EARLY DEVONIAN ECHINODERMS FROM SOUTH AFRICA PETERA. JELLANDJOHANNES N. THERON Jell, P.A. & Theron. J.N., 1999 06 30: Early Devonian echinoderms from South Africa. Memoirs ofthe QueenslandMuseum 43( 1): 1 15-199. Brisbane. ISSN 0079-8835. EchinodermsoftheLowerDevonianBokkeveldGroupintheCapeProvince, SouthAfrica, haveplayedanimportantroleinsedimentarystudiesoftheregionbuttheirtaxonomicstatus hasbeenknown fromonly a fewcursorypapers. Wehereprovidetaxonomictreatmentofall availablecrinoid(15species),asterozoan(11)andblastoid(2)speciesrevisingallpreviously described taxa and morethan doublingtheknowndiversity. Palaeobiogeographicaffinities appeartobewith EuropeandtheUSAbutknownfaunasofSouthAmericaandAustraliaare small andalmostcertainly incompletelyknown. New taxadescribedarethecrinoid genera Mcmdehterinus nelsom\ Eekidoevinus interhrachiatus, Sacrinus gamkaensis, S. hexensis, Monaldicrinus johni and Othozechnus royi and the asterozoan genera Aulacolatiaster breviramus and Hoichkissastermaerodentatus. Hexuraster is introduced as a replacement for preoccupied Hexura Spencer. New species are the crinoids Kopjlcrinus halbichi, Crudeocrinus plenarius and Thalamocrinus arenaceus and the asterozoans Marginura hilleriandEugasterellaafricana, 3SouthAfrica, crinoids, starfish, ophiuroids, Early Devonian, Bokkeveld. Peter A. Jell, Queensland Museum, P.O. Box 3300, South Brisbane 4101, Australia; JohannesN. Theron, GeologicalSurveyofSouthAfrica, P.O. Box572, Bellville 7530, South Africa; 20September. 1998. Echinoderms were first recorded from the (1936) described carpoids from Gamkapoort, Lower Devonian Bokkeveld Group of South Breimer & Macurda (1972) described blastoids Africa as early as 816 byDrG. Thorn, aclergy- from the Ceres/De Dooms area and Ruta & 1 man by occupation but also an ardent amateur Theron (1997) described carpoids in detail. In fossil collector. He gathered 'endlessnumbersof thispaperwe have revisedthe description and in specimens of shells, trilobites and encrinites or many cases the assignment of previously stonelilies'fThorn, 1830).Thuscrinoidswerethe described echinoderms (crinoids, blastoids and first echinoderms described (Salter, 1856). The asterozoans) and have described substantial new Devonian age for the Bokkeveld fossils was collections from the South African Museum, the assignedaboutthe sametime(Sandberger, 1852; Geological Survey of South Africa (mainly Sharpe & Salter, 1856) but in the second halfof collected by J.N.T. during stratigraphic field the 19th century very little was attempted on the mapping during the 1970s to 1990s) and the identification of these fossils. Rogers and private collection of Mr Roy Oosthuizen of Schwarz mapped these rocks in detail beginning Klaarstroom. in 1895 and assembled extensive fossil STRATIGRAPHIC SETTING collections that formed the subject ofnumerous studies illuminating the fossil distribution and The clastic Cape Supergroup borders the stratigraphical setting. Their Devonian age was southern and western parts of South Africa for also confirmed by comparison with faunas from 800km eastwards and almost 300km northwards South America and Europe (Corstorphine, 1897; from Cape Town (Fig. 1). The Supergroup is Schwarz, 1906; Reed, 1904, 1906; Knod, 1908; divided into a lower, predominantly arenitic Clarke, 1913; Kozlowski, 1923). In a Table Mountain Group, conformably overlain by comprehensive review ofthe Bokkeveld fauna. the markedly argillaceous Bokkeveld Group, Reed (1925) recorded the first carpoid, blastoid which in turn is overlain by the more arenitic andstarfish. Echinodermscompriseonlyaminor Witteberg Group (Fig. 2). element in the fauna however, and detailed The Bokkeveld Group consists of a cyclical descriptions of the various echinoderms in alternation of predominantly argillaceous and several collections have been rare. Ophiuroids arenaceous units. Each ofthese extensive Iitho- have been mentioned by Rossouw (1933), stratigraphic units is given formation status (Fig. Spencer(1930, 1950a) and Rilett (1971).Rennie 2). The 6 lower formations which can be traced 116 MEMOIRS OF THE QUEENSLAND MUSEUM -30 100 200 Km i i i - 1 BOKKEVELD GROUP N *1 Vanrhynadorp * \ 1i \k -32 OO +> $> t <* " Ceresi•e5f^c--^>rfs e*^t2^^^T^if- _ S^ -34 Cape Town If—1 01 "£port Elizabeth ^LV^~P*^V*""" INDIAN OCEAN 18 22 24 26— 28 30 i_ i I i i i i j 1 1 FIG. 1. Sketch map ofSouth Africashowingoutcrop areasofthe BokkeveldGroup in solidblack, throughout the outcrop area are collectively their stratigraphic occurrence so that for many referredtoastheCeres Subgroup. Theupperpart yearstherewasnoclarityastowhetheranyzonal ofthe sequence in the west, with5 formations, is schemecouldbe developed. Thefaunas varyata designated the Bidouw Subgroup, whilst gross level with geography (Schwarz, 1906; eastwardsthelaterallyequivalentTakaSubgroup Theron, 1972; Oosthuizen, 1984) in that consists of3 formations (Theron, 1972; Theron brachiopods and echinodermsaremorecommon & Johnson, 1991). Thickness ofthe Bokkeveld in the west, with conulariids, corals and hyoliths Groupismuchgreaterintheeastthaninthewest. more prevalent towards the east. These alternating lithostratigraphic units Usually, marine invertebrate faunas are most represent 5 major, sheet-like, superimposed, commonintheCeres Subgroup,butarefoundup coarsening-upward cycles which feather out to the level ofthe Karoopoort Formation in the southwards into a relatively homogeneous westandtheKariesFormationintheeast(Fig.2). mudstone-siltstone sequence. This southward Although present throughout the Bokkeveld decrease of coarser elastics is linked to a Group, plantandespeciallytrace fossils,become progressive thickening ofthe argillaceous units abundant in the northwestern outcrop areas. A and of the Bokkeveld Group. The arenaceous wide variety oftypically shallow marine ichno- units vary from fine-grained quartz arenites to genera occur with large numbers ofa variety of immature arkosic arenites, either horizontally the uncommon pentameral stellate trace fossil laminated or planar to trough cross-bedded. Asteriacites (Fig. 3) at various horizons within Hummocky cross stratification becomes a these proximal arenites (Theron, 1972). prominent structure northwards (Theron et al., 1995). Theargillaceousunitsconsistofdarkgrey Examination of sediment/phyla associations shale, mudstone and siltstone with thin reveals distinct affinities ofcertain species for a intercalated lenses of fine to medium grained particular lithology (Reed, 1907; Theron, 1972; lithic sandstone. The latter reveal swaley Oosthuizen, 1984). Since a large percentage of cross-stratificationandoftenmarkedripplecross the Bokkeveld fauna is benthic organisms, they laminated zones towards the north. are likely to be fades controlled. Trilobites and cephalopodstendtooccurmainly inargillaceous Weathering of the sequence gives rise to horizons in contrast to the gastropods, bivalves, hogback topography, the more resistant arenites andbrachiopodswhich are foundmore evenly in creatingridgeswhereas the interveningargillites arenites and argillites. Among echinoderms, the generally weather predominantly recessively. crinoids are found in a variety ofsediment types This distinctive weathering minimises good from mudstonesto lithic arenites. Although stem exposures ofthe argillites. fragmentsareprolific,well-preservedcrownsare Althoughnumerousfossilshavebeencollected largely confined to finer grained sediments. and described, little attention has been paid to Although scarce, ophiuroids, carpoids and EARLY DEVONIAN ECHINODERMS OF SOUTH AFRICA 117 Q«*rti«»« iiitdiltM,alttalana.ulnarinndatnna.amdhm-tafbi*-«<aln*d.thin-I*thtak-bnddarf.planar andtroann aroaa-baddad. KAROOPOORT FORMATION hSoIrHtaetanantaalaannddarakand>raatalaaaa,thltaatttaadr,prripapdtoaajnlanrattaiaenanarmthownarIdmar,aafltaaaal-llaaaaaaaad.hMbraa-tgwrraslanlandd,,rtahrienpblaadndtardr,aaa>p«ta. OSBERQ FORMATION aadalaaaand arttatana,Hna-laawdlnai aretnnd.tMn-tatMeb-bnddad.aartiaatalandrfc*a*tlaarinatad, planarand trowphornaa-baddad,chananhwaaaeare.Inlraalaallanaaa,blatarbalad.planttranawata. KLIPBOKKOP FORMATION SMtalana.aHtynadalanaand»k*nraandaleaabada,II**-laaadhHa-aralaad.horteaatalandrtppto laarinatnd, planarnraaa-baddlnflpredaaiatataa.traapaaraaa-aaddlnfnaaara,abandnntHp*t*aartia. Intraelaatlanaaa,blaiwrkaiad,aaa>aplanttrapataata. WUPPERTAL FORMATION •ra_tabo>nMttMdaaaarrlbblaaaantlnaaalddnw.,aiitalahadoa,atiatpailnappnllaaaaUnnrtttaatttnnrrdanainphaHltraanantaaaaa.aanftlntar-aatfahaanrdahama--gbraadldaaadd,,abthaiand-atMarIkhplpeMh-atbaardfcdaa,dh.rtbroaralliaaaattalla.naaanad, WA8O0MBERQ FORMATION $C^(3s ahfrttlraataolaaaatalnadnaaataadbaltaataaar.barlaarda,tltailaaabWtaadrdaaadaalaaaadaaataa.aa.aaaarvaarharliaatalandripptalaataalad, BOPLAA9 FORMATION \J3 •aaadndtartaaanfah.aUrnaaa-a-tbaadaaddakdj,rat-hianrabltntnrdaa.latahtinl-anlaaaaI,Maaka-wbnad*daa*d,inrnrilaioantatlaaaanldanrba>apataallapattaaaatlaIdr,anpalaaanlaar, TRA-TRA FORMATION W a•Ibrataadtaaaaalarnipdptaairtayarmkaad,atbalnalaarabnadtlaalnaaarndthtlrna-abaadtdaaada,Haa,atadMantaiantar,aerliapapttalaannadaaa.ilpalraanatrIaraaaaalaaaaitlan.alad, HEXRIVER FORMATION MSffife? aSarnadaaal-abnaad,daldl,aa-tbhliaabiatdrtaaaal-aaalrallannaada,a.thin- ta thlak-baddad,aadlaa aaala plaaarft traapb ^y^t*> ftlltataaa, allty aadataaa,parallal-laalnalad, aaaalva. harltanlal-,rlppla- aadailaraaraaa VO0R3TEH0EK FORMATIOI laalaatad,abandanl rtppla-aarha, hlalarballan,laaallMaraaalaaaaa. m QAMKA FORMATION VA Inndaiann,Una-tamidhna areaid.tMn- I*ihtok-ftaddnd,paraMallaalnalad.plaaararaaa baddad. OVDO FORMATION 4r****0»*.htadatanaI aMalanaft afciartMn-baddad aandatana.aaallaradlaaaMara baddhn.abandaalhtataraalloa Oaartiaaaaandatanaaapaa-MUna aralnad,tMn-tatMak-baddad,planarftahaMawtreat*,areaa-bada FIG. 2. StratigraphicsectionofSouth African Devonian. Thecoarsesandstonesattopandbottom ofsectionare contiguous parts ofthe Witteberg (C3) andTable Mountain (CI) Groups, respectively and indicate upperand lowermarginsoftheBokkeveldGroup(C2).Allsedimentsaresiliciclastics;solidblack=mudslone,horizontal dashes =siltstone and close dots = fine sandstone. Fossil contentis indicated by: star- echinoderms; convex down symbol= shells; convex upsymbol = trilobites; twocurved linescrossingtowardsrighthandend = fish; leafshaped symbol = plant fragments. A shorthand nomenclature to reflect cyclicity within the Bokkeveld Grouphasemergedsothattheshales(S)alternatewiththesandstones(Q)andarenumbered fromthebaseup; thus theGydo Formation isC2S1. the Gamka Formation isC2Q1, the Voorstehoek Formation is C2S2. etc. blastoids are similarly found mainly in mud- northward advance of the shoreline and stones, shales or silty shales. progression of shelf and delta slope sediments Faunal community structures are recognised (Gydo Formation) acrossthe sand-shoal Rietvlei (Boucot, 1971; Hiller & Theron, 1988). The Formation. The latterconstitutingthe uppermost overall decrease ofBokkeveld invertebrates and unitoftheTableMountainGroup,wasdeposited increase in plant fragments and ichnofossils to in a wide shallow embayment open to the the north as the argillaceous units become southeast and flanked by a mature low gradient sandier,suggestsashallowingofthebasin inthat coastal plain (Rust, 1973). direction. There is a corresponding decrease in The Bokkeveld sequence reflects the most fossil content in a southerly direction approach- dynamic phase ofthe Cape Basin development, ing the deep basin (Theron, 1970, 1972; Theron when, at the Pragian-Emsian transition, tectonic &Loock, 1988). activity and accelerated downwarping evolved. PALAEOGEOGRAPHICAL SETTING Pulsatory cyclicity in the vertical stacking ofthe upward coarsening sequences implies techn- The conspicuous change from a few thousand ically controlled regressions and transgressions metres of supermature sand (Table Mountain (Theron, 1972; Tankard & Barwis, 1982). These Group)tothepredominantlymuddysedimentsof majorcyclesrepresenttheprogradation oflobate the BokkeveldGroupthroughouttheCapeBasin wave-dominated deltas along a coastline of & inthe EarlyDevonian, isinterpretedasanoverall moderately high marine energy (Tankard IIS MEMOIRSOFTHE QUEENSLAND MUSEUM Isteriacites sp. A. assemblageo\ i() or more complete or partial individual traces m close proximity. 1 1 J51 from Vanrhynsdorp(C2S2 i. \1 2.| Photocourtesy ofJohn Almond| Barwis. 1982; Thcron & Loock. 1988). coquinites.Fossilsarealsogenerally sparseinthe Nearshorc deposits grade southward into thick reworked sands ofthe delta platform. Wave and shelf mudstones. with the greater thickness tidal activity created interspersed barrier towards the eastern Cape reflecting increased washovcr sheets and tidal inlet and channel fill dounwarpingin that direction, sequences thai were not \ery conducive to die preservationoffossils. An idealised Bokkeveld genetic sequence consists of sediments laid down successively in On the other hand the dark grey mud and the shelf, delta slope and delta platform sihstonesofthe BokkeveldGroupcontaina rich environmentsduring the constructional phase of invertebrate fauna, especially brachiopods and deltagrowth.Thisisinturnoverlainby ncarshorc bivalves, which are preserved as scattered marine reworked deltaic deposits, which internal and external moulds- Coquinites, where represent the sediments that evolved during ihe present,arerclativeh thinbutlaterallypersistent; dcstruclional phase of delta development aswaterdepthincreasedcoquinitesbecamerarer. (Tankard & Barwis. 1982). Storm activity is Ebbingstormsurgecurrentsentrained shellsand well-documented in the delta platform sediment from the scafloor and carried them sediments, which represent the distributary seawards,to where hollowsandslonn-generalcd mouth bar. inlerdistributary bag and tidal flat channels acted as traps in which shells and disarticulated crinoidal material accumulated deposits, espccialh in the northern Bokkeveld (Hiller&Theron. 19X8) fades(TheronetaL 1995) Fossilsaregenerally sparse in these sand-, silt-, and mudstones. but Generally, post-mortem transport of fossils occasional occur as rclativeh thick lenticular was limited as indicated bv the minimal EARLY DEVONIAN ECHINODERMS OF SOUTH AFRICA Grahamstown V 14 FIG. 4. Sketch map of South Africa indicating the localities from which Lower Devonian echinoderms are known. The 2 frames around the Ceres and Ladismith-Prince Albert districts are enlarged in Figs 5 and 6, rPelsaptefcotnitveienl;y.!4Ke=yKataoban/uAmlbeexraenddrilaoc;al1i5ti=esNoouugtsai/dVeretdheefofrrta;me2s3:=5K-euBrubcokolmasntdrsa;nd6;=24G=roWoatrrimvwiaetrehroobgetreg;;1216== Clanwilliam. mechanical damage to shells. Disarticulated in the northern proximal shallow marine beds shellsarecommonbutrarelydisplayevidenceof substantiate the original abundance of starfish abrasion or breakage. Furthermore the and brittle stars in the marginal Bokkeveld seas. vulnerability of the multiplated echinoderm The relative rarity ofasterozoan body fossils in skeletons to post-mortem disaggregation the Bokkeveld sequence is therefore a reflection generally make preservation of whole crowns ofthe disintegration oftheir complex skeletons relatively rare. In the Gydo and Waboomberg after death. Both ophiuroids and asteroids Formations preservation ofechinoderms still in probably constituted quite an important life position, indicates predominantly gentle component of the normal prevalent benthic currents and sudden burial, perhaps by marine biota ofthe Bokkeveld Group. smothering mud clouds. Sudden influxes offine Available data allow correlation (Boucot, sediment may have come either from the rivers 1971; Hiller & Theron, 1988) ofseveral benthic feeding the deltas, or as a result of a storm invertebrate fossil communities with various generating a blanket of wave-stirred mud depositional subenvironments in a delta & (eTnhveirroonn,men1t9a72l;sHcielnlaerrio isThseurpopno,rte19d88b)y. Thihgihs cinoamrptliceuxl:ate1, abrtaidcahlifolpaotdcsomamnudniitnfyaudnoamlinbaitveadlvbeys concentrations of brittle stars (adult as well as inhabited the sheltered, back-barrier environ- immature individuals), constituting lenticular ment; 2, the distributary mouth bar community 'starfish beds' in the Waboombergmudstones in dominated by brachiopods, occupied the association with large numbers of infaunal relatively turbulent shallow water setting at the bivalves preserved at a high angle to bedding seaward edge ofthe delta platform; 3, the delta with their umbones pointing upwards. slope community was of intermediate aspect, Co-occurring fenestellid bryozoans, all with the dominatedbybrachiopodsbut morediverse with apices of their cones directed upwards suggest infaunal bivalves, gastropods, crinoids, overturning by gentle currents. In locally cricoconariids and especially trilobites; 4, the overlying beds well-preserved carpoids are shelfcommunity,whichalthough still dominated associated with an ostracod fauna and with by brachiopods, is the most diverse community; exquisitely preserved Lingula, which are not in brachiopods constitute <l/2 the diversity of the lifeposition (Ruta&Theron, 1997; Beckeretal., assemblage, with trilobites. bivalves and 1994). The frequency ofasterozoan trace fossils gastropods well represented and echinoderms. 120 MEMOIRS OF THE QUEENSLAND MUSEUM FIG. 5. More detailed localitymap ofCeres districtasoutlinedby lefthandframe in Fig. 4. l=Hottentotskloof; 2=Theronsberg Pass; 3=Tafelberg/Boplaas; 4=Matroosberg/Vredelus; 8=Hex River Pass; 9M3ydo Pass; 10=Die Vlakte; 12=Klipfontein/Lakenvlei; 13=Swaarmoed; 21=Eselfontein; 25=Ceres. Thickblack lines are roads; thin crossed line (lowerright) isarailway; thinblack lines are streams. hyolithids, corals, bryozoans, conulariids and In the Gydo and Gamka Formations, which cephalopodscomprisingasignificantproportion. constitute the oldest deltaic cycle, these communities are well-represented. Shelf and EARLY DEVONIAN ECHINODERMS OF SOUTH AFRICA 121 FIG.6.MoredetailedlocalitymapofPrinceAlbert-LadismithdistrictsasoutlinedbyrighthandframeinFig.4.7 =GamkapoortDam; 16=Vleiland; 17=Koudeveld; 18=Gamkaskloof; 19=BosIuiskloof;20=Damascus;22 = Vrischgewaagd. Thick black linesareroads; thin black lines are streams. slope communities are found in the Voorstehoek Formation and in western outcrops of the Waboomberg Formation, shelf community CRINOIDS 1 i 3 4 assemblages have been identified as well. In OphiocrinusslangeriSalter. 1856 G G many of the other formations, available Ophiocrinussp. cfmariae(Kier, 1952) cfS G collections are general&ly too small for com- CorochnusimbecillusSchmidt. 1941 s G munity analysis (Hiller Theron, 1988). Mandelacrinusneisomgen. etsp,nov. cfG cfG FAUNALAFFINITIES Monocycliccamerateindet. cfG All Bokkeveld echinoderm specimens known Arthroacantha?sp. ?G to the authorswere included in thepresentstudy. EckiJocnnusinierbrachiatuss.cn.etsp nov. Affinities of the taxa identified (Table 1) are Kopficrinushatbwhisp.nov. G highly equivocal. One bias in this assessment is Mortaldicrinusjohnigen.etsp.nov. cfG cfG the variation in levels ofknowledge from other Sacrinusgamkaensisgen.etsp.nov. cfG partsoftheworld.ThefaunaofNorthAmericais Sacrinushexensisgen. etsp nov cfG the best known and in general, most recently Cradeocrinusplenariussp. nov G G sktnuodiwend;buitn mEuarnoypehacvoempnaotrabbeleynlgairvgeenfaaumnoasdearme Thalamocnnusarenaceussp. nov. G taxonomic treatment; South America and Othozechnusroyigen etsp.nov. cfG ASTEROZOANS Australia have faunas of this age but they are poorly known (e.g. Australian crinoids (Jell, AulucUihaslcrhreviramusgen etsp.nov. cfG cfG 1999) as demonstrated in this volume). Early Ulrichaste?macrodentusgen etsp nov G G Devonian echinoderms from other parts of the HaughlonasterreediRilett, 1971 cfG cfG world are virtually unknown and not able to be Hexurasicrweitzi(Spencer. 1950a) F F 1- ; compared. At species level the South African Encrinastertischbeinianus(Roemer. 1862) S faunahasacrinoidandanasterozoan incommon Marginurahillerisp nov G Eugasterellaa/ncanasp.nov. & TABLE 1. Faunal affinities of the South African S1t9r7a1tasterohoensisKLeshne LeVasseui; S echinodermsdealtwithhereincomparedwithEurope Stratasterstuckenbergi(Rilett, 1971) G (A1u)s,trNaolirath(4)A.mGer=itchaeg(2e)n,usSoocuctuhrsAimnetrhiactacon(t3i)neanntd; BLASTOIDS cfG-acloselyrelatedgenusoccursincommon; S= PacfwblastusdickiBreimer&Macurda.1972 S the species alsooccurs in thatcontinent; and F =the BrachvschismaootheizeniBreimer & G family is incommon. Macurda. 1972 122 MEMOIRS OF THE QUEENSLAND MUSEUM with Europe, a crinoid and an asterozoan with Subclass CAMERATAWachsmuth North America and a blastoid in common with & Springer, 1881 South America. At the generic level most Order DIPLOBATHRIDA matches are with North America, then Europe, Moore & Laudon, 1943 then a very few with South America and Superfamily RHODOCRINITOIDEA Australia. The 25 South African echinoderms Roemer, 1855 Family OPSIOCRINIDAE Kier.1952 dealt with herein do not provide a statistically large enough sample to make any compelling Although Kier (1958) advocated elimination arguments and thus the affinities must be of the Opsiocrinidae after he recognised that considered unknown at this stage. Brachiopod Opsiocrinus was dicyclic, Ausich ( 1986) found affinities(Boucotetal., 1969)placeSouthAfrica the family useful in his classification of the in the cool water Malvinokaffric Realm Rhodocrinitoidea. Frest & Strimple (1981) and suggesting that further study ofSouth American Ausich (1986) recognised that several of his echinoderms may reveal closer affinities. familial characters are of generic standing in some cases in the same group. With this in mind theclassificationmaybeconsidered preliminary. SYSTEMATIC PALAEONTOLOGY Frest & Strimple (1981) and Ausich (1986) recognised the cofamilial relationship of The following abbreviations indicate Opsiocrinus and Ophiocrinus; weconsiderthese treexpto:s-itoBrriietsisfhorMtuhesemuatmerioafl NdaitsucruaslsedHiisntotrhye (g1e9n8e6r)a cslyanssoinfyicmasti(osneheebreelionwb)u.tWfeolluosweinAgusIiCcZhN5S Article 40 the family name based on the junior (BMNH). Geological Survey of South Africa, synonym remains valid. Pretoria (PRV), Geological Survey of South Africa, Bellville in Capetown (B), Roy Ophiocrinus Salter, 1856 Oosthuizen Collection, Zwartskraal, Prince Albert (RO), South African Museum, Capetown TYPE SPECIES. OphiocrinusstangeiiSalter, 1856from (SAM), Geological Collections, Stellenbosch the Lower Devonian Bokkeveld Series, South Africa; by monotypy. University, South Africa (SU), Rhodes University, Grahamstown (RUGDNH), Natal DIAGNOSIS. Infrabasals 5, forming a pentagon Museum, Durban (NM) and Sedgwick Museum, completely or almost completely concealed by Cambridge University, England (SM A). All stem; interbrachials numerous, depressed, small, illustrationsareoflatexcaststakenfromexternal regular, especially in proximal part ofinterrays; CD moulds unless otherwise stated; they are interray conspicuous, with anitaxis of whitened with a sublimate of ammonium subquadrate anal plates variously developed in chloride forphotography. fieldofsmall irregularplatesoneitherside.Anns 1 or20, freeandbecomingcuneatethenbiserial distal to last ami division, unbranched distally. Class CRINOIDEA Miller, 1S21 Stem circular or pentagonal in section, with narrow marginal crenularium, heteromorphic. Terminology follows Moore & Teichert REMARKS. The only significant differences (1978). Measurements are given as: length, betweenOpsiocrinusKier,1952andOphiocrinus parallel to the central axis; width, transverse to, appear to be the number of amis, length of but never cutting orjoining the central axis; and anitaxis and cross section ofthe stem. Frest & depth, normal to, and mayjoin central axis. Strimple(1981, table 1) showedthatthe2 genera FIG. 7. OphiocrinusstangeriSalter, 1856. A, deformedcrownwithpinnulatebiserial arms, R039, *1. B, C-D interray view ofcrown showing 3 vertical columns ofanal plates B4603, *2. C, small specimen showing uniserial armswell away from thecaandbiserial armon lefthigh up, B4544, x3. D,holotypecrownwithC-D interrayonleft,with 1stinterprimibrachsupporting4analplates,with uniserialbrachialsproximallygradually becomingcuneatethenbiserialdistally,SMA3441,y4.E,basalviewofsmallcupshowingsubpentagonalstem facet, fromtheGydo Formation inaquarryonE sideofroadN fromPrinceAlfred's Hamlet, 1km SofGydo, B4670, ><5.F,smalldeformedcrown SAM13479, x2.G,twocrownscompressedinthesamedirection,thaton left withdiminishedcrownlengthand thaton rightcompressedlaterallyandshowingtheinfrabasal circleton top ofthe stem viewedfrom insidethecup. SAMK972. x 1.25. EARLY DEVONIAN ECHINODERMSOF SOUTH AFRICA 123 124 MEMOIRS OF THE QUEENSLAND MUSEUM aredistinguishedonly bythenumberofarmsand inthenatureofamibrachials. Althoughthereisa reversal (clearly a typographical error) between their text and table 1 with Ophiocrinus being credited with cuneatc brachials in the text bul biserial ones in table 1. Regardless of this confusion the larger collection of O. stangerh now available,allowsconfirmationthat thearms inbothgeneraprogressdistally from rectangular tocuneatctobiserial. Lengthoftheanitaxis,with 4plates inonegenusand2 intheothercouldwell be considered a specific discriminator if CD consistent (1 intcrnn is available for Ophiocrinus and 2 for Opsiocrinus). Some camerate genera contain species with different numbers of arms. One specimen of O, stangeri (Fig. 2C)hasa raywithonly 2amisasopposedto theusual4 inadjacentrays;a2ndspecimen(Fig. IB) showsthebeginningsofthe radial interplate ridge patterns so prominentin some Opsiocrinus mariae Kicr. 1952 (Kesling & Clulman. 1975. frontispiece, pi.40. figs 11-14); several specimens (Fig. iA. 2A, 3B) have slight, barely visible re-entrants in the proximal margin of(he basal plates which probably accomodated the corners of the infrabasal pentagon as in O. mariae. This indicates that orientation of the infrabasal pentagon to the basal circlet changed from the exterior to the interior as describedby Kicr (1958. fig. 1) in 0, mariae because the interiorofthecupin 0. stangeri (Fig. 3E) shows the infrabasal pentagon with the angles at the sutures between basals and the sutures between FIG. 8. Ophiocrinus stangeri Sailer, 1856. plate infrabasalsat thecentreofthebasals.Thestemof diagramshowingstemfacetasdashedcircle,radials the North American species is inferred to be black and only 2 incompleteanus from halfofone pentagonal because of the shape of the ray;posteriorinterray at 12 o'clock. attachment facet on the cup. In O. stangeri the stem is roundbut inatleast I specimen(Fig. 1G) members and we suggest that Ophiocrinus and tpheentaagtotnaaclh.mTenhtusfwaceetsyonrontyhmeis1estthceoselu2mngeanlerias Olipnseiaogcerriantuhsercotnhsatnit2uttheatIhgaednbuseeannsdepbaerlaotnegsitnoceI despite theirgeographicand stratigraphic (Early the Early Silurian (Jell 1999, fig. 2). Devonian vs Middle Devonian) separations. Ausich (1986:87) inferred 2 lineages within the Ophiocrinusstangeri Salter.1856 Opsiocrinidae from the Llandovery into the (Figs 7-10) Devonianwiththe2Devoniangeneraonseparate lineages based on cup shape, prominence of Ophi19a7c8r:imTt4s2Ss.tafnigge.ri23S8a.l2t.er. 1856:223.pi.25, fig.20; IIbaghs, ridgesandarmnumbers.However,cupshapeand ridge pattern are identical in the 2 Devonian MATERIAL. HOLOTYPE: SMA3441 fromDe Dooms. genera and taking die rudimentary ridge pattern 1 lex Rivier Poorl (donated to the Sedgwick Museum. in a specimen of Ophiocrinus even the Cambridgein 1932 fromdiecollectionofDrW. Slanger. interbrachialornament maybeallied.Therelation BB44552263-4f5r3o0m BfurcokmlaGnadsm,kaepaosoterrtn DCaapme (PCr2oSviIn)e.e(BC425S4l4)., of the infrabasal circlet to the basal circlet is B4553, B4603 from Gvdo Pass (C2S1), B4551, B4552 another feature which seems to join the 2 from Gamkapoort Dam (C2S1), RUGDNHl from Klein Devonian genera. Other monophylctic camerate ECaaba, Alexandria district, eastern Cape (Voorstehoek genera are known to have 10 and 20 armed Formation), B4579; RO S1Z RO S20 from Grootrivier.