1,14162 1.,Bulletin de la Société belge de Géologie 98-2 pp.141-148 Bruxelles 1989 Bulletin van de Belgische Vereniging voor Geologie 98-2 pp.141-148 Brussel 1989

OUTSTANDING PROBLEMS OF DINANTILI T CONODONT BIOSTRATIGRAPHY IN THE BRITISH ISLES, WITH SUGGESTIONS FOR THEIR SOLUTION by d'importance primordiale pour le S.O. de l'Angleterre. Ronald L. AUSTIN & Derek MOORE 1 La reconstitution de multiéléments dans les faunes à conodontes du Carbonifère inférieur ne semble ABSTRACT présenter que peu d'intérêt biostratigraphique. Par contre, l'application de techniques morphologiques Current understanding of British Dinantian à l'élément Pa est mieux indiquée pour améliorer conodont biostratigraphy is assessed and attention la classification taxonomique et la précision is drawn to 5 aspects which remain to be resolved. biostratigraphique. Classification of Dinantian rocks in Britain is in need of reappraisal and criteria for the recognition 45 évènements paléobiologiques, basés sur les mo- of stratal units need to be clearly 'defined. Recent ments d'apparition et de disparition des changes concerning the location of the stratotype conodontes, peuvent être reconnus dans le and the criteria adopted for recognition of the base Dinantien de la Grande-Bretagne. of the Carboniferous System are of particular rele- vance to South West England. Reconstruction of Les linéations phylogéniques des conodontes multielement apparatuses for Lower Carboniferous fournissent un canevas pour les études genera appears to have little biostratigraphic use. biostratigraphiques futures. Application of morphometric techniques to the Pa Des études micropaléontologiques intégrant des elements is more likely to provide the basis for re- données sismiques, sédimentologiques et finement of taxonomic division and biostratigraphic géochimiques devraient être appliqués aux precision. 45 Dinantian palaeobiological events stratotypes. L'influence du faciès sur la distribution may be recognised in Britain related to the appear- des conodontes serait mieux comprise après ance and disappearance of conodont genera. l'intégration des études sédimentologiques et Conodont lineages provide a framework for future micropaléontologiques et par l'utilisation de tech- biostratigraphic studies in Britain. Integrated niques nouvelles facilitant l'extraction des micropalaeontological studies related to seismic, conodontes de roches non-carbonatées. sedimentological and chemical data should be ref- erenced to stratotype sections. The influence of facies on conodont distribution will be better un- KEY WORDS derstood following integrated sedimentological and microfaunal studies and by the application of new Biostratigraphy, conodonts, Dinantian, techniques to provide greater yields of conodonts Carboniferous, British Isles, facies control. from non-carbonate lithotypes. MOTS CLE RESUME Biostratigraphie, conodontes, Dinantien, L'évaluation de l'échelle biostratigraphique des Carbonifère, Grande Bretagne, contrôle de faciès. conodontes dinantiens a attiré l'attention sur cinq problèmes importants à résoudre. I. INTRODUCTION Une révision de la subdivision lithostratigraphique du Dinantien est nécessaire, suivant des critères Twenty years have elapsed since the publication of clairement définis. Des modifications récentes dans a description of British Avonian conodonts from le choix du stratotype et des critères de reconnais- the type Avonian sequence at the Avon Gorge, sance de la base du système carbonifère sont Bristol (Rhodes et al., 1969). Much new informa-

Department of Geology, University of Southampton - GB-Southampton S09 5N1-1, England.

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tion is now available concerning the distribution of TOURNAISIAN 3 VISEAN Dinantian conodonts in the British Isles. Varker CO U R C E YA N CHADIAN ARUNDIANTHOLKERIAN ASBIAN BRIGANTIAN & Sevastopulo (1985) provide a useful update and important publications have appeared subsequently ®1 (Armstrong & Purnell, 1987 ; Sevastopulo & Nudds, 1987 ; Mitchell et al., 1986 ; Waters & Lawrence, 1987 ; Dickson et al., 1987; Austin, 1987). 4 5 6 This contribution focuses attention on five aspects 7 of British Dinantian conodont biostratigraphy 8 - S which currently are in need of resolution. These 9 may be summarised as follows : 10 11 a) classification of Dinantian rocks in the 12 British Isles ; 13 b) the base of the Carboniferous System and 14 its recognition in the British Isles ; 15- c) the taxonomy of Dinantian conodonts with 16-- reference to multielement apparatuses ; 17- d) the evolutionary sequence of Dinantian 18- conodonts and the definition and recognition 19- 20- of conodont biozones related to Dinantian 21 s events ; 22. e) the recognition of facies-control on the dis- 23 tribution of Dinantian conodonts. 24 Ir 25 a 26 aleISIMIMB 27 a) Classification of Dinantian rocks in 28 the British Isles 29-- 30 ► Before correlating strata there has to exist a well 31 established standard which may be based for ex- ample on biostratigraphic, chronostratigraphic, magnetostratigraphic, E-logs, seismic or Figure 1. Range of Dinantian Conodont genera in tephrochronologic subdivision. Great Britain: 1. Elictognathus George et al. (1976) proposed a new classification 2. Nodognahthus for British Dinantian rocks based on defined 3. Protognathodus stratotyped stages, to provide the framework of a 4. Siphonodella comprehensive recorganisation as a standard for 5. Branmehlia correlation by any convenient means. Their divi- 6. Mehlina sions are chronostratigraphic. The new stages re- 7. Bispathodus placed Vaughanian and other comparable divisions. 8. Patrognathus 9. Clydagnathus Only two of the stage-boundaries proposed by 10. Pseudopolygnathus George et al. (1976) for the British Dinantian cor- 11. Polygnathus respond with zonal boundaries, thus causing diffi- 12. Hindeodus culties in correlation of sequences with the defined 13. 'Apatognathus' stratotypes ; difficulties which are increased by the 14. Gnathodus absence of faunal lists for the stratotypes. To a 15. Bactrognathus large extent the disadvantages of the system which 16. Pelekysgnathus has been proposed by George et al. are a direct 17. Dollymae 18. Eotaphrus consequence of the introduction of stage names by 19. Doliognathus definition before the faunas and floras had been 20. Scaliognathus adequately studied. Details of the faunas in the 21. Mestognathus stratotype sections have appeared slowly (for ex- 22. Cloghergnathus ample Ramsbottom, 1981 ; Fewtrell et al., 1981 ; 23. Taphrognathus Austin, 1987 ; Simpson & Kalvoda, 1987). 24. Embsaygnathus 25. Lochriea The approach of George et al. (1976) to Dinantian 26. Cavusgnathus subdivisions was essentially different from that 27. Kladognathus 28. Idioprioniodus adopted by one of us (Austin, 1973) and by conti- 29. Diplognathodus nental geologists. On the continent the macrofossil 30. Vogelgnathus and microfossil distributions were studied in detail 31. Geniculatus before proposals were made concerning sub- divi- sions of the Dinantian Subsystem. A stratigraphie Conil et al. (1977) has subdivisions which relate to chart for the Dinantian Subsystem presented by faunas and the Stage boundaries usually coincide

142 with faunal changes. Increasingly it has become England and it is in rocks (probably subsurface) of recognised that the proposals made by George et this region of the British Isles that eventually the al. should be reappraised (see for example Austin, S. praesulcata - S. sulcata evolutionary sequence 1987 ; Austin & Davies, 1984). may be found (see Stewart in Varker & Sevastopulo, 1985). Sections lacking the Discussion as to Series names is at this time super- Siphonodella evolutionary sequence may be corre- fluous. As noted by George et al. (1976), in the lated with the stratotype using spores, since sections discussion of George & Wagner (1972) and in which demonstrate the S. praesulcata - S. sulcata Bouroz et al. (1978), the status of Dinantian, conodont lineage also contain spores. Kasig & Toumaisian and Viséan continues to change and Paproth (1981) have shown a sequence of LL, LE, doubtless will be considered again in the near fu- LN and VI spore associations in four rock se- ture. However, George et al. (1976) imply usage quences of Upper Devonian age in Germany. In of the Courceyan as a Series name "a new term Ireland the base of the VI Biozone (Higgs et al., (Courceyan) is proposed to include all the strata of 1988a, 1988b) is marked by the disappearance of a that part of the Toumaisian which is of Dinantian distinctive group of taxa. The base of the zone age". Ramsbottom & Mitchell (1980) published a approximates to the Devonian-Carboniferous paper entitled "The recognition and division of the boundary and also equates with the base of the Toumaisian Series in Britain", response to which Courceyan Stage (see also Neeves et al., 1972 ; appeared a year later in contributions from Fewtrell Clayton et al., 1978 and Marchant et al., 1984). & Smith (1981) and Clayton & Sevastopulo (1981). Chlupac et al. (1981) discussed the use of Series or Stage names within the Carboniferous System, as c)The taxonomy of Dinantian conodonts have Lane & Manger in Lane & Ziegler, 1985. reference to rnultielement apparatuses b) The base of the Carborr-gons System ail.: its recognition in the British Since the publication of Rhodes et al. (1969), sys- tematic taxonomic study of Dinantian conodonts Isles within the British Isles has remained relatively static. A few new species and subspecies have been The Subcommission on Carboniferous described in terms of form-taxa, but there have Stratigraphy has clearly stated (George & Wagner, been few alternative approaches to species- 1972) that there should be coincidence of System, definition of conodonts. Hill (1974) published a Series and Stage boundaries at the base of the preliminary report of a biometric approach, fol- Carboniferous System. In Western Europe the lowing a study of gnathodoid populations, but this base of the Carboniferous System, by definition, approach has not been taken up and developed by has for a long time been taken at the first appear- other researchers. ance of Gattendorfla subinvoluta, following a re- commendation made by the 1935 Heerlen Few studies have been undertaken in Britain since Carboniferous Congress and subsequently endorsed the work of Druce et al. (1972) regarding the com- by later meetings of the same body (George & position of Dinantian conodont apparatuses Wagner, 1972). Meetings of the Subcommission (Alridge et al. in Aldridge, 1987). A limited number on Carboniferous Stratigraphy have long held the of Lower Carboniferous taxa have been recon- opinion that when considering subdivision of the structed in recent years in terms of multielement Carboniferous System, goniatites are to be given taxonomy. They include reconstructions of the priority. Nevertheless one of us backed a proposal apparatus for species of "Apatognathus" (Nicoll, made at a meeting of the 7th Carboniferous Con- 1980), Cavusgnathus (Rexroad & Merrill, 1985), gress held in Krefeld in 1971 that the base of the Gnathodus (Norby, 1976), Hindeodus (Baesemann, Carboniferous System be redefined at a point in an 1973 ; Sweet in Ziegler, 1977), Idioprioniodus evolutionary sequence of conodonts where the (Baesemann, 1973 ; Merrill & Merrill, 1974 ; von species Siphonodella sulcata arises from Bitter, 1973), Kladognathodus (Rexroad, 1981), Siphonodella praesulcata. The selection of a hori- Lochreia (Norby, 1976), Polygnathus (Klapper & zon in a boundary stratotype for the base of the Philip, 1971 ; 1972), Vogelgnathus (Norby & Carboniferous System subsequently has been con- Rexroad, 1985), Pseudopolygnathus, Scaliognathus, sidered by a working group of the International Bactrognathus, Doliognathus and Staurognathus Union of Geological Sciences (Paproth, 1978 ; (Chauff, 1981). It is doubted if such multielement Paproth & Streel, 1984 ; Flajs et al., 1988). Should refinements will lead to a more useful taxonomy for the proposal that the first appearance of biostratigraphic or palaeoecologic investigations of Siphonodella sulcata be accepted as the definitive Dinantian strata in Britain. Chauff (1981), for ex- criterion for the base of the Carboniferous System, ample, has suggested a multielement reconstruction it may not in itself greatly assist correlation of for a number of Lower Carboniferous species in- British sections with the agreed stratotype, the rea- cluding the biostratigraphically important forms son being that the genus Siphonodella is not present Polygnathus communis carina and Pseudo- in many British rock sequences of late Devonian to polygnathus multistriatus. He interpreted the spe- early Carboniferous age. Siphonodella is sparse in cies as having vicareous Pb M Sa Sb and Sc ele- the British Lower Carboniferous sequences of shelf ments in addition to the distinctive Pa elements. aspect. However, the genus is relatively common Chauff further suggested that an additional in Lower Carboniferous sequences of South West hindeodinan Sb element may also have formed part

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of the apparatus. The apparatuses were thus either & Jones, 1985) ; partial range biozone (Johnston sexi- or septimembrate in composition, but were and Higgins, 1981) ; Acrozone (of Groessens, distinctive only in terms of their Pa element. 1976a ; Varker & Sevastoulo, 1985) and assemblage zones (Rhodes et al., 1969) are some Of more significance with regard to biostratigraphic of the biostratigraphic terms which have been ap- applications have been advances in understanding plied, following regional studies of British the evolutionary development of the Pa element of Dinantian conodont sequences. We believe that it apparatuses. The evolutionary development of the is now time to standardise biostratigraphic termi- characteristic Lower Carboniferous genus nology as far as possible. Siphonodella has been documented (Sandberg et al., 1978), as has the evolutionary development of Marchant et al. (1984) related microfossil the genera Bispathodus (Ziegler et al., 1974), (conodont, foraminifer and spore) data to 16 Clydagnathus and Patrognathodus (Austin & Hill, biostratigraphic events in the Irish Tournaisian Se- 1973). The evolutionary development of Dollymae ries. This integrated micropalaeontological ap- bouckaerti and related forms (Groessens, 1976) and proach with subsequent updating has much to of certain species of Pseudopolygnathus (Rhodes et commend it and in our opinion indicates the most al., 1969 ; Johnston & Higgins, 1981) is now rea- useful direction for future biostratigraphic studies sonably well documented. (both mega- and micro-faunal). Such a study should also be related to seismic, sedimentological Problems remain regarding the origins of and chemical data pertaining to Dinantian strata Cavusgnathus, Taphrognathus, Cloghergnathus, and referenced to stratotype sections. Mestognathus and related genera. The development of the zonally important Dinantian form genus On the evidence of the record of Dinantian Gnathodus and its relatives remains unresolved. conodont appearances and extinctions (Aldridge, Some conodont researchers (e.g. Belka, 1985) have 1988) a number of important events took place preferred to recognise a number of separate species, during the Dinantian Subperiod(see also fig. 1). but the definitions of the types often have not been Nine genera made their first appearance and ten adequate to distinguish precisely a particular species genera became extinct. Another 13 genera ap- or subspecies from others of similar morphology. peared and disappeared. Thus at the generic level Lane et al. (1980), in synonomising a number of there are 45 palaeobiological events which, because species, adopted a different approach which is con- of geographic and ecologic factors, may not all be venient and may make good taxonomic sense, but represented in one particular region. Appearance which nevertheless overlooks the subtle and minor and disappearance of species considerably increases morphological changes which individual species the number of events. There is an urgent need for underwent. These often have biostratigraphic sig- first and last appearances of conodont species to nificances. be accurately recorded within the British Dinantian succession and for conodont ranges to be accurately Conodont taxonomists, unlike their colleagues who related to the distribution of other fossil groups. study the wall structure of foraminifera in minute detail in thin section, have seldom carried out de- Certain Lower Carboniferous conodont lineages tailed analysis of conodont-morphology. A de- are now well understood. These should be utilised tailed study of the morphology of the species to provide a framework for future biostratigraphic Siphonodella sulcata and S. praesulcata has been studies. It is suggested that the following lineages published recently (Flajs & Feist, 1986 in Flajs et should form the basis for the establishment of al., 1988). Such a study is long overdue and others zones and standardisation of biostratigraphic ter- should follow. For example a morphotype minology in the British Isles : Gnathodus bilineatus is widely recognised as being characteristic of Upper Dinantian strata but sys- (i) the Siphonodella lineage ; tematic biometric analysis of the species and SEM examination of its surface-development (Conway (n) the Pseudopolygnathus multistriatus Morris & Harper, 1988) has not been undertaken. Polygnathus mehli lineage ; Application of morphometric techniques (e.g. the Eotaphrus cf. bultyncki - Eotaphrus Macleod & Carr, 1987 ; Klapper & Foster, 1986) bultyncki - Dollymae bouckaerti lineage ; to the study of Dinantian conodonts, particularly the Pa elements, should in future provide the basis (iv) the Scaliognathus pre-anchoralis for precise recognition of species and refinement of Scaliognathus anchoralis lineage ; taxonomic division. (v) the Mestognathus pre-beckmanni Mestognathus beckmanni lineage. d) The evolution of Dinantian cor—donts Two additional lineages, (vi) the Gnathodus lineage and the definition and recognition of and (vii) the shallow-water lineages involving conodont biozones related to Dinantian Cavusgnathus and related genera, may form the ba- sis for future refinement, when their evolutionary events sequence has become fully documented, under- stood and established. Conodont faunal zones, subzones, biozones, lineage zones (Sevastopulo & Nudds, 1987) ; local The opinion of Sevastopulo & Nudds (1987), who range biozone, local range subbiozone (Somerville favour use of lineage zones, is endorsed, although

144 we are not convinced that such zones are conodonts from non-carbonate lithotypes by the isochronous. We wish to see lineage zones estab- use of new techniques (see Austin, 1987a). lished within a framework of Dinantian events, with local range zones and local range biozones applied regionally. We favour an integrated 2. CONCLUSION European biozonation and restate the opinion ex- pressed previously (Austin, 1973) that no zonation To solve the problems addressed in this article, in- will be better for any region than one defined for creased co-operation will be necessary between use in that region and that the greater the detail of biostratigraphers working on the classic sections of the study the greater will be its value. Recent Europe. The scientist honoured in this volume has studir;s of Dinantian conodonts in Ireland and been to the forefront in stimulating original South Wales support this opinion. 'biostratigraphic research and has encouraged dis- cussion across national boundaries. Increased international co-operation which she has fostered e) The recognition of facies control on should lead to the rapid solution of most of the the distribution of Dinantian cGa:.:3nts outstanding problems.

The proliferation of regionally applicable conodont REFERENCES biozones in the British Isles (see Varker & Sevastopulo, 1985, for a summary) provides a clear ALDRIDGE, RJ., Ed. 1987 - Palaeobiology of indication that facies-control has been a major in- Conodonts. Ellis Norwood, Chichester, fluence on British Dinantian conodont- 1-180. distribution. Varker & Sevastopulo (1985) provide a summary of the evidence relating to a distinction ALDRIDGE, Ri., 1988 - Extinction and Survival between shelf and basin faunas. In a discussion of in the Conodonta. In : G.P. Larwood (Ed.) the Courceyan of Ireland, Sevastopulo & Nudds Extinction and Survival in the Fossil Record. (1987) refer to a zonal scheme for the shell, utilizing Systematics Ass. Spec. Publ., 34: 231-256. species of Bispathodus, Pseudopolygnathus and ARMSTRONG, H.A. & PURNELL, M.A., 1987 Polygnathus whereas on the more distal parts of the - Dinantian conodont biostratigraphy of the shelf species of Eotaphrus and Dollymae are utilised Northumberland Trough. Jour. for zonal purposes. Interestingly these authors Micropalaeontology, 6: 97-112. claim that "the base of the P. mehli lineage zone is not facies-controlled because in the many sections AUSTIN, R.L., 1973 - Modification of the British where it has been recorded in Ireland it is not as- Avonian conodont zonation and a reappraisal sociated with any consistent lithological change" of European Dinantian conodont zonation and "although the conodonts used to recognise and correlation. Ann. Soc. Geol. Belg., 96: distal shelf zones are environmentally restricted, the 523-532. bases of the E. bultyncki and D. bouckaerti sub- AUSTIN, R.L., 1976 - Evidence from Great zones and the Sc anchoralis Zone are not linked to Britain and Ireland concerning west lithology". European Dinantian conodont Paleoecology. Unlike studies in Ireland, the relationship between In : C.R. Barnes (Ed.) Conodont Geol. Assoc. Canada Spec. Dinantian conodont distribution, lithology and en- Paleoecology. Pap., 15: 201-204. vironment of deposition has not been adequately studied in Great Britain (see Austin, 1976), since AUSTIN, R.L., 1987 - Conodonts of the there have been few co-ordinated sedimentological Arundian (Dinantian) stratotype boundary and palaeontological investigations. Lees & beds from Dyfed, South Wales. In : M. B. Hennebert (1982) analysed the microfacies of the Hart (Ed.) Micropalaeontology of Carbonate Knap Farm Borehole, similar microfacies analysis Environments, Ellis Horwood, Chichester, of British Dinantian sequences in South West En- 238-255. gland has been carried out by Professor Lees and his students (see Conil et al., 1988). Such analyses AUSTIN, R.L., Ed. 1987a - Conodonts : Investi- enable the environmental conditions to be better gative Techniques and Applications. Ellis understood and provide a framework for interpret- Horwood, Chichester, 1-422. ing the distribution of faunas, both macro and mi- AUSTIN, R.L. & DAVIES, R.B., 1984 - Prob- cro. In the future, closer collaboration between lems of recognition and implications of sedimentologists and palaeontologists (Simpson & Dinantian conodont biofacies in the British Kaldova, 1987, for example) is essential if the effect Isles. In: D.L. Clark (Ed), Conodont of facies (Faulkner, 1988 ; Wright, 1986, for exam- Biofacies and Provincialism. Geol. Soc. ple) on conodont-distribution in Great Britain is to America, Spec. Publ., 196: 195-228. be more meaningfully and accurately assessed. There are encouraging signs that such integrated AUSTIN, R.L. & HILL, P.J., 1973 - A Lower studies are being undertaken (Whittaker & Green, Avonian (K zone) conodont fauna from near 1983 ; Waters & Lawrence, 1987). It is also anti- Tintern, Monmouthshire, Wales. Geologica cipated that researchers will endeavour to obtain et Palaeontologica, 7: 123-129.

145 BAESEMANN, J.F., 1973 - Missourian (Upper storm-dominated early Carboniferous ramp. Pennsylvanian) conodonts of northeastern Geol. Jour., 23: 85-100. Kansas. Jour. Paleont., 47: 689-710, FEWTRELL, M.D., RAMSBO FIOM, W.H.C. BELKA, Z., 1985 Lower Carboniferous & STRANK, A.R.E., 1981 - Carboniferous. conodont biostratigraphy in the northeast In: D.G. Jenkins & J.W. Murray (Eds.) part of the Moravia-Silesia Basin. Acta Geol. Stratigraphical Atlas of Fossil Foraminifera, Polonica, 35: 33-60. Ellis Horwood Limited, Chichester, 15-69, BOUROZ, A., EINOR, O.L., GORDON, M.Jr., FEWTRELL, M.D. & SMITH, D.G., 1981 - Dis- MEYEN, S.V. & WAGNER, R.Ii., 1978 - cussion on the recognition and division of the Proposals for an International Toiimaisian Series in Britain. Jour. geol. Soc. Chronostratigraphic Classification of the London, 138: 103-104. Carboniferous. C.R. 8ème Congr. Int. Strat. Geol. Carb., 1975, 36-39. FLAJS, G., FEIST, R. & ZIEGLER, W., Eds., 1988 Devonian-Carboniferous Boundary - CHAUFF, K.M., 1981 - Multielement conodont Results of recent studies. Cour. Forsch. Inst. species from the Osagean (Lower Senckenberg, 100: 1-245. Carboniferous) in midcontinent North America and Texas. Palaeontographica, Abt. GEORGE, T.N., JOHNSON, G.A.L., A, 175: 140-169. MITCHELL, M., PRENTICE, J.E., RAMSBOTTOM, W.M.C., SEVASTO- CHLUPAC, I, FLÜGEL, H. & JAEGER, H., PULO, G.D. & WILSON, R.B., 1976 - A 1981 Series or Stages within Palaeozoic correlation of Dinantian rocks in the British systems ? Newsl. Stratigr., 10: 78-91. Isles. Spec. Rep. geol. Soc. London, 7: 1-87. CLAYTON, G., HIGGS, K., KEEGAN, J.B. & GEORGE, T.N. & WAGNER, R.H., 1972 - SEVASTOPULO, G.D., 1978 - Correlation International Union of Geological Sciences. of the palynological zonation of the Subcommission on Carboniferous Dinantian of the British Isles. Palinologia, 1: Stratigraphy. Proceedings and Report of the 137-147. General Assembly at Krefeld, August 21-22. CLAYTON, G. & SEVASTOPULO, G.D., 1981 C.R. 7ème Congr. Int. Strat. Geol. Carb., - Discussion on the recognition and division 1971, 1: 139-147. of the Tournaisian Series in Britain. Jour. geol. Soc. London, 138: 104-105. GROESSENS, E., 1976 Hypothèse concernant l'évolution de conodontes utiles à la CONIL, R., GROESSENS, E., HIBO, D., biostratigraphic du Dinantien. In : J. LALOUX, M., LEES, A. & POTY, E., 1988 Bouckaert & M. Streel (Eds.), Int. Symp. on - The Tournaisian-Visean boundary in the Belgian Micropal. Limits, 16: 1-16. type area. Field Guide. Inst. Geol. UCL. Louvain-la-Neuve. Pal. Ass. Carboniferous GROESSENS,E., 1976a - Preliminary range chart Group Field Trip 1988. of conodont biozonation in the Belgian Dinantian. In : J. Bouckaert & M. Streel CONIL, R., GROESSENS, E. & PIRLET, H., (Eds.), Int. Symp. on Belgian Micropal. 1977 - Nouvelle Charte stratigraphique du Limits, 17: 1-193. Dinantien type de la Belgique. Ann. Soc. géol. Nord, 96: 363-371. HIGGS, K., CLAYTON, G. & KEEGAN, J.B., 1988a - The stratigraphie and systematic CONWAY MORRIS, S. & HARPER, E., 1988 - palynology of the Tournaisian rocks of Genome size in conodonts (Chordata) : In- Ireland. Geol. Surv. Ireland Spec. Paper, 7: ferred variations during 270 million years. 1-110. Science, 241: 1230-1232. HIGGS, K.T., McPHILEMY, KEEGAN, J.B. & DICKSON, E.C., RHODES, F.H.T. & AUSTIN, CLAYTON, G., 1988b New data on R.L., 1972 - Statistical analysis of British palynological boundaries within the Irish Carboniferous conodont faunas. Jour. Geol. Dinantian. Rev. Palaeobotany Palynology, Soc. London, 128: 53-70. 56: 61-68. DICKSON, J.A.D., FORD, T.D. & SWIFT, A., 1987 - The stratigraphy of the Carboniferous HILL, P., 1974 - Biometric analysis of gnathodoid rocks around Castletown, Isle of Man. Proc. populations from the Waulsortian mudbank Yorkshire Geol. Soc., 46: 203-229. complex (Middle Dinantian) of Ireland. Geol. Soc. Amer. N. Central Section 8th Ann. DRUCE, E.C., RHODES, F.H.T. & AUSTIN, Mtg., 214 p. R.L., 1972 - Statistical analysis of British Carboniferous conodont faunas. Jour. Geol. JOHNSTON, I.S. & HIGGINS, A.C., 1981 - Soc. London, 128: 53-70. Conodont faunas from the Lower Carboniferous rocks at Hook Head, County FAULKNER, T.J., 1988 - The Shipway Wexford. Jour. Earth Sci. R. Dublin Soc., 4: Limestone of Gower : Sedimentation on a 83-96.

146 KASIG, W. & PAPROTH, E., 1981 - Wales. Proc. Yorkshire Geol. Soc., 46: Carboniferous Limestone and Kuhn in the 11-14. northern part of the Rheinisches Schierfergebirge (Germany) and east of the NEEVES, R., GUEINN, K.J., CLAYTON, G., Brabant Massif (Belgium). Guidebook Pal. IONNIDES, N. & NEVILLE, R.S.W., 1972 Ass. Carboniferous Group Field Meeting in - A scheme of miospore zones for the British Germany and Belgium., 1-48. Dinantian. C.R. 7ème Congr. Int. Strat. GéoL Carb., 1971, 1: 347-353. KLAPPER, G. & FOSTER, C.T.Jr., 1986 - Quantification of outlines in Frasnian (Upper NICOLL, R.S., 1980 - The multielement genus Devonian) platform conodonts. Canad. Jour. 'Apatognathodus' from the late Devonian of Earth Sci., 23: 1214-1222. the Canning Basin, Western Australia. A lcheringa, 4: 133-152. KLAPPER, G. & PHILIP, G.M., 1971 - Devonian conodont apparatuses and their NORBY, R.C., 1976 - Conodont Apparatuses vicarious skeletal elements. Lethaia, 4: from Chesterian (Mississippian) strata of 429-452. Montana and Illinois. Unpublished Ph. D. Thesis. Illinois, 1-295. KLAPPER, G. & PHILIP, G.M., 1972 - Familial classification of reconstructed Devonian NORBY, R.C. & REXROAD, C.B., 1985 - conodont apparatuses. Geologica & Vogelgnathus a new Mississippian conodont Palaeontographica, SB1: 97-114. genus. Indiana Geol. Sun,. Occasional Paper, 50/12: 1-3. LANE, H.R., SANDBERG, C.A. & ZIEGLER, W., 1980 - Taxonomy and phylogeny of PAPROTH, E., 1978 - The Devonian- some Lower Carboniferous conodonts and Carboniferous boundary working-group. preliminary standard post-Siphonodella Lethaia, 11, 280 p. zonation. Geologica et Palaeontologica, 14: PAPROTH, E. & STREEL, M., Eds., 1984 - The 117-164. Devonian Carboniferous Boundary. Cour. Forsch. Inst. Senckenberg, 67: 1-256. LANE, H.R. & ZIEGLER, W., Eds., 1985 - To- ward a boundary in the middle of the RAMSBOTTOM, W.H.C., Ed., 1981 - Field Carboniferous : Stratigraphy and Palaeon- guide to the boundary stratotypes of the tology. Cour. Forsch. Inst. Senckenberg, 74: Carboniferous stages in Britain. Subcom. on 1-195. Carb. Strat., 1-146. LEES, A. & HENNEBERT, M., 1982 - RAMSBO ITOM, W.H.C. & MITCHELL, M., Carbonate rocks of the Knap Farm Borehole 1980 - The recognition and division of the at Cannington Park, Somerset. In : The Tournaisian in Britain. Journ. geoL Soc. Geology of the I.G.S. deep borehole London, 137: 61-63. (Devonian-Carboniferous) at Knap Farm Cannington Park, Somerset. Report of the REXROAD, C.B., 1981 - Conodonts from the Inst. of Geol. Sci., 82/5: 18-36. Vienna Limestone Member of the Branchville Formation (Chesterian) in MACLEOD, N. & CARR, T.R., 1987 - southern Indiana. Indiana Geol. Surv. Oc- Morphometrics and the analysis of shape in casional Paper, 34: 1-16. conodonts. In : R.L. Austin (Ed.), Conodonts : Investigative Techniques and Ap- REXROAD, C.B. & MERRILL, G.K., 1985 - plications, Ellis Horwood, Chichester, Conodont biostratigraphy and paleoecology 168-187. of Middle Carboniferous rocks in Southern Illinois. Cour. Forsch. Inst. Senckenberg, MARCHANT, T.R., SEVASTOPULO, G.D. & 74: 35-64. CLAYTON, G., 1984 - Preliminary Corre- RHODES, F.H.T., AUSTIN, R.L. & DRUCE, lations of Irish Tournaisian Conodont, E.C., 1969 - British Avonian (Carboniferous) Foraminiferal and Miospore Zonal Schemes. conodont faunas and their value in local and C.R. 9ème Congr. Int. Swat. Geol. Carb., 2: intercontinental correlation. Bull. British 282-288. Museum (Natural History), Geology Supple- MERRILL, G.K. & MERRILL, S.M., 1974 - ment, 5: 1-313. Pennsylvanian non-platform conodonts 11-A SANDBERG, C.A., ZIEGLER, W., the dimorphic apparatus of Idioprioniodus. LEUTERITZ, K. & BRILL, S.M., 1978 - Geologica et Palaeontologica, 8: 119-130. Phylogeny, speciation and zonation of Siphonodella (Conodonta, Upper Devonian MITCHELL, M., STRANK, A.R.E., and Lower Carboniferous). Newsl. THORNBURY, B.M. & SEVASTOPULO, Stratigr., 7: 102-120. G.D., 1986 - The distribution of platform conodonts, corals and foraminifera from the SEVASTOPULO, G.D. & NUDDS, J.R., 1987 - Black Rock Limestone (late Tournasian and Courceyan (Early Dinantian) biostratigraphy early Visean) of Tears Point, Gower, South of Britain and Ireland. Coral and conodont

147 zones compared. Cour. Forsch. Inst. Kansas. Univ. Kansas Paleontol. Contrib., Senckenberg, 98: 39-46. 59: 1-105. SIMPSON, J. & KALVODA, J., 1987 - Sedi- WATERS, R.A. & LAWRENCE, D.J.D., 1987 - mentology and foraminifèral biostra- tigraphy Geology of the South Wales Coalfield, Part of the Arundian (Dinantian) stratotype. In : III, the country around Cardiff. British Geol. M. B. Hart (Ed.), Micropalaeontology of Surv. Mem. for 1:50 000 geological sheet Carbonate Environments, Ellis Horwood, 263, 1-114. Chichester, 226-237. WHITTAKER, A. & GREEN, G.W., 1983 - Geology of the country around Weston- SOMMERVILLE, I.D. & JONES, G.L., 1985 - Super-Mare. British Geol. Surv. Mem. for The Courceyan stratigraphy of the 1:50 000 geological sheet 279. New Series, Pallaskenry Borehole, Country Limerick with parts of sheets 263 and 295, 1-147. Ireland. Geol. Jour., 20: 377-400. WRIGHT, V.P., 1986 - Facies sequences on a VARKER, W.J. & SEVASTOPULO, G.D., 1985 carbonate ramp : the Carboniferous of South - The Carboniferous System : Part 1 - Wales. Sedimentology, 33: 221-241, Conodonts of the Dinantian Subsystem from ZIEGLER, W., Ed., 1977 - Catalogue of Great Britain and Ireland. In : A.C. Higgins conodonts. Schweizerbart Stuttgart, 111: & R.L. Austin (Eds.), A Stratigraphical In- 1-514. dex of Conodonts, Ellis Horwood, Chichester, 167-209. ZIEGLER, W., SANDBERG, C.A. & AUSTIN, R.L., 1974 - Revision of Bispathodus group VON BITTER, P.H., 1973 - Environmental con- (Conodonta) in the Upper Devonian and trol of conodont distribution in the Shawnee Lower Carboniferous. Geologica et Group (Upper Pennsylvanian) of eastern Palaeontologica, 8: 97-122.

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