the elaborateform Ancyrochifina sp. 1. Ile siltstonelithology of the samplefrom which this assemblagewas extracted indicateslow-moderate energy levels at the time of deposition. 267 The SHurian. All the sedimentsanalysed from the Silurian in the presentstudy are marine in origin. Palynomorph preservationis moderateto good relative to the assemblagesanalysed from the Ordovician. The CarbonaceousShale Formation. (see Tilia sir-ap111). 17hepalynomorph assemblages recorded from the CarbonaceousShale Formation are accompaniedby abundantamorphous sapropelic material. The assemblagesthemselves are largely dominatedby thick walled spheromorphicacritamhs (e. g. Leiosphaeridiamicrocystis) and prasinophyceanalgae (e. g. Tasmanitesmedius). The acanthomorphicacritarch and the chitinozoanassemblages are generally impoverishedin this formation. A probableanoxic, low energy, deepwater abyssalenvironment of depositioncan be inferred for theseassemblages. This is consistentwith the carbonaccous,very fine grainednature of the lithology of the samples. Within this formation, thereare two stratigraphiclevels at which the grosscomposition of the assemblagesis somewhat different. At the Monograptus tu?7iculatus-M. crispus Zone (early Telychian), the assemblagerecovered from sample DW 246, acanthomorphs are dominant over the spheromorphs with a higher diversity of acritarchs recorded. This suggests a difference in the depositional regime at this level, probably related to increased nutrient supply associatedwith a more oxygenated water column as a result of higher energy conditions. 7bis may also be the case for the time interval at the Monograptus riccartonensis-Cynograptus rigidus Zonal boundary (mid Sheinwoodian, early Wenlock). The sample analysed from this level, DW 367, has an acritarch assemblagedominated by spheromorphic forms but also contains a flood of Angochitina sp. 1. Mie abundant occurrence of this relatively small but non the less elaborately ornamented form, in association with the spheromorphs, implies a depositional setting on the outer part of the shelf. it is interestingto note the coincidencein ageof thesebasinal palynofacies with the postulatedhigh standsituation prevailing during the Middle Silurian (Vail, Mitchum & Thompson 1977), fig. 21. Given the relatively stabletectonic situation in Northern Gondwanaat this time, it would appearlikely that suchmajor fluctuationsin the palynoflora are a reflection of eustaticas opposedto tectonic influences. From a palaeogeographicview-point, it is interestingto note the absenceof the Deunffla and Domasia group of acritarchsin Morocco in early Silurian agedsediments. The recordsof this group in paiaeolatitudeparallel Ilbya at this stratigraphiclevel (e.g. Hill & Molyneux 1988) suggeststhe control on their distribution to be more complexthan suggestedby the model of latitudinal control of microplanktonfirst proposedby Cramer(1970). Further investigationof the palaeogeographyof the Northern Gondwanandomain, a subjectbeyond the scopeof this thesisdue to time constraints,may well provide answersto theseanomalies. 269 Figure 2 1. First and second order global cycles of relative change of sea level during Phanerozoic time, from Vail, Mitchurn & Thompson 1977. 1ST-OROERCYCLES 2NO-ORDERCYCLE S (SLIPERCYCL ES) RELATIVECHANGES OFSEA LEVEL CHANGESOF SEALEVEL PERIODS EPOCHS RELATIVE NOTA- -RISING FALLING -RISING FALLING-TIONS lb 0 1.0 5 0 .5 PLIO-PLEIST- 0 0- O:-_Td: MIOCENE Tc OLIGOCENE TERTIARY EOCENE TF PAIFU= T&-.' L Kb PRESENTCRETACEOUS 100 E -Ka SEA LEVEL - to cn cc cr_ JURASSIC - E ' 200- TR 200 TRIASSIC PRESENT ? z _E SEALL EVE p z K3 PERMIAN L C= E ------300- PENNSYLVANIAN m TP -300 MISSISSIPPIAN =Eý D-M - DEVONIAN E 400- 2 -400 S:2 SILURIAN L CDcm - =E L - i O-S - CDLAJ - ORDOVICIAN m - 500- =E -500 CAMBRIAN m C-0 ýKRECAMBRIANE 269 The ArizillaceousShale Formation. (see Tilia graphsII& 12). The assemblagesrecovered from samplesfrom the Argillaceous ShaleFormation are generally of moderateto high speciesdiversity. Ile thick walled spheromorphswhich dominatedthe underlying CarbonaceousShale Formation are relatively insignificant in terms of abundanceand the acanthomorphicforms are far more evident. The chitinozoanassemblages are also more diverse in their speciescomposition with very elaborateforms evident e.g. Ancyrochitina spp. The miosporesare rare constituting lessthan I% of the palynomorphsum in eachassemblage. The palynomorphassemblages studied generally indicate a mid to outer shelf setting for the samples analysedfrom this formation,possibly more towardsthe outer shelf basedon the rarity of spores. 7`he proportions of taxa groupingsrecorded from sampleJW 224 (earliestLudlow) would appearto indicate that a deeperbasinal setting would be more appropriatefor this assemblagewhich is largely composed of indeterminatespheromorphic acritarchs. Suchan interpretationcould be seriouslyquestioned on the basisof the very poor preservationof this particular assemblage. Tle OrthocerasLimestone-Shale formation. (seeTilia graRh12). Only one samplewas analysedfrom this formation, DW 215.7be sparsepalynoflora recoveredis too poorly preservedto makeany confidentinterpretations of the depositionalenvironment based on the proportions of palynomorphsalone. However, the high proportion of acanthomorphicacritarchs recoveredindicating a mid to outer shelf depositionalsetting is consistentwith the environment indicatedby the bio sparitic packstonelimestone lithology. This lithology suggestsa high energy, probably mid shelf depositionalsetting with negligible clastic input. The CalcareousShale Formation. Black ShaleMember. (seeTilia graph 13). The assemblagesrecovered from this formation are consistentin their grosscomposition. Acanthomorphicacritarchs are dominant(ca. 60 % of the acritarchsum) with spheromorphicforms presentin significant numbers(ca. 40 % of the acritarchsum). The miosporesare rare, consistently making up lessthan I% of the palynomorphsum and the chitinozoansare relatively modestin their grossmorphology with ancyrochitinidforms rare in theseassemblages. An outer shelf setting can be interpretedfor the depositionof thesesediments which is supportedby the fine grainednature of the lithology indicating depositionunder low energyconditions. 270 The Devonian. The Devonian agedsamples analysed are all marinein origin. The preservationof the assemblagesis good relative to thosefrom the Ordovicianand Silurian. ne Lmhaifid Formation. (see Tilia gmph 14). The two palynologicalassociations defined from the Lmhaifid Formation eachhave characteristic gross palynological compositions. Association24 hasa relatively high proportion of sporesin the assemblage(ca. 30 %) with acanthomorphicforms dominatingthe acritarch element. Simple flask shapedforms d9minatethe chitinozoanassemblages. A mid to inner shelf position for the depositionof this associationcan be inferred from the acanthomorphicacritarchs, the flask shapedchitinozoans and the abundanceof terrestriallyderived miospores. A low energyenvironment of depositioncan be inferred from the dark, micaceousshale lithology. Association 25, in contrast, has a relatively low proportion of spores in the assemblagesmaking up approximately 4% of the palynomorph sum. Acanthomorphic acritarchs are very abundant and Ancyrochitinid chitinozoans are common. This combination of morphotypes implies a probable outer shelf setting of deposition for the assemblagesof association 25 which, when compared with the depositional setting proposed for the assemblagesof Association 24, indicates fluctuations in the depositional regime within the Lmhaifid Formation with time. Ile AssaFormation. (seeTilia graph 14). The assemblagesanalysed from the Assaformation are similar in grosscomposition to thosefrom Association24 within the Lmhaifid Formation. The miosporesare prominent making up approximately 45% of the palynomorphsum, with acanthomorphicforms dominatingthe acritarch component. The chitinozoanassemblages are primarily composedof flask shapedforms with ancyrochitinid forms rare. An inner shelf settingcan be proposedfor the depositionof this assemblage.The dark, micaceous shalelithologies indicatethat low energyconditions prevailed. 271 The Mdaour el Kbir-N'Kheila Formations(see Tilia grapb 14), Ilie samples analysed from this interval yielded palynological assemblagesof similar gross composition. The assemblagesare dominatedby acanthomorphicacritarchs with the terrestrially derived miospores comprising between10-33 % of the palynomorphsum. Spheromorphicacritarchs; and prasinophytesare low in numbers. The chitinozoans,when recorded,are commonly elaborateforms of the genera Ancyrochitina andAngochitina. The depositionalsetting inferred from the relatively high proportion of miospores,the dominantacanthomorphic acritarchs and the elaboratechitinozoans is inner to mid shelf. 7be dark, fine grained,largely micaceousshale lithologies indicate depositionunder low energy conditions. The Anou SmairaFormation (see Tilia graph 14). The notable feature of the assemblageanalysed from this formation is the high numbers (21 % of the palynomorph sum) of Prasinophyceanalgae recorded (e. g. Tasmanites spp. ). Miospores form approximately 14 % of the palynomorph sum and the acritarch component is once again dominated by the acanthomorphs (ca. 46 % of the palynomorph sum). The chitinazoans are represented by an almost monospecific assemblageof the flask shapedspecies Sphaerochitina pilosa. There appearsto be contradictoryelements within this assemblagewhen we try and apply the environmentalmodel of Doming (1987). Ile abundantacanthomorphic acritarchs, the common miosporesand the monospecificflask shapedchitinozoan assemblage all indicate an inner shelf depositionalsetting. Ile abundanttasmanitids would appearto contradictthis idea, theseforms commonly proliferating in deepwater, low energy,anaerobic conditions. The dark, laminated, fine grained shalessupport the interpretationof probabledeeper water sedimentationunder low energy conditions. The Drag Formation (seeTilia grat)h 14). The two palynologicalassociations described from the Dma Formation, Associations29 and 30, possessabundant amthomorphic acritarchswith negligible spheromorphicforms suggestingdeposition of the assemblagescomprising these associations occurred on the continentalshelf. Association29, however, has a noticeablyhigher proportion of terrestrially derived miosporeswhich makeup 9% approximately of the palynomorphsum. In contrast,Association 30 has a negligible proportion of the assemblagescomposed of miospores. It can be inferred that the assemblagesof Association29 were 272 depositedin a moreproximal setting,probably inner to mid shelf, while the assemblagescomprising association30 were depositedmore distally, probably in the outer shelf region. The Ixfdar Formation(see Tilia Qravh14). The assemblageanalysed from this formation is dominatedby acanthomorphicacritarchs with a significant abundanceof miosporespresent (ca. 19% of the palynomorphsum). A probablemid to inner shelf settingfor the depositionof this assemblagecan be inferred from this grosscomposition. The fine grained,laminated sWe lithology of the sampleindicates that depositiontook place under low energy conditions. 273 Chapter 9. Conclusions. Of the approximately300 samplesprocessed for palynology in the first year of the study, 118 were selectedfor further palynologicalinvestigation based on three criteria. Firstly, that they could be assignedto a lithostratigraphicformation on the evidenceavailable from field notebooks,the Moroccan geologicalmaps and the lithology; secondly,wether the sampleshad beendated by their macrofossil content and thirdly, wetherthe sampleshad yielded palynomorphs. Ile geographicand stratigraphic information for the 118 samplesthat was availableprior to the onsetof the palynological investigations is collated in Appendix1. Palynologicalpreparation of samplesproved to be a problem from the onsetof the study due to the high thermal maturity aqd the commonlyindurated nature of the rocks. As statedin the aims and objectives of the study (chapter2), it was intendedto developa preparationtechnique that would be applicablefor industrial practice. Initial attemptsto processlarge amountsof rock (> 75g) to enhancethe abundance of palynomorphsrecovered were found to be unsuccessfuldue to the induratedsediments requiring severalweeks to breakdown in cold HF. Between20-50g of rock were found to be the optimum quantity dependingon the lithology of the sample. Intenseoxidation of the majority of sampleswas necessaryfor meaningfulpalynological analysis. Extendedoxidation times in normal Schulze's solution of the 'baked' and brittle palynomorphs;had adverseeffects on their preservationresulting in completefragmentation of the palynomorphspresent. This problem was resolvedby the use of a short sharp shocktechnique using fuming Schulze'ssolution as the oxidising agent. The time period involved in this techniqueis as little as 1-15 minuteswhich is also advantageousin terms of time saved comparedto other techniques. Investigationof the supragenericschemes in current use for the acritarchs;and the chitinozoahas revealedinherent problems in adoptingpurely morphologicalschemes for biological groupswhose affinity is, as yet, unknownto us. The unknownrelative biological significanceof morphological featureshas brought abouta plethoraof schemesfrom authorsstressing the importanceof particular morphologicalfeatures of the individuals concerned. It is concludedthat the adoption of such arbitrary classificationschemes at the supragenericlevel can only lead to frustration for future workers wishing to locatetaxa in a schemewhen that schemeis no longer in vogue. Ile acritarchsand chitinozoaare consequentlyarranged in alphabeticalorder in the presentstudy pending further biological information as to the relative significanceof the respectivemorphological features of the taxa included in these groups- Ile taxonomyadopted at the genericand specific levels is basedon observationsusing the light microscope. No SEM analysisare includedin the study due to time constraints. Splitting of someof the rather broad 'bucket' speciesbelow the level of specieshas been attempted, e. g. Ditmallophasis denticulata. The introduction of varietieswithin thesebroad specieswas attemptedto enhancetheir biostratigraphicvalue. This approachhas been found to be successfulin severalcases revesling certain 274 morphologicalvariants of broadspecies (e. g. Die-w1lophasisdenticulata var. A, late Pridoli-early Gedinnian)apparently having restricted biostratigraphic ranges. Ile biostratigraphicanalysis of the palynomorphassemblages recovered from the samplesstudied was the major objectiveof the project. Assemblagesfrom a broad stratigraphicinterval, Ordovician- Devonian, havebeen investigated which havebeen grouped into 33 defined palynological associations. Ile initial aim, to producea completepalynological zonation for the Ordovician to Devonian interval, was found not to be possibledue to the limited samplesavailable for the project. However, the adoption of an associationconcept enables the recognitionof a seriesof biostratigraphicallyuseful palynological associationswith the stratigrsphicgaps in the data acknowledged. Ile associationsare defined on the basisof the presenceand abundancesof taxa recordedwith the aid of cluster analysisof the assemblagesgeýerated by the computingpackage TIM. Within the Ordovicianinterval, 12 Associationsare definedon the basisof the generallypoorly by preservedacritarch and chitinozoanassemblages. Dating of the associationsis primarily comparison with previouspalynological studies from Northern Gondwana(e. g. Paris 1981, Elaouad-Debbaj1984, 1986 & 1988), however,dated shelly macrofossilassemblages recorded in someof the Arenig, the Llanvim and the Caradocsamples provide substantiveevidence. Ile Silurian samplesselected for the study are all biostratigraphicallyconstrained by the graptolitic assemblagesrecorded from them. Ten palynologicalassociations are defined from this interval and comparisonsare madewith palynologicalassemblages previously recordedin the literature, e.g. Paris 1981, Hill & Molyneux 1988,Le Herrise 1989. The Devonianassemblages are generallywell preservedand are composedof diverseacritarchs, prasinophytes,chitinozoans and spores. Elevenassociations are defined through this interval, the ages of which are largely definedon the basisof comparisonwith the well establishedspore stratigraphy (e.g. Loboziac& Streel 1989,Richardson & McGregor 1986, Steemans1989). PreviousLower and Upper Devonianmicroplankton records were also found to be useful for comparison,e. g. Deunff 1980, Playford 1977,Wicander 1983,Martin 1981& 1984, as were the Lower to Middle Devonian chitinozoanstudies of Paris (e.g. 1985,1988) and co workers. In addition to thesemicrofossils, rich graptolite assemblagesin someLower Devoniansamples provide independentevidence for their age. The palaeoenvironmentalmodel of Doming (1987) hasbeen applied to the palynological assemblages recorded. Taxa havebeen grouped into broad morphologicalcategories and the trends in the relative abundancesof thesemorphogroups have been illustrated and analysedusing the 71lia package. A generalinterpretation of the environmentof depositionfrom the palynological data, in conjunctionwith the lithological evidence,can be drawn (i. e. basinal, outer shelf, inner shelf, littoral). However, one must bewareof interpretingpoorly preservedassemblages, such as thoserecorded from the Ordovician in the presentstudy, in which selectivepreservation of the palynomorphgroups can be misleading. 275 The analysesrevealed evidence for marinedeposition in all of the formations studied from the Ordovician throughDevonian and it appearsthat varying continental shelf settingsof deposition prevailed for much of this interval. However, during the Llandovery and the Wenlock (Carbonacoous ShaleFormation) thereappears to be a notablechange in the grosspalynological composition with thick walled spheromorphicacritarchs totally dominatingthe low diversity assemblages.The high abundance of amorphoussapropelic kerogen and the fine shalelithologies corroboratethe palynological evidence for deepbasinal, low energydeposition through this stratigraphicinterval. A similar trend is evident in the Frasnian(Anou SmairaFormation) with abundanttasnumitids suggesting a basinaldepositional setting at this level. It is believedthat suchfluctuations in sealevel in Morocco are largely eustatically controlled given the relatively stabletectonic situation prevailing through the Ordovician to Devonian interval. 276 Chapter 10. Further work. The broad natureof the studyundertaken has revealed much scopefor future palynological work in the Anti Atlas region and in the North African-Middle Easternrealm. With regardto palynologicaltechniques, despite the successof the processingprocedure adopted here, I feel there is much potentialfor processingof problematicPalaeozoic samples using the microwave technology currently undergoingresearch at SheffieldUniversity. This rapid breakdownand oxidation method would appearto haveconsiderable advantages for induratedand thermally maturesamples which are commonfrom the Palaeozoicand shouldenhance palynological recovery. 17hereare many taxa recordedin the presentstudy that remain in open nomenclatureprimarily due to the need for fiwther detailedinvestigation of the taxabefore I considerthem to be worth formalising in the literature. The fiwther investigationprior to formalisationof thesetaxa will involve biometrical analysisand, in someinstances, particularly with the chitinozoans,SEM analysis. Within the Ordovicianof the Anti Atlas, detailedsampling of outcrop sectionsadditional to those studiedby Elaouad-Debbaj(1984,1986,1988) would fill gapsin the existing data. Emphasisshould be placedon samplingof the oolitic ironstonedeposits reported to be widely extensiveover Northern Gondwanathrough the Ordoviciansystem (Young 1989, pers. comm. 1992; Paris pers. comm. 1992). Investigationof the ageand extentof suchdeposits would enhanceour understandingof the genetic relationshipof the Ordoviciansequences in this realm. It would also give insight into the eustatic fluctuations in sealevel for this period given that the region was relatively tectonically stableat that time. A study of samplescollected across the Ordovician-Silurianboundary in North Africa would be informative as to the apparentclimatic effectson the microplanktondue to the well documented glaciation that occurredduring that time. The considerabledata base that has now accumulatedon the effectson the microplankton acrossthe Quaternaryglaciations (e. g. Harland 1983, Dale 1976, Wall et aL 1976)would makefor interestingcomparison. As with the Ordovician, thereare severalgaps in the data from the Silurian interval in the Anti Atlas that needto be addressed.7be prolific graptolite assemblagespresent in sedimentsof this ageprovide considerableincentive for further biostratigraphicalwork on the apparentlynear completeSilurian succession.Ile graptolite assemblagesthemselves are largely unpublishedfrom the Anti Atlas (Destombes,Hollard & Willefert 1985)and severalnew lineagesare apparentfrom the assemblages incorporatedinto the presentstudy that were analysedby Dr. R.B. Rickards (pers. comm. 1991). Previousbiostratigraphic palynological investigations of the Devonian strataof Northern Gondwana interpretations have their age basedon comparisonswith other palynologica investigationswhich 277 equally lack independentage data from other biostratigraphicallyuseful groups. Goniatite dated sectionsare presentin the Anti Atlas in carbonatefacies (G. Wade pers. comm. 1990)which, to date, have beenavoided by palynologistsdue to the relatively low yields of palynomorphsper gram from such sediments. Palynologicalinformation from suchindependently dated sections would be invaluable to resolve someof the conjectureinvolved in the dating of Devonian sectionsin Northern Gondwana. 278 References Achab, A. 1977a. Les Chitinozoairesde I& zonea Dicellograptus complanatus,Formation de Vaureal, Ordovicien superieur,lie d' Anticosti, Quebec.Can. J. Earth, Sci., v. 14, p. 413-425. Achab, A. 1977b. Les Chitinozoairesde la zonea Climacograptusprominens-elongxus, de ]a Formation de Vaureal, Ordoviciensuperieur, Ile d' Anticosti, Quebec. Can. J. Earth Sci., v. 14, p. 2193-2212. Achab, A., 1980. Chitinozoairesde I'Arenig inferieur de la Formation de Levis, Quebec,Canada. Rev. Palaeobot.Palynol., v. 31, p.219-239. Achab, A. 1989. Ordovicianchitnozoan zonation of Quebecand westernNewfoundland. J. Paleont. v. 63, p. 14-24. Achab, A. 1984. Chitinozoairesde l'Ordovicien moyende subsurfacede Ile Anticosti. Rev. Palaeobot.Palynol., v. 43, p. 123-143. Achab, A. 1989. Ordovicianchitinozoan zonation of Quebecand westernNew Foundland. J. Palaeont.,v. 63, p. 14-24. Al-Ameri, T. K. 1986. Observationson the wall structureand the excystmentmechanism of acritarchs. Joumal of Micropakeontology, v. 5, no.2, p. 27-35. Aldridge R.J., Doming, K. J. & Siveter,D. J. 1981. Distribution of microfossil groups acrossthe Wenlock shelf of the Welsh Basin. In: Neale,J. W. & Braisier, M. D. eds. Microfossils of recentand fossil shelf seas,p. 18-30. Allen, K. C. 1965. Lower and Middle Devonianspores of North and Central Vestspitsbergen. Palaeontology,v. 8, no.4, p. 687-748. Benoit, A. & Taugourdeau,P. 1961. SurquelquesChitinozoaires de I'Ordovicien du Saham. Rev. Fr. Petrole, 16, Inst. v. p. 1403-14 . Bloeser,B., Schopf,J. W., Horodysky, J.R. & Breed, W. J. 1977. Chitnoizoansfrom the Late PrecambrianChuar Group of the Grand Canyon,Arizona. Science,v. 195, p. 676-679. Bockelie, T. G. 1978. Commentson ChitinozoanClassification. Norsk. Geol. Tidsskr., v. 58, p. 301- 304. 279 Bockelie, T. G. 1980. Early OrdovicianChitinozoa, from Spitýýrgen. Palynology v. 4, p. I- 14. Bockelie, T. G. andKjellstrom, G. 1979. Middle Ordovician acritarchsfrom the island of Odinsholm, Estonia. GeologiskaForeningens i StockholmForhandlingar, V. 101, p. 205-216. Bondon, J. & Neltner, L. 1933. Sur la seriecambrienne des plataux du Draa (Sud Marocain) et la presencedu Gorgiendans cette serie. C. R. Acad. Sci. Paris, v. 197, p. 170. Bondon, J., Cladiond, L& Neltner, L. 1933. Une nouvelle coupedu Djebel Sarro,(Maroc Saharien). C. R. Acad. Sci. Paris, v. 198, p. 590. Boumenjel,K., Loboziae,S., Pads, F., Steemäns,P. & Streel, M. 1988. Biostratigraphiedes miosporeset deschitinozoaires du Silurien superieuret du Devoniendaas le bassind'Illizi (S.E. du SaharaAlgerien). Geobios,no. 21, p. 329-357. Bourcart, J. 1927. Decouvertdu Cambriana Archaeocyathusdans I'Anti Atlas morocain. C. R. somm. Soc. geol. Fr., V. 1, p. 10- Brito, I. M. 1965. Novos microfosseisDevonianos do Maranhao. Universidadeda Bahia, Escolade Geologia,v. 2, p. 1-4. Brito, I. M. 1967a. Silurian and DevonianAcritarcha from MaranhaoBasin, Brazil. Micropaleontology,v. 13, no.4, p. 473-482. Brito, I. M. 1967b. Contribuicaoso conhocimentodos microfosseisDevonianos de Pemambuco.Il. Acritarcha. Pteromorphitae.Anais da Academiabrasileira de Ciencias,v. 39, no.2, p. 285-287. Brito, I. M. 1967d. Novo subgrupo de Acritarcha do Devoniano, do Maranhao. Anais da Academiabrasileira de Ciencias,v. 39, no. 1, p. 163-166. 280 Brito, I. M. and Padilhade Quadros,L. 1994. Novas ocorrenciasde Acritarchaeno Devoniano da Bacia do Pamaiba. Universidadede SaoPaulo, Instituto de Geociencias,Boletim, v. 15, p. 15-19.Brito, I. M. and Santos,A. S. 1965a. Contribuicaoao conhecimentodog microfomis Silurianosy Devonianos;da Baciado Maranhao. Divisao de Geologia e Mineralogia, Rio de Janeiro, XDCCongresso Brasileiro de Geologia,no. 40, p. 57. Brito, I. M. and Santos,A. S. 1965b. Contribuicaoao conhecimentodos microfosseisSilurianos e Devonianosda Baciado Maranhao. DepartamentoNacional da ProducaoMineral, Divisao de Geologia e Mineralogia, Notas Preliminares e Estudos (Rio de Janeiro, Brasil), no. 129, p. 1-2 1. Burmann, G. 1968. Diacrodienaus dem unteren Ordovizium. PaleontologischeAbhandlungen, Abt. B, v. 2, no.4, p. 635-652. Burmann, G. 1970. Weitereorganische Mikrofossilien aus dem unterenOrdovizium. Paleontologische Abhandlungen, Abt. B, v. 3, no. 3-4, p. 289-332. Burmann, G. 1972. Problematika aus der Lausitzer Grauwacken formation. Jahrbuch fur Geologie, v. 4, p. 387-423. Burmann, G. 1973. Das Ordoviziumder nordlichenPhyllitzone. Teil I. Paschlebener Vorsprung. ZeitschriftfurGeologischeWissenschaften,v. 1, no.7. p. 757-787. Burmann, G. 1976. Sporen und Phytoplankton aus den Devon/Karbon-Grenzschichten des Harzes (lepidophytus- Zone). Zeitschrift für Geologische Wissenschaften, v. 4, no. 6, p. 805- 835. Byvsheva,T. V., Higgs, K. and Streel,M. 1984. Sporecorrelations between the RhenishSlate Mountains and the Russianplatform near the Devonian-Carboniferousboundary. In: E. Paoroth and M. Streel(eds. ), The Devonian-Carboniferous Boundary. Courier Forschungsinstitut Senckenberg, v. 67, p. 3745. Calandra, F. 1964. Sur un presume dinoflagelle Arpylorus nov. Sen. du Gothlandien do Tunisie. Comptesrendus de I'Acadamiedes sciences, Paris, v. 258, p. 4112-4114. Cashman,P. B. 1990.7be affinity of the chitinozoans: New evidence. Modem Geology, v. 15, p. 59-69. Cashman,P. B. 1991. Lower Devonianchitinozoan juveniles - oldest fossil evidenceof a Juvenilestage in protists, with an interpretationof their ontogenyand relationshipto the allogromfid foraminifera. Journal of Forameniferal.Research, v. 21, p-269-281. 281 Chlupac, I., Lukes, P., Paris, F. and Schonlaub,H. P., 1985. The Lochkovian-Pragian boundaryin the Lower Devonianof the Barrandianarea, Czechoslovakia.Jahrb. Cool. B. A. v. 128, p. 9-42. Clioubert, G. 1963. Histoire geologiquedu Precambriende I'Anti Atlas. Tome 1. Notes & M. serv. gool Maroc, v. 162. Choubert, G., Hindermeyer, J. & Hupe, P. 1955. Decouverte du Tremadoc dans I'And Atlas (Maroc). C. R. Acad. Sci. Paris, v. 24 1, p. 1592. Cocks, L. R. & R.A. Fortey 1988.Lower Palaeozoicfacies and faunasaround Gondwana. In M. G. Audley-Charles& A. Hallam (eds). Gondwanaand Tethys. GeologicalSoc. London SpecialPubl. 37, p. 183-200. Colbath, G.K. 1979. Organic-walledmicrophytoplankton from the Eden Shale(Upper Ordovician), Indiana, U. S.A. Palaeontographica,Abt. B, v. 171, no. 1-3, p. 1-38. Colbath, G.K. 1981. Synonymyof Edenian(Late Ordovician) organic-walled microphytoplanktontaxa. Journalof Paleontology,v. 55, no. 1, p. 273-274. Colbath, G.K. 1983. Fossil prasinophyceanphycomata (Chlorophyta) from the Silurian BainbridgeFormation, Missouri, U. S.A. Phycologia,v. 22, no.3, p. 249-265. Colbath, G.K. 1986. The Lower Paleozoicorganic-walled phytoplankton (acritarch) genus Frankea Burmann1970. Micropaleontology,v. 32, no. 1, p. 72-73. Colbath, G.K. 1987. Orygmahapsis,a new genusof prasinophytephycoma from the Siluro- Devonian. NeuesJahrbuch fur Geologieund Paleontologie,Monatshefte, v. 42, p. 65-68. Collinson, C. & SchwalbH. 1955. North AmericanPalaeozoic Chitinozoa. Illinois StateGeol. Surv., v. 186, p. 1-33. Collinson, C& Scott, A. J. 1958. ChitinozoanFaunule of the Devonian CedarValley Formation. Illinois StateGool. Surv., v. 247 : p. 1-34. Combaz,A. 1962. Sur un nouveautype de microplanctontecenobial fossile du Gothlandiende Libye, Deflandrastrwnnov. gen. Comptesrendus des seancesde I'Academie des sciences, v. 255, p. 1977-1979. 282 Combaz,A. 1967a. Un microbiosdu Tremadociendaas un sondaged'Hassi-Messaoud. Actes de la SocieteLinneenne de Bordeaux,v. 104, no.29, p. 1-26. Combaz,A. 1967b. LeiosphaeridaceaeEisenack, 1954, et ProtoleiosphaeridaeTimofeev, 1959 - leurs affinites, leur role sedimentologiqueet geologique. Review of Palawbotany and Palynology, v. 1, p. 309-321. Combaz,A. 1967c. Sur un microbiosd'age Tremadocien Hassi-Messaoud.Actes de la SocieteLinneenne de Bordeaux,vol. special,Congres de I'Association franeaisepour I'avancementdes sciences (A. F. A. S.), 1967,p. 115-119. Combaz,A. 1972.- Stratigraphiedes Chitinozoaires. Mem. Bur. Rech. Geol. Min., v. 77, p. 311-316. Combaz, A. and Peniguel, G. 1972. Etude palynostratigraphique do I'Ordovicien dans quelques sondages du Bassin de Canning (Australia Occidentale). Societe nationale des petroles d'Aquitaine, Centre de recherche de Pau, Bulletin, v. 6, no. 1, p. 121-167. Combaz,A. & Poumot, C. 1962- Observationssur la structuredes Chitinozoaires.Rev. Micropal., v. 5, p. 147-160. Combaz, A. and Streel, M. 1970. Microfossiles vegetaux du Tournaisien inferieur dans le core- drill de Brevillers (Pas-de- Calais, France). Colloque sur I& Stratigraphie du Carbonifere, Liege, Les Congres et Colloques de lUniversite de Liege, v. 55, p. 227-240. Combaz, A., Lange, F. W. and Pansart, J. 1967. Les Leiofusidae Eisenack, 1938. Review of Palaeobotanyand Palynology,V. 1, p. 291-307. Combaz,A., Calandra,F., Jansonius,J., Millepied, P., Poumot, C. & van Oyen F. H. 1967. Microfossilesorganiques du Pale-ozoic.2. Les Chitinozoairs. Morphographie. CentreNation. Roch. Sci., Paris. Cookson,I. C. & Eisenack,A. 1960. Microplankton from Australian Cretaceoussediments. Micropalaeontology, v. 6, p. 1-18. Cookson,I. C. & Eisenack,A. 1962. SomeCretaceous and Tertiary microfossils from Western Australia. Proc. Roy. Soc. Victoria, v. 75, p. 269-273. Cooper, A. H. & Molyneux, S.G. 1989. The ageand correlation of Skiddaw Group (early Ordovician) sedimentsin the CrossFell inlier (northernEngland). Geol. Mag., v. 147-157. 283 Coquel, R. 1980. Les Sporesin La Trachee de I& Lezais, Emsien Superieur du Massif Annoricain (France). Sedimentologie, Paleontologie, Stratigraphie. Mem. Soc. Geol. Mineral. Bretape, v. 24, p. 43-54. Coquel, R. and Moreau-Benoit,A. 1986. Les sporesdes seriesStruniennes et Tournaisiennes de Libye Occidentale(Strunian and Tournaisianspores of westernLibya). Revuedo micropaleontologie,v. 29, no. 1, p. 17-43. Cramer, F. H. 1963. Nota provisionalsobre la presenciade microplankton y esporomorfasen las rocassedimentarias del DevonicoInferior en las MontaeasCant bricas. Estudiosgeologicos, 19, p. 215-218. Cramer, F. H. 1964a. Someacritarchs from the SanPedro Formation (Gedinnien)of the CantabricMountains in Spain. Bulletin de la Societebelge de geologie, de paleontologieet d'hydrologie, v. 73, no. I. p. 33-38. Cramer, F. H. 1964b. Microplankton from threePalaeozoic formations in the Province of Leon, NW Spain. LeidseGeologische Mededelingen, v. 30, p. 253-361. Cramer, F. H. 1966a. Palynologyof Silurian and Devonianrocks in northwestSpain. Instituto Geologicoy Minero de Espaea,Boletin, v. 77, p. 225-286. Cramer, F. H. 1966b. Hoegispheresand other microfossilsincertae sedis of the SanPedro Formation (Siluro-Devonianboundary) near Valporquero,Leon, NW Spain. Instituto Geologicoy Minero de Espaea,notas y comunicacionesno. 86, p. 75-94. Cramer, F. H. 1966c. Additional morphographicinformation on somecharacteristic acritarchs of the SanPedro and Furadaformations (Silurian-Devonian boundary) in Leon and Asturias, Spain. Instituto Geologicoy Minero de Espana,notas y comunicacionesno. 83, p. 2748. Cramer, F. H. 1966d. Palynomorpbsfrom the Siluro-Devonianboundary in NW Spain. Instituto Geologicoy Minero de Espana,notas y comunicacionesno. 85, p. 71-82. Cramer, F. H. 1967a. Chitinozoansof a CompositeSection of Upper Llandoverian to Basal Gedinniansediments in Northern Leon, Spain. A preliminary Report. Bull. Soc. BeIg. Geol., v. 75, p. 69-129. Cramer, F. H. 1967b.- An Evaluationof the ChitinozoanGenus Clathrochitina. Not. Commun.Inst. Geol. Miner. Espana,v. 94, p. 45-52. 284 Cramer, F. H. 1967c.- Palynologyof Silurian and Devonian Rocks in NorthwesternSpain. Bol. Inst. Geol. Miner. Espana,p. 77, p. 225-296. Cramer, F. H. 1969a. Palynologicmicrofossils of the Middle Silurian Maplewood Shalein New York. Revuede micropaleoutologie,v. 11, no.2, p. 61-70. Cnuner, F. H. 1969b. Considerationspaleogeographiques e propos d'une associationde microplanctontesde I& seriegothlandienne de Birmingham (Alabama, U. S.A. ). Bulletin de la Societegeologique de France,7e ser., no. 10, p. 126-131. Cramer, F. H. 1969a. Geron, an acritarch genug from the Silurian. Bulletin de la Societe beige de geologic, de paleontologic et d'hydrologie, v. 77, no. 2, p. 217-225. Cramer, F. H. 1969b. Possibleimplications for Silurian paleogeographyfrom phytoplancton assemblagesof the RoseIUII and Tuscaroraformations of Pennsylvania. Journal of Paleontology,v. 43, no.2, p. 485491. Cramer, F. H. 1969c. Consideracionessobre la palinologia y las paleolatitudessiluricas a proposito del microplanctonsilurico de las MontaeasCant bricas del Noroestede Espana. Comunicacoesdos Servicosgeologicos de Portugal,v. 53, p. 67-94. Cramer, F. H. 1970. Distribution of selectedSilurian acritarchs.An accountof the palynostratigraphyand paleogeographyof selectedSilurian acritarchtaxa. Revistaeqmola de micropaloontologia, numero extraordinario, p. 1-203. Cramer, F. H. 1971. Implicationsfrom Middle Paloozoicpalynofacies transgressions for the rate of crustal movement,especially during the Wenlocidan. Anais da Academiabrasileira do ciencias,v. 43, p. 51-66. Cramer, F. H. 1971. A PalynostratigraphicModel for Atlantic Pangeaduring Silurian Time. Mem. Bur.Rech. Geol. Min (B. R. G. M), v. 73, p. 229-233. Cramer, F. H. 1973. Middle and Upper ChitinozoanSuccession in Florida Sub-surface.J. Paleont., v. 47, p. 279-288. Cramer,F. H. and Diez, M. del C.R. 1968. Consideracionestaxonomicas sobre lag scritaivAs del Silurico Medio y Superiordel Norte de Espaea. Instituto Geologicoy Minero de Espana, Boletin, v. 79, no.6, p. 541-574. 285 Cramer, F. H& Diez, M. del C. R. 1970. Rejuvenation of Silurian Chitinozoans from Florida. Rev. Espan. Micropal., v. 2, p. 45-54. Cramer,F. H& Diez, M. del C. R. 1970. Acritarchs from the Lower Silurian Neahga Formation, NiagaraPeninsWa, North America. CanadianJournal of Earth Sciences,v. 7, no.4, p. 1077-1085. Cramer,F. H &. Diez, M. del C. R. 1972a. Acritarchs from the upper Middle CambrianOville Formation of Leon, northwesternSpain. Revistaespanola de micropaleontologia,numero extraordinario XXX Aniversario E. N. Adaro, p. 39-50. Cramer, F. H& Diez, M. del C. R. 1972b. North American Silurian palynofacies and their spatial arrangement. Acritarchs. Palaeontographica, Abt. B, v. 138, no. 5-6, p. 107-180. Cramer,F. H& Diez, M. del C. R. 1976a. Acritarchs from the La Vid Shales(Emsian to lower Couvinian) at Colle, Leon, Spain. Palaeontographica,Abt. B, v. 158, no. 1-4, p. 72-103. Cramer,F. H& Diez, M. del C. R. 1976b. Sevennew Late Arenigian speciesof the acritarch CoryphidiumVavrdov 1972. PalaeontologischeZeitschrift, 50, 3-4, 201-208. genus , v. no. p. Cramer,F. H& Diez, M. del C. R. 1977a. Late Arenigian (Ordovician) acritarchsfrom Cis- Saharan,Morocco. Micropaleontology,v. 23, no.3, p. 339-360. Cramer,F. H& Diez, M. del C. R. 1977b. OWa, generonuevo de Acritarcos del Gediniense de Arabia Saudita. Revistaespanolademicropaleontologia,v. 9, no. l, p. 85-88. Cramer, F. H& Diez, M. del C. R. 1978. Iberian Chitinozoans1. Introduction and Summary of Pre-Devoniandata. Palinologia,Num. ext. p. 149-201. Cramer,F. H& Diez, M. del C. R. 1979. Lower Paleozoicscritarchs (Acritarcos del PaleozoicoInferior). Instituto de investigacionespalinologicas, Apartado 244, Leon, Espana, p. 17-160. Cramer, F. H., Diez, M. del C.R. and Cuerda,A. I. 1974. Late Silurian chitinozoansand acritarchsfrom Cochabamba,Bolivia. NeuesJahrbuch fer Geologieund Paleontologie, Monatshefte,no. 1, p. 1-12. Cramer, F. H., Allam, R., Kanes,W. H. and Diez, M. del C.R. 1974. Upper Arenigian to Lower Llanvirnian acritarchsfrom the subsurfaceof the Tadja Basin in Morocco. Palaeontographica,Abt. B, v. 145, no.5-6, p. 182-190. 286 Cramer, F. H., Kanes,W. H., Diez, M. del C.R. and Christopher,R. A. 1974. Early Ordovician acritarchsfrom the TadlaBasin of Morocco. Palaeontographica,Abt. B, v. 146, no. 3-6, p. 57-64. Da. Costa,N. M. 1967. QuitinozoariosSilurianose Devonianos da Bacia Amazonicae Sua Coffelatc.ao Estratigrafica.Geocieencias, v. 1, p. 87-119. Da Costa, N. M 1971. Quitinozoarios Brasileiros e Sua Importancia Estratigrafica. An. Acad. Brasil. Cienc., 43 209-272. v. , p. Daemon, R. F., Quadros,L. P. and Da Silva, L. C. 1967. Devonian PalYnologyand Biosratigraphyof the ParanaBasin. In: IJ Bigarella(Edtor), Problemsin Brazilian Devonian Geology. Rol. Parana,Gooscience., v. 21/22, p. 99-132. Dale, B. 1976. Cyst Formation,sedimentation, and preservation:factors affecting dinoflagellateassemblages in Recentsediments from Trondsheims6ord,Norway. Rev. Pal. Pal. v. 22, p. 39-60. Davey, R.J. and Williams, G.L. 1966a. The generaHystrichosphaera and Achomosphaera. In: R. J. Davey, C. Downie, W. A. S. Satjeantand G.L. Williams, Studieson Mesozoicand Cainozoicdinoflagellate cysts. Bulletin of the British Museum(Natural History), Geology, Supplement3, p. 28-52. Davey, R. J. and Willisarns, G. L. 1966b. The genus Hysuichosphaeridium and its allies. In: R. J. Davey, C. Downie, W. A. S. Sadeant and G. L. Williams (eds.), Studies on Mesozoic and Cainozoic dinoflagellate cysts. Bulletin of the British Museum (Natural History), Geology, Supplement 3, p. 53-106. Davey, R.J., Downie, C., Sadeant,W. A. S. and Williams, G.L. 1966. Fossil dinoflagellate cysts attributedto Baltisphaeridium. In: R.J. Davey, C. Downie, W. A. S. Saýeantand G.L. Williams, Studieson Mesozoicand Cainozoicdinoflagellate cysts. Bulletin of the British Museum(Natund History) Geology, Supplement3, p. 157-175. Davey, R. J., Downie, C., Sadeant,W. A. S. and Williams, G.L. 1969. Genericre-allocations. In: R. J. Davey, C. Downie, W. A. S. Sadeantand G.L. Williams, Appendix to Studieson Mesozoicand Cainozoicdinoflagellate cysts. Bulletin of the British Museum (Natural History) Geology, Appendix to Supplement3, p. 1-24. 287 Dean, W. T. and Martin, F. 1978. Lower Ordovicianscritarchs and trilobites from Bell Island, eastern Newfoundland. Geological Survey of Canada, Bulletin 284, p. 1-35. Dean, W. T. and Martin, F. 1982. The sequenceof trilobite faunas and acritarch microfloras at the Cambrian-Ordovician boundary, Wilcox Pass, Alberta, Canada. In: M. G. Bassett and W. T. Dean (eds.), The Cambrian-OrdovicianBoundary. Sections,Fossil Distributions, and Correlations.Geological Series (National Museum of Wales), no. 3, p. 131-140. Debbaj, Z. 1979. Acritarchesde I'Ordovicien Superieurdu synclinal de Bucaco(Portugal). Systematique,Biostratigraphie, Interet Paleogeographique.These Universite de Rennes,p. 1- I 10. Rennes. Deflandre, G. 1934. Sur les microfossilesd'origine planctonique,conserves e 1'etatde matiere organiquedans les silex de la craie. Comptesrendus des seancesde I'Acaderniedes sciences, 199, p. 966-968. Deflandre, G. 1935. Considerationsbiologiques sur les microorganismesd'origine planctoniqueconserves dans les silex de I& craie. Bulletin biologique de I& Franceet de )a Belgique, v. 69, p. 213-244. Deflandre, G. 1936a. Microfossilesdes silex creutm. Premierepartie. Generalites.Flagelles. Annalesde paleontologie,v. 25, p. 151.191. Deflandre, G. 1936b. Les flagellesfossiles. Apereu biologique et paleontologique.Role Geologique. Actualitesscientifiques et industrielles,no. 335, p. 1-97. Deflandre, G. 1937b. Microfossilesdes silex creWes. Deuxiemepartie. Flagellesincertae sedis. Hystrichosphaerides.Sarcodines. Organismes divers. Annalesde paleontologie,v. 26, p. 51-103. Deflandre, G. 1938. Microplankton desmers jurassiques conserve dans les mamesde Villers- sur-Mer (Calvados).etude liminaire et considerationsgenerales. Travaux de,la Station zoologiquede Wimereuz, v. 13, p. 147-200. Deflandre, G. 1941. Le microplanctonIdmeridgien. d'Orbagnoux et Vorigine des huiles suMrees naturelles. Academiedes sciences (France), Memoires v. 65, no.5, p. 1-32. Deflandre, G. 1942. Sur les Hystrichospheresdes calcairessiluriens de I& MontagneNoire. Comptesrendus des seancesde I'Academiedes sciences,v. 215, no.20, p. 475-476. 288 Deflandre, G. 1944. Microfossilesdes Calcaires Siluriens de I& Montape Noire. Ann. Paleont., v. 31, p. 41-75. Deflandre, G. 1943. Sur quelquesnouveaux Dinoflagelles des silex cretam. Bulletin de la Societegeologique de France,Se ser., v. 13, p. 499-509. Deflandre, G. 1945a. Microfossilesdes calcaires siluriens de,la MontagneNoire. Annalesdo paleontologie,v. 3 1, p. 41-75. Deflandre, G. 1945b. Fichier micropaleontologique- serieS. Dinoflagelles 11.Gymnodiniales et dinoflagellesincertae sedis. Flagelles incertae sedis. Archives originales, Centredo documentation;Centre national do la recherchescientifique, France, no. 207, p. I-XII, p. 752- 859. Deflandre, G. 1946a. Fichier micropaleontologique- serie 6. HystrichosphaeridesIl. Especes du Secondaireet du Tertiaire. Archivesoriginales, Centrede documentation;Centre national de la recherchescientifique, France, no. 235, p. 1-V, p. 860-1019. Deflandre, G. 1946b. Radiolaireset Hystrichosphaeridesdu Carboniferede la MontagneNoire. Comptes rendus des seancesde I'Academie des sciences, v. 223, no. 13, p. 515-516. Deflandre, G. 1946c. Fichier micropaleontologique- serie 8. HystrichosphaeridesIll. Especes du Primaire. Archives originales,Centre de documentation;Centre national de I& recherche scientifique, FnLnee,no-257, I-V, p. 1096-1185. Deflandre, G. 1947a. Le problemedes Hystiichospherea. Bulletin de l'Institut oceanographique (Monaco), no. 918, p. 1-23. Deflandre, G. 1947b. Sur quelques microorganismes planctoniques des silex Jurassiques. Bulletin de I'Institut oceanographique (Monaco), no. 921, p. 1-12. Deflandre, G. 1954. SYstematiquedes Hystrichosphaerides. Sur Facceptiondu genre CymatiosphaeraO. Wetzel. Compterendu sommaireet bulletin de la Societegeologique de France,v. 4, no.9-10, p. 257-258. Deflandre, G. 1966. Addendume mon Memoire. Microfossiles des silex cretaces. Cahiersde micropaleontologie,ser. 1, no.2 (Archives originales, Centrede documentation,Centre national de la recherchescientifique, no. 419), p. 1-9. 289 Deflandre, 0.1967. Sur I& conservation de vestiges pyritises do Deflandrastrum (Chlorophycees) et sur une curieuse forme nouvelle du Siluro-Devonien d'Afrique du Nord. Comptes rendus des seancesde I'Academie des sciences, ser.D, v. 265, p. 1776-1779. Deflandre, 0.1968. Sur Vexistence,dans le Precambrien,d'acritarches du type Acanthomorphitae,Eomicrhystridium nov. gen. Typification du genrePalaeoc? ypildium Defl. 1955. Comptesrendus des seances de I'Academiedes sciences,ser. D, v. 266, p. 2385-2389. Deflandre, G. & Cookson,I. C. 1955. Fossil microplanktonfrom Australian We Mesozoic and Tertiary sediments.Australian Journal of Marine and FreshwaterResearch, v. 6, p. 242-313. Deflandre, G. and Courteville,H. 1939. Note preliminaire sur les microfossilesdes silex cretacesdu Cambresis.Bulletin de la Societefrancaise de microscopie,v. 8, p. 95-106. Deflandre, G. and Deflandre-Rigaud,M. 1958. Fichier micropaleontologique- serie 10. HystrichosphaeridesIV et genresincertae sedis. Especesdu Secondaireet Tertiaire (Supplement 1). Archives originales,Centre de documentation;Centre national de I& recherchescientifique (France),no. 366, p. I-XX, p. 1294-1750. Deflandre, G. and Deflandre-Rigaud,M. 1962. Nomenclatureet systematiquedes Hystrichospheres(sens. lat. ), observationset rectifications. Revuede micropaleontologie,v. 4, no.4, p. 190-196. DegardinJ. M. & Paris, F. 1978. Presencede ChitinozoairesDans Las CalcairesSiluro- Devoniensde la SierrraNegra (PyreneesCentrales Espagnoles). Geobios, v. 11, p. 769-777. Destombes, J. and Willefert, S., 1988. The Ordovician-Silurian boundary in Morocco. Bull. Br. Mus. Nat. Hist. (Geol. ), v. 43, p. 165-170. Destombes,J., Hollard H. and Willefert, S., 1959. Destombes,J., Hollard H. and Willefert, S., 1985. Lower Palaeozoicrocks of Morocco. in: C.Holland (Editor), Lower Palaeozoicof North-westernand West Central Africa. Wiley, Chichester,pp 91-336. Deunff, J. 1951. Sur la de presence microorganismes(Hystrichospheres) dans les schistes du Finistere. Comptes des ordoviciens rendus seancesde IAcademic des sciences,v. 233, no.4, p. 321-323. 290 Deunff, J. 1954a. Sur un microplanctondu Devoniendu Canadarecelant des typesnouveaux d'Hystrichosphaerides.Comptes rendus des seances de I'Academie des sciences,v. 239, no. 17, p. 1064-1066. Deunff, J. 1954b. Microorganisms planctoniques(Hystrichospheres) dans le Devonien du Massif armoricain. Compterendu sommaire de I& Societegeologique de France, ser.6, v. 4, p. 239-242. Deunff, J. 1954c. Veryhachium,genre nouveau d'Hystrichospheres du Primaire. Comptorendu som ire des seancesde la Societegeologique de France,no. 13, p. 305-306. Deunff, J. 1955a. Un microplanctonfossile Devonien e Hystrichospheresdu ContinentNord- Americain. BuUetinde microscopieappliquee, ser. 2, v. 5, nos.11-12, p. 138-149. Deunff, J. 1955b. Aremoricanim, genrenouveau d'Hystrichospheres du Silurien breton. Compterendu sommaireet bulletin de I& Societegeologique de France,v. 5, no.9, p. 227-229. Deunff, J. 1957. Microorganisms nouveaux(Hystrichospheres) du Devoniendo I'Amerique du Nord. Bulletin do la Societegoologique et mineralogiquede Bretagne,nouvelle ser, no.2, p. 5- 14. Deunff, 1.1958. Microfossiles Planctoniques du Primaire Armoricain. 1. Ordovicien du Veryhac'h (Presqu'ile de Crozon). Bull. Soc. Geol. Mineral. Bretagne, n. ser., v. 2, p. 1-4 1. Deunff, J. 1959. Microorganisms planctoniquesdu prin3aireArmoricain. I. Ordovicien du Veryhac'h (presqu'ile de Crozon). BuUetinde I& Societegoologique ot mineralogiquedo Bretagne,nouvelle ser., no.2, p. 1-41. Deunff, J. 196Ia. Un microplanctone Hystrichospheresdans le Tremadocdu Sahara. Revue de micropaleontologie, v. 4, no-1, p. 37-52. Deunff, J. 1961b. Quelquesprecisions concemant les Hystrichosphaerideesdu Devonien du Canada. Compterendu sommairedes seances de la Societegeologique de France, no. 8, p. 216- 218. Deunff, J. 1964a. Systematiquede microplanctonfossile e Acritarches;revision de deux genres de I'Ordovicien inferieur. Revuede micropaleontologie,v. 7, no.2, p. 119-124. Deunff, J. 1964b. Le genreDuvenuzysphaera Staplin. GranaPalynologica, v. 5, no.2, p.210- 215. 291 Deunff, J. 1965a. Acritarchesdu Devonien superieurde I& presqu'ile de Crozon. Compte rendu sommairedes seancesde I& Societegeologique de France, no.5, p. 162-164. Deunff, J. 1965b. Sur une seric c acritarchesdans le Devonien moyen du Finistere. Bureau de recherchesgoologiques et minieres,Paris, Memoire 33, p. 27-28, I pl. Deunff, J. 1966. Acritarchesdu Devonien de Tunisie. Compterendu sornnuire des amem de la Societegeologique de France,no. 1, p. 22-23. Deunff, J. 1967a. Presenced'Acritarches dansune serie devoniennedu lac Huron (Caua). Compterendu sommairedes seancesde la Societegeologique de France, no.6, p. 258-259. Deunff, J. 1967b. Recherchessur les microplanctonsdu Devonien (Acritarcheset Dinophyceae). Bulletin de la Societegeologique et mineralogiquede Bretagne,nouvelle ser., 17-25. Deunff, J. 1967c. Sur une seriee acritamhesdans le Devonien moyen du Finistere. Colloque sur le DevonienInferieur et sesLimites (Rennes,16-24 Septembre),Bureau de recherches geologiqueset minieres,Paris, Memoire 33, p. 341-347. Deunff, J. 1968a. Arbusculidiwn, gewe nouveaud'acritamhe du Tremadocienmarocain. Compterendu sommairedes Bmc" de la Societegeologique de Fmnce, no.3, p. 101-102. Deunff, J. 1968b. Sur une forme nouvelle d'Arcritarche possedantune ouverturepolaire (Veryhachiummiloni u. sp.) et sur la presenced'une colonie de Veryhachiumdans le Tremadocienmarocain. Comptesrendus des seancesde I'Academie des sciences,v. 267, p. 46. 49. Deunff, J. 1971. Le genre PoWryxiwn Deunff. Revision et observations. In: S. Jardine (ed. ), Microfossiles Organiques du Paleozoique, 3. Acritarches. Commission internationale de Editions du de la microflore du Paleozoique, Centre national recherche scientifique, Paris, p. 7- 48. Deunff, J. 1976a. Les Acritarchesin Les Schisteset CalcairesEodevoniens de Saint-Cenere (Massif Armoricain, France).Sedimentologie, Paleontologie, Stratigraphie. Mem. Soc. Geol.Mineral. Bretagne,v. 19, p. 59-91. 292 Deunff, J. 1976b. Las acritarches. In: H. Lardeaux(ed. ), Les Schisteset Calcaires Eodevoniensde Saint-Cenere(Massif Armoricain, France). Sedimentologie,paloontologie. stratigraphie.Memoire de la Societegeologique et mineralogiquede Bretagne,no. 19, p. 59-77. Deunff, J. 1977a. Un microplanctone Acritarchesdam les schistesIlanvirniena do I'Anti-Atlu (Zagora-Maroc). Notes, Servicegeologique du Maroc, v. 38, no.268, p. 141-ISI. Deunff, J. 1977b. Winwaloeusia,genre nouveau d'Acritarche du Devonien. Gcobios, v. 10, no.3, P.465-469. Deunff, J. 1978. Lanveociaet Candelwphaeridium,genres nouveaux d'Acritarches des Gres do Landevennee(Godinnieninferieurdel&RadedeBrest-Finistere). Goobios,v. ll, no. l, p. 113- 117. Deunff, J. 1980. La Paleoplancton des Gros de Landevennoc (Gedinnien de la Rade de ]Brut. Finistere) etude biostratigraphique. Geobios, v. 13, no. 4, p. 483-539. Deunff, J. 1981. Observationspreliminaires sur le paleophytoplanctonde la coupedo Caffiers (Givetien-FmsnienduBoulonnais,France). Annalesdela Societegeologique du Nord, v. 100, p. 65-71. Deunff, J. and Chateauneuf,J-J. 1976. Sur la presenced'un riche microplanctonSiluro- Devoniena Acritarches,spores, et Chitinozoairesau sommetdes Schisteset Quartzitesde Plougastel(Rade de Brest-Finistere);son interet stratigraphique. Goobios,V-9, no. 3, p. 337- 343. Deunff, J. & Chauvel,J. J. 1970. - Un Micropl&nctona Chitinozoaireset AcritarchesDans des Niveaux Schisteuxdu GresArmOricain (Mayenne et Sud do Rennes).C. R. Somm. Soc. Geol. France,v. 6, p. 196-198. Deunff, J. and Evitt, W. R. 1968. Tunisphaeridium,a new acritarchgenus from the Silurian and Devonian. StanfordUniversity Publications,Geological Sciences, v. 12, no. 1, p. 1-13. Deunff, J., Gorka, H. and Rauscher,R. 1974. Observationsnouvelles et precisionssur les Acritarchesa large ouverturepolaire du Paleozoiqueinferieur. GeDbios,v. 7, no. l, p. 5-18. Deunff, J. and Massa,D. 1975. Palynologieet stratigraphiedu Cambro-Ordovicien(Libye des de IAcademie nord-occidentale).Comptes rendus seances des sciences,ser. D, v. 281, p. 21- 24. 293 Deunff, J. and Paris, F. 1972. Presenced'un paleoplanctone acritarches,chitinozoaires, spores,scolecodontes et radiolairesdans les formationssiluro-devoniennes de la region do Plourach(Cotes-du-Nord). Bulletin de la Societegeologique et mineralogiquedo Bretagne, ser.C, v. 3, no.2, p. 83-88. Deunff, J., Lefort, J-.P. and Paris, F. 1971. Le microplanctonLudlovien des Fonwtions Inunergeesdes Minquiers (Manche)et sa placedans I& distribution du palooplanctonSilurien. Bulletin de la Societegeologique et mineralogiquede Bretagne,ser. C, v. 3, no. 1, p. 9-28. Deunff, J., Peniguel,G. and Poumot, C. 1961. De correlation palynoplanctologiquedans ]a Cambro-Ordoviciende Sahara. Societenationale, des petroles d'Aquitaine, Centre de recherches de Pau, Memoiresd'etudes, no. 65, p. 1-17. Diez, M. del C.R. and Cramer,F. H. 1974. Silurian acritarchs. Distribution and trends. Review of Palaeobotanyand Palynology, v. 18, p. 155-170. Diez, M. del C. R. & Cramer,F. H. 1974. Morphology of PseudoclWhrochitinaCarmenchul (Cramer 1964), A Chitinozoan-Speciesfrom the IxWow of Spain. Brev. Geol. Asturica, v. 13, p. 9-167. Diez, M. del C. R. & Cramer,F. H. 1978. Iberian Chitinozoans.- 1. Introduction and Summaryof Pre-DevonianData. Palinologia, num. ext. 1, p. 149-201. Diez, M. del C. R. & Cramer,F. H. 1976. Acritamheset miosporesdu Ludlovien de Corniero, ProvincedeLeon, Espagne. Revuedemicropaleontalogie,V. 19, na. 3, p. 121-133. Diez, M. del C. R. & Cramer,F. H. 1977. Rangechart of selectedLower Paloozoicacritarch taxa. Il. Index to parts I and H. Review of Palae6botanyand Palynology, v. 24, p. 1-48. Diver, W. L. and Peat, C.J. 1979. On the interpretationand classificationof Precambrian organic-walledmicrofossils. Geology, v. 7, p. 401-404. Doming, K. J. 1981. Silurian acritarchs from the type Wenlock and Ludlow of Shropr1ire, England. Review of Palae6botany and Palynology, v. 34, no. 2, p. 175-203. Doubinger, J. 1%3a. ChitinozoairesOrdOviciens et Siluriens des Schistesdo SteigeDans Les Vosges. Bull. Serv. CarteGeol. Als. Loff., v. 16, p-125-136. Doubinger,J. 1963b. Etude Palyno-Plancologiquesde QuelquesEchantillonsdu Devonien inferieur (Siegenien)du Cotentin.Bull. Serve.Carte. Gool. Als. Loff., v. 16, p. 261-273. 294 Doubinger, J. & Eller, J. P. von 1963. Decouvertede ChitinozoairesWage Silurien Dam Les Schistes;de Steige(Vallee del' Andlau, Vosges).C. R. Acad. Sc., v. 256, p. 469-471. Doubinger, J. & Ruhland,M. 1963. Decouverted'une faune de Chitinozoairesd'age Devonien au Treh (Regionde Markstein,Vosges Meridionales). C. R. Acad. Sc., v. 256, p. 2894-2896. Doubinger, J. & Poncet,J. 1964. Presencede Nombreux Chitinozairesd=s le Devonien inferieur (Siegenien) du Cotentin- C. R. Somm. Soc. Gool. France, v. 3, p. 104-105. Downie, C. 1958. An assemblageof microplanktonfrom the ShinetonShales (rrenudocian). Proceedingsof the Yorkshire GeologicalSociety, v. 3 1, no. 12, p. 331-349. Downie, C. 1959. Hystrichospheresfrom the Silurian Wenlock Shaleof England. Palaeontology,v. 2, no. 1, p. 56-71. Downie, C. 1960. Deuqffia and Domasia, new genera of hystrichospheres. Micropaleontology, v. 6, no. 2, p. 197-202. Downie, C. 1963. 'Hystrichospheres'(acritarchs) and sporesof the Wenlock Shales(Silurian) of Wenlock, England. Palaeontology,v. 6, no.4, p. 625-652. Downie, C. 1974a. Intercontinentalcorrelation of the Lower Cambrianbased on acritarchs. In: Palynologyof Proterophyteand Palaeophyte.Proceedings of the Ul InternationalPalynological Conferencein Novosibirsk, Moscow, p. 21-24. C. 1974b. Acritarchs from Downie, near the Precambrian-Cambrian boundary -a preliminary account. Review of Palaeobotany and Palynology, v. 18, no. 1-2, p. 57-60. Downie, C. 1979. Devonianacritarchs. In: The DevonianSystem. special papersin Palaeontology,no. 23, p. 185-188. C. 1982. Lower Cambrian Downie, acritarchsfrom Scotland,Norway, Greenlandand Canada. Transactionsof the Royal Societyof Edinburgh, v. 72, p. 257-285. Downie, C. 1984. Acritarchs in British stratigrRphy. GeologicalSociety of London, Special Report, no. 17, p. 1- 26. C. Sadeant,W. Downie, and A. S. 1963. On the interpretationand statusof some hystrichospheregenera. Palaeontology,v. 6, no-1, p. 83-96. 295 Downie, C. and Soper, N. J. 1972. Age of the Eycott Volcanic Group and its conformable relationship to the Skiddaw Slates in the English IAke District. Geological Magazine, v. 109, no. 3, p. 259-268. Downie, C., Evitt, W. R. and Saýeant,W. A. S. 1%3. Dinoflagellates, hystrichospheres,and the classificationof the acritarchs. StanfordUniversity Publications, Geological Sciences,V. 7, p. 1-16. Downie, C., Williams, G.L. and Sadeant,W. A. S. 1961. Classificationof fossil microplankton. Nature, v. 192, no.4801, p. 471. Dunn, D. L. 1959. DevonianChitinozoans from the CedarValley Formation in Iowa. J. Paleont., v. 33, p. 1001-1017. Dunn, D. L& Miller, T. H. 1964. A distinctive ChitinozoanFaunule from the Alpena Limestone(Middle Devonian)of Michigan. J. Paleont., v. 38, p. 725-728. Dutta, S.K. and Sah, S.C. D. 1970. Palyno-stratigraphyof the Tertiary sedimentaryformations of Assam. S. Stratigraphyand palynology of South Shillong Plateau. Palaeontographica, Abt. B, v. 131, no. 1-4, p. 1-72. Eisenack,A. 1931. NeueMikrofossilien desbalfischen Silurs. 1. Palaeontologische Zeitschrift, v. 13, no. 1-2, p. 74-118. Eisenack,A. 1932. - NeueMikrofossilien desBaltischen Silurs II. Palaont. Ze.. v. 14, p. 257- 277. Eisenack,A. 1934. NeueMikrofossilien desbaltischen Silurs IN und neueMikrofossilien des Silurs I. PalaaontologischeZeitschrift, 16, 1-2 52-76. bohmischen v. no. , p. Eisenack, A. 1937. - Neue Mikrofossilien dm ]BaltiKhen Silurs IV. Palaont. Zeitschr., v. ig, p. 217-243. Eisenack,A. 1938a. Hystrichosphaerideenund verwandteForm= im baltischenSilur. Zeitschrift fer Geschiebeforschungund Flachlandsgeologie,v. 14, no. 1, p. 1-30. Eisenack,A. 1938b. Die Phosphoridmollender Bernsteinformationals eberlieferertertieren Planktons. Schriftender Physikalisch-okonomischenGesellschaft zu Konigsberg, v. 70, no.2, P. 181-188. 296 Eisenack, A. 1938c. Neue Mikrofossilien des baltischen Silurs IV. Palaaontologisch Zeitschrift, v. 19, no. 3-4, p. 217- 243. Eisenack,A. 1939. - Chitinozoenund Hystrichosphaeridiumim Ordovizium des Rheinischen Schiefergebiges.Senckenbergiam, v. 21, p. 135-152. Eisenack,A. 1944. Eber einigepflanzliche Fundein Geschieben,nebst Bemerkungenzum Hystrichosphaerideen-Problem. Zeitschrift fer Geschiebeforschungund Flachlandsgeologie, v. 19, p. 103-123. Eisenack,A. 1951. Eber Hystrichosphaerideenund andereKleinformen ausbaltischem Silur und Kambrium. SenckenbergianaLedum, v. 32, no. 1-4, p. 187-204. Eisenack,A. 1954a. Hystrichospherenaus dem baltischenGotlandium. Senckenbergiana Lethaea,v. 34, no.4-6, p. 205-211. Eisenack,A. 1954b. Mikrofossilien aus Phosphoritendes samlendischenUnteroligozens und eber die Einheitlichkeit der Hystrichosphaerideen.Palaeontographica, Abt. A, v. 105, no.3-6, p. 49-95. Eisenack,A. 1955a. Chitinozoen,Hystrichospheren und andereMikrofossilien aus dem Beyrichia-Kalk. SenckenbergianaLethaea, v. 36, no. 1-2, p. 157-188. Eisenack,A. 1955b.- Neu Chitinozoenaus dem Silur desBaltikums und dem Devon der Eitel. SenckenbergianaLedum, v. 36, p. 311-319. Eisenack,A. 1957. Mikrofossilien in organischerSubstanz aus dem Las Schwabens (Seddeutschland).NeuesJahrbuchferGeologieundPaloontologie, Abhandlungen, V. 105, no.3, p. 239-249. Eisenack,A. 1958a. TasmanitesNewton 1875und Leiosphaeridian. g. als Gattungender Hystrichosphaeridea.Palaeontographica, Abt. A, v. 110, no. 1-3, p. 1-19. Eisenack,A. 1958b. Mikrofossilien aus dem Ordovizium des Baltikums. 1. Markmitschicht, Dietyonema-Schiefer,Glaukonitsand, Glaukonitkalk. SenckenbergianaLethau, v. 39, no.5-6, p. 389-405. 297 Eisenack,A. 1958c. Mikroplankton aus dem norddeutschenApt nebst einigen Bemerkungen eber fossile Dinoflagellaten. NeuesJahrbuch fer Geologieund Paleontologie, Abhandlungen, v. 106, no.3, p. 383422. Eisenack,A. 1959a. Neotypenbaltischer Silur-Hystrichospheren und neue Arten. Palaeontographica,Abt. A, v. 112, no.5-6, p. 193-211. Eisenack,A. 1959b. Was ist Membranilamax? NeuesJahrbuch fer Geologieund Paleontologie,Monatshefte, no. 7, p. 327-332. Eisenack,A. 1961. Einige Erurterungeneber fossile Dinoflagellaten nebst ebersichteber die zur Zeit bekanntenGattungen. NeuesJahrbuch fer Geologieund Paleontologie,Abhandlungen, v. 112, no.3, p. 281-324. Eisenack,A. 1962a.- NeotypenBaltischer Silur-Chitinozoen und Neue Arten. NeuesJb. Geol. Palaont.Abh., v. 114, P.291-316. Eisenack,A. 1962b. Einige Bemerk:ungen zu neuerenArbeiten eber Hystrichospheren. Neues jahrbuch fer Geologieund Paleontologie,Monatshefte, no. 2. p. 92-101. Eisenack,A. 1962c. Mikrofossilien aus dem Ordovizium des Baltikums. 2. Vaginatenkalkbis Lyckholmer Stufe. SenckenbergianaLethaea, v. 43, no.5, p. 349-366. Eisenack,A. 1962d. Neueproblematische Mikrofossilien. NeuesJahrbuch fer Geologieund Paleontologie,Abhandlungen, v. 114, no.2, p. 135-141. Eisenack,A. 1963a. ebereinige Arten der Gattung TasmanitesNewton, 1875. Grana Palynologica, v. 4., no. 2, p. 203-216. Eisenack,A. 1963b. Mitteilungen zur Biologie der Hystrichospherenund eberneue Arten. NeuesJahrbuch fer Geologieund Paleontologie,Abhandlungen, v. 118, no.2, p. 207-216. Eisenack,A. 1964. Katalog der fo6silenDinoflagellaten, Hystrichospheren und verwandten Mikrofossilien. Bmd 1. Dinoflagellaten. E- Schweizerbld'566 Verlagsbuchhandlung, Stuttgart, 899 p. Eisenack,A. 1965a. Die Mikrofauna der Ostseekalke.1. Chitinozoen,Hystrichogherm. NeuesJahrbuch fer Geologieund Paleontologie,Abhandlungen, v. 123, no.2, p. 115-148. Eisenwk, A. 1965b. Eber einige Mikrofossilien des samlendischenund norddeutwJ= Tertiers. NeuesJahrbuch fer Geologieund Paleontologie,Abhandlungen, v. 123, no.2, p. 149-159. 298 Eisenack,A. 1965c. Mikrofossilien um dem Silur Gotlands. Hystrichospheren,Problematik&. NeuesJahrbuch fer Geologieund Paleontologie,Abhandlungen, v. 122, no. 3, p. 257-274. Eisenack,A. 1967a. Katalog der fossilenDinoflagellaten, Hystrkhosphaerenund verwandten Mikrofossilen. BandI. Dinoflagellaten1. Ergenzungslieferung.E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, 241 p. Eisenack,A. 1967b. Axisphaeridiwnn. g., ein axialsymmetrischeHystrichosphere aus dem baltischenOrdovicium. NeuesJahrbuch fer Geologieund Paleontologie,Monatshefte, no. 5, p. 398-400. Eisenack, A. 1968a. eber die Fortpflanzung paleozoischer Hystrichospheren. Neues Jahrbuch fer Geologie und Paleontologie, Abhandlungen, v. 13 1, no. 1, p. 1-22. Eisenack, A. 1968b. Mikrofossilien eines Geschiebesder Borkholmer Stufe, baltisches Ordovizium, F2. Mitteilungen ausdem GeologischenStaatsinstitut in Hamburg, no.37, p. 81- 94. Eisenack,A. 1969a. Zur Systematikeiniger paleozoischerHystrichospheren (Acritarcha) des baltischenGebietes. NeuesJahrbuch fer Geologieund Paleontologie,Abhandlungen, v. 133, p. 245-266. Eisenack,A. 1969b. Bemerkungenzur Systematikder fossilenDinoflagellaten. Neues Jahrbuchfer Geologieund Paleontologie,Monatsbefte, no. 6, p. 337-343. Eisenack,A. 1969c. Kritische Bemerkungenund Richtigstellungenim Gebiet der fossilen Dinoflagellatenund Acritarchen(Critical review of somefouil dinoflagellatesand acritarchs). NeuesJahrbuch fer Geologieund Paleontologie,Abhandlungen, v. 134, no.2. p. 101-116. Eisenack,A. 1970. Mikrofossilien aus dem Silur Estlandsund der Iml osel. Geologiska Fureningensi StockholmForhandlingar, v. 92, no.542, p. 302-322. Eisenack,A. 197la. Die Mikrofauna der Ostseekalke(Ordovizium) 3. Graptolithen, Melanoskleriten,Spongien, Radiolarien, Problematika nebst 2 Nachtregeneber Foraminiferen und Phytoplankton. NeuesJahrbuch fer Geologieund Paleontologie,Abhandlungen, v. 137, no. 1, p. 337-357. Eisenack,A. 1971b. Weitere mikrOfmilien ausdem BeYrichienk&lk(Silur). Nem Jahrbuch fer Geologieund Paleontologie,Monatshefte, no. 8, p. 449-460. 299 Eisenack,A. 1972a. Chitinozoenund andereMikrofossilien aus der Bohning Leba, Pommern. Palaeontographica Abt A, v. 140, p. 64-87. Eisenack,A. 1972b. Kritische Bemerkungzur GattungPterospermpsis (Chlorophyta, Prasinophyceae).Critical remarksabout Pierospermopsis. Neues Jahrbuch fer Geologie und Paleontologie,Monatshefte, no. 10, p. 596-601. Eisenack,A. 1974. Beitmgezur Acritarchen-Forschung.Neues Jahrbuch fer Geologie und Paleontologie,Abhandlungen, v. 147, no.3, p. 269-293. Eisenack,A. 1976. Mikrofossilien ausdem Vaginatenkalkvon Helludden, eland. Palaeontogmphica,Abt. A, v. 154, no.4-6, p. 181-203. Eisenack,A. 1979. Nollia eifelensis(Acritamha), ein Pyrocystis-ehnlichesMikrofossil aus dem Unter-Devonder Eifel. SeackenbergianaLethaea, v. 60, no. 1-3, p. 51-53. Eisenack,A., Cramer,F. H. and Diez, M. del C.R. 1973. Katalog der fossilen Dinoflagelisiten, Hystrichospheren und verwandten Mikrofossilien. Band III Acritarcha 1. Teil. B. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, 1104 p. Eisenack,A., Cramr, F. H. and Diez, M. del C.R. 1976. Katalog der fossilenDinoflagellaten, Hystrichospherenund verwandtenMikrofouilien. Band IV Acritarcha 2. Teil. E. Schweizertbart'scheVerlagsbuchhandlung, Stuttgart, 863 p. Eisenack,A., Cramer,F. H. and Diez, M. del C.R. 1979a. Katalog der fossilen Dinoflagellaten,Hystrichogheren und verwandtenMikrofossilien. Band V Acritarcha 3. Teil. E. Schweizerbart'scheVerlagsbuchhandlung, Stuttgart, 529 p. Eisenack,A., Cramer,F. H. and Diez, M. del C.R. 1979b. Katalog der fossilen Dinoflagellaten, Hystrichospheren und verwandten Mikrofouilien. Band VI Acritarcha 4. Teil. E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, 531 p. Eiserhardt,K. H. 1984. Capinatosphaeridiumn. g. (Acritarcha) aus einemejiemyr- FlintgeschiebeGotlands (ob. Ordoviz). NeuesJahrbuch fer Goologieund Paleontologie, Monatshefte,no-9, p-521-528. Elaouad-Debbaj,Z. 1978. Acritarchesde I'Ordovicien superieurdu Synclinal de Bueaco (Portugal); systematiqw-biostratigraphie-interet paleogeographique. Bulletin de la Societe geologiqueet mineralogiquede Bretagne,ser. C, v. 10, no.2, p. 1-101. 300 Elaouad-Debbai.,Z. 1984a.Chitinozoaires ashgilliens do I'Anti-Atlas (Maroc). Goobios, v. 17, p. 45-88. Elaouad-Debbaj,Z. 1984b.Acritarches et Chifino"res de l'Arenig-Llanvirn de l'Anti-Atlas (Maroc). Rev. palaeobot. Palynol, v. 43, p. 67-68. Elaouad-Debbai, Z. 1986. Chitinozoaires de la Formation inferieure du Ktaoua, Ordovicien superieur de l'Anti-Atlas (Maroc). Hercynica, v. 2, p. 35-55. Elaouad-Debbaj, Z. 1987. Acritarches ot Chitinozoaireg do L'Ordovicien du Maroc. systematiquebiostratigraphie coffelations. These Univ. Rennes,3 10 pp (unpubl). Elaouad-Debbaj,Z. 1988a.Acritarches de l'Ordovicien superieur(Camdoc-Ashgill) de l'Anti- Atlas, Maroc. Rev. Micropaleontol,v. 30, p. 232-248. Elaouad-Debbaj,Z. 1988b.Acritarches et Chitinozoairesdu Tremadocdo I'Anti-Atlas Centml (Maroc). Rev. Micropaleontol.v. 31, p. 85-128. Elaouad-Debbaj,Z., Founier-Vinas,Ch. & Destequ,C. 1987. Presencede Chitinozoaires Ordovicienset Devoniensdans la Boutonnieredes Zekkara, region of d'Oujda (Maroc oriental). Sci.Geol. Bull., v. 40, p. 363-379. Evitt, W. R. 1963. A discussionand proposalsconcerning fossil dinoflagellates, hystrichospheres,and acritarchs,1. Proc. Nat. Acad. Sci. Washington,v. 49, p. 159-164. Fensome,A. F., Williams, G.L., Barss,M. S., Freeman,J. M. & Hill, J.M. 1990. Acritarch and fossil prasinophytes:an index to genera,species and intraspecifictam A. A. S.P. Contribution Series,No. 25. Fombella, M. A. 1977. Acritarcosde edadCambrico medio-inferior de la Provincia de Leon, Espana. Revistaespanolademicropaleontologia,v. 9, no. l. p. 115-124. Fombella, M. A. 1978. Acritarcos de la FormacionOville, edadCambrico medio-Tremadoc, Provincia de Leon, Espana.(Acritarchs of the Oville Formation, Middle Cambrian-Tremadocian age, Provinceof Leon.) Palinologia,numero extraordinario 1, p. 245-261. Fombella, M. A. 1979. Palinologiade la FormacionOville al norte y sur de la Cordillera Cant brica, Espana(Palynology of the Oville Formation, N and S of the CantabrianMountains, Spain). Palinologia, v. 1, p. 1-5. 301 FombeRa-Blanco,M. A. 1982. Determinacionpalinologica del Tremadoc en I& localidad de Verdiago, Provincia de Leon, no de Espana. Revistaespanola de micropaleontologia, v. 14, 13-22. Foml>--lla-Blanco,M. A. 1986. EI transito Cambrico-Ordovicico,palinologia y diacronismo, Provineia de Leon, No de Espana. Revistaespanola de mieropaleontologia,v. 18, no.2, p. 165- 179. Fombella-Blanco,M. A. 1987. Resemblancesand differencesbetween the palynological associationsof Upper Cambrianage in the NW of Spain(Vozmediano) and north of Africa [Similarites et differencesentre les associationspalynologiques d'ege Cambriensuperieur du Nord-ouestde I'Espagne(Vozmediano) et dAfrique du Nord]. Revue de micropaleontologie, v. 30, no.2, p. 111-116. Foumier-Vinas, C. 1985. AcritarchsOrdoviciens des Zekkara (Maroc Oriental). Geobios, v. 18, p. 907-813 Goldstein,R. F., Cramer,F. H. & Andress,N. 1%9. -Silurian Chitinozoansfrom Florida Well Samples. Trans. Gulf CoastAssoc. Geol. Soc., v. 19, p. 377-384. Gorka, 1-1.1969. Mikroorganisnxs de l'Ordovieien de Pologne. PalaeontologiaPolonica, no.22, P. 1-102. Grahn, Y. 1978. ChitinozoanStratigraphy and Palaeoecologyat the Ordovician Silurian Boundaryin Skane,Southermost Sweden. Sveriges Gool. Under., C, v. 744, p. 1-16. Grahn, Y., 1980. Early Ordovician Chitinozoan from Oland. Sver. Geol. Unders., Ser. C, v. 775, P-1-41. Grahn, Y., 1981a. Middle Ordovician Chitinozoa from Oland. Sver. Geol. Unders. Ser. C., v. 784, p. 1-5 1. Grahn, Y., 1981b. OrdovicianChitinozDa from the StoraAsbotorp Boring in Vastergotland South-CentralSweden. Sver. Geol. Unders. Ser. C., v. 7 87, p. 1-40. orahn, Y., 1981a. Caradocianand Ashgillian Chitinozoafrom the subsurfaceof Gotland. Sver.Geol- Unders., Ser. C., v. 788, p. 1-66. Grahn, Y., 1982b.Palaeobiology and biostratigraphyof ordovician chitinozoa from Sweden. Acta Univ. Ups. Abstr. UppsalaDiss. Fac.Sci-, v. 629, p. 1-16. 302 Grahn, Y., 1982c.Early CamdocChitinozoa from Ostergodand,south central Sweden.Cool. Foren. Stockhok. Forh., v. 105, p. 269-272. GrahanY., 1994. OrdovicianChitinozoa from Tallinn, Northern Estonia. Rev. Palaeobot. Palynol., v. 43, p. 5-31. Grahn, Y., 1988. Chitinozoanstratigraphy in Ashgill and Uandovery. Bull. Br. Mus. Nat. Hist. (Geol), v. 43, p. 317-323. Graindor, M. J., Robardet,M. & TaugourdeauPh. 1966. Chitinozoaizu du Siluro-Devonien Dans le Nord du Massif Armoicain. Ann. Soc. Geol. Nord, v. 85, p. 337-343. Gray, J. and Boucot, A. J. 1989. Is Moyeria a euglenoid? Lethaia, v. 22, p. 447-456. Greuter, W., Burdet, H. M., Chaloner,W. G., Demoulin, V., Grolle, R., Hawksworth, D. L., Nicholson, D. H., Silva, P. C., Stafleu,F. A., Voss, E. G. and McNeill, J.M. 1988. InternationalCode of BotanicalNomenclature. Repum vegetabile,v. 118,328 p. Grignani, D. 1967. - Correlationwith Chitinozoain the Devonianand Silurian in someTunisian Well Samples.Rev. palaeobot-Palynol., Y.5, p. 315-325. Grignani, D. & Mantovani, M. P. 1964.- Les Chitinozoairesdu SondageOum Doul-I (Maroc). Rev. Micropal., v. 6, p. 243-258. Harland, R. 1983. Distribution of Recentdinoflagellate cysts in bottom sedimentsfrom the North Atlantic Oceanand adjacentareas. Palaeontology,v. 31, p. 877-903. Hemer, D. O. and Nygreen, P.W. 1967. Algae, scritarchsand other microfossils incertaesedis from the Lower Carboniferous of Saudi Arabia. Micropaloontology, v. 13, no. 2, p. 183-194. Higgs, K. 1975. Upper Devonianand Lower Carboniferousmiospore ammblages fi-omHook Head, County Wexford, Ireland. Micropaleontology,v. 21, no.4, p. 393-419. Hill, P.J. 1974. Stratigraphicpalynology of acritarchsfrom the type areaof the 11andoveryand the Welsh Borderland. Review of Palaeobotanyand Palynology, v. 18, no. 1-2, p. 11-23. Hill, P.J. 1978. A review of Cymbosphaeridiumpilar and comparisonwith Multiplicisphaeridiumpachymunim sp. nov. from the Ilandovery and Wenlock of Shropshire, GreatBritain. Palynology, v. 2, p. 181-18S. 303 Hill, P.J. & Molyneux, S.G. 1988. Biostratigraphy,palynofacies and provincialism of Late Ordovician- Early Silurian acritarchsfrom northeastUbya. In: Al-Arnauti, A., Owens, R. & Thusu, iR. (eds). subsurfacePalynostratigraphy of NortheastUbya, p. 27-43. Hill, P.J., Paris, F. & Richardson,J. B. 1985. Silurian Palynomorphs. In: 77husu,R. & Owens,B. (eds). Palynostratigraphyof North-EastUbya. J. Micropalaeont., v. 4, p. 27-48. Holland, C. H., 1985. Seriesand Stagesof the Silurian System.Episodes, V. 8, p. 101- 103. Hal, M, 1965. Precisionssur I& stratigraphieet la repartition de que1quesespeces importantesdu Silurien superieuret de l'Eodevoniendu Maroc presaharien. Not« & M. Serv. geol. Maroc, v. 183, p. 23. Jaglin, J-C. & Paris, F. 1992. Exemplesde tetralogiechez les chitinozoaim du Pridoli de Libye et implications sur la signification biologique du groupe. Lethaia, v. 25., p. 151-164 Jansonius,J., 1964. Morphology and clawification of someChitinozoa. Bull. Canad.petrol. Gool., V. 12, P.901-918. Jansonius,J., 1970. Classificationand stratigraphicapplication of Chitinozoa. Amer. Paleont. conv. 1969,0, p. 789-808. Jardine, S. and Yapaudjian,L. 1968. Lithostratigraphieet palynologie du Devonien- GothlandienGreseux du Bassinde Polignac(Salmm). Revuedo I'lastitut franeaisdu petrole, v. 23, no. 4, p. 439-468. Jardine, S., Combaz,A., Magloire, L., Peniguel,G. and Vachey, G. 1972. Acritarchesdu siiurien temünal et du Devoniendu SaharaAlgerien. Comptesrendus 7c Congrer,international de stratigraphieet de geologiedu Carbonifere,Krefeld, August 1971,v. 1, p. 295-311. Jardine, S., Combaz,A., Magloire, L., Peniguel,G. and Vachey, G. 1974. Distribution stratigraphiquedes Acritarches dans le Paleozoequedu SaharaAlgerien. Review of Palaeobotanyand Palynology,v. 18, no. 1-2, p. 99-129. Jeffrey, C. 1977. Biological Nomenclature. Edward Arnold Limited, London, England, 72 p. Jenkins,W. A. M. 1967. OrdovicianChitinozoa from Shropsbire.Palaeont0logy, v. 10, p. 436- 488. 304 Jenkins, W. A. M. 1969. Chitinozoa from the Ordovician Sylvan Shale of the Arbuclde Mountains Oklahoma. Palaeontology,v. 13, p. 261-288. Jenkins,W. A. M. 1970. Chitinozoa. Gooscienceand Man. v. 1, p. 1-21. Jenkins,W. A. M. & Legault, J. A. 1979. StratigmphicRanges of SelectedChitinozoa. Palynology, v. 3, p. 235-264. Johnson,N. G. 1985. Early Silurian palynomorphsfrom the TuscaroraFormation in central Pennsylvaniaand their paleobotanicaland geologicalsignificance. Review of Palaeobotanyand Palynology, v. 45, p. 307-360. Kar, R. K. & Bose,M. N. 1976. Palaeozoicsporae dispersae from Zaire (Congo). XII: Assise a couchesde houille from Greinerville region. Museeroyal de I'Afrique centrale, Annales, ser. in-8, sciencesgeologiques, no. 77, p. 23-133. Kedo, G. 1.1955. Sporesof the Middle Devonianof the NortheasternByelorussian SSR; Institute of GeologicalSciences. Paleontology and Stratigraphyof BSSR, Stomik v. 1, p. 5-59. Keegan,J. B., Rasul, S. M. and Shaheen,y., 19S8. Palynostratigraphyof the Lower Palaeozoic(Cambrian to Silurian) sedimentsof the HashemiteKingdomof Jordan. Int. Symp. Circum-Mediteffanean.Palynol., Zeist. p. 13-23. Keff, J.W., McGregor, D. C. and McLaren, D. J. 1965. An unconformity betweenMiddle and Upper Devonianrocks of BathurstIsland, with commentson Upper Devonian faunasand microfloras of the Parry Islands. Bulletin of CanadianPetroleum Geology, v. 13, no.3, p. 409- 431. Kiryanov, V. V. 1978. Akritarkhi BilumVolyno-Podolii. AkademiyaNauk Ukrainskoi SSR, Institut GeologieheskikhNauk, Kiev, NaukovaDumka, p. 1-116 Kjellstrom, G. 1971a. Ordovicianmicroplankton (baltisphaerids) from the Grotlingbo Borehole No. 1 in Gotland, Sweden. SverigesGeologiskaUndersokning,ser. C, no.655, v. 65, no. l, p. l- 75. Kjellstrom, G. 1971b. Middle Ordovicianmicroplankton from the Grodingbo BoreholeNo. I in Gotland, Sweden. SverigesGoologiskaUndersokning,ser. C, no.669, v. 65, no. 15, p. 1-35. 305 Kjellstrom, G. 1974. Baltisphaeridiwnmukiechinatwn nom. nov. pro Bakisphaeridiiun echinatwnKjellstrom, 1971. GeologiskaFureningens i Stockholm Furhandlingar, v. 96, p. 21 I- 212. Kjellstrom, G. 1976. Lower Viruan (Middle Ordovician) microplankton from the Ekon BoreholeNo. 1 in estergodand,Sweden. SverigesGeologiska Undersokning, ser.C, no.724, v. 70, no.6, p. 1-44. Mapper, G. & Ziegler, W. 1979.- Devonian ConodontBiostratigraphy. In HousesM. R., Scurtton, C. T. & Basset,M. G. (ed.) 1979. The Devonian System. Spec.Pap. Palaeont.,V. 23, p. 199-224 Kozlowski, R. 1963. Sur la Nature des Chitinozoaires.Act& Palacont. Polonica, v. 9, v. 42S- 449. Kriz, J. & Paris, F. 1981. Pridolian and Lochkovian Faunas (Bivalvia and Chitinozoa) from LA Meignanne ( S. E. Brittany - France). Laufeld, S. 1967. CaradocianChitinozoans from Dalarna, Sweden. Geol. For. Stockh. Forh. v. 89, p. 275-349. RestevoBeds Podolia, LAufeld, S. 1971.- Chitinozoaand Correlationof the Moldova and of USSR. Mem. Bur. Recch.Geol- Min. (B, R. G.M) v. 73, p. 281-300. Laufeld, S. 1974. Silurian Chitinozoafrom Gotland. Fossils and Strata,v. 5,130 Laufeld, S. 1977a. Chitinozoans.71e Silurian-Devonian. IUGS. SeriesA, v. 5, p. 301-302. Legault, J. A. 1973a. Chitinozoaand Acritarchaof the Hamilton Formation (Middle Devonian), South-WesternOntario. Geol. Sur. CanadaBull., v. 221,103 p. Legault, J. A. 1973b. - Mode of aggregation of Hoegisphaera (Chitinozoa). Can. J. Earth. Sci., v. 10, p. 793-797. Legrand, Ph. 1970. Essaisur I& Paloogeographicde I'Ordovicien au SaharaAlgerien. CompagnieFrancaise des Petroles, Notes et Mem., v. 11, p. 121-138. LegrandPh. 1977.- LesChaines d'Ougarta, au SaharaAlgerien. Ile Silurian-Devonian Boundary.TUGS. Series A, v. 5, p. 195-202. 306 Legrand, Ph 1985. Lower PalaeozoicRocks of Algeria. In : C. H. Holland (Editor), Lower Palaeozoicof North-westemand West-central Africa. p 5-89. Legrand, P., 1988.7be Ordovician-Silurianboundary in the Algerian Sahara.Bull. Br. Mus.Nat. Hist. (Cool), v. 43, p. 171-176. Le Herisse,A. 1983. Les sporesdu Devonien inferieur du Synclinorium de Laval (Massif Armoricain). Palaeontographica,Abt. B, v. 188, no. 1-3, p. 1-81. Le Herisse, A. 1984. Microplancton a paroi organique du Silurien de Gotland (Suede). Observationsau microscopeelectronique de structuresde desenkystement.Review of Palaeobotanyand Palynology,v. 43, p. 217-236. Le Herisse,A. 1989. Acritarcheset kystesd'algues Prasinophycees du Silurien de Gotland, Suede. PalaeontographicaItalica, v. 76, p. 57-302. Lentin J.K. & Williams, G. 1989. Fossil dinoflagellates. Index to generaand species,1989 edition. AmericanAssociation of StratigraphicPalynologists, Contributions Series,no. 20, p. I- 473. Lessuise,A., Streel,M. and Vanguestaine,M. 1979. Observationspalynologiques clans le Couvenien(Emsien Terminal et Eifelien) du bord oriental du synclinorium.de Dinant, Belgique. Annalesde la Societegeologique de Belgique, v. 102, p. 325-355. Lewis, H. P. 1940. Ile microfossils of the Upper Camdocian phosphate deposits of Montgomeryshire, North Wales. Annals and Magazine of Natural History, ser.2, v. 5, no. 25, p. 1-39. Li Jun 1987. Ordovicianscritarchs from the Meitan Formation of Guizhou Province, south- west Chirm. Palaeontology,v. 30, no.3, p. 613-634. Lister, T. R. 1970. The acritarchsand chitinozoafrom the Wealock and Ludlow Seriesof the Ludlow and Millichope areas,Shropshire. PalaeontographicalSociety Monographs, v. 124 (publication528), no. 1, p. 1-100. Lister, T. R. and Downie, C. 1974. The stratigraphicdistribution of the acritarchsin the Ludlow successionat Ludlow. Review of Palaeobotanyand Palynology, V. 18, p. 25-27. 307 Loboziak, S. and Streel,M. 1981.Miospores in Middle Upper Frasnian to Famennian sedimentspartly datedby conodonts(Boulonnais, France). Rev. Palaeobot.Palynol., v. 34, p. 49 -66. Loboziak, S. and Streel,M. 1989. Middle-Upper Devonian miosporesfrom the Chadamis Basin Crunisia-Libya): systematicsand stratigraphy. Rev. Palae6bot.Palyn., V.58, p. 173-196. LDboziak,S., Streel,M. and Vanguestaine,M., 1983. Miospores et acritarchesdo Is Fonmtion d'Hydrequent(Frasnien superieur a Famennieninferieur, Boulonnais, France). Ann. Soc. Cool. BeIg., v. 106, p. 173-183. Loeblich, A. R. 1970a. Morphology, ultrastructumand distribution of Poloozoicacrit=hs. Proceedings of the North American Paleontological Convention, Chicago, 1969, pad 0, v. 2, p. 705-788. Loeblich, A. R. 1970b. Dicommopalla, a new acritarch genusfrom the Dillsboro Formation (Upper Ordovician)of Indiana, U. S.A. Phycologia,V. 9, no. 1, p. 39-43. Loeblich, A. R.. and Drugg, W. S. 1968. New acritarchsfrom the Early Devonian (Late Gedinnian)Haragan Formation of Oklahoma,U. S.A. Tulane Studiesin Geology, v. 6, no.4, p. 129-137. Loeblich, A. R. and MacAdam,R. B. 1971. North American speciesof the Ordovician acritarch genusAremoricanium. Palaeontographic&,Abt. B, v. 135, no. 1-2, p. 41-47, pl. 15-19. Loeblich, A. R. and Tappan,H. 1969. Acritarch excystmentand surfaceultrastructure with descriptionsof someOrdovician taxa. Revistaespanola de micropalcontologia,V. 1, no. 1, p. 45- 57, pl. 1-4. Loeblich, A. R. and Tappan,H. 1970.7hysanoprobolus,a new acritarch genusfrom the Early Devonian(LAte Gedinnian) Haragan Formation of Oklahoma,U. S.A. Proceedingsof the Biological Societyof Washington,v. 83, no.24, p. 261-266. Loeblich, A. R. and Tappan,H. 1971a. Two new Onhosphaeridium(Acritarcha) from the Middle and Upper Ordovician. Transactionsof the American Microscopical Society, v. 90, no.2, p. 182-188. Loeblich,A. R. andTappan, H. 1971b.New observations of theultrastructure of Askelopalla, an Ordovicianacritarch. Journal of Paleontology,v. 45, no.5, p.899-901. 308 Loeblich, A. R. and Tappan, H. 1976. Some new and revised organic-walled phytoplankton microfossil genera. Journal of Paleontology, v. 50, no. 2, p. 301-308. Loeblich, A. R. and Tappan, H. 1978. Some Middle and Late Ordovician microphytoplankton from centralNorth America. Journalof Paleontology,v. 52, no. 6, p. 1233-1287. Loeblich, A. R. and Wicander,E. R. 1974. New Early Devonian (Late Gedinnian) microphytoplankton. Demorhethiumlappaceum n. g., n. sp., from the Bois d'Arc Formation of Oklahoma,U. S.A. NeuesJahrbuch fer Geologieund Paleontologie,Monatshefte, no. 12, p. 707-711. Loeblich, A. R. and Wicander,E. R. 1976. Organic-walledmicroplankton from the Lower DevonianLate GedinnianHaragan and Bois d'Arc Formationsof Oklahoma, U. S.A., Part 1. PalaeontographicaAbt. B, v. 159, no. 1-3, p. 1-39. T mann, H. 1904. Eier und sogenannteCysten der Plankton-Expedition. Anhang. Cyphonautes.Ergebnisse der Plankton-Expeditionder Humboldt-Stiftung, v. 4, p. 1-62. Loquin, M. V. 1981. Affinites fongiquesprobables des chitinozoaires devanant Chitinomycetes. Cah. Micropalaeont.,v. 1, p. 29-36. Lu Lichang and Wicander,R. 1998. Upper Devonianacritarchs: and sporesfrom the HonggulelengFormation, HefengDistrict in Xiqiiang, China. Revistaespanola de micropaleontologia,v. 20, p. 109-148. Madler, K. A. 1963. IH. Die figurierten organischenBestandteile der Posidonienschiefer. GeologischesJahrbuch, Beihefte, v. 58, p. 287-406. Magloire, L. 1967. Etude Stratigraphique, par I& Palynologie, des Depots Argilo-Grew=du Silurien et due Devonien Inferieur Dans I& Region du Grand Erg Occidentoal (Sahara Algerien). International Symposium on the Devonian System, H: p. 473-49 1. Martin, F. 1966a. Les Acritarchesdu sondagede la brasserieLust, e Kortrijk (Courtrai) (Silurien beige). Bulletin de la Societebeige do geologie,de paleontologieet d'hydrologie, v. 74, no.2, p. 3S4-400. Martin, F. 1966b. Les Acritarchesde Sart-Bernard(Ordovicien belge). Bulletin de JaSociete belge de geologie,de paleontologieet d'hydrologie, v. 74, no.2, p. 423-444. 309 Martin, F. 1967. Les Acritarchesdu parc de Neuville-sous-Huy(Silurien belge). Bulletin de la Societebelge de geologic,de paleontologicet d'hydrologie, v. 7S, no. 3, p. 306-33S. Martin, F. 1968. Im Acritarchesde I'Ordovicien et du Silurien belges. Determination et.valeur stratigraphique. Institut royal des sciencesnaturelles de Belgique, Memoire, no. 160, p. 1-175. Martin, F. 1969. Chitinozoaireade L'Arenig Superieur- Danvirn Inforitur a Condroz (Belgique). Rev. Micropal., v. 12, p. 99-106. Martin, F. 1972. Les Acritarchesde I'Ordovicien inferieur do la MontagneNoire (Herault, France). Institut royal dessciences naturelles de Belgique, sciencesde ]a terre, Bulletin, v. 48, no. 10, p. 1-61. Martin, F. 1973. Ordoviciensuperieur et Silurien inferieur a Deerlijk (Belgique). Institut royal des sciencesnaturelles de Belgique,Memoire, no. 174, p. 1-71. Martin, F. 1978. Sur quelquesAcritarches Llandoveriem de Cellon (Alpez Camiques Centmles, Autriche). Goologische Bundesanstalt, Verhandlungen, v. 2, p. 35-42. Martin, F. 1981. Acritarches du Famennien inferieur a Villers-sur-Losse (Belgique). Institut royal des sciencesnaturelles de Belgique, sciencesdo I& terre, Bulletin, v. 52, no. 2, p. 1-55. Martin, F. 1982. Someaspects of late Cambrianand early Ordovician scritarchs. In: M. G. Bassettand W. T. Dean (eds.), The Cambrian-OrdovicianBoundary. Sections,Fossil Distributions, and Correlations.Geological Series (National Museumof Wales), no.3, p. 29-39. Martin, F. 1983. Chitinozaire8et AcritarchesOrdoviciens de la plate-formedu Saint-Laurent (Quebecet sud-estdel'Ontario). GeologicalSurvey of Canada,Bulletin 310, p. 1-59. Martin, F. 1984a. New Ordovician (Tremadoc)acritarch taxa ftom, the middle memberof the SurveyPeak Formation at Wilcox Pass,southern Canadian Rocky Mountains, Alberta. In: Current Research,part A. GeologicalSurvey of Canada,Paper 84-1A, p. 441-448. Martin, F. 1984b. Acritarchesdu Frasnienguperieur et du Famennieninferieur du bord meridional du Bassinde Dinat (ArdenneBelge). Institut royal des sciencesnaturelles de Belgique, sciencesde I& terre, Bulletin, v. 55, no.7, p. 1-57. Martin, F. and Dean, W. T. 1981. Middle and Upper Cambrianand Lower Ordovician acritarchsfrom RandomIsland, easternNewfoundland. GeologicalSurvey of Canada,Bulletin 343, p. 1-43. 310 Martin, F. and Dean,W. T. 1983. We Early Cambrianand Early Middle Cambrian acritarchs from ManuelsRiver, easternNewfoundland. In: Current Research,part B. Geological Survey of Canada,Paper 83-1B, p-353-363. Martin, F. and Dean, W. T. 1984. Middle Cambrianacritarchs from the ChamberlainsBrook Research, and ManuelsRiver formationsat RandomIsland, easternNewfoundland. In: Current part A. GeologicalSurvey of Canada,Paper 84-1A, p. 429-440. Martin, F. and Dean, W. T. 1988. Middle andUpper Cambrianacritarch and trilobite zonation at ManuelsRiver and RandomIsland, easternNewfoundland. Geological Survey of Canada, Bulletin v. 381,91pp. Martin, F. and Rickards,B. 1979. Acritarches,chitinozoaires et graptolites ordoviciens et siluriens de la Vallee de la Sennette(Massif du Brabant,Belgique). Annales de I& Societe goologiquede Belgique,v. 102, p. 189- 197. Martin, F. and Yin Uiming 1988. Early Ordovicianacritarchs from southernJilin Province, northeastChina. Palaeontology,v. 3 1, part 1, p. 109-127. Massa,D., 1989.Paleozique de Ubye occidentale.Stratigraphie et Paleogeographic.71hese. Univ. Nice. 514 pp. (unpubl). Massa,D. & Moreaux-Benoit, A. 1976.- Essaide SyntheseStratigraphique et Palynologique du SystemeDevonien en Libye Occidentale.Rev. Inst. Frane. Petrole, V.31, p. 287-333. Massa, D. and Moreau-Benoit, A. 1985. Apport de nouvelles donnees palynologiques a I& biosratigraphic at a la Palcogeographie du Devonian an Libya (sud du Basin de Rhadames) Sc. Geol. Bull. v. 38, p. 5-18. Matte, P. 1996. Structureprofonde et evolution de I& croutehercynienne d'Europe; Seance specialiseede I& SocieteGeologique do France. Bulletin de la SocieteGoologique de France, Huitieme Serie, v. 2, p. 9-41. McGregor, D. C. 1960. Devonianspores from Melville Island, CanadianArctic Archipelago. Palaeontology,v-3, part 1, p. 26-44. McGregor, D. C. 1979.- DevonianSpores from the BarrandianRegion of Czechoslovaldaand their Significancefor InterfaciesCorrelation. In: Current Research,B. Geol. Surv. Canada, Paper79-1 B, p. 189-197. 311 McGregor, D. Cand Camfield, M., 1976. Upper Silurian to Middle Devonian sporea of the Moose River Basin, Ontario. Geol. Surv. Can. Bull., v. 263,63p. McGregor, D. C.and CamfieldM., 1982. Middle Devonian Miospores from the Cap do Bray, Weatheralland Hecla Bay Formationsof NortheastMelville Island, CanadianArctic. Geol. Surv. Can. Bull. v. 348,105 pp. McLure, H. A., 1988. the Ordovician-Silurianboundary in Saudi Arabia. Bull. Br. Mus. Nat. Hist. (Cool). v. 43, p. 155-163. Molyneux, S.G. 1987. H. Appendix. Acritarchsand Chitinozoa from the Arenig Seriesof south-westWales. In: Ile Arenig Seriesin SouthWales. Stratigraphyand Palaeontology. Bulletin of the British Museum(Natural History), Geology, v. 41, no. 3, p. 309-364. Molyneux, S.G. & Doming, K. J. 1989. Acritarch dating of latestTremadoc-earliest Arenig (early Ordovician)sediments in the Carmarthendistrict, south Wales. Geol. Mag.. v. 126, p. 707-714. Molyneux, S. and Paris, F. 1985.lAte Ordovicianpalynolmorphs. In: B. T. Thusu and B. Owens(Editors). lbe palynostratigraphyof northeastUbya. J. Micropalaeontol. v. 4, p. 11-26. Molyneux, S.G. and Rushton,A. W. A. 1988. The ageof the Watch Hill Grits (Ordovician), English Lake District. Structuraland palaeogeographicalimplications. Transactionsof the Royal Societyof Edinburgh, Earth Sciences,v. 79, p. 43-69. Moreau-Benoit,A. 1966. etudedes sporesdu Devonieninferieur d'Avrille (Le Flechay), Anjou. Revuede micropaleontologie,v. 8, no.4, p. 215-232. Moreau-Benoit,A. 1967.Premiers resultats: d'une etudepalynologiques du Devonien delacarrieredes Fours a Chauxd'Angers (Maine-et-Loire). Rev.Micropaleontol., v. 9, p. 219- 240. Moreau-Benoit,A. 1967. Quelquesmieroplanctontes du Devonieninferieur de l'Anjou. Revue de mieropaleontalogie,v. 10, no.3, p. 200-208. Moreau-Benoit,A. 1969. etudepalynologique des formationsschisto-gresmses &ssmiees au Calcairede Chalonnesaux carrieresSaint-Charles et Tarareen Chaudefonds(Maine-et-Loire). Bull. Soc. Et Sci. Anjou, n. s., v. 7, p. 93-99. 312 Moreau-Benoit, A. 1972. Palynologie stratigraphique du Silurien et du Devonien clans le sud- est du Massif Armoricain (Synclinoriums de Saint-Juien-de-Vouvantes et d'Ancenis). 7e Congres international de stratigraphie et de geologie du Carbonifere, Krefeld, 197 1, v. 1, p. 285- 293. Moreau-Benoit,A. 1974a. Recherchesde Palynologieet de Plancologiesur le Devonien et QuelquesFormations Siluriennes Dans le Sud-Est du Massif Armoricain. Mem. Soc. Geol. Mineral. Bretagne,v. 18, p. 1-248. Moreau-Benoit,A. 1974b. Recherchesde Palynologieet de Planctologie. Sur le Devonien et quelquesformations siluriennes dans le Sud-Estdu Massif Armoricain. Memoires de I& Societe geologiqueet mineralogiquede Bretagne,no. IS, p. 1-248. Moreau-Benoit, A. 1976. Leg Spores et Les Debris Vegetaux. In Les Schistes et Calcairs F,odevoniens de Saint-Cenere(Massif Armoricain, France). SedimentolOgie,Paloontologie, Stratigrapbie.Mem. Soc. Geol.Mineral. Bretagne.v. 19, p-27-57. Moreau-Benoit,A. 1979. Las sporesdu Devoniende Libye, lere partic. Cah. Micropaloontol., v. 4, p. 58. Moreau-Benoit, A. 1980. L« spoers du Devonien de Lbye, 2eme partie. Cah. Micropaleontol.. v. 1, p. 3-53. Moreau-Benoit,A. 1984. Acritarcheset Chitinozoairesdu Devonienmoyen et superieurde l1bye occidentale. Review of Palaeobotanyand Palynology, v. 43, p. 187-216. Moreau-Benoet,A. and Poncet,1.1982. Les Schisteset Calcairesoodevoniens de Nehou dans la coupedo Barneville (nord-estdu Massif armoricain). Sedimentologie,palynologie, planctologie,stratigraphie. Bulletin du Bureaude recherchesgeologiques et minieres, sect.1, nos.1-2, p. 81-114. Morzadec, P. & Paris, F. 1976. COnfrOnt9tiOndes DOnDee8ot Comparaisons Avec des SuccessionsEodevoniennes d'Europe et d'Afrique du Nord. In Us Schisteset Calcaires E,odevoniens de Saint-Cenere(Massif Armoricain, France). Sedimentologie,Paleontologic, Stratigraphie. Mem. Soc. Cool. Mineral.Bretagne, v. 19, p. 7-14. Morzadec,P., Paris F. & Racheboeuf,P. 1973. - Une TrancheeDans le Devonien du Menez- Belair (SynclinoriumMedian Armoricain). Bull. Soc. Gool. Mineral. Bretagne,(C), v. 4, p. III- 114. 313 Morzadoc,P., Paris, F. & Racheboeuf,P. 1980. COnclusionsStratigraphique8 in La Trancheo de 1A Lezais, EmsienSuperieur du Massif Armoricain. Sedimentologie,Paleontologie, Stratigraphie.Mem. Soc. Gool. Mineral. Bretagne,v. 24, p. 11-18. Muir, M. D. and Sarjeant,W. A. S. 1971. An annotatedbibliography of the Tasmanaceaeand of relatedliving forms (Algae. Prasinophyceae).In: S. Jardine(ed. ), Microfossils Organiquesdu Paleozoique,3. Acritarches.Commission internationale do microflore du paloozoique,Editions du Centrenational de I& recherchescientifique, Paris, p. 59-117. Muller, J. 1959. Palynologyof RecentOrinoco Delta and shelf sediments,Reports on the Orinoco Shelf Expedition. Micropalaeontology,v. 5, p. 1-32. Naumova, S.N. 1939. Spores and pollen of the coals of the U. S. S.R. Report of the WIT International Geological Congress, 1937, v. 1, p. 353-364. Naumova,S. N. 1950. Spory nizImegosilum (Sporesof the Lower Silurian). Trudy Konferentsiipo Sporovo-Pyltsevomu Analizu, 1948God&, Geografichesidi Facultet, lzdatelstvo MoskovskogoUniversiteta, p. 165-190. Naumova,S. N. 1953,Spore-pollen assemblages of the Russian platform and their stratigraphic significance.Trans. Inst. Geol.Sci. Acad.Sci. USSR,(Geol. Ser., 60), v. 143,204pp. Neves, R. 1961. N'Lmurianplant sporesfrom the southernPennines, England. Palacontology, v. 4, no.2, p. 247-279. Neves, R. 1964. Report of C.I. M. P. Working Group No. 5. Knoxisporites(Potonie & Kremp) Neves 1961. CompteRendu, 5e Congresinternational de stratigraphieet de geologie carbonifere,v. 3, p. 1063-1069. Neves,R. and loannides,N. S. 1974. Palynologyof the Lower Carboniferous(Dinantian) of the SpilmersfordBorehole, East Lothian Scotland. GeologicalSurvey of Great Britain, Bulletin 45, p. 73-97. Newton, E.T. 1875. On Tasmaniteand Australianwhite coal. Geological Magazine, v. 12, no. 8, p. 337-342. Obut, A. M. 1973. Sur la Distribution Geographique,La Mortphologie Corapam, pEcologie, La Phylogenieet la Position Systernatiquedes Chitinozaires. (0- Geograficheskom Rasprostranenii,Sravnitel' Noi Morfologii, Ekologii, Filogenii i sißtematicheskom 314 polozheniikhitinozoa). In: Betelhtina,0. A. & Zhuravievea,1. T. (Eds). L'eavironement et la Vie Au Coursdes Temps Geologiques. p. 72-74. Ostenfeld,C. H. 1910. Halosphaeraand Flagellata. Bull. Trimest. ResumePlankton. Cons. Perm. Int.. Explor. Mer., v. 1, p. 20-38. OuyangShu and ChenYongxiang 1987. Miospore assemblagesfrom the Devonian- Carboniferoustransition in Jurongof southernJiangsu with specialreference to the geological ageof the WuntungGroup. Memoirs of Nanjing Institute of Geology and Palaeontology, no.23, p. 87-140. Owens,B. 1971.Miospores from the Middle and early Upper Devonianrocks of the western QueenElizabeth Islands, Arctic Archipelago.Geol. Surv. Can. pap., 70 - 98,157 pp. Owens, B., Downie, C. and Reynolds, M. I. 1977. Micropalaeontology of the Devonian sediments. In: Stratigraphy of the Steeple Aston Borehole, Oxfordshire. Geological Survey of Great Britain, Bulletin 57, p. 28-40. Padilhade Quadros,L. 1986. Ocorreniciade microfosseis(Acritarchae) Ordovieianos na Sub- BaeiadoAltoAmazonas, Brasil. B. toc. Petrobrs, RiodeJaneiro, v. 29, no.3, p. 181-191. Padilhade Quadros,L. 1988. ZoneamentoBioestratigr fico do Paleozoicoinferior e medio (SenaoMarinha) da Baciado Solimoes. Lower and Middle Paleozoicbiostratigraphy (marine section)of the SolimoesBasin. Boletin de Geocienciasda Petrobres,v. 2, no. 1, p. 95-110. Paris, F. 1976. Les Chitinozoairesin Les Schisteset CalcairesEodevoniens de Saint-Cenere (Massif Armoricain, France).Sedimentologie, Paleontologic, Stratigraphie. Mem. Soc. Cool. Mineral. Bretagne, v. 19, p. 103-133. Paris, F. 1978. Distribution des Chitinozoaires dans I'Ordovicien Superieur du Synclinal de Bucaco (Portugal). Palinologia. Num. Ext. 1, p. 367-368. Paris, F. 1979a. Les Chitinozoaires de la Formation de Louredo, Ordovicien Superieur du Synclinal de Bucaco (Portugal). Paleontographica, Abt. A, v. 164, p. 24-5 1. Paris, F. 1980a. lAs Chitinozoairesin Les Schisteset Calcairesde l'Armorique (Devonien Inferieur, Massif Armoricain). Sedimentologie,Paleontologie, Stratigmphie. Mem. Soc. Geol. Mineral. Bretagne,Y. 23, p. 111-128. 315 Paris, F. 1980b. Les Chitinozoaires in LA Tranchee de la Lezais, Emsien Superieur du Massif Armoricain. Sedimentologie, Paleontologie, Stratigraphie, Mem. Soc. Geol. Mineral. Bretagne, v. 24, p. 52-82. Paris, F., 1981. Les Chitinozoairesdans le Paloozoiquedu Sud-Ouestde I'Europe (Cadre goologique-Etudesystematique-Biostratigraphie). Mem. Soc.Geol. Mineral. Bretape, 26,496 PP. Paris, F. 1988a. Late Ordovicianand early Silurian Chitinozoansfrom centraland southern Cyrenaica(Libya). In: A. El Arnauti, B. Owensand B. Ilium (Editors), subsurface palynostratigraphyof northeastLibya. GaryounisUniv. Publ., Benghazi,p 61-71. Paris, F., 1988b.New chitinozoansfrom the late Ordovician-lateDevonian of NortheastLibya. In : A. EI-Amauti, B. Owensand B. lbusu. (Editors), subsurfacepalynostratigraphy of northeastLibya, GaryounisUniv. publ., Benghazi,p 73-87. Paris, F., 1989. Biostratiraphyof selectedSilurian chitinozoan.In: Ch.Holland and M. G.Bassett (Editors), A global standardfor the Silurian System.Nat. Mus. Wales. Geological SerieNo. 9, p 280-284. Paris, F. 1990.The OrdovicianchitinozDan biozones of the Northern Gondwanadomain.Rev. Palaeobot. Palynol. v. 66, p. 181-209. Paris, F. 1992. Application of chitinozoansin long-distancecorrelations. In: Webby, B. D. & Laurie, J.R. eds., Global perspectiveson OrdovicianGeology, p. 23-33. Paris, F. & Deunff, J. 1969.Decouverte dun Riche Microbiosa Acritarcheset Chitinozoaires dansles Formationsdu SynclinoriumMedian (Massif Armoricain, Environs de Saint-Medard- sur-Ille). Presencede sporeset de Scolecodontes.C. R. Acad. Sc., v. 269, p. 308-311. Paris, F. and Deunff, J. 1970. Le paleoplanctonUanvimien de la Roche-au-Merle(Commune de Vieux-Vy-sur-Couesnon,Ille-et-Vilaine). Bulletin de I& Societegeologique et mineralogique de Bretagne,ser. C, v. 2, no. 1, p. 25-43. Paris, F., Laufeld, S. & Chlupac,1.1980. The Chitinozoaof the Type-Sectionsof the Silurian- DevonianBoundary, in Bohemia.Sver. Geol. Unders,p. 3-29. Paris, F., Richardson,J. B., Riegel, W., Streel,M. and Vanguestaine,M. l9gS. Devonian (Emsian-Famennian)palynomorphs. Joumal of Micropalaeontology,v. 4, no.2, p. 49- 82. 316 Paris F. & RobardetM. 1978. Paleogeographieet RelationsIbero-Armoricaines au PaleozoiqueAnte-carbonifere. BuU. Soc. Geol. France(7), V. 19, p. 1121-1126. Paris, F. and Robardet,M., 1990.Early Palaeozoicpalaeogeography of the varis= ]3elt. Tectonophysicsv. 177, p. 193-213. Parke, M. 1966. The genus Pachysphaera (Prasinophyceae). In: Barnes, H. (ed. ). Some contemporary "ies in marine science, p. 555-563. Parke, M., Roalch,G. T., Jowett, R. & Harbour, D. S. 1978. Ile genusPterosperma (Prasinophyceae):species with a single equatorialala. J. Mar. Riol. Ass. U. K., v. 58, p. 239- 276. U. K., Parke, M. & Hartog -Adams,1.1965. Three speciesof Halosphaera. J. Mar. Biol. Ass. v. 45, p. 537-557. Pittau, P. 1985. Tremadocian (Early Ordovician) acritarchs of the Arburese Unit, southwest Sardinia (Italy). Bollettino della Societe paleontologica italiana, v. 23, no. 2, p. 161-204. Playford, 0.1962. Lower Carboniferous microfloras of Spitsbergen. Palaeontology, v. 5, no. 3, p. 550-618, pl. 78- 87.1963a. Miospores from the Mississippian Horton Group, eastern Canada. Geological Survey of Canada, Bulletin 107, p. 1-47. Playford, G. 1963b. Lower Carboniferous microfloms of Spitsbergen - part two. Palaeontology, v. 5, no. 4, p. 619- 678. Playford, G. 1965. Plant microfossils from Triassic sediments war Poatina, Tasmania. Geological Society of Australia Journal, v. 12, no. 2, p. 173-210. Playford, 0.1976. Plant microfossils from the Upper Devonian and Lower Carboniferous of the Canning Basin, Western Australia. Palaeontographica, Abt. B, v. 158, no. 1-4, p. 1-71. Playford, G. 1977. Lower to Middle Devonianacritarchs of the MooseRiver Basin, Ontario. GeologicalSurvey of Canada,Bulletin 279, p. 1-87. Playford, 0.1978. Lower Carboniferousspores from the DucabrookFormation, Drummond Basin Queensland.Palaeontographica, Abt. B, Y. 167, no.4-6, p. 105-160. Playford, G. 1981. Late Devonianacritarchs from the GneudnaFormation in the western CarnarvonBasin, WesternAustralia. Geobios,v. 14, no.2, p. 145-171. 317 Playford, G. and Dring, R. S. 1981. LAW Devonian acritarchs from the Carnarvon Basin, Western Australia. Special Papers in Palaeontology, no. 27, p. 1-78. Playford, G. and Martin, F. 1984. Ordovicianacritarchs from the CanningBasin, Western Australia. Alcheringa,v. 8, p. 187-223. Playford, G. andWicander, R. 1988. Acritarch palynoflora of the CoolibahFormation (Lower Ordovician), GeorginaBasin, Queensland.In: P.A. Jell and G. Playford (eds.), Palynological and PalaeobotanicalStudies in Honour of Basil E. Balme. Associationof Australasian Palaeontologists,Memoir 5, p. 5-40. Pocock, S.A. J. 1972. Palynologyof the Jurassicsediments of WesternCanada. Part H. Marine Species. Palaeontographica,Abt. B, v. 137, p. 85-153. Poumot, C. 1968. - Amphorachitina,Ollachitina, Velatachitina; Trois NouveauxGenres do Chitinozoairesde I'Erg Oriental (Algerie-Tunisie). Bull. Cent.Rech. Pau, v. 2, p. 45-55. Poumot, C. & van Oyen, F. H. 1968. RepartitiondesChitinozoairs typiques (Document of the chitinozoansub-commission, C. I. M. P.). Pothede Baldis, E. D. 1981. Paleomicroplanctony mioesporasdel Ludloviano inferior de la FormacionLos Espejosen el perfil los azulejitos,en la Provincia de SanJuan, Republica Argentina. Revistaespaeolademicropaleontologia,v. 13, no.2, p. 231-265. Potonie, R. and Lele, K. M. 1959. Studiesin the Talchir flora of India. 1. Sporaedispersae from the Talchir Redsof SouthRewa, GondwanaBasin. The Palaeobotanist,v. 8, no. 1-2, p. 22- 37. Potter, T. L. 1974. British Cambrianacritarchs -a preliminary acc:otmt. Review of Palaeobotanyand Palynology,v. 18, no. 1-2, p. 61-62. Poumot, C. & Van Oyen, F. H. 1964. Repartitiondes Chitinozoairestypiques (document inteme sous-commissionChitinozoairs C. I. M. P.) Priewalder,H. 1987. Acritarchenaus dem Silur des Cellon-Profils (karnischeAlpen, esterreich). Abhandlungender GeologischenBundesanstalt, v. 40, p. 1-121. Rasul, S.M. 1976. New speciesof the genusVulcanisphaera (Acritamha) from the Tremadocianof England. Micropaleontology,v. 22, no.4, p. 479-484. 318 Rasul, S.M. 1979. Acritarch zonationof the TremadocSeries of the ShinetonShales, Wrekin, Shropshire, England. Palynology, v. 3, p. 53-72. Rauscher,R. 1973. Recherchesmicropaloontologiques et stratigraphiquesdans I'Ordovicien et le Silurian en France.etude des acritarches, des chitinozoaires et des spores. Sciences Geologiques,Universite Louis Pasteurde Strasbourg,Institut de geologie, Memoire 38, p. I- 224. Reid, P. C. &John, A. W. G. 1981. A possiblerelationship between chitinozoa and tintinnids. Review of Palaeobotanyand Palynology,v. 34, p. 251-262. Richardson,J. B. 1964. Middle Old Red Sandstonespore assemblages from the Orcadianbasin, north-eastScotland. Palaeontology,v. 7, no.4, p. 559-605. Richardson,J. B. and Lister T. R. 1969. Upper Silurian and Lower Devonianspore assemblagesfrom the Welsh Borderlandsand SouthWales. Palawntology. v. 12, p. 201-252. Richardson,J. B. and McGregor, D. C. 1996. Silurian and Devonianspore zones of the Old Red SandstoneContinent and adjacentregions. Geol. Surv. Can. Bull., v. 364,79 pp. Richardson,I. B. and Rasul, S.M. 1978. PalYnOmorphsin Lower Devoniansediments from the Apley Ram Borehole,southern England. Pollen et Spores,v. 20, no.3, p. 423-462. Richardson,J. B., Rasul, S.M. and Al-Ameri, T. 1981. Acritarchs, miosporesand correlation of the Ludlovian-Downtonian and Silurian-Devonian boundaries. Review of Palacobotany and Palynology,v. 34, p. 209-224. Roche, E. 1933. Sur deux gisements fossiliferes dam le gre6 d'Ougarta (Confins algero- morocainsdu sud). C.R. somm. Soc. geol. Fr., v. 3, p. 30. Round, F. E. 1971. The taxonomyof the ChlorophytaH. British PhycologicalJournal, v. 6, p. 235-264. SadeantW. A. S. 1968. Microplankton from the Upper Callovian.and Lower Oxfordian of Normandy. RevuedoMicropalaeontologie, V-10, p. 221-242. SadeantW. A. S. 1978.Aipylorus antiquus Calandra, emend., a dinoflagellatecyst from the UpperSilurian. Palynology,v. 2, p. 167-179. 319 Savornin,J. 1921. Observationsur le Paleozoiquede Rabat(Maroc). C.R. Acad. Sci. Paris, 172, p. 1587. Schallreuter,R. 1963. Neue ChitinozoenAus OrdovizichenGmhieben und Bemerkungenzur GattungIllichitina. PalaeontologischeAbh., v. 1, p. 392-405. Schaarschmidt,F. 1963. Sporenund Hystrichosphaerideenaus dem Zechsteinvon Budingenin derWetterau. Palaontographica,AbtB, v. 113, p. 38-91. Scotese,C. R. & Barrett S.F. 1990. Gondwana'smovement over theSouthPole during the Palaeozoic:evidence from lithological indicatorsof climate. In: W. S. McKerrow & C. R. F. Scotese(eds), PalaeozoicPalaeo-geography and Biogeography. GeologicalSoc. London, Mem. 12, p. 75-85. Scotm, C.R. & McKeffow, W. S. 1990. In: McKerrow, W. S. & Scotm, C.R. ads. PalaeozoicPalaeogeography and Biogeography. Geol. Soc. London Mem. 12. Seagroves,K. L. 1967. Cutinizedmicrofossils of probablenonvascular origin from the Permian of WesternAustralia. Micropalaeontology,v. 13, p. 289-305. Sinha, V. 1969. Some"scritarchs' and other microfossilsfrom the BarakerStage of the Lower Gondwanas,India. The Palawbotanist,v. 17, p. 326-331. Smelror, M. 1986. Early Silurian acritarchsand prasinophyceanalgae from the Ringerike District, Oslo Region (Norway). Review of Palaeobotanyand Palynology,v. 52, p. 137-159. Smith, A. H. V. and Butterworth, M. A. 1967. Miosporesin the coal seamsof the Carboniferous of GreatBritain. SpecialPa4)ers in Palaeontology,no. 1, p. 1-324. Sommer,F. W. 1956. SouthAmerican Palaeozoic sporomorphae without haptotypic-structures. Micropalacontology, v. 2, p. 17S-181. Sommer,F. W. andvan Boekel, N. M. 1963. Somenew Tasmanaceaefrom the Devonianof Par Anais da Academiabrasileira de Ciencias,v. 35, no. 1, p. 61-65. Staplin, F. L. 1960. Upper Mississippianplant sporesfrom the GolataFormation, Alberta, Canacla.Palaeontographica, Abt-B, v. 107, no. 1-3, p. 1-40. Staplin, F. L. 1961. Reef-controlleddistribution of Devonianmicroplankton in Alberta. Palaeontology,v. 4, no.3, p. 392-424. 320 Staplin, F. L., Jansonius,J. and Pocock,S. A. J. 1965. Evaluationof someacritarchous hystrichospheregenem. NeuesJahrbuch fer Geologieund Paleontologie,Abhandlungen, v. 123, 2 167-201. no. , p. Steemans,P. 1985. Microflora. In: W. Rebske,Ch. Rebske,M. J.M. Bless, E. Paprothand P. Steemans,Over enkelefossielen uit de Klerf-Schichten(Onder-Emsien) bij Waxweiler (Eifel, B. R. D. ) en hun.leefinilieu. NederlandseGoologische Vereniging, Grondbooren Hamer, no.5, p. 149-154. Steemans,P. 1989. Etude Palynostratigraphicluedu DevonienInferieur dansl'ouest de I'Europe. Mem. Expl. CartesGoologiques et Minieres de I& Belgique,no. 27,453p. Stockmans,F. and Williere, Y. 1960. Hystrichospheresdu Devonionbelge (Sondagede l'Asile d'alieneseToumai). SenckenbergianaLethaea, v. 4l, no. 1-6, p. 1-11. Stockmans,F. and Williere, Y. 1962a. Hystrichosphom du Devonienbelge (Sondagedo I'Asile d'alienese Tournai). Bulletin de la Societebelge do goologie,de paloontologieet d'hydrologie, v. 71, p. 41-77. Stockmans,F. and Williere, Y. 1962b. Hystrichospheresdu Devonienbelge (Sondagede Wepion). Bulletin de la Societebelge de geologie,de paleontologieet d'hydrologie, v. 7 1, no. 1, p. 83-99, pl. 1-2. Stockmans, F. and Williere, Y. 1963. Ies Hystrichospheres ou mieux les Acritarches du Silurien Belge. Sondagede la Brasserie Lust e Courtrai (Kortrijk). Bulletin de la Societe belge de geologie, de paleontologie et d'hydrologie, v. 71, no. 3, p. 450-481. Stockmans, F. and Williere, Y. 1969. Acritarches du FamannsenInferieur. Academie royale des sciences, des lettres et des beaux artes de Belgique, Classe des sciences, Memoires, v. 38, no.6, p. 1-63. Stockmans,F. and Williere, Y. 1974. Acritarchesde ]a Trancheede Senzeille(Frasnien superieuret Famennieninferieur). Acadernieroyale des sciences,des lettres et desbeaux artes de Belgique, Classedes sciences, Memoires, v. 41, p. 3-79. K. lzboziak, S., Riegel, W. Steeman P., 1987. Spore Streel, M., Higgs, and , stratigraphy and correlationwith faunasand floras in the type marienDevonianof the Ardenne-Rhenish regions. Rev. palaeobot.Palynol., v. 50, p. 211-229. 321 Streel, M. and Loboziak, S. 1987. Nouvelle datation par miospore du Givetien-Frasnien des sediments non marins du sondagede Booischot (Bassin deCampine, Belgique). Bull. Soc. Gool. Belgique. v. % (2), p. 99-106. M. Paris,F., Riegel, W. Vanguestaine, Streel, , and M., 1988. Acritarch,chitinozoan and spore stratigraphyfrom the Middle and Upper Devoniansubsurface of NortheastLibya. In : E. Arnaut, B. Owenset B 17husu.(Eds). Aspectof NortheastLibyan Biostratigraphywith emphasis on Palynomorphs.Gariounis Univ. Spec.Publ. Tappan,H. 1966- Chitinozoanclassification. J. Paleont., v. 40, p. 1394-1396. Tappan,H. 1980. The Paloobiologyof Plant Protists. W. H. Freemanand Company,San Francisco,1028p. Tappan,H. and Loeblich, A. R. 1971. Surfacesculpture of the waIl in Lower Paleozoic acritarchs. Micropaleontology,v. 17, no.4, p. 385-410. TaugourdeauPh. 1961. Chitinozoairesdu Silurien d'Aquitaine. Rev. Micropal., v. 4, p. 135- 154. TaugourdeauPh. 1962. Associationsde Chitinozoairesdansquelques sondages de la region d'Edjele (Sahara)Rev. Micropal., v. 4, p. 229-236. TaugourdeauPh. 1963. Etude de Quelquesespeces critiques de Chitinozoairesde la region d'edjele et complementsa la faunelocale. Rev. Micropal., v. 6, v. 130-144. TaugourdeauPh.1966. Les Chitinozoaires,techniques d'etudes, morphologie et classification. Mem. Soc. Geol. France,n. ser., v. 45,64 p. TaugourdeauPh. 1967. Neotypesde Chitinozoaires.Rev. Micropal., v. 9, p. 258-264. TaugourdeauPh. & JekhowskyB. (de) 1960. Repartitionet descriptiondes Chitinozoires Silur-Devoniensde quelquesSondages de la C.R. E. P.S., de la C.F. P.A. et de la S.N. Repal au Sahara.Rev. Inst. Fr. Petrole,v. IS, p. 1199-1260. TaugourdeauPh. & Magloire, L. 1964. Developmentinterne et croissancechez quelques Chitinozoaires.Grans, Palynologica, v. 6, p. 128-146. 322 TaugourdeauPh., Bouche,P., Combaz,A., Magloire, L., & Mille-pied,P- 1967. Microfossiles organiquesdu Paleozoique.Les Chitinozoaires.(1). C.I. M. P. Ed. du Centre National de la RechercheScientifique, 96p. Timofeev, R.V. 1956a. Hysttichosphaeridaekembriya. AkademiyaNauk SSSR(Doklady FArth ScienceSections), v. 106, p. 130-132. Timofeev, B. V. 1956b. 0 vozmste ortrozhskikh Sloev na Volyni i ikh polozhenii v razreze palaozoiskikh otlozenii. Akademiya Nauk SSSR (Doklady Earth Science Sections), v. 107, no. 6, p. 871-874. Timofeev, R. V. 1956c. Spory proterozoiskikh i rannepaloozoiskikh otlozhenii vostochnoi Sibiri i ikh stratigraficheskoe zaachenie. In: Trudy Mezhduvedomstvennogo Sobeshchaniyapo Razrabotke Unifitsirovannykh Stratigraficheskikh Skhem Sibiri, Akademiya Nauk SSSR, p. 226- 230. Timofeev, B. V. 1958. eberdas Alter sechsischerGrauwacken Mikropaleophytologische Untersuchungenvon Probenaus der Weesensteinerund LausitzerGrauwacke. Geologie,v. 7, no. 3-6, p. 826-845. Timofeev, B. V. 1959. Drevneishaya flora Pribaltiki i ec stratigraficheskoe zaachenie. Vsesoyuznyi Neftyanoi Nauchao-Issledovatelsldi Geologorazvedochnyi Institut, Ixaingrad (VNIGRI), Trudy, no. 129, p. 1-136. Timofeev, B. V. 1966. Mikropaloofitologicheskoeissledovanie drevnikh svit. AkademiyaNauk SSSR,Isdatelskvo Nauka, Moskva, p. 1-147,pl. 1-89. PublishedEnglish translationdated 1974 by British Library - Lending Division, Yorkshire, England,214 p. Tongiorgi, M., Albani, R. and Di Milia, A. 1984.7be SolammSandstones of central Sardinia. new paleontologicaldata (acritarchs) and an attemptof geologicalinterpretation (a post- Sardinianmolasse? ). Societegeologique de France,Bulletin, 7e ser., v. 26, no.4, p. 665-680. Tongiorgi, M., Di Milia, A., Stouge,S. and Bagnoli, G. 1988. Acritarchs from the Upper Cambrian-LowerTremadocian section of Degerham.Road at Oeland,Sweden. Seventh InternationalPalynological Congress, Brisbane, Australia, Abstracts,p. 164. Turner, R.E. 1994. Acritarchs from the type areaof the Ordovician CaradocSeries, Shropshire,England. Palaeontographica,Abt. B, v. 190, no.4-6, p. 87-157. 323 Turner, R. E. 1985. Acritarchs from the type area of the Ordovician Llandeilo Series, South Wales. Palynology,v. 9, p. 211-234. Turner, R. E. 1986. New and revisedscritarch taxa from the Upper Devonian(Frasnian) of Alberta, Canada. CanadianJournal of Earth Sciences,v. 23, no.5, p. 599-607. Turner, R. E. and Wadge,A. I. 1979. Acritarch dating of Arenig volcanismin the LAke District. Proceedingsof the Yorkshire Goo&ogicalSociety, v. 42, part 3, no.23, p. 405-414. Vail, P.R., Mitchum, R. M. & Thompson,S. 1977. Seismicstratigraphy and global changesin sealevel, part 4: Global cyclesof relative changesin sealevel. In: Payton, C.E. (ed). A. A. P.G. Memoir 26. SeismicStratigraphy: Application to hydrocarbonexploration, p. 83-97. Van Oyen, F. H. & Calandra,F. 1963. Note sur les Chitinozoaires.Rev. Micropal., v. 6, p. 13- 18. Vangpestaine,M. 1978. Criterespalynostratigraphiques conduisant a la reconnaissanced'un pli coucherevinien dansle sondagede Grand-Halleux. Annalesde I& Societegeologique de Belgique,v. 100, p. 249-276. Vavrdova, M. 1965. Ordovicianacritarths from centralBohemia. Vestnik UstrednihoUstavu Geologickeho,v. 40, no.5, p. 351-357. Vavrdova, M. 1966a. Mikroorganismy(Acritarcha) z ProterozoickychBulimikL Cech. CasopisNarodniho Muzoo, Oddil Prirodovedny,v. 13S,no. 2, p. 93-96. Vavrdova, M. 1966b. Palaeozoicmicroplankton from centralBohemia. Casopispro Mineralogii a Goologii, v. 11, no.4, p. 409-414. Vavrdova, M. 1972. Acritarchs from Klabava Shales (Arenig). Vestnik UstrednihO UstAvu Goologickeho, v. 47, p. 79-86. Vavrdova, M. 1973. New acritarchsfrom BohemianArenig (Ordovician). Vestnik Ustredniho Ustavu Goologickeho,v. 48, no.5, p. 285-289. Vavrdova, M. 1976. Excystmentmechanism of Early Paleozoicacritarchs (Mechanis excystaceuranepaleozoickychaMtanh). Casopispro Mineralogii a Geologii, v. 21, no. 1, p. 55-64, pl. 1-4.1977. Acritarchs from the SorkaFormation (IJanvimian). Vestnik UstrednihoUstavu Geologickeho,v. 52, p. 109-118. 324 Vavrdova, M. 1978. Nethromorphitaeand someother acritarchsfrom the BohemianLower Ordovician. In: V. Pokorny (ed.), PaleontologickeKonference Katedry Paleontologiena Prirodovedecke F"te Univerzity Karlovy, Praha, p. 61-74. Vavrdova, M. 1982a. Recycledacritarchs in the uppermostOrdovician of Rohemist (Redeponovanakiitarcha v nejvyssimceskem Ordoviku). Casopispro Minemlogii a Geologii, v. 27, no. 4, p. 337-345. Vavrdova, M. 1982b. Phytoplanktoncommunities of Cambrianand Ordovicianage of central Bohemia. Vestnik UstrednihoUstavu Geologickeho,v. 57, no.3, p. 145-155. Vavrdova, M. 1994. Some plant microfossils of possible terrestrial origin from the Ordovician of central Bohemia. Vestnik Ustredniho, Ustavu Geologickeho, v. 59, no. 3, p. 165-170. Vavrdova, M. 1986. New genera of acritarchs from the Bohemian Ordovician (Nove rody akritamhzCeskehoOrdoviku). Casopis pro Mineralogii a Goologii, v. 31, no. 4, p. 349-359. Vavrdova, M. 1990. Coenobialacritarchs and other palynomorphsfrom the Arenig\Llanvim boundary,Prague basin. Volkova, N. A. 1988. New speciesof acritarchs from the Lower Tremadocian of Estonia. In: A. F. Chlonova (ed. ). Palynology in the U. S. S.R. Papers of the Soviet Palynologists to the VII International Palynological Congress, Brisbane, Australia, 1988, p. 79-82. Wall, D., Dale, B., Lohmann,G. P. & Smith, W. K. 1977. The environmentaland climatic distribution of dinoflagellatecysts in modemmarine sedimentsfrom regionsin the North and SouthAtlantic Oceansand adjacentseas. Marine Micropalaeontology,v. 2, p. 121-200. Wetzel, 0.1933a. Die in organischerSubstanz erhaltenen Mikrofossilien desbaltischen Kreide- Feuersteinsmit einemsediment-petrographischen und stratigraphischenAnhang. Palaeontographica, Abt. A, v. 77, p. 141-186. Wetzel, 0.1933b. Die in organischerSubstanz erhaltenen Mikrofossilien desbaltischen Kreide-Feuersteinsmit einemsediment-petrographischen und stratigraphischenAnhang. palaeontographica,Abt. A, v. 78, p. 1-110. Wetzel, W. 1967. Charakteristikdes marinen Planktons im unterstenOrdovizium (B3). Der Geschiebesammler,v. 2, no.2, p. 35-50. 325 Whelan, G. M. 1988.Preliminary acritarchand chitinozoandistribuitions acrossthe Ordovician-Silurianboundary stratotype at Dob's Linn, Scotland.Bull. Br. Mus. Nat. Hist. (Gool), v. 43, p-41-44. White, H. H. 1842. On fossil Xanthidia. MicroscopicalJournal, London, v. 11, p. 35-40. Wifte, H. H. 1844a. On fossil Xanthidia. MicroscopicalSociety of London, Transactions,v. 1, p. 77-86. V;Wte, H. H. 1844b. On a new speciesof fossil Xanthidiwn. MicroscopicalSociety of London, Transactions,Y. 1, p. 87. Wicander,E. R. 1974. Upper Devonian-LowerMississippian acritarchs and prasinophycean algaefrom Ohio, U. S.A. Palaeontographica,Abt. B, v. 148, no. 1-3, p. 9-43. Wicander,E. R, 1978. The type speciesof the acritarchgenus Pustulisphaeridium Wicander, 1974. Journalof Paleontology,v. 52, no.3, p. 716. Wicander,E. R. 1983. A catalogand biostratigraphicdistribution of North AmericanDevonian acritarchs. AmericanAssociation of StratigraphicPalynologists, Contributions Series, no. 10, p. 1-133. Wicander,E. R. 1986. Lower Devonian(Gedinnian) acritarchs from the HaraganFormation, Oklahoma,U. S.A. Review of Palaeobotanyand Palynology,v. 47, no.3/4, p. 327-363. Wicander, E. R. and Loeblich, A. R. 1977. Organic-walled microphytoplankton and its stratigraphicsignificance from the Upper DevonianAntrim Shale,Indiana, U. S.A. Palaeontographica,Abt. B, v. 160, no.4-6, p. 129-165. Wicander,E. R. and Playford, G. 1985. Acritarchsand sporesfrom the Upper DevonianLime CreekFormation, Iowa, U. S.A. Micropaleontology,v. 31, no.2, p. 97-138. Wicander, E. R. and Wood, G. D. 1981. Systematics and biostratigraphy of the organic-walled microphytoplankton from the Middle Devonian (Givetian) Silica Formation, Ohio, U. S.A. American Association of Stratigraphic Palynologists, Contributions Series, no. 8, p. 1-137. Wilson, L. R. & Hedlund, R. W. 1964. - Calpichitina scabiosa,a New Chitinozoanfrom the Sylvan Shale(Ordovician) of Oklahoma.Oklahoma Geol. Notes, v. 24, p. 161-164. 326 Wilson, L. R. & Hedlund, R. W. 1971. Electron microscopestudies of the marine palynomorphQuisquilites. Micropaleontology,v. 17, no.2, p. 239-243. Wilson, L. R. and Urban, J.R. 1963. An incertaesedis palynomorph from the Devonianof Oklahoma. OklahomaGeology Notes, v. 23, no. 1, p. 16-19. Wilson, L. R. and Urban, J.B. 1971. Electronmicroscope studies of the marinepalynomorph Quisquilites. Micropalaeontology,v. 17, p. 239-243. Winslow, M. R. 1962. Plant spores and other microfossils from Upper Devonian and Lower Mississippian rocks of Ohio. United States Geological Survey, Professional Paper, no. 364, p. 1-93. Wood, G. D. 1974. Chitinozoa of the Silica Formation (Middle Devonian, Ohio) : Vesicle Ornamentation and Paleoecology. Mich. State Univ., Museum Publ., Paleont. Series. v. 1, (4), p. 127-162. Wright, R. P. 1976. - Occurence, stratigraphic distribution and abundanceof Chitinozoa from the Middle DevonianColumbus limestone of Ohio. Ohio. J. Sc., v. 76, p. 214-224. Wright, R. P. 1978. - Biogeographyof Middle DevonianChitinozoa of the MidwesternUnited States.Palinologia, Num. Extr. 1, p. 501-505. Wrona, R. 1980. Upper Silurian-Lower Devonian chitinozoa from the subsurface of southeasternPoland. Palaeontologica.Polonica, v. 25, p. 103-165. Young, T. P. 1989. Eustaticallycontrolled ooidal ironstonedeposits: faciesrelationships of the Ordovicianopen-shelf ironstones of WesternEurope. In: Young, T. P. & Taylor, W. E. G. eds. PhanerozoicIronstones. Geol. Soc. Spec.Publ. no.46, p. 51-63. Ziegler, A. M., C. R. Scotese,W. S. McKerrow, M. E. Johnson& R. K. Bambach1979. Palaeozoicpalaeogeography. Ann. Rev. Earth Plant. Sci. v. 7, p. 473-502. 327