Early Middle Cambrian Representatives of the Superfamily Acrotretoidea (Brachiopoda) from Morocco

Z. dt. geol. Ges. 15011 p. 27-87, 26 fig., 9 tab., 6 pt. Stuttgart, Mai 1999

Early Middle Cambrian representatives of the superfamily Acrotretoidea (Brachiopoda) from Morocco

MICHAEL STRENG*

STRENG, M. (1999): Early Middle Cambrian repre ist bislang von Vorkommen außerhalb Marokkos sentatives of the superfamily Acrotretoidea (Bra bekannt. Zwei Arten, die nur durch jeweils ein chiopoda) from Morocco. [Frühe mittelkambri Exemplar repräsentiert sind, werden zusätzlich in sche Vertreter der Überfamilie Acrotretoidea formell beschrieben. Die verschiedenen Arten (Brachiopoda) aus Marokko.] - Z. dt. geol. Ges., gehören fünf Gattungen an, von denen die Cera 150: 27-87; Stuttgart. tretiden Acanthatreta, Almohadella und Mono phthalma und der Acrotretide Tingitanella neu Abstract: Acrotretoid brachiopods of the families sind. Die Gattung Vandalotreta wird emendiert. Im Acrotretidae and Ceratretidae from the early Gegensatz zu den untersuchten Acrotretidae wei Middle Cambrian of Morocco are described. The sen die ceratretiden Arten eine hohe Variabilität in fauna comprises seven species, five of which are den gemessenen Größenproportionen auf. Funkti new and two species are informally described. The onsmorphologische Untersuchungen an der Schale species are assigned to five genera of which the von Acanthatreta lassen eine primitive Artikulation ceratretid genera Monophthalma, Acanthatreta and der beiden Klappen vermuten. Die Schalenstruktur Almohadella, and the acrotretid Tingitanella are eines Teils der beschriebenen Taxa wurde unter newly introduced. The acrotretid genus Vandalotre sucht. Die acrotretide Gattung Vandalotreta besitzt ta is emended. In contrast to measurements on the eine zweilagige Schale. Im Gegensatz dazu haben Acrotretidae, those for most of the Ceratretidae die ceratretiden Gattungen Acanthatreta, Almoha show a wide variation of proportions. Functional della und Monophthalma eine typisch dreilagige morphologic observations on the shell of Acantha Schale. Bohrlöcher, die offenbar von räuberischen treta suggest a primitive hinge articulation, a Organismen erzeugt wurden, wurden auf zahlrei characteristic of many acrotretoid genera. The shell chen Klappen der untersuchten Stücke gefunden. structure of some of the Moroccan specimens is Insgesamt konnten fünf verschiedene Typen von studied and described. The acrotretid genus Vanda Bohrlöchern unterschieden werden. Die phyloge lotreta has a shell that consists of two layers in con netische Entwicklung der kambrischen Acrotre trast to the ceratretid genera Acanthatreta, Almoha toidea wurde unter besonderer Berücksichtigung della, and MOl1ophthalma, which are characterized der marokkanischen Gattungen und 12 weiterer by a three-Iayered shell. Borings have been ob kambrischer Gattungen untersucht. Die gewonne served in several specimens and are interpreted as nen Kladogramme lassen eine Unterteilung der Fa to be of predatory origin. Distinguishable are five milie Ceratretidae in zwei Gruppen vermuten, die different types of boreholes. The phylogeny of the als Unterfamilien interpretiert werden. Cambrian acrotretoid brachiopods is reevaluated based on special consideration of the Moroccan Keywords: Brachiopoda (Acrotretidae, Ceratreti species and 12 additional Cambrian genera. De dae), Middle Cambrian, classification, new taxa, rived cladograms suggest a subdivision of the Cera shell structure, biometry, borings, phylogeny, cladi tretidae into two subfamilies. stic analyses.

Kurzfassung: Vertreter der Superfamilie Acro High Atlas, Antiatlas, Morocco. tretoidea (Brachiopoda) aus mittelkambrischen Schichten Marokkos werden beschrieben. Von den Contents insgesamt sieben Arten sind fünf neu und nur eine 1. Introduction ...... 28 *Address of the author: Michael STRENG, Univer 2. Cambrian lithostratigraphy and biostrati sität Bremen, Fb-5 Geowissenschaften, Postfach graphy of the Souss Basin of southern 330440, D-28334 B'remen, Germany. Morocco ...... 29

1 AIlMersld 2 Akka Tzem 3 Aqdz 4 Assermo 5 Ber1

lJ'l1l Areas presumed or known 10 Include h, Neoprolerozolc (?)-Cambrian rock G.::iJ Older Neoprolerozolc rock .nd +' crystalline basemenl o 100 km

Fig, 1: Schematic geological map of the High Atlas and Anti-Atlas regions, Morocco, showing sampled localities and distribution of Late Proterozoic and Cambrian rocks, Modified after GEYER (1993, fig, 1), Abb, 1: Geologische Übersichtskarte des Hohen Atlas und des Anti-Atlas, Marokko, Dargestellt sind die Lokationen der beprobten Schichten und die Ausbisse spätproterozoischer und kambrischer Serien, Verän• dert nach GEYER (1993, fig, 1).

3. Methods ...... 29 biozone ) and from probably basal Upper Cam 4. Systematic paleontology ...... 30 brian layers. MERGL (1983) reported billing 5. Quantitative analyses ...... 63 sellid and protorthid genera from the Middle 6. Shell structure ...... 67 7. Evidence for predation from boreholes ..... 70 Cambrian of the Central Anti-Atlas and the 8. Phylogenetic analysis ...... 76 High Atlas, respectively. Obolellide brachiopods, 9. Acknowledgements ...... 80 an abundant element of the Lower and Middle 10. References ...... 81 Cambrian of Morocco have recently been 11. Appendices ...... 85 described by GEYER (1994) and GEYER & MERGL (1995). 1. Introduction Lingulate brachiopods (sensu WILLIAMS et al. 1996) from the Cambrian of Morocco have Although brachiopods are a relatively common only been dealt with by MERGL (1988), who part of the Cambrian fauna of Morocco, they introduced the acrotretid Vandalotreta vavra have been neglected widely. The first record of and the botsfordiid Botsfordia epigona, and Moroccan Cambrian brachiopods was made by additionally mentioned an obolide brachiopod, TERMIER & TERMIER (1950) who described which was tentatively assigned to Lingulella sp. "Eoorthis Romingeri BARRANDE" from Cambrian The genus Vandalotreta MERGL 1988, described strata of the Moroccan Meseta. Further prot herein in detail, has been restricted to Morocco orthacean brachiopods have been described by until recently HOLMER et al. (1996), suggested HAVLICEK (1971) and GEYER & MERGL (1997) Lllhotreta MERGL & SLEHOFERovA 1990, from from the medial Middle Cambrian (Badulesia Bohernia to be a junior synonym (see Discus- Acrotretoidea (Brachiopoda) from Morocco 29 sion under Vandalotreta below). HOLMER & Akka Formation USHATINSKAYA (1994) also mentioned Vandalo Goulimine Formation Jbel Afraou Formation treta? sp. from glacial erratic boulders of pro bably late Early Cambrian age from Sweden. Tarhoucht Member HINZ-SCHALLREUTER (1997: pI. 1, fig. 17-19) Jbel Wawrmast Formation Breche a Mfcmacca figured an undetermined acrotretid from the ? Member Middle Cambrian of Bornholm which appears to be c10sely related to Vandalotreta. Further Cambrian lingulate brachiopods of western Africa are documented by POULSEN (1960) from the Zemmour region of northern Tislit Issafen Formation Formation Mauritania. The described fauna, which has been tentatively assigned to Early Cambrian Pig. 2: Lithostratigraphic units of the Lower-Middle age, yielded specimens distinguished as Neobo Cambrian transition of Morocco showing subdivi lus cf. N warthi WAAGEN 1885, Lingulella cf. L. sion of the upper Tata Group through the Feijas fuchsi REDLICH 1899, Botsfordia paucigranulata internes Group. After HELDMAIER & LANDING (in POULSEN 1960, Acrothele sougyi POULSEN 1960, press). Abb. 2: Lithostratigraphische Einheiten im Bereich and Acrothele spinulosa POULSEN 1960. des Übergangs vom Unter- zum Mittelkambrium. However, besides Vandalotreta no repre Nach HELDMAlER & LANDING (im Druck). sentative of the superfamily Acrotretoidea, has been recorded from Morocco so far, although they are an abundant element of the early Middle Cambrian fauna of Morocco. themselves are split into several formations (see GEYER & LANDING 1995; HELDMAIER & LANDING, in press). 2. Cambrian lithostratigraphy and The material described herein comes, for the biostratigraphy 01 the Souss Basin most part, from the Jbel Wawrmast and Jbel Afraou Formations (Feijas internes Group), 01 southern Morocco except two sampies from the Tatelt Formation The Cambrian lithostratigraphic framework of (Tata Group). the Anti-Atlas and High Atlas, Morocco, based For lithologic description, fossil re cord, and initially on investigations of Georges Choubert depositional environments of the various (e. g., CHOUBERT 1952; CHOUBERT 1953) and formations, as well as synonymy see GEYER & Henri Hollard (e. g., HOLLARD 1985) for the LANDING (1995), HELDMAIER & LANDING (in Lower Cambrian, and of DESTOMBES (1985) for press) and HELDMAIER (1997). the Middle to Upper Cambrian, has been sub sequently precised and c1arified by GEYER (1989, 1990a, 1990b), GEYER & LANDING 3. Methods (1995), and HELDMAIER & LANDING (in press). Biostratigraphic units based on trilobites were The material described herein was mainly first established by HupE (1953) and have been collected by G. Geyer (since 1981) and W. Held modified by HupE (1960). GEYER (1990a, maier (since 1994) in the course of their investi 1990b) and GEYER & LANDING (1995) revised gations of the Cambrian of Morocco. Further the biostratigraphic zonation and introduced material came from sampies collected by P. four stages and 13 trilobite zones for the Lower Hupe (mainly in 1955), K. Sdzuy (in 1968), and and Middle Cambrian. J. Destombes (during the 70ies). The material The Cambrian lithostratigraphy of the was isolated by digestion of ca1careous and cal Moroccan Atlas regions is divided into four cium carbonate cemented rocks in dilute formic groups, termed the Taroudant, the Tata, the acid (about 10%), sorted, mounted on alumi Feijas internes, and the Tabanite Groups, which num stubs, sputter-coated with gold film, and 30 M.Streng photographed by a scanning electron micro internal pedic1e opening. Dorsal valve with scope at the Theodor-Boveri-Institut für Bio wide median groove, defined laterally by sm all wissenschaften (ZEISS DSM 962) and the Ab propareas; interior of dorsal valve either divid teilung für Experimentelle Zahnmedizin ed by median septum, median ridge, or variably (ZEISS DSM 940), both University of Würz• developed anterocentral swelling, or undivided; burg. Additional photo graphie artwork was per median buttress indistinct, barely elevated; me formed at the Institut für Paläontologie, Würz• dian septum, if developed, may buttress dorsal burg, by H. Schönig. The studied material is re pseudointerarea; cardinal musc1e scars of both posited in the collection of the Institut für valves developed typically as raised platforms Paläontologie, Universität Würzburg, Gennany in adult specimens; pedic1e foramen not en (acronym PIW). c10sed within the larval shell. Occurrence. - Monophthalma eggegrlln densis (WIMAN 1903) from the late Early Cam 4. Systematic paleontology brian of Sweden possibly is the oldest known representative of the Ceratretidae. However, Measurements (in microns) on valves are do~u the Swedish material is known only from glacial mented in the respective figures. Abbreviations: erratic boulders of Eggegrund Island, South L, W, H = length, width, height of valve; Lw = Bothnian Sea, which have tentatively been as , m length at maximum width; Lm W = length, signed as late Early Cambrian in age (HOLMER width of cardinal musc1e scars; Lp' W p = length, & USHATINSKAYA 1994). The youngest known width of pseudointerarea; W g = width of medi representative is Ceratreta dilatata WILLIAMS & an groove; Hf = height of foramen; Lc' Wc = CURRY 1985, from the Early Ordovician length, width of apical process cavity, La = posi (Arenig) of Ireland. Ceratretid brachiopods tion of maximum height; L"p = length of apical were recorded from Baltoscandia, Ireland, process. Additional abbreviations: N, number of Morocco, Kazakhstan, Siberia, Australia, and specimens; MIN, minimum value of respective North America. measurement; MAX, maximum value of re Genera included. - Keyserlingia PANDER spective measurement; u, standard deviation; 1861 (= Clistotrema ROWELL 1963); Ceratreta STD. ERROR, standard error; VAR, variance; BELL 1941; Bozshakolia USHATINSKAYA in GEO. MEAN, geometrie mean. USHATINSKAYA et al. 1986; Kleithriatreta The description of morphologie characters ROBERTS & JELL 1990; Erbotreta HOLMER & of lingulate brachiopods follows the list shown USHATINSKAYA 1994; MOl1ophthall71a gen. nov.; in WILLIAMS & ROWELL (1965, H139-H155). Acanthatreta gen. nov.;Almohadella gen. nov. Additional terms are explained and summa Discussion. - The ceratretids are usually rized by HOLMER (1989). dealt with as a subfamily of the Acrotretidae (ROWELL 1965). More recently, USHATINSKAYA (in USHATINSKAYA et al. 1986) proposed family Subphylum Linguliformea WILLIAMS et al. 1996 rank for the ceratretids, a view that was fol Class Lingulata GORJANSKY & PoPOV 1985 lowed by HOLMER & Popov (1990), SOBOLEV Order Acrotretida KUHN 1949 (1992), PUURA & HOLMER (1993), and HOLMER Suborder Acrotretidina KUHN 1949 & USHATINSKAYA (1994). However, some of the Superfamily Acrotretoidea SCHUCHERT 1893 early ceratretids, and especially the Moroccan species, apparently differ in several characters from typical ceratretids, such as Ceratreta, Key Family Ceratl'etidae ROWELL 1965 serlingia and Kleithriatreta, which are charac terized by (1) a moderately to highly conical Diagnosis. - Shell thick, transversely ellip ventral valve, (2) a long, dorsally directed tical to subcircular in outline; pedic1e valve with pedic1e tube, (3) strongly elevated dorsal cardi ridge- to septum-like apical process that bridges nal musc1e sc ars, and (4) a characteristically anterior and posterior slopes of valve and bears bulging median septum. In contrast, the Moroc- Acrotretoidea (Brachiopoda) from Morocco 31

I Monophlhalma cf. M. eggegrundensis (WIMAN 1903) early Middle Cambrian (Morocco) 1.1 Monophlhalma eggegrundensis (WIMAN 1903) late Early Cambrian? (Sweden) 2 Kleithrialrela lamellosa ROBERTS & JELL 1990 early Middle Cambrian, Ordian (Australia) 3 Acanlhalrela meiwirlhae gen. et sp. nov. early Middle Cambrian (Morocco) 4 Almohadella braunae gen. et sp. nov. early Middle Cambrian (Morocco) 5 Erbolrela singularis HOLMER & USHATINSKAYA 1994 Middle Cambrian, Amgan (Siberia) 6 Bozshakolia coniformis USHATINSKA YA 1986 upper Middle Cambrian, Mayan (Kazakhstan) Cz 7 Ceralrela lanneri (METZGER 1922) <{ Upper Cambrian (Baltoscandia) 0:: (!) ~ <3 0:: W, 0:S:' ..J' Fig. 3: Stratigraphie occurrences of the Cambrian ceratretid genera. Sagittal seetions of Erbotreta and Bozshakolia after BOLMER & USHATINSKAYA (1994), of Ceratreta after measurements and description of Ce raO'eta tanneri by BOLMER & Popov (1990) of Kleithriatreta after the description of ROBERTS & JELL (1990). Abb. 3: Schematische Darstellung der zeitlichen Verbreitung der kambrischen ceratretiden Gattungen. Querschnitte von Erbotreta und Bozshakolia nach Abbildungen von BOLMER & USHATINSKAYA (1994), von Ceratreta nach Messungen von BOLMER & Popov (1990) an Ceratreta tanneri, von Kleithriatreta nach der Beschreibung von ROBERTS & JELL (1990).

can specimens are typically ventribiconvex, lack feature of the Australian genus Kleithriatreta. a median septum, and possess a short pedicle Details on the foramen of Bozshakolia were tube. Erbot/'eta and Bozshakolia are inter not described. mediate between these two graups. Erbotreta is Accordingly, the ceratretids are a variable most similar to Ceratreta in its conical ventral taxon in respect to their morphologic charac valve and the long dorsally directed pedicle ters. A sub division of the Family Ceratretidae tube, but lacks a median septum. Bozshakolia into two or more subfamilies would be appro resembles the Moroccan specimens in its con priate. However, the number of species known vex ventral valve, the development of the ven presently is insufficient to permit definition of tral pseudointerarea and the barely elevated clear phylogenetic relationships and weighting median ridge, but differs in having a long dor of individual morphologic differences. sally deflected pedicle tube. Also noteworthy is The family Ceratretidae is distinguished the different style of the pedicle foramen. Three from the family Acratretidae SCHUCHERT 1893, types can be distinguished: (1) a foramen locat in having (1) large cardinal muscle sc ars, which ed centrally within an elliptical cavity, typically are occasionally thickened and elevated, (2) for the Moroccan specimens and prabably also poorly developed propareas of the dorsal valve, for the Swedish MOllophthalma eggegrundensis and (3) an apical process that is usually a well (WIMAN 1903); (2) a listrium-like foramen such developed ridge bearing the internal pedicle as in Ceratreta, Keyserlingia, and Erbot/'eta; and opening. The family Ceratretidae is distinguish (3) a foramen that is located at the dorsal ed fram the Linnarssoniidae ROWELL 1965, in extremity of an elongate, elliptical cavity; a having the interna! pedicle opening within the 32 M.Streng apical process and by a wider median graove. Genus MOllophthalma gen. nov. However, the Moroccan genera resemble the Linnarssoniidae in their ventribiconvex shape Etymology. - Named after the Greek and in the development of the ventral pseudo monophthalmos, one-eyed. interarea. Type species. - Acrotreta eggegrul1densis The Moroccan genera described herein are WIMAN 1903; late Early Cambrian (?) of Egge best distinguished fram each other and fram the grund Island, South Bothnian Sea, Sweden. remaining ceratretids by the absence of a dorsal Diagnosis. - Ventral valve convex to low median septum and by the shape of the apical subconical in lateral profile; ventral pseudo process. The apical process of MOl1ophthalma interarea steeply procline to slightly apsacline; gen. nov. is a simple, short ridge characterized pedicle foramen not enclosed within larval by a collar-like thickening around the internal shell. Ventral interior characterized by a coIlar pedicle opening, whereas the apical pracess in like thickening of the apical process surround Acanthatreta gen. nov., Almohadella gen. nov., ing the internal pedicle opening; apical pracess and Bozshakolia USHATINSKAYA 1986, is much a low ridge that extends short distance anterior more elevated above the valve floor and usually ly and posteriorly from internal pedicle fora extends more towards the anterior. Acanthatreta men along valve slopes; dorsal valve convex, and Almohadella are best distinguished by the with relatively wide pseudointerarea dominated width of the apical process anterior to the inter by a transversely elongated, subtriangular me nal pedicle opening, which decreases anteriorly dian graove; propareas smalI; median buttress in Acanthatreta and is fairly constant in Almo and median ridge minute and inconspicuous or hadella. This feature also serves to distinguish absent; cardinal muscle scars of both valves Acanthatreta from Bozshakolia. Almohadella is oval in outline and widely separated; larval most similar to Bozshakolia in having astrang shell ornamented with circular pits of fairly uni ridge-like apical process that bears a muscle form size. platform. However Almohadella is distinguish ed fram Bozshakolia in (1) the absence of a MOllophthalma cf. M. eggegl'ulldellsis (WIMAN dorsal median ridge, (2) the direction of the 1903) pedicle tube, which is dorsally deflected in Bozshakolia and anteriorly directed in Almoha Figs. 5, 17.4-17.10, 23.2, 23.5; Plate 1 della, (3) in having a less developed muscle platform, and (4) bearing an apical process with * 1903 Acrotreta eggegl'lll1densis n. sp. WIMAN, a fairly constant width, whereas the apical pro p. 55, Plate 2, figs. 23-29. cess of Bozshakolia is narrower posterior to the 1912 Acrotreta eggegrundensis WIMAN-WAL internal pedicle opening than anteriorly. Juvenile COTT, p. 684, Plate 70, figs. 2a-d. brachial valves of the three Moroccan genera 1942 ?Acrotreta cf. eggegrundensis WIMAN are generically indistinguishable fram each POULSEN, p. 215, Figs. 12-16. other, so that weIl preserved adult specimens 1994 Bozshakolia eggegrundensis (WIMAN) are needed for precise determination. The HOLMER & USHATINSKAYA, p. 206, Fig. 3. median buttress of Almohadella brmmae gen. et sp. nov. is generally braader and more distinct Material studied. - About 830 ventral than in Monophthalma cf. M. eggegrundensis valves (VV) and 960 dorsal valves (DV) fram (WIMAN 1903). Nonetheless, the dorsal valves 28 different sampIe horizons: Anti Atlas: Tatelt of both species are best distinguished by the section, sampIe horizon TAT-18.35: flexure of the valve floor anterior to the median PIW96X29.1-29.31, PIW96X60 (66 Vv, 104 groove and lateral to the median buttress, which DV) Hupeolenus or Cephalopyge l10tabilis is only developed in Almohadella braunae. biozone; Aqdz, sampIe horizon AQ II!: PIW96X58 (3 VV, 2 DV); Tin Ouagour, sampIe horizon B 123: PIW96X13.4-13.5, PIW96X46, PIW96X128 (8 VV, 10 DV); Berkik, sampIe ho- l r= r

Acrotretoidea (Brachiopoda) from Morocco 33

rizon BK-3: PIW96X63 (2 VV, 6 DV); Hassi syncline, sampie horizon HM-50.6: PIW96X47 Brahim, sampie horizon D 257: PIW96X16.15 (1 VV, 3 DV) - Hllpeolenus or Cephalopyge (1 VV); EI Borj / Tislit n'Ai't Tamassine, sampie nota bilis biozone; Ourika Wawrmas, sampie horizon EB I: PIW96X13.6, PIW96X44 (1 VV, 3 horizon OW 1-20.8: PIW96X43 (2 VV, 3 DV) - DV); Foum Tangarfa, sampie horizon FT-3: Cephalopyge l10tabilis biozone; High Atlas: PIW96X32.2-32.5, PIW96X33.8-33.10, Assermo section, sampie horizon ASS-45.68: PIW96X33.15-33.18, PIW96X41, PIW96X42 PIW96X53 (1 DV) Ornamentaspis frequens (53 VV, 63 DV); EI Hmam syncline, sampie ho biozone. rizon HM-6: PIW96X13.1-13.3, Occurrence. - Hupeolenlls biozone?, PIW96X13.9-13.14, PIW96X56 (5 VV, 12 DV); Cephalopyge notabilis through Ornamentaspis Ifrane d'Anti Atlas, sampie horizon IFR-187.5: frequens biozone. PIW96X66 (3 VV, 1 DV); Ighels, sampie hori Diagnosis. - As for genus (because of zon IL-9: PIW96X57 (4 VV, 7 DV); Jbel Arhou monotypy). ri, sampie horizon JAR-26A: PIW96X2. 1-2.13 , D escription. - Shell ventribiconvex, trans PIW96X27 .1-27 04, PIW96X27 .9-27 .12, versely oval in outline, average length/width PIW96X55 (133 VV, 145 DV); Ourika Wawr ratio about 0.85, maximum shell diameter 2.2 mas, sampie horizons OR-3: PIW96X61 (3 VV, mm. Internal surfaces ornamented with regular 2 DV) and OW-1: PIW96X45 (4 VV, 8 DV); Ta ly spaced, smooth pits (Plate 1, figs. A, Land gragra syncline, sampie horizons TA/MC 3: 0), the presence of which depends on the mode PIW96X51 (4 VV, 4 DV), TA/MC lOT: of preservation. Larval shell with circular pits of PIW96X68 (2 VV, 2 DV), TA/MC 40: ab out 1.5 to 1.8 flm in diameter, which decrease PIW96X69 (8 VV, 8 DV) and TA/MC 5ST: in size towards the boundary with the postlar PIW96X49 (4 VV, 6 DV); Tarhoucht, sampie ho val shell (1.1 to 1.3 flm). Width of larval shell rizon TAR-1.8: PIW96X33.1-33.6, varies between 0.23 and 0.32 mm, about 20 % PIW96X33.11-33.14, PIW96X64 (12 VV, 29 greater than length. Later growth stages with DV); Tinifift, sampie horizon TNF-1: subevenly spaced growth lines, which are more PIW96X15.1-15.9, PIW96X52 (18 VV, 18 DV); distinctive laterally. Tizi n'Telgane, section TNTE I, sampie horizon Ventl'al valve. Ventral valve typically convex TNTE 1-49.8: PIW96X4.1-4.12, PIW96X31.6, in lateral profile, sometimes depressed subconi PIW96X67 (12 VV, 11 DV), seetion TNTE II, cal, with its maximum height at about 20 to 30 % sampie horizons TNTE II-4-6: PIW96X7.1-7.10 of valve length from posterior margin. Anterior (26 VV, 44 DV), TNTE II-6.35: and lateral slopes typically weakly convex, whe PIW96X11.1-11.19, PIW96X31.1-31.5, reas the posterior slope is slightly concave po PIW96X31.7-31.13, PIW96X37 to PIW96X40 sterior to apex and slightly convex or straight di (353 VV, 344 DV) and TNTE II -8.24: stally. Ventral pseudointerarea steeply procline PIW96X18.1, PIW96X65 (2 VV, 7 DV), section or catacline, rarely apsacline, poody defined late TNTE V, sampie horizon TNTE V-3.85: rally, traversed by a broad, often obscure conca PIW96X1.1-1.20, PIW96X27 .5-27 .8, ve zone (intertrough?). Apex blunt, slightly over PIW96X27.13-27.18, PIW96X62 (99 VV, 117 hangs pseudointerarea. Crest of the larval shell DV) - all from Cephalopyge notabilis biozone. strongly declined in lateral view (about 45°) to li High Atlas: Lemdad syncline, section Le XI, ne of commissure. Foramen posterodorsal to sampie horizon Le XI-22b: PIW96X59 (5 VV, 4 apex, slightly elliptical in outline, located within DV); Ounein basin, ENE' Afourigh, sampie a broader elliptical, countersunk cavity. Apical horizon X 211: PIW96X54 (1 VV) - both from process a low ridge, typically weakly concave in Cephalopyge notabilis biozone; Assermo sec lateral profile, characterized by collar-like tion, sampie horizon ASS-45.7: PIW96X48 (6 thickening around the location of penetration of VV,4 DV) - Ornamentaspis freqllens biozone. - internal pedicle tube. Posterior extremity of api Tentatively assigned to Monophthalma cf. M. cal process descends posterior valve slope as a eggegrundensis: 3 VV and 7 DS from three low, often indistinct ridge. Apical process may bi sampie horizons: Central Anti Atlas: EI Hmam furcate short distance anterior to interna I fora------

34 M. Streng men into two low, divergent ridges, which pass the junction of anterior and posterior valve slo into a smooth confluence with the anterior valve pe, situated immediately lateral to apical process slope posterior to valve mid-length; bordered la and anterior to circular internal pedicle opening. terally by baculate vasclila lateralia. Apical pits Cardinal muscle scars of ventral valve broadly generally distinct, moderately impressed, mark separated, large, ovate and not strongly marked.

Plate 1

MOllophthalma cf. M. eggegrundellsis (WIMAN 1903) all scale bars = 200 f.lm, except H, I, J and M. alle Maßstabs balken = 200 f.lm, außer H, I, J and M.

A) PIW96X29.6; detail of ventral interior, revealing pitted internal surface; TAT-18.35. PIW96X29.6; ornamentierte Innenseite einer Ventralklappe; TAT-18.35. B) PIW96X15.10; oblique dorsal view; TNF 1. PIW96X15.10; schräge Dorsalansicht; TNF 1. C) PIW96X4.5; detail of ventral interior, showing apical process; area of thickened shell (arrow) at the loca tion of cardinal muscle scars; TNTE 1-49.8. PIW96X4.5; Innenansicht einer Ventalklappe mit apical process; Lage der Muskelfelder werden durch die Verdickung der Schale angezeigt (Pfeil);TNTE 1-49.8. D) PIW96X32.3; ventral interior, showing distally bifurcated apical process; note minute callosity anterior to apical process (arrow); Fr-3. PIW96X32.3; Innenansicht einer Ventralklappe mit distal geteiltem apical process; beachte kleine Erhe bung vor dem apical process (Pfeil); Fr-3. E) PIW96Xll.2; oblique anterior view, showing apical pits, vascula lateralia, and apical process that is con fluent with the valve floor anteriorly;TNTE II-6.35. PIW96Xll.2; schräge Frontalansicht; zu sehen sind die apical pits, die vascula lateralia und der apical process; TNTE II-6.35. F) PIW96X11.5; lateral view of ventral valve; TNTE II-6.35. PIW96X11.5; Seitenansicht einer Ventralklappe; TNTE II-6.35. G) PIW96X29.3; ventral interior;TAT-18.35. PIW96X29.3; Innenansicht einer Ventralklappe; TAT-18.35. H) PIW96X27.7; detail of ventral interior, showing apical process; TNTE V-3.85; scale bar = 100 f.lm. PIW96X27.7; Innenansicht einer Ventralklappe mit apical process; TNTE V-3.85; Maßstabsbalken = 100 f.lm. I) PIW96X1.1O; posterior view of ventral valve; TNTE V-3.85. 1; scale bar = 100 f.lm. PIW96X1.1O; Rückseite einer Ventralklappe; TNTE V-3.85. 1; Maßstabsbalken = 100 f.lm. J) PIW96X4.6; dorsal exterior, showing ornamentation of post-larval shell;TNTE 1-49.8; scale bar = 100 f.lm. PIW96X4.6; Ornamentation der dorsalen postlarvalen Schalenoberfläche; TNTE 1-49.8; Maßstabsbalken = 100 f.lm. K) PIW96X1.8; exterior of dorsal valve;TNTE V-3.85. PIW96X1.8;Außenansicht einer Dorsalklappe;TNTE V-3.85. L) PIW96X31.1; detail of dorsal interior, showing small median buttress supporting overhanging pseudoin terarea; cardinal muscle scars defined centrally by distinct ridges;TNTE II-6.35. PIW96X31.1; Detail der Innenansicht einer Dorsalklappe mit kleinem median buttress, der die leicht überhängende Pseudointerarea stützt; die Muskelfelder werden nach innen von kleinen Rücken be grenzt;TNTE II-6.35. M) PIW96X1.11; pitted surface of a dorsal larval shell; note gradual decrease laterally in size of pits; TNTE V-3.85; scale bar = 50 f.lm. PIW96X1.11; mit kleinen Gruben ornamentierte dorsale Larvalschale; beachte das graduelle Abnehmen der Grubengröße nach außen; TNTE V-3.85; Maßstabsbalken = 50 f.lm. N) PIW96X1.1;juvenile dorsal valve;TNTE V-3.8S. PIW96X1.1; juvenile Dorsalklappe; TNTE V-3.85. 0) PIW96X4.4; dorsal interior, showing pitted internal surface and faint median ridge; TNTE 1-49.8. PIW96X4.4; Innenseite einer mit Grübchen und einem schwach ausgebildeten median ridge ornamen tierten Dorsalklappe; TNTE 1-49.8. Acrotretoidea (Brachiopoda) from Morocco 35 36 M.Streng

Tab. 1: MOllophthall1la cf. M. eggeg1'llndensis (WIMAN 1903); measurements and average dimensions (in microns) of ventral and dorsal valves. Tab. 1: Meßwerte der morphologischen Parameter (in Mikrometer) und statistische Daten der Dorsal- und Ventralklappen von MOllophthall1la cf. M. eggegl'lllldensis (WIMAN 1903).

ventral valve L W H Hf Lw Lm Wm We LfW N 67 68 62 51 58 46 43 57 67 MlN 700 740 240 80 360 202 480 170 0.686 MAX 1880 2100 900 600 940 648 1200 660 0.956 (J' 250.0 287.4 123.6 101.6 128.3 86.5 166.6 107.8 0.058 STD.ERROR 30.5 34.8 15.7 14.2 16.9 12.8 25.4 14.3 0.007 VAR 62489 82572 15273 10316 16472 7479 27753 11624 0.003 MEAN 1205 1411 473 269 607 384 886 381 0.849 GEO.MEAN 1178 1380 457 249 594 375 870 366 0.847

dorsal valve L W H Lw Lm Wm Le We LfW LmfWm N 100 100 85 100, 71 72 80 80 100 69 MlN 760 920 178 396 220 400 80 440 0.723 0.412 MAX 1820 2240 440 956 760 1436 300 1380 0.969 0.773 (J' 255.6 300.1 67.7 132.4 99.2 198.9 36.8 179.5 0.050 0.065 STD.ERROR 25.6 30.0 7.3 13.2 11.8 23.4 4.1 20.1 0.005 0.008 VAR 65346 90097 4578 17527 9835 39548 1353 32213 0.002 0.004 MEAN 1238 1463 295 658 475 885 156 790 0.847 0.542 GEO.MEAN 1212 1432 287 644 464 837 148 752 0.846 0.539

L L

<+---Wm--- '-0----___ W -----...,

Fig. 4: Location of measurements on Monophthall1la cf. M. eggegl'lllldensis (WIMAN 1903); left, ventral valve - right, dorsal valve. Abb. 4: Messungen 'an Monophthall1la cf. M. eggeg/'lllldensis (WIMAN 1903); links: Ventralklappe - rechts: Dorsalklappe. Acrotretoidea (Brachiopoda) from Morocco 37

Fig. 5: Probable gerontic stages of Monophthalma cf. M. eggeg/'ll11densis (WIMAN 1903); all scale bars = 200 11m. 1,2, PIW96X31.6; TNTE II-6.35. 1, ventral yiew of dorsal valve bearing a anterocentrally balcony-like structure. 2, detail of 1, showing lateral view of balcony-like structure. 3, PIW96X27.8; fragment of a dorsal valve with a similar structure as in 1; TNTE V-3.85. Abb. 5: Möglicherweise gerontische Stadien von Monophthalma cf. M. eggegrundensis (WIMAN 1903); alle Maßstabsbalken entsprechen 200 11m. 1,2, PIW96X31.6; TNTE II-6.35. 1, ventrale Ansicht einer Dorsalklap pe, die eine balkonartige Struktur im anterozentralen Bereich aufweist. 2, Detailansicht von 1, die die bal konartige Struktur von der Seite zeigt. 3, PIW96X27.8; Bruchstück einer Dorsalklappe mit einer zu Stück 1 vergleichbaren Struktur;TNTE V-3.85.

DOl'sal valve. Dorsal valve gently convex swelling, cardinal muscle scars are not defined with wide pseudointerarea of 45 to 70 % of by ridges and vasclila lateralia are less distinct. valve width. Pseudointerarea characterized by Furthermore the anterior edge of the dorsal transversely elongate, subtriangular, weH de pseudointerarea appears to be typicaHy con veloped median groove; slightly overhanging cave in juvenile and straight in adult valves. The posterior part of inner valve surface, supported apical process of the ventral valve is less point by minute median buttress (Plate 1, fig. L). ed in juveniles, and its anterior part is only Propareas small, bordering orthocline median weakly developed as weH as the apical pits. groove as often obscure, variably developed di Brephic and neanic stages of both valves are vergent ridges. Vascula lateralia baculate, de not distinguishable. T\vo dorsal valves probably fined centraHy by low, more-or-Iess distinct represent a gerontic stage of Monophthalma cf. ridges, which originate directly anterior to M. eggegrundensis. They bear a median septum pseudointerarea and diverge anteriorly. Median that is developed as a prominent, transversely septum variably developed as low, laterally elongate balcony-like structure (Fig. 5; see Dis poorly defined swelling, or as relatively indis cussion). tinct ridge that originates between 33 and 59 % Discussion. - Acrotreta eggeg/'llndensis of valve length and extends to ab out 75 % of WIMAN 1903, has been referred to the genus valve length from posterior margin, occupying Bozshakolia USHATINSKAYA 1986, by HOLMER 16 to 42 % of total valve length. Cardinal & USHATINSKAYA (1994). However, A. egge muscle sc ars of dorsal valve oval, slightly grzmdensis differs from the type species, diverging anteriorly and defined centrally and Bozshakolia conifo/'111is USHATINSKAYA 1986, in anterocentrally by weH developed ridges. having (1) a dorsal valve with an extremely low Ontogeny. - The characters mentioned or vestigial median ridge, which is more distinct above are typical for adult valves and not and elevated in B. conifo/'l11is, (2) a conspi visible in the larger part of the collected shells. cuously lower ventral valve, (3) a distinctly Juvenile dorsal valves lack a median ridge or smaHer size (the maximum width of B. conifo/'- 38 M. Streng mis exceeds the maximum width of B. egge eggegrllndensis. In addition, the monospecific grundensis by more than one millimeter; see composition of the sampie also supports the HOLMER & USHATINSKAYA 1994), and, most sig assignment of the two valves to M. cf. M. egge nificant, (4) a less elevated apical process that grllndensis. Further investigations are needed lacks a distinct musc1e platform. A. eggegl'lln to prove if either the two valves represent a densis is therefore not assigned to Bozshakolia, new species 01' are conspecific with Monoph but signifies a new genus Monophthalma n. gen. thalma cf. M. eggegrllndensis. Monophthalma cf. M. eggegrllndensis is a The apical process of a pedic1e valve, figured variable species. Especially the proportions of and assigned by HINZ (1987: plate 12, fig. 20) as length to width and length to height show re "Acrothyra cf. sera MATTHEW 1902" from the markable variations (Tab. 1). Such variations Early Cambrian of Comley, England, somewhat were already noted by POULSEN (1942) for M. resembles that of M. cf. M. eggegrllndensis. eggegrundensis and c1early shown by measure However, the Comley specimen is readily dis ments of HOLMER & USHATINSKAYA (1994). tinguished from the Moroccan material in hav They may partly be due to imperfect preserva ing a conical shape and a circular outline of the tion, although weIl preserved specimens of the valve and lacks apical pits. Moroccan material also show a wide range of For further comparison of M. cf. M. egge variation, even in specimens from a single grundensis see Discussion under Family Cera sampie. Such a variability of proportions is also tretidae above. observed in Acanthatreta meiwirthae gen. et sp. nov. and in Almohadella braunae gen. et sp. nov. Measurements on Bozshakolia coniformis and Monophthalma sp. A Erbotreta singularis (see HOLMER & USHATINS KAYA 1994) show a high variability of propor Fig.6 tions, too, so that such a variability appears to be anormal case in the early ceratretids. Also Ma terial. Single ventral valve; sample noteworthy is the variable lateral profile of the locality Jbe1 Arhouri, Anti Atlas, sample hori larval shell of M. cf. M. eggegl'llndensis observed zon JAR-26.4, Jbel Wawrmast Formation, in some of the Moroccan specimens. This larval Breche a Micmacca Member; Cephalopyge not shell is normally characterized by a flat, indis abilis biozone. tinct transition to the postlarval shell. However, Discussion. - Although it occurs together the anterior and lateral slopes of the larval shell with Monophthalma cf. M. eggegrundensis are sometimes steeper than adjacent postlarval (WIMAN 1903), a single ventral valve is inter shell surfaces so that the apex appears pointed preted to represent another, new species. It (Plate 1, fig. K). strongly resembles Monophthalma cf. M. egge The presumably gerontic stage of the dorsal g/'llndensis in the characteristic coIlar-like valve of Monophthalma cf. M. eggegrllndensis thickening that surrounds the intern al pedic1e (see Description) is represented by only two opening and also in shape and additional valves from a single sample horizon (Tizi nl'el characters. However, Monophthalma sp. A gane, section V, sampie horizon TNTE V-3.85), differs in its anterior extension of the apical one of which is fragmentary (Fig. 5.3; process, that is a bulging, nod-like callosity PIW96X27.8) and the other poorly preserved which is separated from the coIlar-like thicken and lacks distinctive characters (Figs. 5.1, 5.2; ing by a distinct constriction. PIW96X31.6). The absence of these characters could be interpreted to be primary so that it would represent another, yet unknown species. Genus Acanthatl'eta gen. nov. This is supported by the stronger convexity of PIW96X31.6. However, PIW96X27.8 depicts Etymology. - Named after the Greek the distal part of a distinct ridge bordering the akantha, spine, and tretos, perforated, pierced. vasclila lateralia, which is typical for M. cf. M. Type species. - Acanthatreta meiwirthae Acrotretoidea (Brachiopoda) from Morocco 39 gen. et sp. nov.; early Middle Cambrian, Moroc co (Cephalopyge l10tabilis biozone ). Diagnosis. - Shell ventribiconvex, trans versely oval in outline. Ventral valve with a poorly defined pseudointerarea, typically steep ly proc1ine, bisected by an intertrough. Circular to elongate oval foramen located within a coun tersunk cavity posterior to apex, not enc10sed within larval shell. Apical process forms a ridge that connects posterior and anterior valve slopes, bearing an internal pedic1e opening at posterior extremity of ridge. Apical process an terior to internal foramen ornamented with a filigree spine. Dorsal valve with broad and deep, tri angular median groove, bordered late rally by small propareas. Larval shell ornament ed with circular pits of rather uniform size. Fig. 6: Monophthalma sp. A. PIW96X27.4; detail of ventral interior, showing bulging anterior extension of apical process; JAR 26.4; scale bar = 100 11m. Abb. 6: Monophthalma sp. A. PIW96X27.4; Aus Acanthatl'eta meiwil'thae sp. nov. schnitt des Innenbereichs einer Ventralklappe; sichtbar ist eine ungewöhnliche, wulstartige Verlän• Figs. 23.1,23.3,23.4,23.6,23.7; Plate 2 gerung des apical process; JAR 26.4; Maßstabs bal ken = 100 11m. E tymolo gy. - In honor to Kirsten Mei wirth. Holotype. - Ventral valve, PIW96X25.15 (Plate 2, fig. L). - Type locality and stratum: coming gradually indistinct and sm aller towards Tachguelt, High Atlas, sampie horizon 387 in the margins of larval shell. the Jbel Wawrmast Formation, Breche a Mie Ventral valve. Anterior and lateral surfaces maeea Member; Cephalopyge l10tabilis biozone. of ventral valve moderately convex, anterior Material. - 244 ventral and 240 dorsal surface flattened or convex. Pseudointerarea valves from a single sampie locality: Tachguelt, typically steeply proc1ine, sometimes catac1ine sampie horizon 387, Cephalopyge l10tabilis bio or slightly apsac1ine, passing into adjacent valve zone; PIW96X25.1-25.25, PIW96X30.1-30.2, surfaces without distinct flexure; intertrough PIW96X34, PIW96X35, PIW96X36, broad, extends dorsally into a small' convex lip. PIW96X125, PIW96X126. Maximum height anterior to blunt apex, at Occurrence. Cephalopyge Ilotabilis bio- about 25 % of length from posterior margin. zone. Foramen circular, elongated elliptical or slit Diagnosis. - As for genus (because of like in outline, located below valve apex within monotypy). a countersunk, elongated elliptical cavity that Description. - Shell ventribiconvex and occupies apical third of intertrough. Ventral transversely oval in outline, average length/ larval shell slightly overhangs intertrough; the width ratio about 0.81 and up to 2.2 mm in dia line of its margin in lateral view inc1ined at meter. Internal surfaces of weIl preserved shells ab out 50 to 60° to commissUl'al plane. Ventral ornamented with a smooth pattern of circular interior characterized by thin, ridge-like apical pits, extern al surfaces covered by faint growth process which connects posterior and anterior lines. Larval shell flat and discoidal in outline, valve slopes, perforated at its thickened dorsal 180 to 220 11m wide, ornamented with circular end by short pedic1e tube. Apical process orna pits of rather uniform size (1.9 to 2.4 11m in dia mented anterior to interna I pedic1e opening by meter) that do not overlap each other, be- a filigree, ventrally deflected spine, which 40 M. Streng obviously may reaeh to the anterior valve slope Dorsal valve. Dorsal valve moderately to to form an areh. Apieal pits unknown. Cardinal strongly eonvex, with broad, deep, typieally ana musde sears large, oval in outline, poorly dine to orthodine, tri angular median groove marked, not reeognizable on most of the valves. defined laterally by strongly diverging sm all or

Plate 2

Acallthatreta meiIVirthae gen. et sp. nov. sampie horizon 387; all scale bars = 200 /lm, except F, G, H, land 1. Proben horizont 387; alle Maßstabsbalken = 200 /lm, außer F, G, H, land 1.

A) PIW96X25.9; lateral view of strongly convex, apsaeline ventral valve. PIW96X25.9; Seitenansicht einer stark konvexen, apsaelinen Ventral klappe. B) PIW96X125.3; posterior view of ventral valve, showing dorsal extension of pseudointerarea and location of foramen within a counters unk cavity. PIW96X125.3; Rückseite einer Ventralklappe mit dorsaler, zahnartiger Verlängerung der Pseudointer area; Stielloch liegt innerhalb einer ovalen, kraterartigen Vertiefung. C) PIW96X30.1; lateral view of ventral interior, showing ventrally deflected spine of apical process. PIW96X30.1; Seitenansicht des Inneren einer Ventralklappe mit einem nach ventral gebogenem dorn artigen Fortsatz des apical process. D) PIW96X25.8; lateral view of convex ventral valve showing convex, proeline pseudointerarea. PIW96X25.8; Seitenansicht einer konvexen Ventralklappe mit schwach konvexer, proeliner Pseudointer area. E) PIW96X125.4; ventral interior. PIW96X125.4; Innen ansicht einer Ventralklappe. F) PIW96X30.1; detail of C, suggesting a primary connection of the spine with valve floor; scale bar = 50 /lm. PIW96X30.1; Detail von C, das eine primäre Verbindung des Fortsatzes mit dem Schalenboden vermu ten läßt; Maßstabs balken = 50 /lm. G) PIW96X25.11; anterior view of apical process with scar of broken off spine; scale bar = 100 /lm. PIW96X25.11; Frontalansicht eines apical process mit abgebrochenem Fortsatz; Maßstabsbalken 100/lm. H) PIW96X25.11; detail of G, showing elose-up of scar of broken off spine; scale bar = 20 /lm. PIW96X25.11; Ausschnittsvergrößerung von G mit AbbruchsteIle des Fortsatzes; Maßstabsbalken = 20 /lm. I) PIW96X30.2; detail of ventral interior, showing apical process and scar of broken off spine; note pitted surface of valve slopes; scale bar = 100 /lm. PIW96X30.2; Ausschnittsvergrößerung einer Ventralklappe mit apical process und AbbruchsteIle des Fortsatzes; beachte Ornamentierung der Schalenoberfläche seitlich des apical process; Maßstabsbalken = 100 /lm. J) PIW96X25.12; detail of dorsal larval shell, showing decrease in size of pits towards the edge of larval shell and transition to recrystallized post-larval shell; sc ale bar = 20 /lm. PIW96X25.12; Übergang von ornamentierter Larvalschale zu rekristallisierter, postlarvaler Schalen oberfläche; Maßstabsbalken 20 /lm. K) PIW96X25.14; oblique lateral view of dorsal interior. PIW96X25.14; schräge Innenansicht einer Dorsalklappe. L) PIW96X25.15; holotype; oblique view of ventral interior; note pitted valve floor anterior to apical pro cess. PIW96X25.15; Holotypus; schräge Innen ansicht einer Ventralklappe mit ornamentierter Oberflächer an terior zum apical process. M) PIW96X126.2; dorsal interior view. PIW96X126.2; Innenansicht einer Dorsalklappe. N) PIW96X125.8; dorsal exterior. PIW96X125.8;Außenansicht einer Dorsalklappe. 0) PIW96X125.7; ventral exterior. PIW96X125.7; ventrale Ansicht einer Ventralklappe . P) PIW96X126.1; dorsal interior view. PIW96X126.1; dorsale Ansicht einer Dorsalklappe. Acrotretoidea (Brachiopoda) from Morocco 41 42 M. Streng

Tab. 2: Acanthatreta meiwirthae gen. et sp. nov.; measurements and average dimensions (in microns) of ventral and dorsal valves. Tab. 2: Meßwerte der morphologischen Parameter (in Mikrometer) und statistische Daten der Dorsal- und Ventralklappen von Acallthatreta meiwirthae gen. et sp. nov.

ventral valve L W H Lw Lm Wm We LfW N 35 33 33 27 5 4 27 33 MIN 800 919 260 424 420 700 242 0.719 MAX 1600 1820 735 760 680 1220 620 0.902 (J 205.3 251.3 111.8 94.7 102.4 263.0 104.3 0.054 STD.ERROR 34.7 43.7 19.5 18.2 45.8 131.5 20.1 0.009 VAR 42129 63127 12490 8967 10480 69167 10874 0.003 MEAN 1108 1381 528 584 504 965 447 0.806 GEO.MEAN 1090 1358 515 577 497 938 435 0.804

dorsal valve L W H Lw Lm Wm Le We LfW LmlWm N 39 39 26 39 16 13 31 27 39 13 MIN 484 600 120 240 260 640 64 530 0.726 0.459 MAX 1900 2160 380 1024 700 1140 260 1154 0.897 0.781 (J 272.7 308.6 74.5 151.5 118.6 168.8 43.8 175.4 0.041 0.082 STD. ERROR 43.7 49.4 14.6 24.3 29.7 46.8 7.8 33.8 0.007 0.023 VAR 74386 95263 5552 22958 14077 28502 1920 30783 0.002 0.007 MEAN 1055 1284 259 576 478 886 184 829 0.821 0.586 GEO.MEAN 1022 1247 249 556 464 871 178 811 0.820 0.581

w~- '-<----Wm------ '-<------W ------+' '-<------W ------+' Fig. 7: Location of measurements on Acanthatreta meiwirthae gen. et sp. nov.; left, ventral valve right, dorsal valve. Abb. 7: Messungen an Acallthatreta meiwirthae gen. et sp. nov.; links: Ventralklappe - rechts: Dorsalklappe. Acrotretoidea (Brachiopoda) from Morocco 43 indistinct propareas. Pseudointerarea slightly Montana), by KRAUSE & ROWELL (1975) for overhangs posterior valve floor, supported by Ephippelasma spinoswll (from the Ordovician sm all median buttress. Cardinal musc1e scars of Nevada), by ROWELL & HENDERSON (1978) large, broadly elliptical in outline, gently diverg for Quadrisonia minor (trom the Late Cambri ing anteriorly, reaching to mid-Iength of valve. an of Utah and Nevada), and by HENDERSON & Median ridge not developed; only one of the MACKINNON (1981) for Stilpnotreta magna studied valves bears a small, pear-shaped swell (from Middle to Late Cambrian rocks of New ing at about 70 % of valve length from posteri Zealand). Several other species of Cambrian or or margin. Vascula lateralia of both valves bacu Ordovician age show similar structures, which late, inconspicuous, defined centrally by ob suggest a primitive articulation, too, e. g., Phy scure ridges. sotreta spinosa from the early Late Cambrian of Discussion. - The ornamentation of the Nevada (see ROWELL 1966: pI. 3, fig. 26), Hisin apical process with a ventrally deflected spine gere!la billingensis from the Middle Ordovician in Acanthatreta meiwirthae appears to be (Llandeilo) of Sweden (see HOLMER 1989: p. 91, unique within the Acrotretida, because no fig. 61H), and Angulotreta sublata from the Late similar structure is known yet. Unfortunately, Cambrian of North China (see MEI 1993: pI. V, the spine is completely preserved in only one fig. 8) as well as Angulotreta microscopica from specimen, whereas on all other ventral valves, the Late Cambrian of Texas (see BELL & EL in which the apical process is observed, it is LINWOOD 1962: pI. 60, figs. 8 and 9). All forms, broken off, leaving a small, circular scar (Plate except the ephippelasmatine Ephippelasma spi 2, figs. G, H, I). Thus, the variability of its shape nOSWl1, show a distinct dorsally directed deflec and its general orientation are not known. tion of the growth lines medially of the ventral If the spine is broken away, Acanthatreta pseudointerarea and bear a well developed dor meiwirthae is similar to Almohadella braunae sal median groove. Because of the inadequate gen. et sp. nov. and Bozshakolia coniformis, but potential of preservation of the margin of the can best be distinguished by (1) the shape of its ventral valve, a dorsally projection of the ven apical process, which is thinner anterior to the tral pseudointerarea is probably a feature of internal pedic1e foramen, tapering anteriorly many other acrotretoids bearing such morpho and thus lacking a musc1e platform, and (2) by logic details (such as Almohadella brazmae gen. the location of the pedic1e tube that penetrates et sp. nov.). the apical process at its distal posterior end im mediately adjacent to the posterodorsal valve slope. The dorsal valves of Monophthalma cf. Genus Almohadella gen. nov. M. eggegJ'l/l1densis differ from those of Acan thatreta meiwirthae in having smaller propareas Etymology. - Named after the Almohads, and a smooth median ridge. Nevertheless, small founders of Tinmal Mosque, north of type and juvenile valves as well as poorly preserved locality. specimens that all lack these features do not Type species. -Almohadella braunae gen. allow a precise discrimination between both et sp. nov.; early Middle Cambrian, Morocco species (see also Discussion und er Family Cera (Cephalopyge notabilis through Ornamentaspis tretidae ). frequens biozone ). Remarks. - The dorsally directed exten Diagnosis. - Shell ventribiconvex, trans sion of the ventral pseudointerarea in Acantha versely oval in outline. Ventral pseudointerarea treta meiwirthae described above (see Descrip steeply proc1ine, poorly delineated from adja tion) fits into the median groove of the dorsal cent valve surfaces, with broad intertrough valve and is, in accordance to HENDERSON & diverging dorsally; pedic1e foramen slit-like, MACKINNON (1981), interpreted as a primitive located within an elliptical cavity posterior to hinge articulation. SimilaI' structures have been apex. Apical process forms robust ridge, described, e. g., by BELL (1941) for LinJlarsso connecting posterior and anterior valve slopes, nella e!ongata (from the Late Cambrian of perforated posteriorly by short pedic1e tube. 44 M.Streng

Dorsal pseudointerarea dominated by a broad, section Le XI, sampie horizons Le XI-24b: triangular or lenticular median groove; prop PIW96X13.7-13.8, PIW96X105 (1 VV, 3 DV) areas obscure; median buttress broad, extend and Le XI-24e: PIW96X130 (1 DV); section Le ing anteriorly. Median septum not developed, XII, sampie horizon Le XII-lII: but dorsal valve with swollen area anterocen PIW96X18.2-18.3 (2 VV) - all Ornamentaspis trally. jreqllens biozone. Occurrence. - Early Middle Cambrian (Cephalopyge nota bilis through Ornamentaspis Almohadella bl'aunae sp. nov. jrequens biozone ). Diagnosis. - As for genus (because of Fig. 18; Plate 3 monotypy). Description. Shell ventribiconvex, Etymology. - In honor to my best friend typically transversely oval in outline, sometimes Barbara Braun. broadly oval or suboval, average length/width Holotype. - Ventral valve, PIW96X3.14 ratio about 0.81 (N = 144), up to 2.2 mm in dia (Plate 3, figs. C, D).- Type locality and stratum: meter. External surface of shell with fine, sub Lemdad sync1ine, High Atlas, section Le XI, evenly spaced growth lines, which are usually sampie horizon Le XI-51.9 in the Jbel Wawr superimposed laterally, producing distinct con mast Formation, Breche a Micmacca Member; centric steps indicative of growth stops. Outline Ornamentaspis jrequens biozone. and ornamentation of larval shell not known. Material studied. - 281 ventral valves Ventral valve. Posterior and lateral surfaces (VV) and 536 dorsal valves (DV) from eleven of ventral valve convex, anterior surface sampie horizons of seven sections and localities, flattened or slightly convex in lateral view; all from the High Atlas: Itsiar, sampie horizon maximum height at about 27 % of valve length 397: PIW96X115 (4 VV, 1 DV); Ijoukak, sampie from posterior margin, anterior to blunt apex; horizon X 242: PIW96X102 - both Cephalopyge height on average about 23 to 30 % of length. notabilis biozone; Lemdad sync1ine, section Le Pseudointerarea steeply proc1ine, divided by a X, sampie horizon X 223: PIW96X18.4-18.15, broad, dorsally diverging intertrough, across PIW96X113 (10 VV, 20 DV), section Le XI, which growth lines are deflected dorsally. Con sampie horizons Le XI-4: PIW96X107, spicuous, oval, countersunk cavity with the slit PIW96X127 (11 VV, 15 DV), Le XI-24c: like foramen is located immediately posterior PIW96X8.1, PIW96X8.3-8.14, PIW96X106, to apex, occupying at least apical third to half of PIW96X117 (20 VV, 43 DV), Le XI-51.65: intertrough. Apical process a robust ridge, PIW96X10.6-10.10, PIW96X10.14-10.17, connecting posterior and anterior valve slopes, PIW96X104 (8 VV, 19 DV), Le XI-51.9: perforated posteromedially by a short pedic1e PIW96X3.1-3.20, PIW96X26.1-26.15, tube; sides of apical process alm ost parallel, PIW96X114 (79 VV, 162 DV) and X 214: with distinct thickening laterally to circular in PIW96X21.1-21.10, PIW96X109, PIW96X110, ternal pedic1e foramen, often slightly diverging PIW96X121, PIW96X122 (61 VV, 83 DV), sec anteriorly and mm'king subtriangular musc1e tion Le XII, sampie horizon X 217: platform; length of anterior part of apical pro PIW96X111, PIW96X112, PIW96X123, cess anterior to internal pedic1e foramen PIW96X124 (15 VV, 31 DV), section Le XVI, variable. Cardinal musc1e sc ars of ventral valve sampie horizon Le XVI-30: PIW96X10.1-10.5, large, oval in outline and more-or-Iess parallel. PIW96X10.12-10.13, PIW96X19.3-19.11, Dorsal valve. Dorsal valve with weil de PIW96X108 (9 VV, 29 DV); Lemdad sync1ine, veloped, short, wide, triangular 01' lenticular Jbel Wawrmast, sampie horizon X 52: median groove, typically anac1ine, bordered PIW96X22.1-22.15, PIW96X23.1-23.12, laterally by obsolescent propareas. Pseudointer PIW96X103, PIW96X118 (65 VV, 128 DV); - all area supported by a broad, barely eie va ted Ornamentaspis jl'eqllens biozone. - Tentatively median buttress that extends anteriorly into assigned to the same species: Lemdad sync1ine, two diverging, often indistinct ridges; median Acrotretoidea (Brachiopoda) from Morocco 45

Tab. 3: Almohadella brallnae gen. et sp. nov.; measurements and average dimensions (in microns) of ventral and dorsal valves. Tab. 3: Meßwerte der morphologischen Parameter (in Mikrometer) und statistische Daten der Dorsal- und Ventralklappen von Almohadella brazl11ae gen. et sp. nov.

ventral valve L W H Lw Lm Wm Wp LIW N 48 49 37 46 27 26 44 48 MIN 594 780 220 300 240 460 240 0.703 MAX 1476 1919 580 758 600 1275 520 0.944 (J 218.9 265.6 85.8 106.3 93.8 231.8 79.8 0.054 STD.ERROR 31.6 37.9 14.1 15.7 18.1 45.5 12.0 0.008 VAR 47919 70567 7362 11306 8797 53740 6376 0.003 MEAN 1027 1277 390 524 362 797 376 0.804 GEO.MEAN 1004 1250 381 513 351 765 368 0.803

dorsal valve L W H Lw Lm Wm Lp Wp LIW LmIWm N 95 96 60 95 73 73 76 71 95 73 MIN 760 940 186 430 318 510 120 460 0.700 0.414 MAX 1843 2013 420 1038 824 1447 249 1200 0.937 0.688 (J 223.0 259.2 56.5 133.3 108.7 220.9 31.7 166.7 0.054 0.059 STD.ERROR 22.9 26.5 7.3 13.7 12.7 25.8 3.6 19.8 0.006 0.007 VAR 49726 67207 3196 17763 11826 48776 1008 27790 0.003 0.003 MEAN 1174 1451 302 647 514 937 169 834 0.812 0.555 GEO.MEAN 1153 1428 297 634 503 911 167 817 0.810 0.552

,----wm------ooJ '+----W m----..J

'------W -----.... '+------W ------Fig. 8: Location of measurements on Almohadella brazlI1ae gen. et sp. nov.; left, ventral valve - right, dorsal valve. Abb. 8: Messungen an Almohadella brazl11ae gen. et sp. nov.; links: Ventralklappe - rechts: Dorsalklappe. 46 M.Streng septum or median ridge absent; instead, with lateral to median buttress (Plate 3, figs. H, L), swollen area that occupies the central to sometimes even crossing the median buttress. anterocentral part of the valve (Plate 3, fig. M). Cardinalmuscle scars large, broadly separated, Interior valve surface with a characteristic drop-shaped in outline, originating immediately flexure slightly anterior to median groove and anterolateral to median groove, slightly diverg-

Plate 3

Almohadella bralillae gen. et sp. nov. all scale bars == 200 11m, except K alle Maßstabsbalken == 200 11m, außer K

A) PIW96X3.2; lateral view of ventral interior; Le XI-51.9. PIW96X3.2; seitliche Innenansicht einer Ventralklappe; Le XI-51.9. B) PIW96X3.2; anterior view of ventral interior; Le XI-51.9. PIW96X3.2; Frontalansicht einer Ventralklappe; Le XI-51.9. C) PIW96X3.14; holotype; elose-up of apical process; detail of D; Le XI-51.9. PIW96X3.14; Holotypus; Nahaufnahme des apical process; Detail von D; Le XI-51.9. D) PIW96X3.14; holotype; oblique anterior view of ventral interior, showing distinct vascula lateralia and pitted surface of posterior and anterior valve slopes; Le XI-51.9. PIW96X3.14; Holotypus; schräge Frontalansicht der Innenseite einer Ventralklappe mit deutlichen vas cula lateralia und ornamentierter Schalenoberfläche; Le XI-51.9. E) PIW96X18.5; oblique view of ventral interior; X 223. PIW96X18.5; Innenasicht einer Ventralklappe; X 223. F) PIW96X10.8; lateral view of a prominent apical process; Le XI-51.65. PIW96X10.8; Seitenansicht eines erhabenen apical process; Le XI-51.65. G) PIW96X22.6; dorsal interior, showing flexure of valve floor anterior to pseudointerarea which crosses median buttress and anteriorly bifurcating median buttress; X 52. PIW96X22.6; Schaleninnenseite einer Dorsalklappe mit deutlicher ausgebildeter, den median buttress kreuzende Flexur und einem distal geteilten median buttress; X 52. H) PIW96XlO.7; dorsal interior showing pitted surface of valve floor and faint ridges that define cardinal musele scars; Le XI-51.65. PIW96XlO.7; Innenansicht einer Dorsalklappe mit ornamentierter Oberfläche und Muskelfeldern, die von kleinen Rücken begrenzt werden; Le XI-51.65. I) PIW96X23.4; oblique view of dorsal interior, showing faint central swelling; X 52. PIW96X23.4; Inneansicht einer Dorsalklappe mit einer zentralen Schalenverdickung; X 52. J) PIW96X21.3; dorsal exterior; X 214. PIW96X21.3; Außenansicht einer Dorsalklappe; X 214. K) PIW96X18.6; elose-up of posterior apical region, showing slit-like foramen within countersunk cavity; X 223; scale bar == 100 11m. PIW96X18.6; schlitz artiges Stielloch innerhalb einer elliptischen Depression; X 223; Maßstabs balken == 100 11m. L) PIW96X8.1; elose-up of posterior part of dorsal interior, showing median buttress and median groove; Le XI-24c. PIW96X8.1; Pseudointerarea und median buttress einer Dorsalklappe; Le XI-24c. M) PIW96X26.3; oblique lateral view, showing anterocentral swelling of valve floor; Le XI-51.9. PIW96X26.3; Seitenansicht einer Dorsalklappe mit deutlicher, anterozentraler Schalenverdickung; Le XI-5l.9. N) PIW96X22.9; oblique view of dorsal interior; note terraced anterior slope; X 52. PIW96X22.9; Innenansicht einer Dorsalklappe mit einer im vorderen Bereich terrassenartig abgestuften Schaleninnenseite; X 52. 0) PIW96X26.8; Almohadella cf. A. bralillae; fragment of ventral valve, showing anterior part of apical pro cess; probably a gerontic stage; Le XI-51.9. PIW96X26.8; Almohadella cf. A. braul1ae; Bruchstück einer möglicherweiser gerontischen Ventralklap pe; erhalten ist der vordere Teil eines massiven, differenzierten apical process; Le XI-51.9. Acrotretoidea (Brachiopoda) from Morocco 47 48 M. Streng ing anteriorly and extending on average to of a single sampIe. ab out 43 % of valve length from posterior mar gin (max. 51 %, min. 34%, N = 71), defined Family ACl'Otretidae SCHUCHERT 1893 centrally by smooth ridges (Plate 3, fig. H). Ontogeny. - As mentioned above, the lar Genus Tillgitallella gen. nov. val shell of Almohadella brallnae is unknown due to the generally poor preservation of the Etymology. - Named after the Roman external surface of the studied material. AI province Mallretania Tingitana, Morocco was a though a c1ear distinction of series of different part of in the 1st through 3rd century. growth stages is not possible, some features are Type species. - Tingitanella calal1lisca useful to distinguish at least between juvenile, gen. et sp. nov.; early Middle Cambrian, Moroc adult and gerontic growth stages. Obviously, the co (Hllpeolelllls?, Cephalopyge notabilis development of two anteriorly diverging ridges, through Ornamentaspis treqllens biozone ) which originate lateral to the anterior part of Diagnosis. - Shell small, subcircular in the apical process, as weIl as the development outline, width slightly greater than length, of the cardinal musc1e scars as raised platfor)11s posterior margin gently convex or straight. Ven are characteristic for adult or gerontic stages. A tral valve apsaconical to cataconical; highest c1ear assignment of these features to a certain point at apex. Ventral pseudointerarea weIl de growth stage is impossible, because they are not veloped, bisected by a poorly defined inter directly related to certain sizes. Relatively small trough. Pedic1e foramen circular, enc10sed with valves may show both features, whereas larger in the larval shell and extended into a short ex valves have only one and vice versa. Neverthe ternal pedic1e tube. Triangular apical process less, the sm aller juvenile valves generally lack barely elevated and indistinct, characterized by both features. Regarding the dorsal valves, the a central depression. Larval shell of ventral development of the anteriorly extending medi valve flattened; its crest-line parallel to commis an buttress, the development of the central sural plane in lateral profile. Dorsal valve gent swollen area, and the appearance of the ly convex; pseudointerarea with weil develop characteristic flexure anterior to the median ed, orthoc1ine median groove and distinct, ana groove seem to be unambiguous criteria for the c1ine propareas. Median buttress present. adult stage. Indicative for the gerontic stage may be the crossing of the median buttress by the flexure as visible in Plate 3, figs. G and L. Tillgitallella calamisca sp. nov. Discussion. - Almohadella braunae is a highly variable species. The ornamentation of Plate 4 the internal surface of both valves shows wide variations which can partly be put down to Etymology. - Named after the Greek ka different ontogenetic stages (see also Onto lamiskos, small tube, in allusion to the external geny). Such variable features comprise for the foramen extending in a small tube. dorsal valve: (1) the width, the shape, and the Holotype. Ventral valve, PIW96X30.12 length of the median buttress; (2) the visibility (Plate 4, figs. A, D, G, H). - Type locality and of the anterocentral swelling; and (3) the out stratum: Ourika Wawrmas, sampIe horizon OR- line of the median groove. In the ventral valve 3 in the Jbel Wawrmast Formation; Cephalopy differences are observable in: (1) the length and ge nota bilis biozone. the shape of the apical process; (2) the eleva Material studied. 71 ventral valves tion of the cardinal musc1e fields; (3) the visibi (VV) and 93 dorsal valves (DV) from five lity of the vascula lateralia; and (4) the develop sampIe horizons in the central and eastern ment of faint ridges centrally to the vascula Anti-Atlas: EI Hmam, sampIe horizon HM-9.6: lateralia. All variations are assumed to appear PIW96X97 (1 VV), upper Hupeolel1l1s biozone; in conspecific specimens, because the range of Ourika Wawrmas, sampIe horizon OR-3: these characters is unbroken even in specimens PIW96X30.7-30.32, PIW96Xl00, PIW96XlOl Acrotretoidea (Brachiopoda) from Morocco 49

(54 VV, 69 DV) and sampie horizon OW-1: slopes of larval shell (Plate 4, fig. B); its crest PIW96X99 (1 VV, 3 DV); Tatelt section, sampie line as well as a great part of its anterior slope horizon TAT-67.9: PIW96X98 (6 VV, 7 DV); in lateral profile parallel to plane of commis Jbel Tirounbai', sampie horizon A 936a: sure. PIW96X133 (2 VV, 2 DV); all Cephalopyge 110- Dorsal valve. Dorsal valve slightly convex in tahilis biozone; Alt Mersid, sampie horizon D lateral profile; apex at posterior margin. 2077: PIW96X16.1, PIW96X16.4-16.6, Pseudointerarea wide, occupies on average 79 PIW96X16.24-16.26, PIW96X96 (8 VV, 15 DV), % of the total width; median groove well de Ornamentaspis frequens biozone. veloped, orthocline, of 54 to 59 % the width of Occurrence. - Upper Hupeolenus through pseudointerarea; propareas triangular, slightly 01'11 am entaspis frequens biozone. anacline. Median buttress subtriangular, promi Diagnosis. - As for genus (because of nent, extends anteriorly to ab out 15 to 20 % of monotypy). valve length, occasionally forked anteriorly, en Description. - Shell small, up to 1.1 mm closing triangular sunken area (Plate 4, fig. M). in diameter, thin-walled, subcircular in outline, Cardinal muscle sc ars drop-shaped, originate average length/width ratio about 0.94; mCjxi immediately anterior to junction of median mum width at ab out midlength; posterior mar groove and the propareas; cardinal muscle sc ars gin generally barely convex to straight, diverge anteriorly and occupy about 28 to 35 % especially in ventral valve. Interior surface of of valve length and 53 to 60 % of valve width; both valves locally covered by a polygonal pat no central muscle sc ars discernible. Median tern (Plate 4, figs. C, L, M). Larval shell ab out septum unknown, apparently not developed. 0.15 to 0.25 mm wide, with circular pits of ab out Larval shell of dorsal valve normally poorly de 1.4 to 1.6 flm in diameter; pits of smaller sizes lineated, declined posteriorly, sometimes bear possibly created by diagenetic effects. Distal ing a pair of distinct elevations separated by a part of anterior slope of larval shell sometimes shallow, median furrow. steeper than in later growth stages so that larval Ontogeny. - Differentiation between, as shell appears pointed. well as identification of, juvenile and adult Ventral valve. Ventral valve generally apsa stages of Tingitanella calamisca is difficult. The conical or cataconical; lateral and anterior small size, the thin-walled shell and the absence slopes straight to faintly convex, posterior slope of typical adult features, such as a median ridge, is slightly concave or straight. Maximum height prominent muscle sc ars, or a conspicuous apical at umbo. Ventral pseudointerarea flattened and process, appear to indicate all studied indivi thus distinguishable from adjacent valve seg duals to be juveniles. Nevertheless, some differ ments; traversed by a concave zone which ences are visible between shells of different originates at the margin of larval shell. Triangu sizes: Small valves have an internal pedicle lar apical process situated on anterior slope, opening that lies within the posterior slope, in barely elevated above valve floor, bears central contrast to later growth stages where the inter depression (Plate 4, fig. C). Pedicle tube short nal pedicle opening marks the junction between with circular internal pedicle opening. Apical anterior and posterior valve slopes. Simul pits inconspicuous, anterolaterally to internal taneously, the apical pits become more distinct. pedicle opening. Ventral vascula lateralia bacu Furthermore, the median buttress is only late, obviously short, but not visible in most val forked in the relatively large, rare individuals. ves. Muscle scars unknown. Larval shell flatte Nonetheless, the median buttress appears to be ned, with the external pedicle foramen extend an early ontogenetic character, because it is ed into a short tube that faces posteriorly and weIl developed and prominent in both small overhangs the pseudointerarea; height of larval and large valves. shell of about 30 % of its length; foramen cir Discussion. - The apsaconical shape of cular in outline, 38 to 45 flm in diameter, some Tingitanella calamisca somewhat resembles (1) times surrounded by several minute radial Canthylotreta ROWELL 1966, described from ridges which extend anteriorly along lateral Middle to Upper Cambrian sections in North 50 M.Streng

America (ROWELL 1966), Greenland (ZELL & Australia (BISCHOFF & PRENDERGAST 1987). ROWELL 1988), and North China (MEI 1993); Canthylotreta is c1early distinguished from Till (2) EllIytreta ROWELL 1966, recorded from Up gitanella calamisca in having a sulcus on the per Cambrian to Middle Ordovician strata of outer surface of the dorsal valve, a median North America (ROWELL 1966; KRAUSE & Ro septum, and the internal pedic1e opening dorsal WELL 1975), Europe (e. g., Popov & HOLMER to the apical process. In addition, the ventral 1994), and Kazakhstan (KONEVA & Popov valve of Canthylotreta as weH as those of Eury 1988; Popov & HOLMER 1994); and (3) Aphelo treta and Aphelotreta, are convex with an apsac treta ROWELL 1980, from the Middle Cambrian line pseudointerarea rather than apsaconical as of Nevada (ROWELL 1980), the Siberian Plat in T. calamisca. Nevertheless, T. calamisca is form (USHATINSKAYA 1994), and probably from most similar to Eurytreta in having a foramen

Plate 4

Tingitanella calalllisca gen. et sp. nov. . sampie horizon OR-3; all sca1e bars = 100 [lm, except Band L Probenhorizont OR-3; alle Maßstabsbalken = 100 [lm, außer Bund L

A) PIW96X30.12; holotype; oblique lateral view of pseudointerarea of D. PIW96X30.12; Holotypus; schräge Seitenansicht der Pseudointerarea von D. B) PIW96X30.9; elose-up of ventral larval shell, showing foramen surrounded by faint radial ridges and minute pitting of larval shell; sc ale bar = 20 [lm. PIW96X30.9; Nahaufnahme der Larvalschale einer Ventralklappe, deren Stielloch von feinen radialen Rücken umgeben ist; Maßstabsbalken = 20 [lm. e) PIW96X134.1; oblique view of ventral interior, showing triangular apical process with central depression. PIW96X134.1; Innenansicht einer Ventralklappe mit triangularem apical process. D) PIW96X30.12; holotype; ventral view of ventral valve. PIW96X30.12; Holotypus; Ventralansicht einer Ventralklappe. E) PIW96X30.11; ventral interior; note that no cardinal museIe scars are visible. PIW96X30.11; Innenansicht einer Ventralklappe; beachte, daß keine Muskeleindrücke sichtbar sind. F) PIW96X30.8; ventral interior, showing barely elevated apical process; note area of thickened shell (arrow), probably indicating location of cardinal museIe sc ars. PIW96X30.8; Innenasicht einer Ventralklappe mit schwach erhabenen apical process; ein Bereich mit lokal verdickter Schale (Pfeil) indiziert möglicherweise die Lage der Muskelfelder. G) PIW96X30.12; holotype; lateral view of D. PIW96X30.12; Holotypus; Seitenansicht von D. H) PIW96X30.12; holotype; elose-up of ventral larval shell, showing small tube of posteriorly extending foramen. PIW96X30.12; Holotypus; Nahaufnahme der ventralen Larvalschale, die ein nach posterior verlängertes Stielloch zeigt. I) PIW96X134.2; dorsal exterior, showing ornamentation of post-larval shell. PIW96X134.2; Ornamentierung der Außenseite einer Dorsalklappe. J) PIW96X30.14; elose-up of dorsal pseudointerarea; detail of K. PIW96X30.14; Nahaufnahme der Pseudointerarea von K. K) PIW96X30.14; dorsal interior, showing median buttress, median groove, and anacline propareas. PIW96X30.14; Innenansicht einer Dorsalklappe mit median buttress, Pseudointerarea und anaelinen Propareas. L) PIW96X30.13; polygonal pattern preserved on internal surface of dorsal valve; scale bar = 10 [lm. PIW96X30.13; polygonales Muster auf der inneren Schalenoberfläche einer Dorsalklappe; Maßstabsbal• ken = 10 [lm. M) PIW96X30.15; dorsal interior, showing distally forked median buttress; note polygonal pattern anterior to median buttress (arrow). PIW96X30.15; Innenansicht einer Dorsalklappe mit distal geteiltem median buttress; beachte polygona les Muster anterior zum median buttress (Pfeil). Acrotretoidea (Brachiopoda) from Morocco 51 ----- W ----->-'

Fig. 9: Location of measurements on Tingitanella calamisca gen. et sp. nov.; left, ventral valve - right, dorsal valve. Abb. 9: Messungen an Tingitanella calamisca gen. et sp. nov.; links: Ventralklappe rechts: Dorsalklappe. Acrotretoidea (Brachiopoda) from Morocco 53

that is enc10sed within the larval sheIl, a cata ternal pedic1e opening. Dorsal valve gently con c1ine to apsac1ine ventral pseudointerarea, and vex in lateral profile. Dorsal pseudointerarea a semicircular depression anterior to the inter with weIl developed tri angular median groove, nal pedic1e opening. Especially Eurytreta dis bordered laterally by a pair of distinct prop cors Popov in KONEVA & PoPOV 1988, from the areas. Median buttress variably developed, but middle Late Cambrian of the Malyi Karatau, always present. Median ridge low, normally in Kazakhstan, c10sely resembles the Moroccan distinct. species. However, Eurytreta discors is dis Species inc1uded. - Vandalotreta vafra tinguished from T. calamisca in having a poorly MERGL 1988; Luhotreta pompeckji MERGL & defined ventral pseudointerarea, c10sely placed SLEHOFERovA 1990, Middle Cambrian, Jince dorsal cardinal musc1e sc ars, and a median Formation, Bohemia; Vandalotreta fragilis sp. septum or ridge. nov.; Vandalotreta minima sp. nov.; Vandalotreta Aphelotreta is c1early distinguished by its sp. A; ? acrotretider Brachiopode, gen. et sp. small to obsolescent propareas, the weIl indet. (HINZ-SCHALLREUTER 1997). developed median septum and the position of Acrotreta limoensis WlMAN 1903, a species the external pedic1e opening, which is not <,Iis known only from glacial erratics of the Island tinctly within the larval shell. of Limän in the South Bothnian Sea, has been Remarks. - 1\vo features of Tingitanella referred to Vandalotreta by HOLMER et al. calamisca need further explanation: (1996). (1) The polygonal pattern of the interna I Occurrence. - Early Middle Cambrian surface of the shell is apparently homologous to (Cephalopyge notabilis through Ornamentaspis the smooth pattern of circular pits, which can frequens biozone); Morocco; Middle Cambrian, be observed, e. g., in the Moroccan ceratretids. central Bohemia; probably early Middle Cam (2) No musc1e scars are observable in the brian, Island of Limön, South Bothnian Sea, ventral valve, probably either due to the state Sweden. of preservation or to primarily faint markings. Discussion. - As discussed by HOLMER et However, the location of the ventral cardinal al. (1996), Luhotreta MERGL & SLEHOFERovA musc1e scars is obviously indicated by an area 1990, differs from Vandalotreta only in the ab of thickened shell on the lateral internal slope sence of a median ridge and an external orna (arrow in fig. F, Plate 4). mentation. Luhotreta is therefore considered as a junior synonym of Vandalotreta. Vandalotreta is distinguished from other Genus Vandalotl'eta MERGL 1988 genera of the Acrotretidae by its characteristic massive apical process, which bears a distinct Type species. - Original designation by cavity, and by its poorly developed or vestigial MERGL (1988, p. 293); Vandalotreta vafra, early median ridge. However, the shape and/or the Middle Cambrian, probably Cephalopyge nota outline of the valves of Vandalotreta resemble bilis biozone, Yagour inlier, the High Atlas, those of some other Middle and Late Cambrian Morocco. acrotretids, such as Prototreta BELL 1938, Angu Emended diagnosis. - Outline of shell lotreta PALMER 1954, Hadrotreta ROWELL 1966, subcircular, width slightly greater than length. Treptotreta HENDERSON & MACKINNON 1981, Ventral valve proconical to cataconical; ante and Batenevotreta USHATINSKAYA 1992. In addi rior and posterior slopes straight or slightly tion to the two characters mentioned above, convex or concave in lateral profile. Pseudo Vandalotreta is distinguished from Treptotreta interarea of pedic1e valve deltoid, poorly de in having the foramen not within the larval fined laterally, typically weakly concave, with sheIl, in the more distinctly developed inter distinct intertrough. Apical process occupies trough and in the obsolescent median septum; entire or almost entire apex and extends prima from Prototreta by a shorter dorsal pseudo rily along anterior valve slope, characterized by interarea; from Hadrofl'eta in the shape of the a conspicuous apical process cavity bearing in- apical process cavity, in the direction of the 54 M.Streng pedic1e tube, whieh is short and anteriorly Member, eentral Anti-Atlas; Cephalopyge nota direeted in Hadrotreta (ROWELL 1966) and bilis biozone. dorsally direeted in Vandalotreta, and, further Material studied. - 705 ventral valves more, in the loeation of the apieal pits, whieh (VV) and 311 dorsal valves (DV) from eight are lateral to posterolateral to the internal sampie horizons of six loealities in the Anti pedic1e opening in Hadrotreta rather than Atlas, most of them fragmentary: Hassi Brahim, posterior as in Vandalotreta (Fig. 12). sampie horizon D 257: PIW96X24.1-24.l4, Hadrotreta djagoran KRUSE 1990, from the PIW96X16.7-16.14, PIW96X16.16-16.24, Middle Cambrian of Australia has been refer PIW96X81 (53 VV, 55 DV); Jbel bou Ifersikt, red to Vandalotreta by HOLMER et al. (1996), sampie horizons D 2090: PIW96X92 (3 VV) and but lacks a distinet apieal proeess eavity and D 2094: PIW96X9.1-9.15, PIW96X79 (72 VV, differs in the loeation of the apieal pits, whieh 23 DV); Tagragra sync1ine, sampie horizon are lateral or anterolateral to the internal TA/MC 38: PIW96X116 (1 ventral) and sampie pedic1e opening in Hadrotreta djagoran and horizon TA/MC 40: PIW96X20.1-20.17, posteriorly in Vandalotreta. Hadrotreta djagor PIW96X30A, PIW96X83 (51 VV, 43 DV) - all an is therefore not assigned to Vandalotreta. Cephalopyge notabilis biozone; Jbel Assadam, The type material of Hadrotreta djagoran sampie horizon D 2080: PIW96X5.1-5.l6, KRUSE 1990, c10sely resembles Kostjubella PIW96X89, PIW96X90 (137 VV, 78 DV) - Ce PoPov et al. 1996 from the Middle Cambrian of phalopyge nota bilis or Ornamentaspis jrequens Kazakhstan in its ventribieonvex shape, in the biozone; Alt Mersid, sampie horizon D 2357: shape of the apieal proeess, the loeation of the PIW96X80 (7 VV) - probably Ornamentaspis apieal pits and in the arrangement of the jrequens biozone; Jbel Arhouri, sampie horizon median buttress and median septum. However, JAR-123.8: PIW96X6.1-6.20, differenees exist in (1) the ventral pseudointer PIW96X30.5-30.6, PIW96X84 to PIW96X88 area of Kostjubella whieh is eatac1ine to apsa (376 VV, 111 DV) - Ornamentaspis jrequens c1ine rather than proc1ine as in Hadrotreta dja biozone. Imperfeetly preserved material from goran, (2) the median ridge of Kostjubella three horizons assigned to Vandalotreta jragilis which is stronger and mueh more e1evated than sp. nov.: Ourika Wawrmas, sampie horizons OW in H. djagoran, and (3) the dorsal eardinal mu II-1: PIW96X74, PIW96X132 (26 VV, 1 DV) sc1e sears of Kostjubella whieh are larger and and OW-7: PIW96X17.5-17.8, PIW96X78 (15 extend more anteriorly than in H. djagoran. The VV, 8 DV); Tinifift, sampie horizon TNF-5: Early Cambrian specimens from glaeial erraties PIW96X93 (1 VV) - all Cephalopyge notabilis of King George Island, Antaretica, assigned to biozone. Hadrotreta djagoran by HOLMER et al. (1996), is Oeeurrenee. Cephalopyge notabilis more-or-Iess identieal with the Australian speei through Ornamentaspis jreqllens biozone. mens, but differs from the type material in Diagnosis. - Shell subeireular to slightly having an apieal proeess with a median depres transversely oval in outline. Pedic1e valve s~on anterior to the internal pedic1e opening. broadly eonieal, its maximum height at the apex. Ventral pseudointerarea proc1ine, poorly defined laterally, divided by distinet inter Vandalotreta fragilis sp. nov. trough. Apieal proeess massive, filling entire apex, with deep apieal proeess eavity that eom Figs. 19,23.8,23.9; Plate 5 prises internal pedic1e opening. Apieal proeess typieally little prominent, defined laterally by E tymolo gy. - Named after the Latin jragi deeply impressed, baeulate vascula lateralia. lis, bri ttle. Foramen not enc10sed in larval shell. Dorsal Holotype. Ventral valve, PIW96X-20.1 valve with broad, short pseudointerarea, whieh (Plate 5, figs. A, D). - TYpe loeality and stratum: bears a transversely elongated tri angular medi Tagragra sync1ine, sampie horizon TA/MC 40, an groove; propareas well developed. Median Jbel Wawrmast Formation, Breche a Micmacca buttress robust, prominent, extending anteriorly. Acrotretoidea (Brachiopoda) from Morocco 55

Description. - Shell subcircular in outline, laterally by deeply impressed, baculate vasclIla on average about 12 % wider than long, up to lateralia. Apical pits also deeply impressed, 3.4 mm in diameter. Transverse axis of plane of located posterior to internal pediele opening, commissural plane deflected dorsaIly. Ornamen mark junction of apical process with the poster tation and dimensions of larval shells poorly ior valve slope. known due to inadequate preservation of apex. Dorsal valve. Dorsal valve gently convex in Nevertheless, some dorsal valves show a pattern lateral profile, with flattened posterolateral of fine pits with slightly varying sizes and a pair sectors in dorsal view. Pseudointerarea wide, of shallow, indistinct grooves elose to the occupies generally well over 50 % of the total posterolateral margins of the larval shell. Later width of the valve. A pair of weIl developed, growth stages with concentric growth lines. anaeline to orthoeline propareas borders the Ventl'al valve. Ventral valve proconical, broad triangular median groove. Width of moderately high, length slightly more than median groove highly variable compared to twice the height; anterior and posterior surfaces width of the entire pseudointerarea, of 37 to 65 more-or-less straight and gently convex or con % of width of pseudointerarea. Median cave, respectively, lateral surfaces typiqllly buttress robust, extends anteriorly and normal straight. Maximum height of ventral valve at ly branches into two fine ridges. Median ridge apex, about 30 to 35 % of the valve length from low, poorly developed, and often invisible; posterior margin. Ventral pseudointerarea originates at about the center of a deltoid area deltoid, poorly defined laterally by a flexure determined by the two distal ridges of median from adjacent valve segments; divided by a buttress and becomes indistinct anteriorly distinct intertrough which slightly broadens ab out 70 % of the total valve length from the dorsally; growth lines across intertrough either posterior margin. Cardinal musele scars of dor barely deflected or absent, in the latter case sal valve small, drop-shaped, diverge anteriorly intertrough occasionally ornamented by nume and commonly determined by a zone of ex rous, fine, ventrally diverging ridges (Pig. 19.3). foliated sheIl; originate immediately anterior to Pe diele foramen immediately below the valve the lateral edges of the median groove; anterior apex, typically elongate, about 30 % higher margin of central musele sc ars at ab out 23 to 32 than wide, varying in size, maximum diameter % of the valve length from posterior margin; no ranges from 75 /lm to 230 /lm (see Discussion central musele sc ars visible. and Fig. 11). Cardinal musele scars broadly Ontogeny. - The development of the separated, elliptical in outline, slightly diverging diagnostic characters of Vandalotreta fragilis is posteriorly. Apical process massive, filling en related to the ontogenetic stage. Juvenile speci tire apex, barely elevated, passes into smooth mens lack the characteristic features, such as an confluence with anterior valve slope; character apical process cavity, a dorsally directed pediele ized by deep, anteriorly broadening apical pro tube, and a dorsal median ridge. cess cavity, which bears the internal pe diele In juvenile specimens, the internal pediele opening. Morphology of apical process cavity opening is located apically within the posterior characterized by semicircular anterior slope valve slope posterior to a semicircular apical and flattened or slightly transversely concave cavity. The apical process is low, barely elevat posterior slope, which converges ventrally to ed, and located anterior to the apical cavity on width of internal pe diele opening. Posterior and the anterior valve slope. In the course of the anterior slopes of apical process cavity separat ontogeny, the apical process becomes thicker ed by two distinct ridges that become obscure and reaches the posterior valve slope to ventrally and terminate dorsally in two gently develop an apical process cavity. Adult speci prominent nodes (Plate 5, fig. M). Internal mens are characterized by a massive apical pro pediele foramen circular in outline, situated cess that fills the entire apex, distinct apical pits elose to the posterior valve slope (Plate 5, figs. and vascula lateralia, and a long, dorsally direct D, M). Pediele ·tube long, gently inelined to ed pediele tube that terminates within a deep posterior valve slope. Apical process defined apical process cavity. A dorsal median ridge as 56 M.Streng weil as a branched median buttress is only ob foramen is thus conjectural. Fig. 11 c1early indi served in large, adult specimens. cates that the variation is enormous even in a Discussion. - The preservation of Vanda single sampie so that diagenetic effects, which laU'eta fragilis sp. nov. is generally insufficient might cause a change in shell thickness and for measurements, because most of the speci consequently in the proportions of the mens, especially the ventral valves, are fragmen foramen, can be exc1uded. If indeed the height tary. Only five complete ventral valves have of the ventral valve directly relates to the been measured. As a consequence, the wide length of the foramen, the widening of the variations of width and length of the foramen foramen would be a result of resorption during can not be referred to certain heights of the ontogeny. ventral valve. A direct dependency between the Remarks. - Juvenile individuals of Vanda height of the ventral valve and the length of the latreta fragilis are similar to juvenile forms of

Plate 5

Vandalotreta fragilis sp. nov. all scale bars 200 11m, except F alle Maßstabsbalken 200 11m, außer F

A) PIW96X20.1; holotype; ventral interior; TA/MC 40. PIW96X20.1; Holotypus; Innenansicht der Ventralklappe; TA/MC 40. B) PIW96X5.5; lateral view of ventral valve; D 2080. PIW96X5.5; Seitenansicht einer Ventralklappe; D 2080. C) PIW96X5.2; posterior view of ventral valve, showing elliptical foramen and narrow intertrough; D 2080. PIW96X5.2; Rückseite einer Ventralklappe mit schmalem intertrough und elliptischem Stielloch; D 2080. D) PIW96X20.1; holotype; dorsal view ofA;TA/MC 40. PIW96X20.1; Holotypus; Dorsalansicht von A; TAIMC 40. E) PIW96X16.9; interior of ventral valve showing deeply impressed apical pits and vascula lateralia; D 257. PIW96X16.9; Innenansicht einer Ventralklappe mit vascula lateralia und tief eingesenkten apical pits; D 257. F) PIW96X16.19; close-up of a foramen; D257; scale bar = 50 11m. PIW96X16.19; Nahaufnahme des Stielloches; D257; Maßstabsbalken = 50 11m. G) PIW96X5.3; exterior of dorsal valve; D 2080. PIW96X5.3; Außenansicht einer Dorsalklappe; D 2080. H) PIW96X9.2; lateral profile of ventral valve; D 2094. PIW96X9.2; Seitenansicht des apikalen Teils einer Ventralklappe; D 2094. I) PIW96X30.6; Sagittal fracture section through apical part of ventral valve, reveals deep apical process cavity, dorsally directed pedicle tube, and thick laminae forming the apical process; JAR-123.8. PIW96X30.6; Querschnitt durch den apikalen Bereich einer Ventralklappe; sichtbar sind die tiefe Höh• lung des apical process, die nach dorsal verlaufende Stielröhre und mächtige laminae, die den apical pro cess aufbauen; JAR-123.8. J) PIW96X6.5; detail of apical region of a dorsal valve, showing well developed pseudointerarea and its multilaminar structure; JAR-123.8. PIW96X6.5; multilaminare Struktur einer dorsalen Pseudointerarea; JAR-123.8. K) PIW96X134.3; lateral view of dorsal interior, showing faint median ridge; D 257. PIW96X134.3; seitliche Innenansicht einer Dorsalklappe mit schwach ausgebildetem median ridge; D 257. L) PIW96X5.9; dorsal interior, showing distally bifurcated median buttress; D 2080. PIW96X5.9; distal geteilter median buttress einer Dorsalklappe; D 2080. M) PIW96X6.7; dorsal view of ventral interior, showing outline of apical process cavity and location of internal pedic1e opening; JAR 123.8. PIW96X6.7; Dorsalansicht einer Ventralklappe; sichtbar sind der Umriß der Höhlung des apical process und die Lage des inneren Stiellochs; JAR 123.8. N) PIW96X5.1; ventral view of extremely large dorsal valve, showing broad median buttress, weIl developed pseudointerarea, and drop-shaped cardinal muscle scars; D 2080. PIW96X5.1; relativ große Dorsalklappe mit breitem median buttress, gut ausgebildeter Pseudointerarea und tropfenförmigen Muskeifeiden; D 2080. Acrotretoidea (Brachiopoda) from Morocco 57 58 M.Streng

Tab. 5: Vandalotreta fragilis sp. nov.; measurements and average dimensions (in microns) of ventral and dorsal valves. Tab. 5: Meßwerte der morphologischen Parameter (in Mikrometer) und statistische Daten der Dorsal- und Ventralklappen von Vandalotreta fragilis sp. nov.

ventral valve L W H Lw L. Lm Wm Lc Wc Le Hf N 5 5 4 5 4 4 4 4 4 5 3 MIN 1280 1520 720 560 520 340 840 520 244 600 660 MAX 1900 2140 900 840 720 520 1120 740 280 1080 820 cr 235.4 230.2 84.9 115.8 82.3 87.3 142.4 116.6 17.4 188.4 87.2 STD.ERROR 105.3 103.0 42.4 51.8 41.1 43.7 71.2 58.3 8.7 84.2 50.3 VAR 55400 53000 7200 13420 6767 7625 20267 13600 304 35480 7600 MEAN 1640 1860 840 742 615 418 1000 640 266 864 760

H L L dorsal valve L W Lw m Wm e We Wß N 19 20 7 17 12 12 14 14 14 MIN 450 520 180 230 290 600 62 460 200 MAX 2260 3471 580 . 1446 752 1694 300 1980 950 cr 496.2 699.8 150.2 335.0 147.5 315.5 74.8 462.0 239.2 STD.ERROR 113.8 156.5 56.8 81.3 42.6 91.1 20.0 123.5 63.9 VAR 246193 489707 22557 112250 21743 99540 5599 213402 57230 MEAN 1254 1493 333 681 509 1058 146 1019 528 GEO.MEAN 1156 1348 307 607 489 1016 130 928 475

'+----- W ------..I

Fig. 10: Location 01 measurements on Vandalotreta fragilis sp. nov.; left, ventral valve right, dorsal valve. Abb. 10: Messungen an Vandalotreta fragilis sp. nov.; links: Ventralklappe rechts: Dorsalklappe. Acrotretoidea (Brachiopoda) from Morocco 59

Vandalotreta sp. A and V. vafra. A shallow which is bisu1cate in outline. The circular inter apical process and a semicircular cavity anterior nal pedicle opening is situated in the posterior to the internal pedicle foramen, which is still part of the apical process cavity, not immediate imbedded in the posterior valve slope, are ly at the posterior valve slope, but separated characteristics of all examined juvenile shells. from it by a faint flexure. The apical pits are As a result, there is no possibility to reliably strikingly deep, located posterolaterally to the distinguish between juveniles of these species. internal pedicle opening and anteriorly to the posterior valve slope. The vasclila lateralia are deeply impressed and diverge anteriorly. The Vandalotl'eta minima sp. nov. mantle canal pattern and the apical process cavity are separated by prominent areas of Plate 6A-H raised shell, immediately anterior to apical pits. Dorsal valve. Dorsal valve gently convex Etymology. - Named after the Latin mini and with slightly dorsally deflected plane of ma, tiny. commis sure in lateral profile. Pseudointerarea Holotype. - Ventral valve, PIW96X28..10 characterized by a tri angular median groove (Plate 6, figs. C, D) - Type locality and stratum: bordered laterally by small anacline propareas. Jbel Arhouri, sampie horizon JAR-0.56 B, Jbel Median buttress distinct, tapers anteriorly and Wawrmast Formation, Breche a Micmacca may bifurcate into two faint ridges. Median Member, eastern Anti-Atlas; Cephalopyge nota septum deve10ped as a faint ridge, which is bilis biozone. generally indistinct. Cardinal muscle scars of Material studied. - 50 ventral valves dorsal valve drop-shaped, gently diverge ante (VV) and 63 dorsal valves (DV) from two riorly and are determined by a zone of exfoliat localities; most of them fragmentary; Jbel ed shell. Arhouri, sampie horizon JAR-0.56 B: Discussion. - Only a few ventral valves of PIW96X28.3-28.32; PIW96X30.3, PIW96X73 the two sampies show the characteristic (47 VV, 63 DV); Tizi n'Tichka, sampie horizon features of Vandalotreta minima sp. nov. de D 2055: PIW96X77, PIW96X129 (3 VV); - both scribed above. The other ventral valves are Cephalopyge nota bilis biozone. either juvenile or insufficiently preserved and Occurrence. - Cephalopyge notabilis bio thus tentatively assigned to Vandalotreta mini zone. ma sp. nov. The dorsal valves show no signifi Diagnosis. Shell relatively small and cant difference to those of Vandalotreta fragilis subcircular in outline. Pedicle valve conical with sp. nov. However, the propareas appear sm aller steep procline pseudointerarea, poody defined and the median buttress is less robust. A medi laterally and bisected by weekly developed an septum has been observed only in a single intertrough. Apical process massive, barely dorsal valve, which closely resembles those of elevated above valve floor, with typical deep V. fragilis. Thus the characters of the dorsal apical process cavity, which is bisu1cate in out valve of V. minima are only tentative. line (Pig. 12C); apical pits strikingly deep, Although Vandalotreta minima is known posterolaterally to internal pedicle opening. with certainty from a few fragmentary ventral D escription. - Shell subcircular in outline, valves, the characteristic apical process indi slightly wider than long. Larval shell unknown, cates reference to Vandalotreta. Vandalotreta due to imperfect preservation. minima differs from V. fragilis in having (1) Ventl'al valve. The ventral valve is pro co deeper and more distinct apical pits in a some nical, with a poody defined, steep pseudointer what more anterior position, (2) an apical pro area bearing an intertrough that is perforated cess cavity with a more concave posterior slope, apically by a small, elliptical to subcircular (3) relatively larger nodes laterally to the apical foramen (see Discussion). The apical process is process cavity, (4) an internal pedicle opening, massive and fills the entire apex. It is character which is not as close to the posterior valve ized by a broad, deep apical process cavity, slope as in Vandalotreta fragilis, and (5) a con- 60 M.Streng siderably smaller foramen. The characters (1) Vandalotreta vafra MERGL 1988 trough (4) also serve to distinguish V minima from V vafra. In addition, V. minima differs Material. -13 ventral valves and 14 dorsal from V. vafra in having a more massive and less valves from the type locality, Yagour inlier, prominent apical process. High Atlas; early Middle Cambrian, probably The modest size of the foramen of all speci Cephalopyge notabilis biozone. The material mens of V minima, which is possibly a specific was put to the author's disposal by Drs. L. E. character, is problematic, because of possible Holmer, Uppsala, and M. Mergl, Plzefl. Photo diagenetic effects (such as limonitization) that graphs of Vandalotreta vafra will be published may cause a feigned sm all size (compare Fig. by HOLMER & MERGL (in prep.). 11). Furthermore, most of the measured speci Diagnosis. Shell subcircular in outline, mens are juvenile and bear a foramen, which width slightly exceeding length. Ventral valve may reflect the ontogenetic stage. As a con steeply proconical, highest point at the apex, sequence the foramen is smaller than in adult which slightly overhangs flat pseudointerarea. valves. Ventral interior with prominent apical process

Plate 6

Vandalotreta minima sp. nov. sampie horizon JAR-0.56 B Probenhorizont JAR-0.56 B

A) PIW96X28.3; lateral profile of ventral valve; scale bar = 200 11m. PIW96X28.3; Seitenansicht einer Ventralklappe; Maßstabs balken = 200 11m. B) PIW96X28.3; posterior view of A; scale bar = 200 11m. PIW96X28.3; Rückseite von A; Maßstabs balken = 200 11m. C) PIW96X28.1O; holotype; lateral view of apical process cavity, showing deeply impressed apical pits; scale bar = 100 11m. PIW96X28.1O; Holotypus; Seitenansicht der Höhlung des apical process und der tief eingesenkten apical pits; Maßstabsbalken = 100 11m. D) PIW96X28.1O; holotype; stereo-pair of ventral interior; scale bar = 200 11m. PIW96X28.1O; Stereobild der Innenseite des Holotypus; Maßstabsbalken = 200 11m. E) PIW96X28.4; ventral interior of juvenile valve; sc ale bar = 100 11m. PIW96X28.4; Innenansicht einer juvenilen Ventralklappe; Maßstabsbalken = 100 11m. F) PIW96X28.12; detail of interior apical region of dorsal valve; scale bar = 200 11m. PIW96X28.12; Pseudointerarea und median buttress einer Dorsalklappe; Maßstabsbalken = 200 11m. G) PIW96X134.4; oblique lateral view of dorsal valve, showing faint median ridge; scale bar = 200 11m. PIW96X134.4; Seitenansicht einer Dorsalklappe mit distal geteiltem median buttress und schwach aus gebildetem median ridge; Maßstabs balken 200 11m. H) PIW96X28.5; exfoliated ventral valve in ventral view; scale bar 200 11m. PIW96X28.5; Ventral ansicht einer korrodierten Ventralklappe; Maßstabsbalken = 200 11m.

Vandalotreta sp. A sampie horizon ATZ-2; all scale bars = 500 11m. Probenhorizont ATZ-2; alle Maßstabsbalken = 500 11m

I) PIW96X14.6; oblique view of ventral interior showing strongly elevated apical process. PIW96X14.6; Innenansicht mit auffällig erhabenem apical process. J) PIW96X14.6; lateral profile of ventral valve; note dorsal extension of apical process. PIW96X14.6; Seitenansicht der Ventralklappe; beachte die relativ große Ausdehnung des apical process nach dorsal. K) PIW96X14.6; detail of ventral interior, showing location of apical pits and apical process in anterior view. PIW96X14.6; Frontalansicht des apical process und der apical pits. Acrotretoidea (Brachiopoda) from Morocco 61 62 M.Streng

35 A 35 B

30 30 ~ JAR-0.568 (n=11) 25 IE] JAR-123.B (n=43) 25 others (n=30) E 20 o § 20 ::I o 0 Ü Ü 15 15

10 10

0 40 length of foramen [~mJ width of foramen [~mJ

130 C

120 0 00 0 E q, p 2;110 cß () 0 0 c: Elo E100 o 0 ~a<§oo 00 ~ 90 0 ,g ~~ CI) 0 o 0 '0 80 0 08> 0 00 "' " JAR-0.568 Ü 70 0 .~ o JAR-123.B 60 S 0 0 0 o others 50

40 40 60 80 100 120 140 160 180 200 220 240 260

length of foramen [~mJ Fig. 11: Comparison of measurements on the pedicle foramen of Vandalotreta minima sp. nov. (sampie JAR O.56B) and Vandalotreta fragilis sp. nov. (sampie JAR-123.8 and others). A, frequency distribution of length of foramen. B, frequency distribution of width of foramen. C, scattergram of length of foramen vs. width of foramen. All measurements in microns. Abb.11: Vergleich von Messungen an Stiellächern von Vandalotreta minima sp. nov. (Probe JAR-O.56B) und Vandalotreta fragilis sp. nov. (Proben JAR-123.8 und andere). A, Häufigkeitsverteilung der Stiellochlänge. B, Häufigkeitsverteilung der Stiellochbreite. C, Verhältnis der Länge zur Breite des Stielloches. Alle Messun gen in Mikrometer.

bearing internal pedicle opening. Internal Ventral valve. Ventral valve conical, with a pedicle opening located in posterior part of steeply procline pseudointerarea; apex slightly sagittally elongated apical process cavity. extends posteriorly and overhangs pseudointer Dorsal valve slightly convex, with vestigial area. Pseudointerarea flat in lateral profile and median ridge and wide median groove. thus distinguishable from adjacent valve SUl' Description. - Shell subcircular in outline face; poorly divided by indistinct, shallow con with the width slightly greater than length cave zone. Foramen minute, subcircular to (average length/width ratio ab out 0.91; N = 9). slightly elliptical in outline. Ventral interior Ornamentation of larval and postlarval shell characterized by raised apical process which unknown. Dorsal larval shell occasionally me bears internal pedicle opening. Internal pedicle dially divided by shallow, indistinct groove. opening located in posterior part of a sagittally Maximum width of both valves at ab out mid elongated, bilobate and shallow apical process length. Growth lines of postlarval shell poorly cavity. Apical pits at junction of apical process preserved, generally not visible. and posterior valve slope, posterolaterally to Acrotretoidea (Brachiopoda) from Morocco 63 internal pedic1e opening. Cardinal musc1e sc ars from the posterior mm·gin. Anterior and lateral not strongly marked, their outline unknown. surfaces straight or nearly so, posterior surface DOl'sal valve. Dorsal valve gently convex, is gently convex. Pseudointerarea narrowly with slightly dorsally deflected plane of deltoid, divided by intertrough and poorly de commis sure in lateral profile. Pseudointerarea fined laterally. Outline and size of foramen un wide but short, occupies about 41 to 52 % of known due to the imperfectly preserved apex, total width of valve; wide, tri angular median but apparently small and immediately posterior groove laterally defined by small, often indis to apex. Ventral interior domina ted by a conspi tinct, anac1ine propareas. Dorsal interior with cuous, prominent apical process, plugs the en barely elevated median buttress that may ex tire apex and forms a robust ridge that extends tend a short distance anteriorly, and vestigial, dorsally to about 60 % of valve height from generally absent median ridge. Cardinal musc1e apex. Deep apical process cavity with concave scars small, drop-shaped, diverge anteriorly, anterior slope and flattened lateral and poste occupy about half of total width and extend to rior slopes, the latter two separated by two about 24 % of total length from posterior indistinct ridges. Shape of internal pedic1e margin. opening and its position inside apical process Discussion. - Vandalotreta vafra MERGL cavity not visible. Lateral sides of prominent 1988, is best distinguished from other species of ridge almost vertical and parallel, slightly Vandalotreta by the shape of its apical process diverging anteriorly, defined by slight.1y diverg and the outline of the apical process cavity. In ing vascula lateralia; anterior side developed as V vafra, the apical process is much more gently concave, relative1y steep slope which prominent than in Vandalotreta fragilis sp. nov. passes into smooth confluence with the anterior and Vandalotreta minima sp. nov. The apical valve slope at about midlength. Apical pits em process cavity of V vafra is shallow, bilobate bedded in the posterior valve slope dorsally to and sagittally elongated in contrast to that of V the ridge of apical process. Cardinal musc1e fragilis and V minima sp. nov., which are more scars poorly preserved, elliptical in outline, di profound and more circular in outline (Fig. 12). verge posteriorly, appear to have been primari The elevation of the apical process of V. vafra is ly areas of thickened shell. Valve covered with quite similar to Vandalotreta sp. A. However, irregularly spaced growth lines. Larval shell un the apical process in V. sp. A extends more known. dorsally than in V vafra. Discussion. The sampie in which Vanda Remarks. - The studied material of Vanda lOU'eta sp. A was found, yielded only few other lotreta vafra is recrystallized and therefore the imperfectly preserved specimens of Vandalotre ornamentation of the external surface is obso tao The dorsal valves in this sampie do not show lescent. For the same reason, the low elevation distinctive differences so that the dorsal valve of the median buttress and the sm all size of the of Vandalotreta sp. A is not known but most propareas are obviously of secondary origin. probably similar to that of other species of Van dalotreta. Vandalotreta sp. A is distinguished from Vandalotl'eta sp. A other forms of Vandalotreta by its extremely large apical process and the position of the Plate 6I-K apical pits. Nevertheless, the shape of the apical process cavity is somewhat similar to that of Ma terial. - Single ventral valve, nearly Vandalotreta fragilis sp. nov. (Fig.12). complete; Akka Tzem, sampie horizon ATZ-2; Cephalopyge notabilis biozone; PIW96X14.6. D escription. Ventral valve proconical, 5. Quantitative analyses subcircular in outline, 3.1 mm long, 3.3 mm wide, and 1.9 mm high, with highest point at the Morphometric measurements have been per apex. Apex located at 34 % of valve length formed on all described species to rationalize 64 M.Streng

,, c D E Fig. 12: Schematic drawings of different species of Valldalotreta. Upper row: Outlines of apical process cavity and location of the internal pedic1e opening. Apical pits indicated by crosses. Lower row: Cross sections of the same species (A and B with juvenile shell). A, Valldalotreta fragilis sp. nov. B, Valldalotreta vafra MERGL 1988. C, Vandalotreta minima sp. nov. D, Valldalotreta sp. A. E, Hadrotreta primaeva (WALCOTI 1902) (for comparison). All not to scale. Abb. 12: Schematische Skizzen verschiedener Arten von Vandalotreta. Obere Reihe: Umrisse der Höhlung des apical process und Lage des internen Stieloches. Lage der apical pits sind durch Kreuze gekennzeichnet. Untere Reihe: Entsprechende Querschnitte der gleichen Arten (bei A und B sind zusätzlich Querschnitte von juvenilen Individuen dargestellt). A, Vandalotreta fragilis sp. nov. B, Vandalotreta vafra MERGL 1988. C, Vandalotreta minima sp. nov. D, Vandalotreta sp. A. E, Hadrotreta primaeva (WALCOTI 1902), (zum Ver gleich). Darstellungen nicht maßstabsgetreu.

~II-----W------+~.,, "","I---~--Wm ~,: ,11 w r- I: -----u:------l-i~l-l-t fjJLrr ) ~____::::::J Fig. 13: Schematic drawings of a dorsal (left) and a ventral valve (right) illustrating locations of measure ments used for statistical analyses. Legend: L, length; W, width; H, height; Lw' length at maximum width; L , p' , length of dorsal pseudointerarea; W width of pseudointerarea; Lm length of cardinal musc1e scars; W;, width of cardinal musc1e sc ars. Abb. 13: Schematische Skizzen einer Dorsal- (links) und einer Ventralklappe (rechts) zur Darstellung der gemessenen Größen. Legende: L = Länge; W = Breite; H = Höhe; Lw = Länge der maximalen Breite; L =

Länge der dorsalen Pseudointerarea; W p = Breite der Pseudointerarea; Lm = Länge der Muskeleindrücke; W m = Breite der Muske1eindrücke.

morphologie variations. Different sampies were larval shells are poorly represented, and the se taken into aeeouht to eharaeterize the variabili leetion of the measured speeimens is biased be ty of the speeies. However, sm all speeimens and eause normality of the data was not obtained in Acrotretoidea (Brachiopoda) from Morocco 65 all cases. As a consequence, the regression ana range to a certain size is indicated though, lyses are not significant statistically and have to albeit the deviation from the ca1culated graph be regarded as of descriptive character. They appears to be mare distinct in valves of medium formally describe relationships between bi and large sizes. However, the data are biased by variate data. The data pairs are generally best the preference in preservation of larger speci described by least-squares regressions (simple mens and by the selection for measurement. regressions) following the general equation y := Correlation of additional data pairs, such as

:= := ) a + bx (with a intercept of line on y where x length of musc1e scars (Lm vs. width of musc1e := ) 0; b slope of curve). Some cases suggest a scars (Wm)' ar length of pseudointerarea (Lp )' polynomial regression (following the equation vs. width of pseudointerarea (Wp show an in 2 y := a + bx + cx ). The retained function para crease in the mean variation of the data, al meters and statistical values are shown in Table though a certain dependency should be expect 6. Abbreviations of measurements used as ed in this case. Those additional data pairs are variable (x) and dependent variable (y) are exemplarily depicted for Monophthalma cf. M. given in Fig. 13. eggegrundensis (Fig. 15). Relationships between height (H), length and width of musc1e scars Results (Lm, W m)' respectively, indicate an allometric growth described by second order polynomial Ceratretids. - The retained scattergrams regressions. However, more data are needed, and trendlines are similar far all three studied especially of juvenile specimens, to confirm ceratretid species and are therefore discussed allometric growth. This is also suggested by together. The number of individuals, on which scattergrams, whieh show the relation between ) the various measurements are based, is given in height (H) and length of musc1e sc ars (Lm and Tab. 6. Variations in the number of individuals a positive allometric growth of the trendline for the different measurements are due to im (Fig.15D), that is implausible. perfect preservation, which did not allow the Comparison of scattergrams of the different entire set of measurements far all of the speci ceratretid species should permit to distinguish mens. The measurements are based for Mo between different genera. However, length vs. nophthalma cf. M. eggegrundensis (WIMAN width and length vs. height ratios of all genera 1903) on valves from nine localities and far Al plot a narrow and similar pattern, which does l110hadella braunae gen. et sp. nov. on valves not permit differentiation between individual from eight localities. In contrast, Acanthatreta genera. Differences in the scattergrams are meiwirthae gen. et sp. nov. is only represented shown, e. g., for length vs. length of musc1e by valves from a single sampie. scars, or width vs. width of musc1e sc ars ratios, The retained regression lines indicate, for whieh indieate a high mean variation though, the larger part, linear relationships between the and are therefore not suitable for differentiation. data pairs, indicative for isometrie growth (Fig. Acrotretids. - The statistieal study on the 14; using the length L as variable and width W, acrotretid species Vandalotreta fragilis sp. nov. height H, and length at maximum width Lw as and Tingitanella calamisca gen. et sp. nov. is dependent variables). However, it should be based on only few complete valves. Vandalotre noted that the data pair L-Lw' which indieates ta fragilis is a quite abundant element of the the best correlation, c1early is dependent. The examined faunas, but the majority of valves is relation of parameters remains constant during fragmented, and complete valves are rare. The ontogeny, because measured larval shells fit in small number of measured valves of Tingitanel to the linear relationship (Figs. 14A and 14B). la calamisca is also due to the rareness of the Further characteristic far the ceratretids is the species. Because of the sm all number of indivi relatively wide scatter of nearly all data pairs. duals, no statistics has been computed far both The correlation of the totallength of the valve species. versus the respective width plots a wide range All ca1culated data pairs are best described of the data pairs. No relation of the observed by linear relationships that indicate isometric 66 M. Streng

Tab. 6: Statistical values for linear relationships between the various measurements of dorsal (left columns) and ventral valves (right columns) of the ceratretid specimens calculated for least square regression. A, MOllophthall11a cf. M. eggegruildellsis (WIMAN 1903). B, Acanthatreta meiwirthae gen. et sp. nov. C, Almaha delta bralillae gen. et sp. nov. Legend: x, variable; y, dependent variable; N, number of individuals; R2, squared Pe ars on coefficient; (f, standard error; a and b, function parameters, with a, intercept of line on y where x = 0; b, slope of line. Tab. 6: Regressionswerte zu den gemessenen Parameter der ceratretiden Arten (links: Dorsalklappen; rechts: Ventralklappen). Alle Regressionsgeraden verlaufen linear und folgen der allgemeinen Gleichung y = a + bx. A, Monophthalma cf. M. eggegrzllldensis (WIMAN 1903). B, Acallthatreta l11ehvirthae gen. et sp. nov. C,All11ohadelta brallllae gen. et sp. nov. Legende: x = Regressor; y = Regressand; N = Anzahl der Individuen; R2 Bestimmtheitsmaß; (f = Standard fehler; a und b = Funktionsparameter, mit a = konstantes Glied und b = Steigung der Regressionsgeraden.

dorsal ventral

x y N R2 er a b x y N R2 er a b A L W 104 0.957 81.43 37.02 1.15 L W 70 0.931 93.03 74.32 1.11 L H 84 0.623 41. 78 40.57 0.21 L 60 0.637 75.24 1.74 0.40 L Lw 104 0.959 35.38 20.28 0.51 L 60 0.932 41.99 13.41 0.49 L 1m 69 0.717 52.02 73.85 0.32 L 46 0.644 51.73 61.44 0.26 W Wm 70 0.826 79.39 35.94 0.58 W Wm 43 0.802 74.75 98.44 0.53 W H 81 0.648 40.43 28.97 0.18 H 60 0.698 68.60 -48.01 0.37 1m Wm 68 0.768 97.91 42.61 1.77 42 0.560 111.51 295.01 1.51

Lp Wp 76 0.659 107.09 167.07 3.97 57 0.440 82.07 35.45 0.29

Lm Wm 68 0.768 97.91 42.61 1.77 43 0.761 81.15 162.23 0.58

B L W 38 0.959 63.44 114.35 1.11 L W 32 0.873 90.91 128.75 1.13 L H 25 0.698 41.76 41.19 0.20 L H 32 0.584 73.21 59.46 0.42 L Lw 38 0.943 36.54 6.31 0.54 L Lw 26 0.867 35.26 113.58 0.42

L 1m 15 0.725 64.40 80.24 0.37 W Wp 26 0.661 61.90 -8.61 0.33

W Wm 12 0.705 95.74 138.09 0.54 W' H 30 0.610 68.63 37.66 0.35 W H 25 0.752 37.87 13.04 0.19

C L W 94 0.863 95.15 196.04 1.07 L W 47 0.912 80.62 74.14 1.17 L H 59 0.669 32.79 51.49 0.22 L H 35 0.812 38.27 -2.64 0.39 L Lw 93 0.914 38.79 -14.20 0.56 L Lw 45 0.928 28.89 52.67 0.46

L Lm 69 0.785 49.62 25.98 0.41 L 1m 26 0.659 55.83 26.68 0.34

W Wm 70 0.893 72.84 -220.22 0.80 W H 36 0.769 41.80 -6.98 0.32

W H 59 0.687 31.87 42.24 0.19 W Wm 25 0.839 94.95 -94.27 0.70

1m Wm 72 0.789 102.24 9.83 1.80 1m Wm 24 0.865 85.12 -11.16 2.18

Lp Wp 70 0.323 138.19 327.53 2.97 L Wp 42 0.694 44.92 78.81 0.29 Lm Wm 72 0.789 102.24 9.83 1.80 L Wm 25 0.818 100.80 -82.49 0.87

growth. In contrast to the ceratretids, the in the dorsal valve of Vandalotreta fragilis are scattergrams for the acrotretid species only apparently better correlated than in the cera show a slight me an variation for length vs. tretids (Pig. 16E). Linear relationships are also width and length vs. height ratios. In addition, indicated for the width of the ventral valve of length and width 'of the cardinal musc1e sc ars as Tingitanella calamisca correlated with the dis weH as length and width of the pseudointerarea tance between the posterior margin of the valve Acrotretoidea (Brachiopoda) fram Moracco 67

A B 2400 2400 2200 2200 2000 2000 ° UH ° UH 1800 [[] 1800 [[] 1600 • U 1600 · 1400 1400 1200 1200 1000 1000 800 800 600 600 400 400 200 200 0 200 400 600 800 1000 1200 1400 1600 1800 2000 0 200 400 600 800 1000 1200 1400 1600 1800 2000 len9th L [~mJ len9th L [~mJ C D 2000 2400 1800 2200 2000 1600 ° UH 1800 ° UH 1400 [[] [[] • U 1600

1000 0 1200 ro 800 1000 o. 800 600 c c 600 400 c 400 ce 200 200

200 400 600 800 1000 1200 1400 1600 1800 200 400 600 800 1000 1200 1400 1600 1800 2000 len9th L [~mJ len9th L [~mJ E F 2000 2200 '0 1800 2000 0 0 00 1600 ° UH 1800 ° UH 1600 1400 [[] i9 00 [[] o SQ • U • U 1400 1200 000 1200 1000 1000 800 800 600 600 400 400 200 200

200 400 600 800 1000 1200 1400 1600 200 400 600 800 1000 1200 1400 1600 1800 2000 len9th L [~mJ len9th L [~mJ Fig. 14: Bivariate scattergrams for standard measurements on the Moraccan Ceratretidae (left column, ventral valves; right column, dorsal valves). A, B, Monophthall11a cf. M. eggegrundensis (WIMAN 1903). C, D, Acanthatreta l11eilVirthae gen. et sp. nov. E, F, Almohadella brazmae gen. et. sp. nov. For legend see Fig. 13. Abb. 14: Bivariate Streudiagramme der morphologischen Parameter der marokkanischen Ceratretiden (lin ke Spalte: Ventralklappen; rechte Spalte: Dorsalklappen) A, B, Monophthalma cf. M. eggegrundensis (WIMAN 1903). C, D, Acanthatreta meilVirthae gen. et sp. nov. E, F, All110hadella brallnae gen. et. sp. nov. Legende in Abb. 13.

and apex (La)' and with the length at the maxi shown in the length vs. height ratio. mum width (L,J In Fig. 16A, the measurements performed on the single valve of Vandalotreta sp. Aare 6. Shell structure plotted in the scattergram of Vandalotreta fragi !is. The data for Vandalotreta sp. A were not in Introduction. - Details of the acrotretoid cluded into the calculation of the trend line so shell structure are known from such studies as that the difference between the two species is by POULSEN (1971), HOLMER (1989), USHATINS- 68 M.Streng

1600 A 1400 B o 1400 o 0

1200

1000

BOO 600

600 400

400 200

200

0 ·200 f---,~~~~~-~~~~-~~~~ 0 100 200 300 400 500 600 700 800 0 50 taO 150 200 250 300 350 400 450 Lm - Lp [~mJ helght H [~mJ

1400 C 1400 0

1200 1200

1000 1000 800 800 o 0 600 000 0 600 OO 400 o 0 "" 400 o 00 0 61 200 o~ 0 200

·200 h~~~....-,~-.-~...---...---,--r--~-r---.-,- 200 400 800 800 1000 1200 1400 1600 1800 2000 100 200 300 400 500 600 700 800 900 1000 length L [~mJ helght H [~mJ

Fig. 15: Bivariate scattergrams of MOllophthalma cf. M. eggegrzllldensis (WIMAN 1903). A, B, dorsal valve. C, D, ventral valve. For legend of correlated data pairs see Fig. 13. Abb. 15: Bivariate Streudiagramme von MOllophthalma cf. M. eggegrundensis (WIMAN 1903). A, B, Dorsal klappe. C, D, Ventralklappe. Legende in Abb. 13.

KAYA (1990, 1994), and WILLIAMS & HOLMER ology was followed by WILLIAMS & HOLMER (1992). According to HOLMER (1989), three (1992) and USHATINSKAYA (1994). However, different shell layers may be distinguished in USHATINSKAYA (1994) defined an additional phosphatic brachiopods: a primary, a secondary, type that has a septate microstructure. Accor and, occasionally, a tertiary 01' inner layer. The ding to USHATINSKAYA (1994), columnar de primary layer is an extremely thin granular velopment of the secondary layer is an an sheet (less than 1 f.Im in acrotretoids according cestral character and typieal for many Early to HOLMER 1989; 2-5 f.Im according to USHA and Middle as weIl as some Late Cambrian TINSKAYA 1994) and generally not preserved. genera. A camerate secondary layer is quite The individual layers are termed laminae if common in Ordovician acrotretoids, but rare in they are thicker and lamellae if they are thinner Middle Cambrian genera. It is only known from than 4 f.Im. Furthermore, HOLMER (1989) intro Anabolotreta ROWELL & HENDERSON 1978, duced the terms "columnar layer" and "came Rhondellina ROWELL 1986, and Kotylotreta rate layer", to distinguish between lamellae KONEVA 1990. This characteristic feature of the connected by minute, hollow columns, and three genera led USHATINSKAYA (1994) to intro lamellae connected by walls that form irregular duce the new family Anabolotretidae, which is polygonal chambers, respectively. He also characterized by a camerate secondary layer. determined three morphologie types of calcium The septate layer type is represented in a single phosphate: (1) granular apatite, (2) acicular genus (Kotuyotreta USHATINSKAYA 1994) from apatite, and (3) cryptocrystalline calcium phos the Late Cambrian of northern Siberia. phate (CCP), the former two of whieh show In contrast to the acrotretids, the shell preferred orientations of the c-axis. This termin- structure of the ceratretids is poorly known. Acrotretoidea (Brachiopoda) from Morocco 69

A ValldalolrelaJragilis sp. nov. (ventral valve) B Tingitallella calamisca gen. et sp. nov. (ventral valve) 3500 1200

3000 ro-uw-l 1000 LIW ~ oUH 2500 [[] '00 " LJL", 2000 111 .. ' 600 1500 .... 400 1000

500 200

500 1000 1500 2000 2500 3000 3500

length L [~ml length L [~ml

C ValldalolrelaJragilis sp. nov. (dorsal valve) D Tillgitallella calamisca gen. et sp. nov. (dorsal valve) 3000 1600

1400 LIW 2500 oUH oUH 0 1200 [[] 2000 [[] " LJL", " LJL", 1000 0 1500 6'S '00 600 1000 400 500 200~~~=== °0F-~20TO--4~00~6~00~'~0-0~1~00-0~1-20~0~1-4rOO--16~00~1'~0~0~20~0~0~2~20~0~2~400 200 400 600 '00 1000 1200 1400

len9th L [~ml len9th L [~ml

E ValldalotretaJragilis sp. nov. (dorsal valve) F Tingifunella calami.\'ca gen. et sp. nov, (ventral valve) 2200 1200

2000 0 Lmfflm I I 1000 \0 W~a I ~:~~ 0 YWp oWIL" 1400 '00 0 1200 0 600 1000 00

'00 400 600 400 200 200

100 200 300 400 500 600 700 '00 1000 1200 Lm . Lp [~ml width W [~ml Fig. 16: Bivariate scattergrams of measurements on Vandalotreta fragilis sp. nov. (left column) and Tingita nella calamisca gen. et sp. nov. (right column). A, B, F, ventral valves, C, D, E dorsal valves of respective species. Filled signs in A refer to Vandalotreta sp. A. All measurements in microns. For legend of correlated data pairs see Fig. 13. Abb. 16: Bivariate Streudiagramme der morphologischen Parameter von Vandalotreta fragilis sp. nov. (linke Spalte) und Tingitanella calamisca gen. et sp. nov. (rechte Spalte). A, B, F, Ventralklappen, C, D, E Dorsal klappen der jeweiligen Arten. Gefüllte Symbole in A beziehen sich auf Vandalotreta sp. A. Alle Messungen in Mikrometer. Legende in Abb. 13.

Only WILLIAMS & ROWELL (1965, H75, H78) herein has not been studied in detail. However, mentioned details of Keyserlingia (= Clistotre a few characteristic features have been observ ma, ROWELL 1965). They distinguished an outer ed. and an inner layer (= secondary and tertiary A primary layer is preserved in many speci layers of HOLMER 1989) that were secreted by mens of Vandalotreta fragilis. It forms the orna the periphery of the mantle and the remainder mentation of the external shell surface, such as of the out er epithelium, respectively. the pitted surface of the larval shell, concentric The Moroccan material. - The shell fila, and a pattern of smooth, dorsally converg structure of the Moroccan genera described ing ridges of the intertrough (Figs. 19.1, 19.3). 70 M.Streng

However, the primaI'Y layer was not observed less interrupted distally (Figs. 17.5, 17.8). The in sagittal section, and its precise thickness is secondary layer is represented by the columnar unknown. The secondary layer is weIl develop type (sensu HOLMER 1989). The lamellae are ed and forms, in contrast to the majority of connected by hollow columns of 2-3 f.lm in dia acrotretoids (HOLMER 1989), all of the internal meter. The central canal of a column may either morphologic structures, because Vandalotreta terminate at the lamina 01' extend into a column fragilis apparently lacks a tertiary layer (Fig. of the following lamina, resulting in a canal 19.2). The absence of a distinctly developed system that may intersect severallaminae (Fig. tertiary layer and the presence of a columnar 17.2). In contrast to Vandalotreta fragilis, a secondary layer that forms all internal morpho tertiary layer is deve10ped in the ceratretid logie structures were also described for the specimens. If recognizable, the tertiary layer Middle Cambrian Prototreta (HOLMER 1989). consists of massive, isotropie calcium phosphate These features probably are ancestral charact without visible structures. (Figs. 17.7,18.1,18.4). ers of the acrotretoids as previously suggested The internal morphologic structures of the by USHATINSKAYA (1994). Moroccan ceratretid specimens are formed by The individual lamellae of the secondilry the tertiary layer. An increase in thickness at layer of Vandalotreta fragilis are connected by elevated morphologie structures, such as the numerous columns aligned perpendieularly to median buttress and cardinal musde scars, is the surfaces of the lamellae. They form laminae obtained by a wedging-in of additionallaminae of varying thickness (up to 90 f.lm in the apical (Figs.18.2 and 17.6). Fig.17.6 shows the abrupt, region). Figs. 19.5 and 19.6 show fracture sec late ontogenetic increase in thickness of the tions through the apical region that reveal the median buttress by a single lamina. Laterly wedging-in of thick columnar lameIlae, respons formed laminae are distinctively thinner and ible for the high stability and consistency of the accentuate the lateral sides of the median apical part of the ventral valve. The single buttress, resulting in the two anteriorly diverg columns are hoIlow, up to 4 f.lm in diameter, and ing ridges (see Description of Monophthalma bear a central canal of 1 to 2 f.lm in diameter cf. M. eggegrundensis) .. (Fig. 19.4). The absence of a weIl developed tertiary layer may explain the high grade of fragmentation of V. fragilis. However, the inter 7. Evidence tor predation trom nal surface of V. fragilis is apparently covered boreholes by a thin layer that drap es the secondary layer (arrow in Fig. 19.2). This thin layer may either Boreholes in phosphatic shells have been re represent an obsolescent tertiary layer 01' an ported by various authors, such as MILLER & ancestral state of the typical tertiary layer, SUNDBERG (1984), CHATTERTON & WHITEHEAD which is developed in the majority of acro (1987), HOLMER (1989) and CONWAY MORRIS & tretoids. Morphologic changes during the BENGTSON (1994). However, only two of them phylogeny of the early Cambrian acrotre dealt with Cambrian organisms and representa toids suggests an increase in thiekness and, tives of the Acrotretoidea. simultaneously, growing stability. The studied material from Morocco yielded In the ceratretids Monophthalma gen. nov. 9 sampies from 72 sampie horizons with deal' and Almohadella gen. nov., the primary layer is evidence for boreholes. Altogether, only 53 occasionally observed. It forms, as in Vandalo valves out of more than 4300 (1.2 %) bear in treta fragilis, the ornamentation of the external debatable borings. These valves vary in their shell surface whieh comprises regularly de frequency within the different sampies as veloped elements of ornamentation, such as shown in Tab. 7. concentric fila and the larval pits. The con Five different types of boreholes have been centrie fila, which create the typieal ornamenta observed: tion of the post-larval sheIl, are interrupted into (1) Irregularly round, relatively large holes, sets of drapes proximally to the larval sheIl, but interpreted as primary circular boreholes, which Fig. 17: 1-3, PIW96X12.6; undeterminable ceratretid. 1, detail of 2, showing granular texture of columnar and lamellar surfaces. Locally the primary orientation of crystallites is preserved; orientation of the c-axis is perpendicular to the respective surface (arrow); x2220. 2, detail of 3, showing interlaminar extension of columns; xll10. 3, exfoliated fragment showing multiple columnar layers; x220. 4-10, MOllophthalma cf. M. eggegrzllldellsis (WnvIAN 1903). 4, PIW96X2.2; detail of recrystallized secondary layer in apical region of a ventral valve; pits on surface are a result of primarily columnar laminae; x460. 5, PIW96X1.7; detail of ex ternal surface of a dorsal valve showing concentric fila; x120. 6, PIW96X13.5; transverse section through median buttress, showing thickening of shell by wedging-in of additional laminae; x220. 7, PIW96X1.4; fracture through anterolateral region of a ventral valve showing partly recrystallized secondary and probably primary layer (a) as weil as relatively thin, recrystallized tertiary layer (b); x385. 8, PIW96X13.1; external surface showing primary layer ornamented with concentric fila, which are interrupted into sets of drapes; x50. 9, 10, exfoliated apical regions showing medially bisected internal mold of the ?Iarval shell. 9, PIW96X25.9; ventral valve; x50. 10, PIW96X27.5; dorsal valve; x90. Abb.17: 1-3, PIW96X12.6; unbestimmbares Bruchstück eines Ceratretiden.1, granulare Struktur der colum naren und lamellaren Oberflächen (Ausschnitt von 2). Lokal ist die primäre Orientation der Kristallite zu erkennen, deren c-Achse senkrecht zur jeweiligen Oberfläche angeordnet ist (Pfeil); x2220. 2, Säulen unter schiedlicher laminae gehen teilweise ineinander über (Ausschnitt von 3); x1110. 3, korrodierte Klappe mit zahlreichen columnaren Lagen; x220. 4-10, Monophthalma cf. M. eggegrulldensis (WIMAN 1903). 4, PIW96X2.2; Detail der rekristallisierten sekundären Schicht im apikalen Bereich einer Ventralklappe; die Löcher auf der Oberfläche werden als Relikte eines primär columnaren Aufbaus der laminae gedeutet; x460. 5, PIW96X1.7; Auschnittsvergrößerung der Außenseite einer Dorsalklappe mit konzentrischen fila; x120. 6, PIW96X13.5; Transversalschnitt durch den median buttress, der die Verdickung der Schale durch den Einbau zusätzlicher laminae verdeutlicht; x220. 7, PIW96X1.4; Schalenquerschnitt im anterolateralen Bereich einer Ventralklappe zeigt eine teilweise rekristallisierte sekundäre und vermutlich auch primäre Schicht (a) sowie eine relativ dünne, rekristallisierte tertiäre Schicht (b); x385. 8, PIW96X13.1; Außenseite einer Dorsalklappe mit erhaltener primärer Schicht, die mit konzentrischen fila ornamentiert ist; x50. 9, 10, abgeblätterte Apikalregionen, die einen zweigeteilten Abdruck des ?Larvalgehäuses zeigen. 9, PIW96X25.9; Ventralklappe; x50. 10, PIW96X27.5; Dorsalklappe; x90. 72 M.Streng

Fig. 18: Almohadella braunae gen. et sp. nov. 1, PIW96X19.5; seetion through posterolateral region of a ven tral valve showing columnar secondary and massive, recrystallized tertiary layer; laminar surfaces of second ary layer reveal granular texture of lamellae, which are penetrated by circular pits; x550. 2, PIW96X19.4; sagittally fractured section through median buttress revealing wedged-in laminae of tertiary layer; x105. 3, PIW96X3.6; external ornamentation of a dorsal valve; x95. 4, PIW96X3.2; seetion through posterolateral region of a ventral valve showing wedge-shaped, columnar secondary and massive tertiary layer; x280. 5, 6, PIW96X8.5. 5, polygonal pattern of surface of a cardinal muscle seal'; x230. 6, detail of 5; x300. Abb. 18: Almohadella brazmae gen. et sp. nov. 1, PIW96X19.5; Schalenquerschnitt im posterolateralen Be reich einer Ventralklappe mit columnarer sekundärer Schicht und massiver, rekristallisierter tertiärer Schicht. Die Oberflächen der sekundären Schicht zeigen die granulare Struktur der lamellae; x550. 2, PIW96X19.4; saggitaler Bruch im Bereich des median buttress. Die tertiäre Schicht wurde durch Ausbildung zusätzlicher laminae in diesem Bereich verstärkt; x105. 3, PIW96X3.6; Ornamentation der Außenseite einer Dorsalklappe; x95. 4, PIW96X3.2; Schalenquerschnitt einer Ventralklappe im posterolateralen Bereich. Zu sehen sind zahlreiche keilförmige lamellae der sekundären Schicht und eine massive tertiäre Schicht; x280. 5, 6, PIW96X8.5. 5, Oberfläche eines Muskelabdruckes mit polygonalem Muster; x230. 6, Ausschnittsver größerung von 5; x300. have been broadened secondarily (Figs. 23.2, (5) Abortive holes with concave bottom 23.5). (Fig. 23.8,23.9). (2) Circular to elliptical holes, which pene The shells usually bear a single hole, but trate the shell more-or-Iess perpendicularly to multiply bored specimens also occur with up to the shell surface (Fig.23.1). three successful holes in a single valve (Figs. (3) Circular to slightly elliptical countersunk 23.1, 23.3). The external maximum diameter holes, the extern al diameter of which exceeds ranges from 40 to 320 11m, with the majority at the inner diameter by up to 60 11m (Figs. 23.3, about 100 11m (Fig. 22). Large holes are either 23.6,23.7), resulting in a distinct shelf. due to a strongly elliptical outline or, as (4) Holes penetrating the shell at an angle to mentioned above, of secondary origin (diagene the out er surface. They are very rare and only sis or breakage), or also a result of extremely found ne ar the margin of the valve (Fig.23.4). thick shell, because the extern al diameter in- Acrotretoidea (Brachiopoda) from Morocco 73

Fig. 19: Vandalotreta fragilis sp. nov. 1, PIW96X14.4; detail of external surface of dorsal valve showing con centric fila and pitted surface of larval shell; x225. 2, PIW96X6.4; fracture section through lateral region of a dorsal valve showing columnar secondary layer; obsolescent, thin tertiary(?) layer drapes internal surface of valve (arrow); x160. 3, PIW96X30.5; detail of ventral pseudointerarea of partly exfoliated ventral valve showing concentric fila and smooth, dorsally converging ridges of intertrough; x170. 4, PIW96X6.9; detail of interlaminar surface showing granular texture of lamellae and closely spaced columns; x460. 5, PIW96X24.3; exfoliated fragment of a ventral valve with thick laminae of apical process and pitted surface of secondary layer; x100. 6, PIW96X20.6; section through apical region showing columnar laminae of apical process; x80. Abb. 19: Vandalotreta fragilis sp. nov. 1, PIW96X14.4; Übergang von Larvalschale zu postlarvaler Schalen oberfläche. Die postlarvale Schalenoberfläche ist im Gegensatz zur Larvalschale mit konzentrischen fila or namentiert. 2, PIW96X6.4; Schalenquerschnitt im lateralen Bereich einer Dorsalklappe mit columnarer se kundärer Schicht und rudimentärer, dünner, ?tertiärer Schicht (Pfeil); x160 .. 3, PIW96X30.5; Ausschnitts vergrößerung der Schalenoberfläche im Bereich einer ventralen Pseudointerarea. Sichtbar sind konzentri sche fila und nach dorsal divergierende kleine Rücken in der Spur des intertrough; x170. 4, PIW96X6.9; Detail der interlaminaren Oberfläche mit granularer Struktur der lamellae und dicht stehenden Säulen; x460. 5, PIW96X24.3; Bruchstück einer Ventralklappe mit mächtigen, den apical process aufbauenden lami nae; xlOO. 6, PIW96X20.6; Querschnitt durch die Apikalregion zeigt die columnaren laminae des apical pro cess;x80.

creases with the depth of the hole (see discus preference for either brachial 01' pedicle valves sion of sampie JAR 123.8 below). as weIl as up to three successful borings in a The presence of abortive as weIl as counter single valve appeal' to indicate absence of high sunk holes indicates that the penetration oc ly developed and distinctly specialized preda curred from the outside and that the boreholes tors. were produced by predators rather than made It is remarkable that aIl of the examined for purposes of habitat (see Discussion). A valves are either bored one to three times single abortive borehole was observed that successfuIly or bear one to three abortive holes suggests start of penetration fram the inside, but no abortive boreholes adjacent to success which is indicative for a postmortal attack of ful ones. This is in contrast to the results of the prey. Postmortal attacks, no preferential CONWAY MORRIS & BENGTSON (1994) for Lin location of the holes (Fig. 20), and no obvious narssonia from the Middle Cambrian of 74 M. Streng

as some trilobites from the Moroccan sampies 0 0 00 _0 yield distinct borings. 0- go. 0 ° 0 Quantitative data on the bored species and 0 • 0 the sampie horizons are given in Table 7. Most 0- 0 0 0 , 0 o.•0 of the sampies do not contain enough speci 'IJI!fJ mens to perform statistics in the ratio of - 0) successful borings between brachial and pedic1e - 0 - valves and in the preference for either brachial Fig. 20: Schematic outlines of a ventral valve (left) or pedic1e valves. Only two sampies, (JAR-123.8 and a dorsal valve (right) showing distribution of and 387) comprise a number of specimens suffi boreholes observed in the Moroccan ceratretid specimens. Filled symbols indicate successful, empty cient for statistical evaluation. Unfortunately, abortive boring; *) location of an abortive boring the former sampie is affected by taphonomic on the inner surface. factors and thus not suitable for statistics. These • Acanthatreta lIleiwirthae gen. et sp. nov. taphonomic factors are indicated (1) by the II1II Almohadella brazmae gen. et sp. nov. number of pedic1e valves which exceeds the • Monophthalma cf. M. eggegrulldellsis (WIMAN number of brachial valves more than three 1903) times (376 ventral and 111 dorsal valves), and Abb. 20: Schematische Umrisse einer Ventralklappe (links) und einer Dorsalklappe (rechts) zur Dar (2) by the selective destruction of the outer stellung der Lage, der an den marokkanischen Ce margin of the valves during deposition, result ratretiden beobachteten Bohrlöcher. Gefüllte Sym ing in the preservation of only massive shell bole kennzeichnen erfolgreiche, leere Symbole un parts, such as the apical part. These factors may vollendete Bohrungen; *) Lage eines unvollendeten explain the obviously feigned preference for Bohrloches auf der Schaleninnenseite. borings of the pedic1e valve (all but one bore • Acallthatreta meiwirthae gen. et sp. nov. holes found in pedic1e valves). The statistical 111 Almohadella bralillae gen. et sp. nov. evaluation of sampie 387, which yields bored • Monophthalma cf. M. eggegrundellsis (WIMAN 1903) specimens of Acanthatreta meiwirthae gen. et sp. nov. is discussed below. Sampie 387. - Sampie 387 (Tachguelt) in c1udes 484 specimens of Acanthatreta meiwir • successful boreholes thae gen. et sp. nov., 24 of which yield successful and abortive boreholes, respectively (see Tab. o abortive boreholes 9). The sampie is characterized by a balanced ratio between ventral and dorsal valves that has '" center of very large abortive apparently not been biased by taphonomic boreholes destroying effects. The distribution of successful and abor whole apex tive holes on Acanthatreta is shown in Fig. 20. Those of Monophthalma and Al1110hadella are Fig. 21: Distribution of boreholes observed on - also indicated. No special pattern in the distri Vandalotreta fragilis sp. nov. The stippled area is bution of boreholes is observed. The ratio of generally not preserved. Abb. 21: Lage der beobachteten Bohrlöcher bei bored dorsal valves to bored ventral valves Valldalotreta fragilis sp. nov. Die schattierte Fläche suggests preference of the dorsal valves. How ist in der Regel nicht erhalten. ever, the successful borehole ratio (sd/sv) is more-or-less balanced so that no preference for either ventral 01' dorsal valve can be assumed. Sweden, where abortive and successful borings Noteworthy is the fact that more abortive holes occur on the same valve, and no valve shows occur in dorsal than in ventral valves of the more than two successful borings. ceratretid genera described herein (all but Boreholes occur on valves of all genera one); a feature that was also mentioned by described herein: In addition, some lingulids CONWAY MORRIS & BENGTSON (1994) for the (tentatively assigned to Lingulella sp.) as weil Middle Cambrian Linnarssonia of Sweden. Acrotretoidea (Brachiopoda) from Morocco 75

Tab. 7: Summary of numerical results of sampies comprising bored specimens. (N, nd, nv' nb total number of specimens, number of dorsal, ventral, and bored valves of the respective sampie ). Tab. 7: Überblick der Proben mit angebohrten Schalen. (N, nd, nv' nb == Gesamtzahl der Klappen der jeweiligen Probe, Anzahl der Dorsal- und Ventralklappen sowie die Anzahl der angebohrten Klappen).

SampIe horizon Species N nv fid nb % bored 387 Acanthatreta meiwirthae gen. et sp. nov. 484 240 244 24 5.0 JAR-123.8 Vandalotretafragilis sp. nov. 487 376 III 16 3.3 TAR-1.8 Monophthalma cf. M eggegrundensis (WIMAN 1903) 41 12 29 1 2.4 X217 Almohadella braunae gen. et sp. nov. 46 15 31 1 2.2 FT-3 Monophthalma cf. M eggegrundensis (WIMAN 1903) ll6 53 63 2 1.7 D 2080 Vandalotretafragilis sp. nov. 215 137 78 3 1.4 OR-3 Tingitanella calamisca gen. et sp. nov. 123 54 69 0.8 X214 Almohadella braunae gen. et sp. nov. 144 61 83 0.7 TNTE II-6.35 Monophthalma cf. M eggegrundensis (WIMAN 1903) 697 353 344 4 0.6

Tab. 8: Numerical results of Valldalotreta fragilis sp. nov. (sampie JAR-123.8) on boreholes. Legend: N, total number of valves; n)nd, relative proportions of ventral (n) and dorsal valves (nd); b)bd, relative proportion of bored ventral (bv) and bored dorsal valves (bd); s)sd' relative proportion of successfully bored ventral (sV> and successfully bored dorsal valves (Sd); n , total number of bored valves; a ' a , number b v d , , of abortive holes in ventral and dorsal valves; nm number of multiple bored valves; nh total number of bore holes. Tab. 8. Zusammenfassung der Bohrlochauswertung von Vandalotreta fragilis sp. nov. (Probe JAR-123.8).

Legende: N == Anzahl der gezählten Klappen; n/nd Verhältnis zwischen Ventral- (nV> und Dorsalklappen (nd); b/bd == Verhältnis zwischen angebohrten Ventral- (bv) und angebohrten Dorsalklappen (bd); S/Sd == Ver hältnis zwischen vollendeten Bohrungen der Ventral- (sV> und vollendeten Bohrungen der Dorsalklappen

(Sd); nb == Anzahl der angebohrten Klappen; av' ad == Anzahl der unvollendeten Bohrlöcher auf der Ventral bzw. Dorsalklappe; nm == Anzahl der mehrfach angebohrten Klappen; nh Gesamtzahl der Bohrlöcher.

N 487 3.33 14.29 2/0 16 13 1 4 21

The sizes of the boreholes in sampie 387 have been proposed and summarized by several range from 50 to 170 /lm. All types of borings authors (e.g., CARRIKER & YOCHELSON 1968; described above occur in this sampie, albeit CHATIERTON & WHITEHEAD 1987; MILLER & with the countersunk type in favor. The SUNDBERG 1984). According to these authors different types of boreholes and two maxima in the following criteria are indicative for domicile the diameter-frequency distribution (Fig. 22) 01' symbiotic boreholes: (1) multiple borings per suggest that the holes were created by two or shell which may penetrate the shell either from more specialized borers that differed in size the outer 01' inner surface; (2) absence of pre and the bore technique. However, size and type ference for either the location of the boreholes of the borehole show no correlation. 01' the valve; and (3) inwards increasing dia Discussion. -'- Characteristic criteria for meter of domicile holes. Following CARRIKER & either domicile excavation or predatory borings YOCHELSON (1968), algae, fungi, lichens, 76 M.Streng

Tab. 9: A, Summary of numerical results of Acanthatreta meiwirthae gen. et sp. nov. (sampie 387) on bore holes. B, Statistical data on the diameter of the bore holes. Measurements in microns. See also Fig. 22. For abbreviations see Tab. 8. Tab. 9: A, Zusammenfassung der Bohrlochauswertung von Acallthatreta meiwirthae gen. et sp. nov. (Probe 387). B, Errechnete statistische Daten der Bohrlochdurchmesser (vgl. Abb. 22). Alle Meßungen in Mikrome ter. Legende in Tab. 8.

A N nv / Ild bv/bd Sv / Sd nb av lld nm nh 484 0.98 0.71 1.11 24 0 5 3 29

B mean max. min. geo.mean mode std. dev. std. error 97 170 50 92 65 34.7 6.4

12 By mean of these eriteria, the Moroeean material deseribed and eharaeterized above ean 10 not be assigned as of domieile or of predatory origin. The oeeurrenee of multiple sueeessful bored valves and absence of a preferred loea tion of the borings suggest a domicile origin. However, countersunk holes are indieative for penetration from the outside and most prob ab ly doeument a predatory origin of the hole. Two 350 additional eriteria are assumed to support a predatory origin of the Moroeean material: (1) Fig. 22: Frequency distribution of maximum dia The massive attaek of the ventral apieal region meter of measured boreholes. Shaded columns of Vandalotreta that bears elongate exeavations refer to Acanthatreta meiwirthae gen. et sp. nov. in addition to deep countersunk abortive bore from samp1e horizon 387. holes (sampie JAR-123.8; Jbel Arhouri) ob Abb. 22: Häufigkeitsverteilung des maximalen viously refleets a multiple but failed attaek of a Durchmessers der an den Ceratretiden vermesse predatory organism (Fig. 23.8, 23.9). (2) The nen Bohrlöcher. Schattierte Säulen beziehen sich direetion of penetration is either perpendicular auf Acanthatreta meiwirthae gen. et sp. nov. aus Pro be 387. or oblique to the shell surfaee, but always di reeted centrally. sponges, bryozoans, eehinoderms, worms, bi 8. Phylogenetic analysis valves, and barnacles are organisms known to ereate domieile exeavations. 8.1. Introduction and methods In eontrast, eriteria for predatory boreholes are defined by the following eharaeteristics: (1) Nine morphologie eharaeters of the valves were preferred loeation of the hole, e. g., on umbonal used for a phylogenetie analysis of the genera areas or muscle sears; (2) single holes per valve; deseribed herein and 14 additional Cambrian (3) penetration from the exterior and ab out aerotretoid genera using the PAUP 3.1.1 pro perpendieular to the extern al shell surfaee; and gram (SWOFFORD 1993). The main intention for (4) boreholes with smooth walls and inwardly the phylogenetie analysis was to rationalize the deereasing diameter. Organisms known to ob relationships of the new genera to other eera tain food by boring into shells include turbella tretids and to other Cambrian aerotretoid rian worms, cephalopods, and gastropods braehiopods, such as Linnarssoniidae and Aero (CARRIKER &YOCHELSON 1968). tretidae. Acrotretoidea (Brachiopoda) from Morocco 77

Fig. 23: Bored specimens. 1, 3, 4, 6, 7, Acanthatreta meilVirthae gen. et sp. nov.; sampie horizon 387. 1, 4, PIW96X25.5. 1, threefold bored dorsal valve; scale bar 200 J.lm. 4, detail of 1, showing obliquely bored hole; sc ale bar = 50 J.lm. 3, 6, PIW96X25.1O; 3, fragment of a threefold bored valve; scale bar = 200 J.lm. 6, pair of countersunk boreholes; detail of 3; sc ale bar = 100 J.lm. 7, PIW96X35.6; countersunk borehole; sc ale bar = 50 J.lm. 2, 5, Monophthalma cf. M. eggegrulldensis (WIMAN 1903); PIW96X27.4; TAR-1.8. 2, dorsal valve, showing secondarily widened, primary circular borehole; sc ale bar = 200 J.lm. 5, close-up of 2; sc ale bar = 100 J.lm. 8, 9, Vandalotreta fragilis sp. nov.; sampie horizon JAR-123.8. 8, PIW96X88.1; relative large abortive borehole; sc ale bar = 300 J.lm. 9, PIW96X88.2; twofold bored ventral valve, both holes are abortive; scale bar = 300 J.lm. Abb. 23: Verschiedene Beispiele angebohrt.er Schalen. 1,3,4,6,7, Acanthatreta meilVirthae gen. et sp. nov.; Probe 387. 1,4, PIW96X25.5. 1, Dorsalklappe mit drei Bohrlöchern; Maßstabsbalken = 200 J.lm. 4, schräg zur Schalenoberfläche gebohrtes Loch (Ausschnitt von 1); Maßstabs balken = 50 J.lm. 3, 6, PIW96X25.10; 3, Bruchstück einer dreifach angebohrten Klappe; Maßstabsbalken 200 J.lm. 6, zwei konisch verlaufende Bohrlöcher (Ausschnitt von 3); Maßstabsbalken = 100 J.lm. 7, PIW96X35.6; konisches Bohrloch; Maßstabs• balken = 50 J.lm. 2, 5, Monophthalma cf. M. eggeg/'lllldensis (WIMAN 1903); PIW96X27.4; Probe TAR-1.8. 2, Dorsalklappe mit einem sekundär verbreitertem Bohrloch; Maßstabsbalken = 200 J.lm. 5, Ausschnittsver größerung von 2; Maßstabsbalken = 100 J.lm. 8, 9, Vandalotreta fragilis sp. nov.; Probe JAR-123.8. 8, PIW96X88.1; relativ großes, unvollendetes Bohrloch; Maßstabsbalken = 300 J.lm. 9, PIW96X88.2; Ventral klappe mit zwei unvollendeten Bohrlöchern; Maßstabsbalken = 300 ~lm.

As discussed by WILLIAMS et al. (1996), the brachiopods is problematic. The organophos position of the paterinid brachiopods as a sister phatic shell of the paterinids suggests reference group of the acrotretids and other lingulate to the lingulate brachiopods. The strophic shell, --li

78 M.Streng

however, the mantle eanal patterns, and the and all hitherto known genera of the family Ce posteromedian musde sears of the paterinids ratretidae were thus taken into aeeount. The resemble those of the orthids. As a eonse analysis was run several times with variations in quenee, the subphylum Linguliformea WIL the number of the genera, in the weighting of LIAMS et al. 1996, whieh indudes all organo eaeh eharaeter, and in the assignment of anees phosphatie braehiopods (dass Lingulata GOR tral states and outgroups. The finally seleeted JANSKY & PoPOV 1985, and dass Paterinata aneestral state is a slight modification, or better WILLIAMS et al. 1996), probably is paraphyletie. a "primordialization" of the morphologie al Nevertheless, the paterinids, represented by the eharaeters of Linnarssonia. It is charaeterized genus Paterina, are used in this study as an by the absenee of a median buttress as well as appropriate outgroup, beeause (1) paterinids, the laek of a medially dividing dorsal element, aeeording to their first stratigraphie appearanee in eontrast to the presenee of a median buttress (late Tommotian, eompare USHATINSKAYA and a median ridge in Linnarssonia. 1995), are the oldest known organophosphatie Topologieal eonstraints on the tree are de braehiopods, and (2) the phylogenetie relation fined to split the outgroup, represented by Pateri ships between the paterinids and the remaining na, at the trees basal node. The dadograms pre organophosphatie braehiopods do not effeet sented here are the result of heuristie searehes in the result of the analysis. For the reasons men volving a stepwise random addition of taxa in tioned above, the use of the paterinids as a ten replieates and the use of different weightsets. direet aneestor of the apparently monophyletie dass Lingulata (WILLIAMS et al. 1996, p. 1178) is doubtful. Henee, the eharaeteristies of Linnars 8.3. Results sonia were seleeted and slightly modified to serve as a reasonable primitive state and to en The tests of more than ten different weightsets sure a rough stratigraphie eonsisteney. Linnars as well as the use of the default weighting by sonia is one of the stratigraphieally oldest aero PAUP (whieh provides an equal weight of "1" tretoids, with its first appearanee in the upper for eaeh eharaeter) provided only two major Atdabanian (USHATINSKAYA 1995). groups of dadograms. The morphologie eharaeters, whieh are The first group indudes the dadograms adopted to define the analyzed Cambrian reeeived by eomputing weightsets three trough organophosphatie braehiopods, are assigned as five, the default weighting (standard veetor) as unordered and undireeted multistate eharaet well as another weight veetor (termed the TRY ers, beeause they ean not be assumed to be ir veetor; for the individual weighting see Appen reversible and synapomorphies are possible. dix ILe). For all heuristic searehes with the in The eharaeters are listed in Appendix ILa and dividual weightings, 54 relatively similar dado set out as a matrix. For details, general eon grams were retained, whieh differ in simple eepts, and proeeedings of the PAUP program reeombinations of the genera between three see SWOFFORD & BEGLE (1993). groups: 1) a linnarssoniid group that is either paraphyletie or monophyletie; 2) a paraphyletie aerotretid group; and 3) a eeratretid group that 8.2. The data matrix is monophyletie and subdivided into two sub groups. One of the most reasonable trees is As mentioned above, the basis for the evalua shown in Fig. 24. It indudes a dade Ceratreti tion is the matrix of 19 seleeted Cambrian gene dae that arises from the paraphyletic Aerotreti ra and 9 morphologie, multistate eharaeters. For dae and is divided into two subgroups, which praetieal purposes, the number of genera was suggest two probable subfamilies (indieated by kept relatively small, and only a few seleeted dashed line). The two subgroups are eonsistent genera of eaeh systematie group were eonsider in the eomposition of genera. It should be not ed for the analysis. However, the relationships ed, however, that no stratigraphie eonsisteney is within the eeratretids are of special interest, given within these two subgroups. Acrotretoidea (Brachiopoda) from Morocco 79

The second major group is obtained by a Paterilla Order Paterinida heuristic search using weightset one and two Kleitlzriatreta (see Appendix ILc) with the result of 1064 Ceratreta Keyserlillgia ~ trees. These trees are characterized by the con MOlWphtiiaillUi ~ - "0 sistently monophyletic Ceratretidae and Acrotre Acalltlzatreta ~ tidae and the paraphyletic Linnarssoniidae. The Allllolzadella 1§ Bozslzakolia Q) ceratretid c1ade is either undivided or, as in the Erhotreta ü first major group, divided into two subgroups, Treptotreta which are not stable in their composition. Two Prototreta of these c1adograms are shown in Fig. 25. They Allgulotreta Hadrotreta demonstrate the polarity in composition of the Valldalotreta two subgroups. Another remarkable characteris Tillgitanella Eurytreta ti~ observed in the large part of the retained Aplzelotreta trees using weightset one or two is the assign Acrotlzyra Linnarssoniidae ment of the ceratretids as a sistergroup of the Lillllarssollia acrotretids, both arising from the linnarssoniids. No tree was retained by any defined weight Fig. 24: PAUP generated cladogram of the selected set that regards all suprageneric taxa as mono Cambrian organophosphatic brachiopods derived phyletie. As a result, a heuristic search using by a heuristic search using a stepwise random addi topologie constraints was performed to com tion in ten replicates within the matrix listed in pare the most parsimonious trees of PAUP with Appendix II.a. Further explanations in the text. a user-defined tree. The topologie constraints Abb. 24: Vom Computerprogramm PAUP durch ei ne heuristische Suche ermitteltes Kladogramm der simply refer each suprageneric taxon (the cera ausgewählten kambrischen phosphatschaligen Bra tretids, acrotretids, and linnarssoniids) to a chiopoden. Die Datenmatrix, die dem Programm single c1ade. The standard weightset was used zu Grunde liegt ist in Appendix Il.a aufgelistet. (referring a weight of "I" to each character) to Nähere Erläuterungen im Text. simplify comparison of the tree lengths. With out the new topologie constraints in use, a mini mum tree length of 55 was the most parsimo canal patterns, and, especially, the microstruc nious solution, resulting in trees of the first ture and ornamentation of the larval and post major group described above. In addition, it larval shell, are not considered in this analysis, comprises a mono- or paraphyletic linnarsso because such detailed information does not yet niid group, a paraphyletie Acrotretidae group, exist for all of the genera inc1uded in the and a ceratretid c1ade (Fig. 26C). Computing analysis. In addition, no stratigraphie consis the data set with the defined topologie tency is given in all trees, except "Linnarssonia" constraints, the minimum tree length increases is chosen as an ancestor. However, the main in just by two (to a tree length of 57). The resul tention of the phylogenetic analysis was focus ting c1adograms assign the ceratretids as a ed on the relationships of the new ceratretid sistergroup of the acrotretids, similar as for the genera. The analysis has shown the following second major group, but it keeps the linnarsso results: niids as aseparate c1ade (Figs. 26A and 26B). (1) A ceratretid c1ade was retained in all of the trees. (2) In the bulk of trees, the ceratretid c1ade 8.4. Discussion was split into two subgroups of varying com position. These variations are restrieted to the The trees presented above are a small selection genera Bozshakolia, El'botl'eta, and Monoph from the great number of equally parsimonious thalma. solutions. Furthermore, one should be aware of (3) The genera commonly assigned to the the fact that characters of apparently important Linnarssoniidae are shown to be polyphyletie in taxonomie value, such as musculature, mantle many of the c1adograms. 80 M.Streng

Paferina Paferina Kleifhriafrefa B Kleifhriafrefa Cerafrefa Cerafrefa Keyserlingia Keyserlillgia Erbofrefa MOllophfhalma MOllophfhalma Acanfhafrefa Acanfhafrefa Almohadella Almohadella Bozshakolia Bozshakolia Erbofrefa Tingitanella Tingifanella Euryfrefa Euryfrefa Vandalofrefa Valldalofrefa Hadrofrefa Hadrofrefa Trepfofrefa Trepfofrefa Allgulofrefa Angulofrefa Profofrefa Profofrefa Aphelofrefa Aphelofrefa Acrofhyra Acrofhyra Lilllwrssonia Linllarssonia

Fig. 25: 1\vo trees obtained by a heuristic search using the same search options as in Fig. 24, but different character weighting. The two trees differ in the composition of the subgroups of the ceratretid clade. Further explanation in the text. . Abb. 25: Zwei Stammbäume, gewonnenen durch heuristisches Suchen und unterschiedliche Gewichtung der einzelnen morphologischen Merkmale. Die zwei Bäume unterscheiden sich in der Zusammensetzung der zwei Gruppen, die die Ceratretidenklade bilden. Nähere Erläuterungen im Text.

The subdivision of the ceratretid c1ade is bution of the ceratretids, which further supports mainly a result of morphologie differences such reliable reconstructions of the phylogenetic as the presence or absence of a median septum relationships between the various genera. Due and ridge and the shape of the ventral valve, to this inadequate present state of knowledge whieh is either conieal or strongly convex. In no new suprageneric taxa are introduced based addition, a sub division of the ceratretids is con on the retained c1adograms. firmed and supported by further morphologie details, which were not considered in the phylo genetic analysis. These inc1ude: (1) The direc 9. Acknowledgements tion and length of the pedic1e tube is either short and anteriorly directed, or long and dor The author is greatly indebted to apl. Prof. Dr. G. sally directed. (2) Described extern al pedic1e Geyer (Institut für Paläontologie, Würzburg) for openings are either listrium-like 01' lie within a providing the material for this study, for critical cavity whieh is located posterodorsally of the comments, discussion and reading, and for his ef apex. (3) If the foramen lies within a cavity, its forts with the improvement of the language. Dr. position is either central or dorsal. (4) The M. Mergl (PIzen, Czech Republic) kindly per morphologie constitution of the internal shell mitted examination of material of Vandalotreta surface varies from strongly bulging and slightly vafra from his collection. Further material and bilaterally asymmetrieal, or bilaterally symme some SEM photographs of Vandalotreta vafra trical with raised cardinal musc1e platforms, to were loaned by Dr. L. E. Holmer (Uppsala, relatively smooth and even. Sweden). Additional sampies were colleeted by However, not enough ceratretid genera are P. Hupe, K. Sdzuy, and J. Destombes. I would known, and further investigations are needed like to thank Prof. G. Krohne and C. Gehring on (1) the microstructure and ornamentation of (Theodor-Boveri-Institut für Biowissenschaf the larval and postlarval shell, (2) the phylo ten, Würzburg) for assistance with the SEM, genetic relevance of the single morphologie and H. Schönig (Institut für Paläontologie), for characters, as well as (3) the stratigraphie dis tri- assistance with photo graphie artwork. Acrotretoidea (Brachiopoda) from Morocco 81

A 5 Palerina B Palerina C ,...--__--"-5 ____ Palerina 0 Kleilhrialrela Kleilhrialrela 1 ~ Kleilhrialrela Ceralrela Ceralrela Ceralrela Keyserlingia Keyserlingia o Keyserlingia Erbolrela 3 Monophlhalllla 2 1 0 Monophlhalllla 2 Monophllllllllla Acalllhalrela o 0 Acall/halrela Amnlhalrela 0 AIlIIohadella o AIlIIohade{{a 0 AIlIIolllldella B07shakolia o Bozsllllkolia 2 Bouhakolia Erbolrela Erbolrela Tillgiwlle{{a Tillgitallella '----"-- Treplolreta EIII)'lrela ElIrylrela '----''--- ProlOfreta 0 Valldalolrela 0 Valldalolrela '----"--- Angl/lolrela 0 Hadrolreta Hadrolrela L-_-"-O__ Hadrolrela Treplolrela Treplolrela '--_--'0'--__ Vandalolrela 1 Allglllolrela Prololrela 2 Tillgilanella Prololrela Allgl/Iolrela EI/rylrela 1 1 Aphelolrela 1 Aphelolrela 1 1 Aphelotrela 0 0 Acrolhyra 0 Acrolhyra o o Acrolhyra 0 LimUlrsson;a 0 Limwrsson;a o Linnarssoll;ll

Fig. 26: Three rectangular cladograms derived by a heuristic search using a stepwise random addition of genera in ten replicates. Character states are equally weighted. Branch lengths are indicated. A, B, clado grams retained by a heuristic search under special topologic constraints referring the ceratretids, acrotretids, and linnarssoniids to monophyletic clades (tree lengths 57); C, rectangular cladogram of Fig. 24 retained without special topologic constraints (tree length = 55). Abb. 26: Drei rechteckige Kladogramme, erstellt durch heuristische Suche unter Benutzung eine schrittwei sen Zufalls addition der Gattungen (bei zehn Verdopplungen). Alle Merkmale haben die selbe Gewichtung. Die Längen der einzelnen Äste sind angegeben. A, B, zwei Kladogramme, die durch heuristisches Suchen unter topologischen Beschränkungen gewonnen wurden und die Ceratretiden, Acrotretiden und Linnarsso niiden zu einer monophyletischen Klade zusammenfassen (Baumlänge = 57). C, Abb. 24 dargestellt als rechteckiges Kladogramm das ohne topologische Einschränkungen erstellt wurde (Baumlänge = 55).

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MATIHEW, G. F. (1902): Additional notes on the dia, Palreontologia Indica, (NS), 1 (1): 1-13; Cal Cambrian of Cape Breton, with descriptions of cutta. new speeies. - Bulletin of the Natural History ROBERTS,1. & JELL, P. A. (1990): Early Middle Cam Soeiety of New Brunswick, No. XX, IV (V): brian (Ordian) brachiopods of the Coonigan 377-426; St. John, New Brunswick. Formation, western New South Wales. - A1che MEI SHI-LoNG (1993): [Middle and Upper Cambri ringa,14 (4): 257-309; Sydney. an inarticulate brachiopods from Wanxian, He ROWELL, A.1. (1963): Some nomenc1atural problems bei, North China]. - Acta Palaeont. Sinica, 32 in the inarticulate brachiopods. - Geol. Mag., (4): 400-429; Beijing. [In Chinese with English 100 (1): 33-43; Cambridge. summary] - (1965): Inarticulata. - In: MOORE, R. C. (ed.): MERGL, M. (1983): New brachiopods (Cambrian Treatise on Invertebrate Paleontology, Part H. Ordovieian) from Algeria and Morocco (Medi Brachiopoda 1 (2): H260 -H296; Boulder and terranean Province). - Casopis pro mineralogii Lawrence (Geological Soeiety of America and a geologii., 28: 337-348; Prague. University of Kansas Press). - (1988): Inarticulate brachiopods of early Middle - (1966): Revision of some Cambrian and Ordovici Cambrian age from the High Atlas, Morocco. - an inarticulate brachiopods. - Univ. Kansas Pa- Vestnfk Ustredniho ustavu geologickeho, 63 (4): 1eont. Contrib., 7: 1-36; Lawrence. 291-295; Prague. (1980): Inarticulate brachiopods of the Lower and - & SLEHOFERovA, P. (1990): Middle Cambrian in Middle Cambrian Pioche Shale of the Pioche articulate brachiopods from Central Bohemia. - Distriet, Nevada. - Univ. Kansas Paleont. Con Sbornfk geologickych ved, Pale ontologie, 31: trib.,98: 1-25; Lawrence. 67-104; Prague. (1986): The distribution and inferred larval di MILLER, R. H. & SUNDBERG, F. A. (1984): Boring spersion of RllOndellina dorei: a new Cambrian Late Cambrian organisms. - Lethaia, 17: brachiopod (Acrotretida). - 1. Paleont., 60 (5): 185-190; Oslo. 1056-1065; Thlsa. PALMER, A. R. (1954): The faunas of the Riley For - & HENDERSON, R. A. (1978): New genera of acro mation in Central Texas. - 1. Paleont., 28 (6): tretids from the Cambrian of Australia and the 709-786; Thlsa. United States. - Univ. Kansas Paleont. Contrib., PANDER, C. H. (1861): In: HELMERSEN, G. VON, Die 93: 1-11; Lawrence. geologische Beschaffenheit des unteren Naro SCHUCHERT, C. (1893): A c1assification of the Bra vathals und die Versandung der Narovamün• chiopoda. - The American Geologist, 11: dung. Acad. Imper. Sei., St Petersburg, 3: co 141-167; Minneapolis. lumns 46-49; St. Petersburg. SOBOLEV, L. P. (1992): Revision of some Middle and Popov, L. & HOLMER, L. E. (1994): Cambrian-Or Upper Cambrian lingulates from Udo-Shatarsk dovieian lingulate brachiopods from Scandina zone (Khabarovsk region). In: REPINA, L. N. & via, Kazakhstan, and South Ural Mountains. - ROZANOV, A. yu. (eds.): Drevnejshie brakhio Fossils and Strata, 35: 1-156; Oslo. pody territorii Severnoj Evrazii: 99-108; Novosi -, - & GORJANSKY, V. Ju. (1996): Middle Cambrian birsk. [In Russian] lingulate brachiopods from the Tarbagatay Ran SWOFFORD, D. L. (1993): PAUP: Phylogenetic Ana ge, Kazakhstan. - Acta Palaeont. Polonica, 41 lysis Using Parsimony, Version 3.1.1. - Compu (3): 299-317; Warsaw. ter program distributed by the Illinois Natural POULSEN, C. (1942): Nogle hidtil ukendte Fossiler History Survey; Champaign. fra Bornholms Exulanskalk. Meddelelser fra - & BEGLE, D. P. (1993): PAUP: Phylogenetic Ana Dansk Geologisk Forening, 10: 212-235; Copen lysis Using Parsimony, Version 3.1, User's Ma hagen. nual. - Center of Biodiversity, Illinois Natural - (1960): Notes on some Lower Cambrian fossils History Survey: 257 pp.; Champaign. from French West Africa. - Matematisk-fysiske TERMIER, G. & TERMIER, H. (1950): Pale ontologie Meddelelser 32 (7): 11 pp.; Copenhagen. marocaine. Tome II. Invert6bres de l'Ere pri (1971): Notes on an Ordovieian acrotretacean maire. Fase. IH. Mollusques. - Notes et Memoirs, brachiopod from the Oslo region. - Bull. Geol. Servo Geol. Moroc, 78: 277 pp.; Paris (Herman & Soc. Denmark, 20: 265-278; Copenhagen. Cie.). PUURA, I. & HOLMER, L. E. (1993): Lingulate bra USHATINSKAYA, G. T. (1990): Mikrostruktura i se chiopods from the Cambrian-Ordovieian bo kretsiya rakoviny u bezzamkovykh brakhiopod undary beds in Sweden. - Geol. Fören. i Stock otryada Acrotretida [The shell microstructure holm Förhandl., 113: 215-237; Stockholm. and secretion in the inarticulate brachiopods of REDLICH, K. (1899/1901): The Cambrian Fauna of the order Acrotretida]. - Paleont. Zhurnal, 1990 the Eastern Salt-Range. - Mem. Geol. Surv. In- (1): 55-65; Moscow. [In Russian] 84 M. Streng

- (1992): Novye srednekembrijskie lingulyaty iz Ba WILLIAMS, A., CARLSON, S. 1., BRUNTON, C. H. c., tenevskogo kryazha (Altae-Sayanskaya skla HOLMER, L. E. & PoPOV, L. (1996): A supra-or dchataya oblast') [New Middle Cambrian lingu dinal classification of the Brachiopoda. - Phil. lates from Batenev Ridge (Altai-Sajan Moun Trans. R. Soc. Lond., B 351: 1171-1193; London. tain Area)]. - In: RE,PINA, L. N. & ROZANOV, A. - & CURRY, G. B. (1985): Lower Ordovician Bra YU. (eds.): Drevnejshie brakhiopody territorii chiopoda from the Tourmakeady Limestone, Severnoj Evrazii: 80-88; Novosibirsk. [In Russi Co. Mayo, Ireland. - Bulletin of the British Mu an] seum (Natural History), Geology, 38 (4): - (1994): Novye sredne-pozdnekembrijskie akro 183-269; London. tretidy (brakhiopody) severa Sibirskoj platfor - & HOLMER, L. E. (1992): Ornamentation and shell my i nekotorye voprosy ikh sistematiki [New structure of acrotretoid brachiopods. - Palaeon Middle and Late Cambrian acrotretids (bra tology,35 (3): 657-692; London. chiopods) from the northern part of the Siberi - & ROWELL, A. 1. (1965): Morphology. - In: an Craton and some questions on their systema MOORE, R. C. (ed.): Treatise on Invertebrate Pa tics]. - Paleont. Zhurnal, 1994 (4): 38-54; Mos leontology, Part H. Brachiopoda 1 (2): cow. [In Russian] H57-H155; Boulder and Lawrence (Geological - (1995): Drevnejshie lingulyaty [The early lingula Society of America and University of Kansas tes]. Trudy Paleont. Instiuta, 262: 1-91; Mos Press). cow. [In Russian] WIMAN, C. (1903): Studien über das Nordbaltische - , GIDASPOV, A. D. & RIAZANTSEV, A. V. (1986): Silurgebiet. I. Olenellussandstein, Obolussand Nakhodki srednekembrijskikh bezzamkovykh stein und Ceratopygenschiefer. - Bull. Geol. brakhiopod v tsentral'nov Kazakhstane [Disco Inst. Univ. Uppsala, 6: 12-76; Uppsala. very of Middle Cambrian inarticulate brachio ZELL, M. G. & ROWELL, A. 1. (1988): Brachiopods of pods in central Kazakhstan]. - Paleont. Zhurnal, the Holm Dal Formation (late Middle Cambri 1986 (3): 35-40; Moscow. [In Russian] an), central North Greenland. - In: PEEL, 1. WAAGEN, W. (1885): Salt Range fossils. Pro ductus S.(ed.): Stratigraphy and palaeontology of the Limestone fossils, Brachiopoda. - Mem. Geol. Holm Dal Formation (late Middle Cambrian), Surv. India, Palreontologia Indica, 13: 729-770; central North Greenland. - Meddelelser om Calcutta. Grpnland, Geoscience, 20: 119-144; Odense. WALCOTT, C. D. (1902): Cambrian Brachiopoda: Acrotreta; Linnarssonella; Obolus; with descrip tions of new species. - Proc. US National Muse um, XXV (1299): 577-612; Washington, D.C. - (1912): Cambrian Brachiopoda. - Monographs of the United States Geological Survey, 51 (I+II): Manuscript received: 25.7.1998 872 pp. + 363 pp., 104 pis.; Washington, D. C. Accepted for printing: 30.1.1999 Acrotretoidea (Brachiopoda) from Morocco 85

11. Appendices

Appendix I: Location of sampie horizons and localities

Abbreviations. - Hup. HupeolenIls biozone; Cpg. = Cephalopyge notabilis biozone; 0/1: = Omamentaspis /requens biozone. TAT Tatelt Formation; JW = Jbel Wawrmast Formation, BaM = Breche a Micmacca Member, Tar = Tarhoucht Member; JAF = Jbel Afraou Formation.

Sampie horizon Biozone Formation Locality Lambert coordinates

387 Cpg. JW,BaM Tachguelt 242,5 / 451.5 397 Cpg. JW,BaM Itsiar 242.6 / 451.6 A 936a Cpg. JW,BaM Jbel Tirounbai' 464/450 AQIII ",Cpg. JW,BaM Aqdz 421 /418 ASS - 45.68 Oft: JW,Tar Assermo section 364.5 /483.6 ASS - 45.7 Oft: JW,Tar Assermo section 364.5 /483.6 ATZ-2 Cpg. JW,BaM AkkaTzem 268/308 B 123 Cpg. JW,BaM . Tin Ouagour 470/456 BK-3 Cpg. JW,BaM Berkik 449/446 D257 Cpg. JW,BaM Hassi Brahim 240/304 D 2055 Cpg. JW,BaM Tizi n'Tichka 214/433 D 2077 Oft: JW,BaM Ai'tMersid 460/435 D 2080 Cpg. / 0/1: JW,Tar Jbel Assadam 412/419 D 2090 Cpg. JW,BaM Jbel bou Ifersikt 387.0/402.1 D 2094 Cpg. JW,Tar? Jbel bou Ifersikt 387.6/402.2 D 2357 0/1: ? JW,BaM Ai'tMersid 460/435 EBI Cpg. JW,BaM EI Borj /Tislit n'Ai'tTamassine 334/407 FT-3 Cpg. JW,BaM Foum Tangarfa 426.0/415.5 HM-6 Cpg. JW,BaM EI Hmam syncline 330/428 HM-9.6 Hllp./Cpg. JW,BilM EI Hmam syncline 330/428 HM-40.5 Cpg. TAT EI Hmam syncline 330/428 HM-50.6 Hup. / Cpg. TAT EI Hmam syncline 330/428 IFR -187.5 Cpg. JW,BilM Ifrane d'Anti-Atlas 102/253 IL - 9 Cpg. JW,BaM Ighels 329/416 JAR-0.56B Cpg. JW,BaM Jbel Arhouri 472 / 487 JAR - 26.4 Cpg. JW,BaM Jbel Arhouri 472/487 JAR - 123.8 0/1: JAF Jbel Arhouri 472 / 487 L II - 30 Cpg. JW,BaM Ounein basin, section L II 237/433 LeXI-4 0/1: JW,BaM Lemdad syncline, section XI 234.6 / 425.3 Le XI - 22b Cpg. JW,BaM Lemdad syncline, section XI 234.6/425.3 Le XI - 24b Oft: JW,BaM Lemdad syncline, section XI 234.6/425.3 Le XI - 24c 0/1: JW,BaM Lemdad syncline, section XI 234.6/425.3 Le XI - 24e 0/1: JW,BaM Lemdad syncline, section XI 234.6/425.3 Le XI - 51.65 0/1: JW,BaM Lemdad syncline, section XI 234.6/425.3 Le XI - 51.9 0/1: JW,BaM Lemdad syncline, section XI 234.6/425.3 LeXII-1/I 0/1: JW,BaM Lemdad syncline, section XII 234.1 /426.2 Le XVI - 30 0/1: JW,BaM Lemdad syncline, section XVI 231.8/430.2 OR-3 Cpg. JW,BaM Ourika Wawrmas 391/414 OW-1 Cpg. TAT? Ourika Wawrmas 391.5/414.0 OW-7 Cpg. JW,BaM Ourika Wawrmas 391.5/414.0 OW-13 Cpg. /0/,: JW,BaM Ourika Wawrmas 391.5 /414.0 OWI -20.8 Cpg. JW,BaM Ourika Wawrmas 391.5 /414.0 OW II-1 Cpg. JW,BaM Ourika Wawrmas 391.5 /414.0 TA/MC3 Cpg. JW,BaM Tagragra syncline 340/396 TA/MC5ST .Cpg. JW,BilM Tagragra syncline 340/396 TA/MC10T Cpg. JW,BilM Tagragra syncline 340/396 86 M. Streng

Sample horizon Biozone Formation Locality Lambert coordinates

TA/MC38 Cpg. JW,BilM Tagragra syncline 340/396 TA/MC40 Cpg. JW,BilM Tagragra syncline 340/396 TAT-18.35 Hup./Cpg. JW,BilM Tatelt section 417.0/417.5 TAT- 33.3 Cpg. JW,BilM Tatelt section 417.0/417.5 TAT- 67.9 Cpg.? JW,BilM Ta telt section 417.0/417.5 TAR-lo8 Cpg. JW,BaM Tarhoucht 536/485 TNF-1 Cpg. JW,BilM Tinifift 512/480 TNF-5 Cpg. JW,BilM Tinifift 512/480 TNTE I - 49.8 Cpg. JW,BilM Tizi n'Telgane, section I 513 1 477 TNTE II - 4-6 Cpg. JW,BilM Tizi n'Telgane, section II 513 1 477 TNTE II - 6.35 Cpg. JW,BilM Tizi n'Telgane, section II 513 1477 TNTE II - 8.24 Cpg. JW,BilM Tizi n'Telgane, section II 513/477 TNTEV - 3.85 Cpg. JW,BaM Tizi n'Telgane, section V 513/476 X52 °fr. JW,BaM Lemdad syncline 234.0/425.5 X 211 Cpg. JW,BilM Ounein basin, ENE' Afourigh 237/433 X214 °fr. JW,BilM Lemdad syncline, section XI 234.6/425.3 X217 Ofr. JW,BilM Lemdad syncline, section XII 234.1 1 426.2 X 223 °fr. JW,BilM Lemdad syncline, section X 234.7 1 424.5 X 242 Cpg. JW,BilM Ijoukak 236.5/447.0

Appendix II: Data sets used in phylogenetic analysis a, Matrix of 9 characters listed in Appendix II.b among the 19 selected Cambrian organophosphatic brachiopods.

1 2 3 4 5 6 7 8 9

Paterina 0 0 0 0 0 0 0 0 0 Kleithriatreta 1 2 3 (01) 2 (02) 1 1 2 Ceratreta 1 2 3 0 2 0 1 1 2 Monophthalma 1 2 (12) (012) 2 1 1 1 1 Acanthatreta 1 2 2 (01) 2 1 1 1 1 Almohadella 1 2 2 (01) 2 1 1 1 1 Tingitanella 2 1 0 (12) 3 2 0 1 3 i Vandalotreta 1 3 (01) 0 3 2 0 1 3 ~ Hadrotreta 1 3 (13) 0 3 2 0 1 3 Treptotreta 1 2 3 0 3 2 0 1 (13) Eurytreta 2 1 (13) (12) 3 0 0 (13) 3 .~ Angulotreta 1 3 3 0 3 2 0 1 0 Prototreta 1 2 3 (012) (23) 2 0 1 0 Aphelotreta 1 1 (01) (12) 2 1 0 1 3 Linnarssonia 1 1 1 (01) 0 (01) 0 1 3 Acrothyra 1 1 1 2 1 1 0 ? 3 Bozshakolia 1 2 (01) (012) 2 1 1 1 1 Erbotreta 1 2 1 0 2 2 1 1 (01) Keyserlingia 1 2 3 (01) 2 2 1 1 2

" Acrotretoidea (Brachiopoda) from Morocco 87 b, List of characters used in the phylogenetic analysis.

1. Foramen delthyrium (0), not within larval shell (1), completely within larval shell (2) 2. Internal pedicle opening delthyrium (0), behind apical process (1), within apical process (2), within apical process cavity (3) 3. Median division of dorsal shell absent (0), median ridge (1), median swelling (2), median septum (3) 4. Ventral pseudointerarea procline (0), catacline (1), apsacline (2) 5. Dorsal pseudointerarea with notothyrium (0), obsolescent prop areas (1), small propareas (2), well developed propareas (3) 6. Shape of ventral valve obtuse conical (0), convex (1), conical (2) 7. Organophosphatic shell with growth lines and/or concentric fila (0), thickened, with growth lines and/or concentric fila on external surface and areas of raised shell on internal surface (1) 8. Ventral median zone homeodeltidium (0), intertrough (1), flat (2), interridge (3) 9. Median buttress absent (0), small, inconspicuous (1), present, connected with median septum (2), present (3)

c, Different weights for individual characters used during analysis.

Character 1 2 3 4 5 6 7 8 9 weightset one 1 2 1 1 5 1 5 1 3 weightset two 1 3 1 1 5 1 5 1 2 weightset three 3 7 3 1 10 1 3 3 3 weightset four 3 10 3 1 10 1 3 3 3 weightset five 3 10 3 1 10 1 3 3 6 standard vector 1 1 1 1 1 1 1 1 1 weightset TRY vector 4 4 1 1 7 1 8 2 3