Echinoids

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    PORTER M. KIER

    S M I T H S O N I A N C O N T R I B U T I O N S T O P A L E O B IO L O G Y

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    SERIES PUBLICATIONS OF THE SMITHSONIAN INSTITUTIONEmphasis upon publ icat ion as a means of "d i f fus ing knowledge" was expressedby the f irst Secretary of the Smithsonian. In his formal plan for the Inst itut ion, JosephHenry out l ined a program that inc luded the fo l lowing statement : " I t is proposed topublish a series of reports, giving an account of the new discoveries in science, andof the changes made from year to year in all branches of knowledge." This themeof basic research has been adhered to through the years by thousands of t i t les issuedin ser ies publ icat ions under the Smithsonian impr int , commencing with SmithsonianContributions to Knowledge in 1848 and cont inuing with the fo l lowing act ive ser ies:

    Smithsonian Contributions to AnthropologySmithsonian Contributions to Astrophysics

    Smithsonian Contributions to BotanySmithsonian Contributions to the Earth Sciences

    Smithsonian Contributions to PaleobiologySmithsonian Contributions to ZoologySmithsonian Studies in Air and Space

    Smithsonian Studies in History and TechnologyIn these series, the Inst itut ion publishes small papers and full-scale monographsthat report the research and collect ions of its various museums and bureaux or ofprofessional colleagues in the world cf science and scholarship. The publicat ions aredist r ibuted by mai l ing l is ts to l ibrar ies, univers it ies, and s imi lar inst i tut ions throug houtthe wor ld.Papers or monographs submitted for series publicat ion are received by theSmithsonian Inst itut ion Press, subject to its own review for format and style, onlythrough departments of the var ious Smithsonian museums or bureaux, where the

    manuscripts are given substantive review. Press requirements for manuscript and artpreparat ion are out l ined on the inside back cover.S. Dillon RipleySecretarySmithsonian Inst i tut ion

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    S M I T H S O N I A N C O N T R I B U T I O N S T O P A L E O B I O L O G Y N U M B E R

    Triass ic Echinoids

    Porter M. Kier

    S M I T H S O N I A N I N S T I T U T I O N P R E S SCity of Washington

    1977

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    A B S T R A C TKier, Porter M. Triassic Echinoids. Smithsonian Contributions to Paleobiology,nu m be r 30, 88 pages, 16 figures, 21 plates, 2 tables, 1977.Although 142 species ofTriassic echino ids have been repor ted , only 24 are based on sufficient m ate rialto permit reliable generic identification. These species are redescribed and illustrated. Twelve of them are from the St. Cassian Beds in the Italian Dolomites.A large collection of specimens from these beds is described, from which areerected two new species, Megaporocidaris mariana and Levicidaris zardinia, andfive new genera: Zardinechinus, a miocidarid, Paurocidaris and Leurocidaris,cidarids, and the psychocidarids, Levicidaris and Megaporocidaris. A new pedi-noid, Hemipedina hudsoni, is described from the Norian of Arab ia. D urin gthe Early and Middle Triassic, only flexible miocidarids were present. Apparentlyall Mesozoic echinoids are descended from them. The first cidarids occur in theLate Triassic (Karnian) together with the first psychocidarids. The first certainpedinoid appears in the Norian. Finally at the close of the Triassic, in theRhaetian, the first hemicidaroid appears.

    OFFICIAL PUBLICATION DATE is handstamped in a l imited number of initial copies and is recordedin the Inst i tut ion 's annual report , Smithsonian Year. SERIES COVER DESICN: The t r i l ob i t e Phacopsrana Green.

    Library of Congress Cataloging in Publication DataKier, Porter M.Triassic echinoids.(Smithsonian contributions to paleobiology ; no. 30)Bibl iography: p.Includes index.Supt. of Docs, no.: SI 1.30:301. Sea-urchins, Fossil. 2. Paleontology T riassic. I. Tit le. II. Series: Sm ithsonian Ins tituti on .Smithsonian contributions to paleobiology ; no. 30.QE701.S56 no . 30 [QE783 .E2] 560'.8s [563'.95] 76-24806

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    ContentsPage

    Introduction . . . . 1P a l e o z o i c A n t e c e d e n t s 2E a r l y T r i a s s i c E c h i n o i d s . 3M i d d l e T r i a ss i c E c h i n o id s . . . . . 3L a t e T r i a s s i c E c h i n o i d s . 4A b b r e v i a t i o n s f o r I n s t i t u t i o n s 5A c k n o w l e d g m e n t s . . . . 5

    Ea r l y T r i a s s i c : Scy t h i an 6F a m i l y MIOCIDARIDAE D u r h a m a n d M e l v i l l e 6

    G e n u s Miocidaris D o d e r l e i n 6Miocidaris pakistanensis L i n c k 6

    G e n u s Lenticidaris Ki e r 6Lenticidaris utahensis K i e r . . . 6

    M i d d l e T r i a s s i c : L a n d i n i a n 6F a m i l y MIOCIDARIDAE D u r h a m a n d M e l v il le 6

    G e n u s Serpianotiaris J e a n n e t 6Serpianotiaris hescheleri ( J e a n n e t ) 6

    L a t e T r i a s s i c : K a r n i a n 7Species f rom th e St . Cass ian Beds 7

    Loca l i t i e s . . . 7Key to the Ec hin oid s f rom the St . Cass ian Beds 7F a m i l y MIOCIDARIDAE D u r h a m a n d M e l v i l le 8

    G e n u s Triadocidaris D o d e r l e i n . . . . . 8Triadocidaris subsimilis ( M u n s t e r ) . . . . 8Triadocidaris suessii ( L a u b e ) 1 0Triadocidaris venusta ( M u n s t e r ) . . . 11Triadocidaris giauensis (Za rd i n i ) , new co m bi n a t i o n . . 12

    F a m i l y CIDARIDAE G r a y 13G e n u s Mikrocidaris D o d e r l e i n 1 3

    Mikrocidaris pentagona ( M u n s t e r ) . . . . 13G e n u s Polycidaris Q u e n s t e d t 1 5

    Polycidaris regularis ( M u n s t e r ) 1 5Zardinechinus, new gen us 16

    Zardinechinus lancedelli ( Z a r d i n i ) , n e w c o m b i n a t i o n 16Paurocidaris, new gen us 18Paurocidaris rinbianchi ( Z a r d in i ) , n e w c o m b i n a t i o n . . . . 18

    Leurocidaris, n e w g e n u s 2 0Leurocidaris montanaro ( Z a r d i n i ) , n e w c o m b i n a t i o n 2 0

    F a m i l y PSYCHOCIDARIDAE Ikeda 21Levicidaris, n e w g e n u s 2 1

    Levicidaris zardinia, new spec ies 21Megaporocidaris, n e w g e n u s 2 2

    Megaporocidaris mariana, new spec ies 23F a m i l y TIARECHINIDAE G r e g o r y . . 24

    G e n u s Tiarechinus N e u m a y r 2 4

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    S M I T H S O N I A N C O N T R I B U T I O N S T O P A L E O B I O L O

    Tiarechinus princeps N e u m a y rG e n u s Lysechinus G r e g o r y

    Lysechinus incongruens G r e g o r yF r a g m e n t a l M a t e r i a l

    Triadocidaris species ATriadocidaris species B

    S p e ci es w i t h C r e n u l a t e T u b e r c l e sSpecies 1Species 2Species 3

    Mesodiadema? F r a g m e n t sM o r p h o l o g i c a l S p e c i m e n s

    Species Not f rom the St . Cass ian BedsO r d e r CIDAROIDA Claus

    F a m i l y MIOCIDARIDAE D u r h a m a n d M e l v i l l eG e n u s Triadocidaris D o d e r l e i n

    Triadocidaris persimilis B a t h e rTriadocidaris immunita B a t h e r

    G e n u s Dicyclocidaris Fe l lDicyclocidaris denticulata Fe l l

    O r d e r PEDINOIDA M o r t e n s e nF a m i l y PEDINIDAE Pomel

    G e n u s Hemipedina W r i g h tHemipedina? incipiens B a t h e r

    L a t e T r i a s s i c : N o r i a nO r d e r PEDINOIDA M o r t e n s e n

    F a m i l y PEDINIDAE P o m e lG e n u s Hemipedina W r i g h t . . .

    Hemipedina hudsoni, new spec iesL a t e T r i a s s i c : R h a e t i a nO r d e r CIDAROIDA C l a u s

    F a m i l y CIDARIDAE G r a yG e n u s Paracidaris P o m e l

    Paracidaris toucasi ( C o t t e a u )Paracidaris Jeanneti L a m b e r t

    O r d e r PEDINOIDA M o r t e n s e n .F a m i l y PEDINIDAE Po me l . .

    G e n u s Diademopsis D e s o rDiademopsis? desori ( S t o p p a n i )

    O r d e r Hemicidaroida B e u r l e nF a m i l y PSEUDODIADEMATIDAE P o m e lG e n u s Pseudodiadema D e s o r

    Pseudodiadema silbinense St e fan i n iG e n e r a Incertae Sedis

    Species Based on SpinesSpec i e s B ased on Fragment s

    C o r r e c t e d O c c u r r e n c e sL i t e r a t u r e C i t e dPla tes 1-21Index

    Page2424242525252626262627272828282828282828292929293030303030323232323232333333333333

    35353638394 386

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    Triass ic EchinoidsPorter M . Kier

    I n t r o d u c t i o n

    During the Early Mesozoic, echinoids underwentgreat diversification. Many new orders developed;and by the end of the era, all the orders ofechinoids now living, except the clypeasteroids andneolampadoids, had developed. Generally, i t hasbeen believed that many of these new orders hadtheir origin in the Triassic. For this reason I haveundertaken a study in detail of the Triassic echi-noid record.Although over 142 species of echinoids have beenreported from the Triassic, most of these speciesare based on spines or isolated plates. Only 24 arebased on sufficient material to permit generic identification. Furthermore, many species attributed tothe Triassic were actually collected in Jurassicrocks.Most of the Triassic echinoids, particularly thosefrom the famous St. Cassian Beds, have not beenstudied in over 100 years. Their original descript ions and i l lustrat ions are inadequate and in manyinstances erroneous. An effort has been made tostudy the type specimens of all species based onadequate material. Most of these specimens havebeen made available through the generosity of thecurators of European museums. All identifiablespecies are redescribed and reillustrated here, except for a few in which the type specimens are lost.The most important Triassic echinoid fauna isfrom the St. Cassian Beds in the Italian Dolomites.Porter M. Kier, Department of Paleobiology, National Museum of Natural History, Smithson ian Institution, Wash ington, D. C. 20560.

    An extraordinary collection of these echinoids been made by Rinaldo Zardini of Cort ina d 'Apezzo. He described and illustrated many of thspecimens in 1973 and has very generously pmitted me to study his material. The echinoids beau tifully preserved an d repre sen t 12 species, cluding those species based only on isolated spian d p lates. Five of these species are referred new genera. Two of these species are new and long to the cidaroid family Psychocidaridae, a faily not previously known to have occurred befthe Late Jurassic.Except for the St. Cassian Beds, the Triasechinoid record is exceedingly poor. Only tidentifiable species are known from the Early Tassic, only one from the Middle Triassic, and onine from the Late Triassic (other than the Cassian species).Although the evidence (Figure 1) is scanty, itnonetheless feasible to suggest the makeup of Tassic echinoid faunas. During the Early and mof the Middle Triassic, only one family of echin

    was livingthe f lexible miocidarids. This grooriginated in the Permian and is the only echinfamily that survived into the Mesozoic. I belithat all Mesozoic echinoids are descended frthem, and none of them are descended from otPaleozoic orders. In the early Late Triassic (Knian), the first echinoids occur with rigid tests aimperforate tubercles. In the Late Karnian occthe first noncidaroid (except for the aberrant plescidaroids). Although known only by fragments, small tubercles and compound plates (the earli

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    RHAETIAN

    NORIAN

    KARNIAN

    LADINIAN

    ANISIAN

    SCYTHIAN

    ST. CASSIAN BEDS L_

    SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLO

    T.immunifa BolhrTriadocidaris

    pitsIm ilisDicyclocidaris

    Paracidaris jeannet/

    Polycidaris regular/s ?Paurocidaris rmbionchiLeurocidaris montanaroMikrocidaris pentagona

    I Diademopsis} ^ jdesor * 'IHemipedina _hudson i 2| Hemipedina ?/'nap/ens Bcih*r

    Megoporocidoris-Levicidaris lordtnia ,

    Serpianotiaris ^ r ^*"">""' CIDAROIDA

    J

    Miocidarispoklstantnsls

    FIGURE 1.Distribution of the Triassic echinoids based on sufficient material to permitgeneric determinat ion.

    known) suggest that it belonged to a pedinoid. Thefirst un do ubte d p edinoid is found in the No rianand described here as a new species, Hemipedinahudsoni. Finally at the close of the Triassic, in theRhaetian, the first hemicidaroid appears. In summary only one order, Cidaroida, is present duringthe Early and Middle Triassic, but two more arepresent by the end of the Triassic, Pedinoida andHemicidaroida.

    During the Jurassic (Figure 2) three new ordersare introduced in the Hettangian: the Diadema-toida, the Phymosomatoida, and the Salenioida.The Pygasteroida originate during the Sinemurian;the Holectypoida, during the Pliensbachian; theCassiduloida and Holasteroida during the Toarcian;and the Arbacioida and Orthopsida during theBathonian. The Echinothurioida appear during theOxfordian, and it is not until the Early Cretaceous(Neocomian) that the Spatangoida occur. In summary, the Triassic is not the time of greatest evolutionary change among the echinoids. Only threenew orders originated then as contrasted to ten inthe Jurassic.

    Paleozoic AntecedentsOnly two families of echinoids have been fouin the Late Permian. One of them is the last of tflexible lepidestids, Pronechinus anatoliensis Kifrom the Late Permian of Turkey. The lepidestihave more than two columns of imbricating platin both the interambulacra and ambulacra. Theisolated ambulacral plates are easily identified their small size and hexagonal shape. None of theplates has ever been found in any post-Permirocks. It is, therefore, a reasonable assumption ththis group became extinct at the end of the PermiaThe other family of Late Permian echinoid is tmiocidarids. These echinoids are descendants of tarcheocidarids (Kier, 1968) and differ from the moern cidaroids primarily in having a test with ibricating plates. It is from this group that all tpost-Paleozoic echinoids evolved. Although Mortesen (1935:50) and Philip (1965) suggested that somof the post-Paleozoic echinoids were derived froPaleozoic noncidarids, Durham and Melvi(1957:250), and Kier (1965:451, 1974:4) can find evidence to support this view and assert that a

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    NUMBER 30

    |C

    AOU

    k

    JRASSIC

    TRIASSIC

    1

    NEOCOMIAN

    PORTLANDIAN vKIMMERIDGIAN/OXFORDIAN /CALLOVIAN

    BATHONIAN

    BAJOCIANTOARCIAN

    PLIENSBACHIANSINEMURIAN

    HETTAN6IAN

    RHAETIAN ;NORIAN

    KARNIANLADINIAN

    ANISIAN

    S CY THI AN

    C I D A R

    D

    :DARI

    MIC

    kRID J

    D

    -EOC JCL

    CIDARIDAE

    O I D

    UJ

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    S M I T H S O N I A N C O N T R I B U T I O N S T O P A L E O B I O L O

    layer on its spines, this layer is also lacking inLenticidaris. However, its test is less flexible thanin the two Early Triassic miocidarids, which is tobe expected considering its younger age.

    Late Triassic EchinoidsIt is not until the Late Triassic that any kind ofechinoids other than miocidarids are found. Themost prolific echinoid fauna of the Triassic occursin the St. Cassian Beds in the Italian DolomiteMountains. They are considered by Silberling andTozer (1968:14) to be lowermost Karnian, but someworkers place them in the late Ladinian and earlyKarnian. Although specimens have been collectedfrom these beds for over one hundred years, the

    most significant collections have been made latelyby Rinaldo Zardini. Many of his specimens areillustrated here.Five species of miocidarids have been found inthese beds: Zardinechinus lancedelli (Zardini), Triadocidaris venusta (Munster), T. suessii (Laube), T.giauensis (Zardini), and T. subsimilis (Munster) .Coinciding with these, the first nonmiocidarids appear. Until this time all the known Triassic echinoids had flexible tests, characteristic of the miocidarids, and perforate tubercles. Two families of the

    Cidaroida having rigid tests first appear in theCidaridae and the Psychocidaridae. Within theCidaridae three species have been found in the St.Cassian Beds: Paurocidaris rinbianchi (Zardini),Leurocidaris montanaro (Zardini), and Mikrocidarispentagona (Munster). Two of these species are referred here to new genera.A fifth cidarid, Polycidaris regularis (Munster),has been reported from these beds; but I suspectthat its type specimen (and only known specimen)came from the Late Jurassic (Oxfordian), not from

    the St. Cassian Beds.Two new species of the Psychocidaridae are present : Levicidaris zardinia and Megaporocidaris ma-riana. Both of these species have imperforate tubercles and nonconjugate pore-pairs. They are theearliest species possessing these characters. All Paleozoic and Early and Middle Triassic cidaroids hadperforate tubercles. No imperforate tubercles arefound in any miocidarids or archeocidarids.Finally, in the St. Cassian Beds, appears the mostunusual echinoid, Tiarechinus princeps Neumayr .

    Among its peculiar characters is the presence ofsingle plate at the peristome in each interambucrum and three plates in the row above. There genital pores in only two of the genital plates, ano madreporite. Some workers have considered tspecies to be related to the Paleozoic echinoids cause of i ts mult icolumned interambulacra. Othhave noted its resemblance to an immature of arbacioid and have postulated that it was ancestto the arbacioids.

    Four Karnian species are known from other ththe St. Cassian Beds. Fell's (1950) Dicyclocidadenticulata from New Zealand is a typical miocidrid as are Bather's two species from Bakony: Tadocidaris persimilis of St. Cassian age and T. imunita from the late Karnian (Raiblian). Althouthese species are based only on fragments, they cbe generically identified.

    A third species described by Bather from tRaiblian of Bakony is the earliest echinoid knowin the Triassic that is not typically cidaroid (excefor the aberrant Tiarechinidae) . Although onfragments have been found of this species, Hempedina? incipiens Bather, enough is known to dicate that it is intermediate in its morphologiccharacters between a miocidarid and pedinoid. has the denticles on its interambulacral plates tycal of a miocidarid, such as Triadocidaris, and tinterambulacral lantern supports of a cidaroid. Tmore advanced features of a pedinoid are evidealso: wide interambulacra, relatively small primatubercles, and large, serially arranged secondatubercles.

    It is later in the Norian that the first certapedinoid is found, Hemipedina hudsoni, new spcies. This species is more advanced than Hemipdina? incipiens. Its lantern supports are in the abulacra, typical of a pedinoid; it lacks denticles its interambulacral plates. No other well-preservechinoids have been found in the Norian.

    Four species are known from the Rhaetian: twspecies of cidaroids, one pedinoid, and the earliehemicidaroid. One of the cidarids, Paracidaris tocasi (Cotteau), is based on an extremely wepreserved specimen, which was in the Cotteau Colection but can no longer be located. The othcidarid, P. jeanneti Lambert, is based on poormaterial but clearly belongs to this genus. Tpedinoid, Diademopsis? desori (Stoppani) has nev

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    NUMBER 30been well described or illustrated; and unfortunately, all the type specimens have been lost. Onecannot be certain of its generic identification, butit is clearly a noncidaroid and probably a pedinoid.

    The type specimen of the earliest hemicidaroid,Pseudodiadema silbinense Stefanini, is also lost.Stefanini's description and illustration are sufficientto show that it is a hemicidaroid and, therefore, theoldest known member of the superorder Echinacea.Although no teeth have been found of this species,they were probably keeled, a character typical ofthis order. This is the only echinoid known fromthe Triassic that is suspected of having had keeledteeth.

    In summary, the echinoids of the Early and Middle Triassic were all miocidarids with flexible testsand simple ambulacra lacking any compounding ofthe plates. At the beginning of the Late Triassic,the first rigid cidaroids appear and also the firstcidaroids having imperforate tubercles, nonconju-gate pore-pairs , and incipient compounding ofplates. The f i rst noncidaroid, a pedinoid, appearslater in the Raibl ian. Final ly in the Rhaet ian thefirst hemicidaroid appears.

    Abbreviat ions for Inst i tut ionsBM NH Bri t i sh Museum (Natura l History) , Lond on, Eng

    l andBSPG Bayerische Staatss amm lung fiir Palao ntologie undHistor ische Geologie , Munich, West Germany

    GB Geologische Bundes ansta l t , V ienna, Austr iaIGP Institut fi ir Geologie und Palaontologie der Un i-

    versi ta t , Tubingen, West GermanyIGPB Instituto df Geologia e Paleontologia, Universita

    di Bologna, ItalyMCA Museo di Co rtina d'Ampezzo, Cor tina d'Ampezzo,

    ItalyNM Naturhisto r ische Museum , V ienna, Austr iaN M NH Nat ion al Museum of Natu ra l History, Smithsonian

    Inst i tut ion, Washington, D. C. (Some specimensuse acronym "USNM" for former Uni ted Sta tesNat ional Museum.)

    NZGS New Zealand Geological Survey, We llingto n, NewZealand

    PIM Palaontologisches Inst i tut und Museum, Universi ta tZurich, Zurich, Switzerland

    AcknowledgmentsI am part icularly indebted to Rinaldo Zardini ofCortina d'Ampezzo, Italy, who made available hisgreat collection of St. Cassian echinoids. He per

    mitted me to study the thousands of specimens afragments that he has unearthed over the last foyears. This collection is the most significant of the Triassic material known. During my visi t Cortin a in Septembe r 1975, he not only guide d to most of his localities (making it possible to clect from these sites), but he also described stratigraphic relationships of the beds. Mr. Zardhas assembled the largest collection of Triassic fsils in the world and has, with characteristic gerosity, made these collections available to speciists throughout the world. His collection is nhoused and beautifully exhibited in the Museo Cortina d'Ampezzo.

    I thank Dr. David L. Pawson of the NatioMuseum of Natural History, Smithsonian Inst ition, and Professor J. Wyatt Durham of the Uversity of California, Berkeley, for reading manuscript and for making many useful suggestioMiss Mary Hurd Lawson, museum technician, dthe photography, helped to sort the St. Cassfragments, and assisted in many other ways in writing of this pap er. Figures 1 and 2 were m aby Larry B. Isham, scientific illustrator.

    Drs. Riccardo Assereto of the Istituto df Geoloat the Universi ta di Milano and Norman J. Si lbling of Stanford University provided valuable strigraphic information and modern dates for some the Triassic formations. Dr. Richard P. S. Jefferof the British Museum (Natural History) mkindly permitted me to study the specimen ofnew species from Arabia.

    Many curators lent Triassic echinoids from thcollections or helped in the search for lost spemens. I thank the following: Dr. H. K. ErbGeologisch-Palaontologisches Institute der Rheischer Friedrich-Wilhelms-Universitat, Bonn; V olker Fahlbu sch, Bayerische Staatssam mlun g Palaontologie u. historische Geologie, Munich; E. Montanaro Gall i tel l i , Inst i tuto df PaleontologUniversi ta di Modena; D r. Richard V . Melvil le, stitute of Geological Sciences, London; Dr. HughOwen, Bri t ish Museum (Natural History) , LondDr. ssa Antonietta Padovani, Instftuto di Geoloe Paleontologia, Universita di Bologna; Dr. DanPajaud, Laboratoire de Palaontologie des Invebr

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    SMITHSONIAN CONTRIBUTIONS T O PALEOBIOLO

    Sud Centre d'Orsay; Dr. Giovanni Pinna, MuseoCivico di Storia Naturale, Milan; Dr. Hans Rieber,Palaontologisches Institut und Museum, UniversitatZurich; Dr. Jean Roman, Museum National d 'Histoire Naturelle, Institut de Palaontologie, Paris;Drs. A. W . Ru ttn er an d H arald Lo bitzer, Geolo-ffische Bund esanstalt , V ienna; Dr. Ortw in Schultz,

    Naturhistorisches Museum, V ienna; Drs. JoWendt and Frank Westphal , Inst i tut und Museufiir Geologie und Palaontologie, Universitat Tubgen; Dr. H. Zapfe, Palaontologisches Institut, Uversitat der W ien, V ienna; Dr. H ans K. ZobeleBayerische Staatssammlung fiir Palaontologie historische Geologie, Munich.

    E a r l y T r i a s s i c : S c y t h i a nFami ly MIOCIDARIDAE Durham and Melvi l le

    Genus Miocidaris DoderleinMiocidaris pakistanensis Linck

    PLATE I: FIGURE 1Miocidaris pakistanensis Linck, 1955:489, figs. 1-4.

    Th is species has been carefully described byLinck and no redescription is necessary. I havestudied the holotype and include new photographsof it. This species is similar to the other EarlyTriassic echinoid Lenticidaris utahensis Kier inhaving a very flexible adapical surface. This flexibility apparently is a primitive character, for it isless developed in Late Triassic miocidarids.LOCATION O F T Y P E SPECIMEN.IGP, Ech. 1058/1.OCCURRENCE.Early Triassic, Scythian ("Untere

    Cerat i ten-Schichten") , Sal t Range, Fundort Mial iwani bei Chhidru, Pakistan.Genus Lenticidaris Kier

    Lenticidaris utahensis KierPLATE 1: FIGURES 2, 3

    Lenticidaris utahensis Kier, 1968:1000, fig. 1, pl. 121: figs2, pl . 122: fig. 103, p l . 123: figs. 3-9.This species has just recently been described, aI have nothing new to add to its description. Tspecies is of special interest because of its strongimbricate adapical surface.LOCATION O F T Y P E SPECIMENS.USNM S508S5096.OCCURRENCE.Early Triassic, Scythian, V irg

    Form ation, lower part of Moenko pi G rou p, 14 kSW of St. George, Utah.

    M i d d l e T r i a s s i c : L a d i n i a nFami ly MIOCIDARIDAE Durham and Melvi l le

    Genus Serpianotiaris JeannetSerpianotiaris hescheleri (Jeannet)

    PLATE 2: FIGURES 1, 2Miocidaris (Serpianotiaris) hescheleri Jeanne t , 1933:1, figs.

    1-2, pl. 30 : figs. 1-13.Serpianotiaris hescheleri (Jeannet) .Mortensen, 1935:298, figs.

    158a-cFell. 1966b:U366a, fig. 271(l)a-c.Dr. Hans Rieber of the Palaontologisches Institutund Museum at the University of Zurich, Switzerland, has most kindly sent me a superb cast andphotographs (Plate 2: figures 1, 2) of the holotype

    housed in his institution. Study of this material rveals no characters not mentioned in Jeannethorough description (except for the presence ofcortex layer on some of the spines) so no redescrition is warranted here.Mortensen (1935:298) believed that this specicould not be a cidaroid because of the presence three characters he thought absent in all cidaroidthe presence of two rows of large secondary tuberclin each interambulacrum, the lack of a cortex layand collar on the spines, and the rounded, projecing adoral edges of the interambulacra. However,can see on several of the spines a slightly developcollar; and some appear to have a thin cortex layeFurthermore, no cortex layer or collar is present oLenticidaris utahensis Kier, a species that is de

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    NUMBER 30nitely'a cidaroid, so the absence of a cortex layercan no longer be considered as excluding a speciesfrom being considered a cidaroid. Some Triassiccidaroids such as Levicidaris zardinia, new species,Zardinechinus lancedelli (Zardini), Triadocidarisvenusta (Munster) , Megaporocidaris mariana, newspecies, and Lenticidaris utahensis Kier, also havethe adoral edges of their interambulacra rounded.Only in having extra rows of tubercles does Serpianotiaris hescheleri differ from other Triassic cida

    roids. I agree with Jeannet (1933:1) that the specbelongs with the miocidarids. Its imbricate plawith the interambulacra dent iculate at their adrial margins and bevel ing over the ambulacra alarge, perforate, crenulate tubercles are characttypical of Miocidaris. It is distinguishe d from tgenus only by the extra tubercles.OCCURRENCE.Middle Triassic, Ladinian, frnear Serpiano (Aqua del Ghiffo, Tessin meridionaSwitzerland.

    L a t e T r i a s s i c : K a r n i a nSPECIES FROM THE ST. CASSIAN BEDS

    LocalitiesPresumably the material described from the St.Cassian Beds by Munster and Laube came fromlocalities near St. Cassiano, but detailed locality information is not given by either author. Mr. Zardini's specimens were collected over a period offorty years from many different localities. I visitedmost of these sites with Mr. Zardini in the fall of

    1975; and although it is still possible to colleechinoid fragments, they are rare. According Mr. Zard ini (1975: pers. comm .), new sites are maavailable when fresh exposures result from lanslides or new excavations. The St. Cassian Beare very extensive in the area around Cortind'Ampezzo, and it can be expected that many moimportant collections will be made from them. M

    10.

    Key to the Echinoids from the St. Cassian BedsMore tha n two columns of p lates in each in teram bulacr um

    Tiarechintis princeps N e u m a y rTwo columns of p lates in each in tera mbu lacru m 2Tubercles perforate throu ghou t test 3Tuberc les perforate adapical ly , imperfor ate adoral ly 6Tuberc les impe rforate 10Tuberc les crenulate 4Tuberc les not crenulate 5Test small , low, few in terambulacral p lates

    Paurocidaris rinbianchi (Zardini) , new combinat ionTest large, many in terambulacral p lates Polycidaris regularis (Munster)Ambulacra extend to apical system, ambulacral p lates more numerous, mamelons large . . . .

    Zardinechinus lancedelli (Zardini) , new combinat ionAmbulacra not extending to apical system, few ambulacral p latesMikrocidaris pentagona (Munster)Tuberc les crenu la te Leurocidaris montanaro (Zardini) , new combinat ionTubercles not crenula te 7Scrobicules transversely elongated Triadocidaris suessii (Laube)Scrobicules circu lar 8Te s t high 9Tes t lo w Triadocidaris venusta (Muns te r )Few in te rambu lacra l p la tes Triadocidaris subsimilis (Munster)N u m e ro u s in te rambu lacra l p la tes Triadocidaris giauensis (Zardini) , new combinat ion

    Te s t circular, ambulacral p lates low Levicidaris zardinia, new speciesTes t pen tagona l , ambu lacra l p la tes h igh Megaporocidaris mariana, new species

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    8 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOZardini's magnificent collection of St. Cassian fossils is housed in the Museo di Cortina d'Ampezzo,where they are well exhibited and available forstudy.

    The echinoids occur in gray and brown limestones (Zardini, 1973a) associated with a rich faunaof corals, sponges, brachiopods, and mollusks. Thefossils are extremely well preserved. Aragonite isstill present in the corals and sponges, and manyof the mollusks retain their color markings. Zardini(1973b:4) estimates that over 800 invertebrate species are present. Although the localities cover alarge area, Zardini (1976, personal correspondence)believes that these beds were deposited at approximately the same time in a similar shallow coralreef-lagoon environment. He bases this conclusionon the presence of many of the same species at allthese localities.The echinoids described herein came from the following localities:Alpe di Specie: SW of base of Mt. Specie, approximately 12

    km NE of Cortina d'Ampezzo, Dolomites, Italy.Boa Staolin: 1 km N E of Alvera, app rox . 2.5 km NE of

    Cortina d'Ampezzo, Dolomites, Italy.Campo: App roximately 2.01 km S of Cortina d'Ampezzo,

    Dolomites, Italy.Cianzope: 2.5 km E of Lago Bai di Dones, approximately

    5.5 km W of Cortina d'Ampezzo, Dolomites, Italy.Forcella Giau: 2.5 km NE of Selva di Cadore , approximate ly

    9 km SW of Cortina d'Ampezzo, Dolomites, Italy.Milieres: 0.5 km W of C am po di Sotto, a town 2.25 km S of

    Cortina d'Ampezzo, Dolomites, Italy.Misurina: 2 km E of base of Mt. Cristallino, 10.5 km NE of

    Cortina d'Ampezzo, Dolomites, Italy.Rumerlo: 0.25-0.5 km S of Rum er lo, tow n 2.5 km W of

    Cortina d'Ampezzo, Italy.Tamarin: 300 m NE of Lake Tamarin, approximate ly 3 km

    NE of Cortina d'Ampezzo, Dolomites, Italy.

    Fami ly MIOCIDARIDAE Durham and Melvi l leGenus Triadocidaris Doderlein

    Triadocidaris subsimilis (Munster)FIGURE 3, PLATE 4: FICURES 3-6, PLATE 5: FIGURE 1

    Cidaris subsimilis Munster, in Wissmann and Munster, 1841:40, pl. 3: fig. 2Laube, 1865a:280, pl. 8b: fig. 4, pl. 9: fig. 1.

    Triadocidaris subsimilis (Munster).Doderlein, 1887:39.Ba ther , 1909:69-76, 78, 93-94 , 244, 259.V enzo, 1934:151,p l. 13: fig. 7.Kier, 1974:17, 43, 44, 71, 79. fig. 41A.

    Two specimens of Miinster's three syntypes (V II 437, in BSPG) are only single in tera m bu lacplates, but the third includes part of two interabulacra and an ambulacrum. This specimen wconsidered by Bather (1909:70) to be the holotybut because Munster did not indicate which his three specimens was the holotype, Bathestatement that one was the holotype constitudesignation of it as the lectotype. It is figured Munster 's plate 3: figure 2 (with the image versed and turned upside down), and on my Pla4: figure 3. It appears to be the same specimen fured by Laube (1865a, pl. 9: fig. Ic). It is 17.7 mwide and 16.5 mm h igh and app aren tly comes frothe ambital region of the test. Portions of six plaare present in one interambulacrum, but onlysmall part of two are present in the other. Tmamelon is preserved on three of the plates. It prominent, rising 1.6 mm above the parapet of tplatform, circular in outline when viewed froabove, and sharply undercut . The two more adaical mamelons are perforate with foramina elogated dorsoventrally; the more adoral mamelon imperforate. The boss has a definite platform wia slightly raised parapet. The scrobicule is slightdepressed below the general level of the test alacks a basal terrace. Only one plate has a coplete ring of scrobicular tubercles preserved wi13 tubercles and a small elongate node separatieach tubercle. The scrobicular rings of two of tadjacent plates are in contact with each other, bmore widely separated (1.5-2.3 mm) between otheA few, irregularly arranged nodes are present these areas outside of the scrobicular rings.

    The ambulacrum is slightly arcuate and 3.1 mwide. It is composed of primary plates with plates abutting against a single interambulacrplate. Each plate curves adapically near the peradial suture. Most of the plates bear a single nobetween the inner pore and the perradial suture ecept the more adoral plates in which this node absent on some of the alternate plates. These platlacking nodes narrow towards the perradial suturA high protuberance is present between the porof each pore-pair. The ambulacral plates bevel uder the interambulacra.

    The orientation of this specimen can be detemined by the fact that in this species the ambulacrplates at the perradial suture curve slightly adap

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    NUMBER 30

    FIGURE 3.Triadocidaris subsimilis (Munster), view of portion of an ambulacrum at the ambitus showing the wideningof every other plate or every third near the perradial suture,X 9. (For photographs of this specimen, see Plate 4: figures

    4-6.)

    cally. T h i s is s h o w n in Laube ' s (1865a , p l . 8: fig. 4)f igured spec i me n (de sc r i bed be l ow) in w h i c h theapica l sys tem is p r e s e n t and the o r i e n t a t i o n of thetest is k n o w n .

    T h r o u g h the k i n d n e s s of Dr. O r t w i n S c h u l t z oft h e N a t u r h i s t o r i s c h e M u s e u m in V i en n a , I h a v eb e e n a b l e to b o r r o w the s p e c i m e n t h a t L a u b e f i g u r e d . It is fa i r l y compl e t e , bu t his i l l u s t r a t i o n is ani n a c c u r a t e r e c o n s t r u c t i o n . T he figure shows perf o r a t e p r i m a r y t u b e r c l e s ; but, all the t u b e r c l e s ont h e specimen are i m p e r f o r a t e . N o n e of the a d a p i c a l t u b e r c l e s h a v e t h e i r m a m e l o n s p r e s e r v e d , so itis not poss i b l e to k n o w w h e t h e r t h i s s p e c i m e n iss i mi l a r to the l e c t o t y p e in h a v i n g the a d o r a l tu b e r c l e s i m p e r f o r a t e and the adapi ca l t ube rc l e s pe r fora t e . It is s i m i l a r in all ot he r re spec t s to thel e c t o t y p e in the w i d t h of the a m b u l a c r u m , n u m b e ro f a m b u l a c r a l p l a t e s a d j a c e n t to an i n t e r a m b u l a c r a lp l a t e , an d n u m b e r an d p o s i t i o n of the s c r o b i c u l a rt ube rc l e s . B ecause t h i s is the best preserved spec i m e n of thi s spec ies , it is d e s c r i b e d in de t a i l be l owand figured on P l a t e 4: figures 4-6.M A T E R I A L . T h e s p e c i m e n is part ial ly flat teneda n d is 25 m m w i d e and 15 m m h i g h . It was p r o b a b l y a p p r o x i m a t e l y 23 mm in h o r i z o n t a l d i a m e t e r .T h e p e r i s t o m i a l r e g i o n is d e s t r o y e d .

    A P I C A L SYSTEM.This is on e of the few Tri assi ce c h i n o i d s k n o w n w i t h any p a r t of its apica l sys temp r e s e r v e d . T he sys tem was o r i g i n a l l y an a p p r o x i m a t e 13 m m in d i a m e t e r w i t h a m a d r e p o r i c g e n i t a lp l a t e s l i gh t l y l a rge r t han the o t h e r s . E a c h g e n i t a lp l a t e has a s i ng l e pore wi t h a ra i sed r im e n c i r c l i n g

    i t . A s l i gh t r im o c c u r s on the i n n e r e d g e of eg e n i t a l p l a t e f o r m i n g a c o n t i n u o u s r im a r o u n dp e r i p r o c t . Tw o to f o u r s e c o n d a r y t u b e r c l e s ar e pe n t on e a c h g e n i t a l p l a t e . T he p e r i p r o c t a l o p e nw a s p r o b a b l y s u b c i r c u l a r o r i g i n a l l y . T he o c up l a t es a r e e x se r t , i m b r i c a t i n g o v e r the g e n i t a l p l aa n d are a p p r o x i m a t e l y o n e - h a l f as l a r g e as geni t a l p l a t e s .

    A M BU L A CRA . T h e a m b u l a c r a are s l i gh t l y a ra te , and t h e i r w i d t h r e m a i n s a p p r o x i m a t e l ys a m e t h r o u g h o u t t h e i r l e n g t h . E a c h a m b u l a c r u m2.6 m m w i d e (11 p e r c e n t D ) . T h e r e are 92 pl a t e sa n a m b u l a c r u m ( b o t h c o l u m n s ) w i t h a p p r o x i m a t1 6 p l a t e s a b u t t i n g a g a i n s t a s i n g l e i n t e r a m b uc r u m p l a t e . T he pl a t e s are all p r i m a r i e s ; bu t evo t h e r p l a t e (or in some ca se s eve ry t h i rd ) nea ra m b i t u s is w i d e r n e a r the p e r r a d i a l s u t u r e , wht he p l a t e s curve adap i ca l l y (F i gure 3 ; P l a t e 4: fig5) . A seconda ry t ube rc l e occurs on t he se wip l a t e s . T he o u t e r p o r e of e a c h p o r e - p a i r is me l o n g a t e d t h a n the i n n e r , and a h i g h p r o t u b e r a( P l a t e 4: figure 5) s e p a r a t e s the p o r e s . T he a ml ac ra beve l unde r the i n t e r a m b u l a c r a .

    INTERAMBULACRA.Each a r e a has seven p l a( b o t h c o l u m n s ) and all the pl a t e s bea r a l at u b e r c l e e x c e p t the f i rs t (adapica l ) pla te in . r i g h t c o l u m n of each a rea and the l a s t p l( a d o r a l ) in e i t h e r the r i g h t or l e f t c o l u m n . Tp r i m a r y t u b e r c l e s h a v e a w e l l - d e v e l o p e d s c r o b i c ucircle 5.5 mm in d i a m e t e r w i t h 15-17 s e c o n dt ube rc l e s in e a c h r i n g . T he s c r o b i c u l e is on same l eve l as the res t of the test an d gent l y r ito the boss . T he m a m e l o n is c i r c u l a r an d u n dcut . T he m a m e l o n s are pre se rved on l y on t ube rc l e s at or b e l o w the a m b i t u s . All of t he sei m p e r f o r a t e .

    R E M A R K S . T h e w i d e n i n g of s o m e of the abul ac ra l p l a t e s nea r the p e r r a d i a l s u t u r e and p r e s e n c e of a t u b e r c l e on t h i s w i d e n e d a r e a ai t s absence on the n a r r o w e r , i n t e r v e n i n g p l a t e sd i ca t e s the d e v e l o p m e n t of a p r i m i t i v e c o m p o ui n g of t he se p l a t e s .

    L A U B E ' S O T H E R S P E C I M E N S . D r . A. W. R ut tof the G e o l o g i s c h e B u n d e s a n s t a l t , V i e n n a , vk i n d l y p e r m i t t e d me to s t u d y the s p e c i m e n s h oi n Lau be ' s (1865a ) p l a t e 9: figures la, b. It csists of a p a r t of two i n t e r a m b u l a c r a l p l a t e s . Is i m i l a r to M u n s t e r ' s s p e c i m e n s and is of spec i a lte res t in t h a t it shows c l ea r l y the g r o o v e s on

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    10 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLO

    inside of the plates where the in te rambu lacrumbevels over the ambu lacru m (Plate 5: figure 1). Thespecimen figured in Laube' s (1865a) plate 9: figurelc is not present at Vienna and appears to beMinist er' s lectotype . Laube (1865a:280) states thatthe specimen figured on his plate 9: figure la isone of Munster's original specimens; but it differsfrom all Munster's syntypes. Presumably, he wasreferring to his plate 9: figure l c , not la.

    O C C U R R EN C E. Th e precise localities for Munster's and Laube's specimens are not known except that they came from the St. Cassian Beds nearSt. Cassiano. One specimen in the Zard ini collectionis from Alpe di Specie and one from Misur ina.

    Triadocidaris suessii (Laube)PLATE 5: FIGURES 2-4

    Cidaris suessii Laube, 1865a:282, pl. 9: figs. 11, 11a.Triadocidaris suessii (Laube).Doderlein, 1887:39.Lambert,

    1900:42.Bather, 1909:69, 75, 76, 78.

    M A T E R I A L . L a u b e ' s two type specimens from theSt. Cassian Beds were borrowed from the Geo-logische Bundesanstalt in Vienna. His figured specimen is selected here as the lectotype. Each specimen consists of part of a single in te rambulacrum.The lectotype (Plate 5: figures 3, 4) is 16.9 mmhigh; although most of an interambulacrum ispresent, part of the adoral area is missing. Thespecimen is 12.4 mm wide, the width of the interambulacrum at the ambitus. Because so little ofthe specimen is preserved, it is difficult to e stimatethe or igi nal size of the echinoid . Ju dg in g from the

    curvature of the test, it was probably 25-30 mm horizon tal diamete r and 20-22 mm high. The palectotype (Plate 5: figure 2) is smaller , 12.0 mhigh and 9.2 mm wide (the width of the intambulacrum). Th e echinoi d was origi nally abo13-16 mm in hor izontal diamet er and 13 mm higThe lectotype consists of 13 in te rambu lacral plawith 3-5 missing adorally. The paratype is an terambulacrum composed of 14 plates with at leaone missing adorally. Measurements of a tuberfor each specimen are on Table 1.

    The primary tubercles on both specimens hacircular perforations, well-differentiated and undcut mamelons, and distinct parapets on the plform of their boss. The scrobicules are wider thhigh, depressed, and nearly confluent, separattransversely by only a single row of secondatubercles.

    Most of the bosses are not crenulate, but seveof the tubercles on both specimens have slignotches in the platforms of their bosses that appeto be crenulations (Plate 5: figure 4).

    The median tract of secondary tubercles (alothe interradial suture) between the scrobicules approximately 2.3 mm wide at the ambitus in tlectotype and 1.5 mm in the paratype.

    The interambulacra of both specimens are beled along their adradial margins, and slight dticulations are present indicating that the intambulacra beveled over the ambulacra as typical Triadocidaris.

    C O M P A R I S O N W I T H O T H E R SPECIES.Triadocidasuessii is easly dis tingui shed from t he ot her specof this genus from the St. Cassian Beds by its higtest and its transversely elongated scrobicules. T

    TABLE 1.Dimensions (in mm) of a tubercle on the ambitus on each specimenof Triadocidaris suessii

    Character measured Lectotype ParalectotypeHeight of interambulacral plateWidt h of inte rambulacral plateHeight of scrobiculeWidth of scrobiculeHeight (transverse) of bossWidth of bossDiameter of platformDiameter of mamelonVertical height from top of mamelon to base of scrobicule

    3.16.72.84.42.452.751.601.051.25

    3.05.32.73.9

    1.250.851.25

    The base of the boss is not clearly differentiated on the paratype.

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    NUMBER 30

    scrobicules are more circular in the other species.O C C U R R EN C E. N o specimens of this species are

    present in Zardini's collections. Late Triassic, earlyKarnian, St. Cassian Beds, Italy.

    Triadocidaris venusta (Munster)P LATE 5: FIGURES 5-8

    Cidaris venusta Munster, in Wissmann and Munster, 1841:41,pl. 3: fig. 4.D'Orbigny, 1849:206.Desor, 1858:4.Laube,1865a:280, pl. 9: fig. 2; 1865b:325.

    Triadocidaris venusta (Munster).Doderlein, 1887:39.Bather, 1909:69, 75.

    Microcidaris venusta (Munster).Lambert, 1900:44.Lambertand Thtery, 1910:140.

    Mikrocidaris venusta (Munster).Mortensen, 1928:64, fig.34:3.Kier, 1974:17.

    ?Cidaris gerana Braun, in Wissmann and Munster, 1841:42,pl. 3: fig. 7.D'Orbigny, 1849:206.Desor, 1858:4.Laube,1865a:282, pl. 9: fig. 10; 1865b:325.Zardini, 1973a:12, pl.5: figs. 21,22, 23.

    }Mikrocidaris gerana (Braun).Doderlein, 1887:39.Mortensen, 1928:64.

    }Microcidaris gerana (Braun).Lambert and Thiery, 1910:140.M A T E R I A L . T h e holotype (AS V II 436, in BSPG)

    is a well-preserved specimen with most of the platesutures visible. T he specimen is very small with ahorizontal diameter (D) of only 4.8 mm and aheight of 2.4 mm (50 percent D).

    A P I C A L S Y S T E M . N o plates of the system arepreserved. T he system had a width of 2.25 mm(47 percent D) an d was pentagonal in outer outlinewith the apices in the ambulacra.

    A M B U L A C R A . T h e ambulacra are moderatelywide with a greatest width of 0.75 mm, 40 percentof the width of the interambulacra. T he areas donot narrow when approaching the peristome bu thave approximately the same widdi from the ambitus to the peristome. T he ambulacra are slightlysinuous, with approximately 36 plates in each area.All the plates are primaries, an d each plate bearsone node between the pore-pair and the parradialsuture forming a vertical series of nodes. T he pore-pairs are oblique with the outer pore of each pairadapical to the inner. T he pores are not conjugate;a ridge lies between pores of a pair.

    INTERAMBULACRA.Each area is composed ofnine plates, the largest of which is the most adapical one . T o t he right of this large plate is a smallplate lacking a tubercle. T he primary tubercles

    have very large, elevated , perforate mamel ons wslightly undercut necks. Their bosses ar estrongly elevated and are not crenulate. T he scroular tubercles extend around the outer marginthe plates with approximately 12 to each primtubercle. T he interambulacra bevel over the abulacra an d have a denticulate margin alongambulacra.

    P E R I S T O M E . T h e peristome is large with a ameter of 2.60 mm or 54 percent the horizondiameter of the test. There appear to be slight slits (Plate 5: figure 8).

    R E M A R K S . A l t h o u g h this specimen is very smthere is no evidence that it is immature. Unftunately, the apical system is not preserved. Itimpossible to know whether or not the genital powere present, but its test is the same size as aduof Mikrocidaris pentagona (Munster).

    Mortensen (1928:65) states that the first interabulacral plate extends the whole way across tinterambulacrum. This conclusion was probabased upon Munster's poor illustrations. Althouthe most adapical plate is very large, there is a sond smaller plate beside it which lacks a tuberc

    The partly flexible test of this species with tinterambulacra beveling over the ambulacra incates that it belongs among the Miocidaridae. Labert (1900:44), Lambert an d Thiery (1910:140), aMortensen (1928:64) considered this species to Mikrocidaris; b u t they had not studied specimof its type-species M. pentagona (Munster). Thefore, they did not know that this species has abulacra that do not reach the apical system ahas very high ambulacral plates with large porFurthermore, they erroneously believed that tadradial sutures in T. venusta are vertical.

    The denticulate interambulacral plates bevelover the ambulacra and the very large adapicalterambulacral plate with a small tubercle-less plbeside it are features this species shares with ttype-species of Triadocidaris subsimilis (Munstewhich is also from the St. Cassian Beds. Doderland Bather were correct in considering this specto be Triadocidaris.

    I have studied five specimens, collected by Rnaldo Zardini, which appear to belong to tspecies. Although all of the specimens are smand some of them are slightly distorted by pomortem crushing, they can be distinguished eas

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    12 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLOTABLE 2.Dimensions of five specimens of Triadocidaris venusta

    MCAcatalogn u m b e r

    164-S-Z2733-S-Z174-M-Z173-T-Z2731-S-Z

    Diameterof test(mm)

    2.94.96.4*7.88.2*

    Height(mm)1.52.73.04.24.6

    (%D)5255475456

    DiameterApicalsyste

    (mm)1.51.553.0

    m

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    NUMBER 30

    A M B U L A C R A . T h e a m b u l a c r a are s i n u o u s an dn a r r o w , 2.50 m m w i d e at the a m b i t u s (10 p e r c e n tD ) and 19 p e r c e n t the w i d t h of an i n t e r a m b u l a c r u m . A l t h o u g h no a m b u l a c r u m is p r e s e r v e dt h r o u g h o u t it s e n t i r e l e n g t h , t h e r e w e r e a p p r o x i m a t e l y 116 p l a t e s in an a m b u l a c r u m w i t h 13 or14 p l a t e s a b u t t i n g a g a i n s t an i n t e r a m b u l a c r u m att h e a m b i t u s . All the p l a t e s are p r i m a r i e s w i t h non-c o n j u g a t e p o r e s ; a h i g h r i d g e s e p a r a t e s the p o r e sof a pa i r (P l a t e 8: figure 2). T he o u t e r p o r e ( n e a r e rt h e a d r a d i a l s u t u r e ) is s i t ua t ed s l i gh t l y adap i ca l oft h e i n n e r . T he p o r e - p a i r s or por i fe rous zones area p p r o x i m a t e l y 65 p e r c e n t the w i d t h of t he amb u l a c r u m . E a c h p l a t e b e a r s a s ingle , smal l , second a r y t u b e r c l e b e t w e e n the i n n e r p o r e of a p o r e - p a i ra n d the p e r r a d i a l s u t u r e . B e c a u s e e a c h p l a t e c u r v e sadapi ca l l y s l i gh t l y t owards the p e r r a d i a l s u t u r e ,t h i s t ube rc l e is s i t u a t e d s l i g h t l y a d a p i c a l to thep o r e - p a i r . T he a m b u l a c r a b e v e l u n d e r the i n t e r a m b u l a c r a .

    I N T E R A M B U L A C R A . E a c h int eram bul acrum is app r o x i m a t e l y 13.2 mm w i d e at the a m b i t u s (54 percen t D). It was p r o b a b l y c o m p o s e d of 14 or 15pl a t e s , bu t no i n t e r a m b u l a c r u m is c o m p l e t e so it isi m p o s s i b l e to be c e r t a i n of the n u m b e r of pl a t e s .

    T h e p r i m a r y t u b e r c l e s a d a p i c a l to the a m b i t u sh a v e l a r g e , s l i g h t l y u n d e r c u t m a m e l o n s w i t h d e e pp e r f o r a t i o n s w h i c h are e l o n g a t e d d o r s o v e n t r a l l y .M o s t of the m a m e l o n s of t u b e r c l e s at and a d o r a l tot h e a m b i t u s are b r o k e n off. Seve ra l adora l onesw h i c h r e m a i n are i m p e r f o r a t e . T he sc rob i cu l e s aredepre s sed s l i gh t l y be l ow the gene ra l l eve l of thet e s t . They are c i r c u l a r an d o c c u p y m o s t of eachp l a t e . T he sc rob i cu l e s at the a m b i t u s an d a b o v ea r e c o m p l e t e , bu t a d o r a l to the a m b i t u s t h e y areconf l uen t . T he s c r o b i c u l a r t u b e r c l e s are l a rge wi t h15 t ube rc l e s in a r i n g on a p l a t e i m m e d i a t e l y a d a p ical to the a m b i t u s . T he a r e a b e t w e e n the r i n g s iso c c u p i e d by m a n y i r r e g u l a r l y a r r a n g e d , s e c o n d a r yt u b e r c l e s w h i c h are a p p r o x i m a t e l y o n e - h a l f asl a rge as the s c r o b i c u l a r t u b e r c l e s . T he t u b e r c l e s app e a r to be n o n c r e n u l a t e , but the p o o r p r e s e r v a t i o nm a k e s it i m p o s s i b l e to be c e r t a i n .

    T h e i n t e r a m b u l a c r a b e v e l o v e r the a m b u l a c r a ,a n d e a c h p l a t e is d e n t i c u l a t e d a l o n g it s a d r a d i a lm a r g i n w i t h a d e n t i c l e p r o t r u d i n g o v e r the adj a c e n t a m b u l a c r a l p l a t e s at t he i r t r ansve rse su t ure s .

    PERISTOME.Unknown.R E M A R K S . T h i s spec ies is r e f e r r e d to the Mi oc i

    d a r i d a e b e c a u s e it s a m b u l a c r a b ev e l u n d e ri n t e r a m b u l a c r a . It has two c o l u m n s in each i na m b u l a c r u m , p e r f o r a t e , n o n c o n j u g a t e p o r e s , au n i s e r i a l a m b u l a c r a l p l a t e s . W i t h it s n o n c r e n u lt u b e r c l e s an d d e n t i c u l a t e , i n t e r a m b u l a c r a l p l at h e r e is l i t t l e d o u b t it b e l o n g s to Triadocidaris.

    I t is s i m i l a r in g e n e r a l a p p e a r a n c e to the tyspec ies of Triadocidaris, T. subsimilis ( M u n s t ea lso from the St. C ass i an B eds . I h a v e c o m p a r e ddi rec t l y to Laube ' s (1865a , p l . 8b: fig. 4) s p e c i mof this species of the s a m e a p p r o x i m a t e s i z e , w hi s de sc r i bed e l sewhe re in t h i s p a p e r ( F i g u r e 3, P l4: figures 4-6). T he h o l o t y p e of T. giauensis diffi n h a v i n g m o r e i n t e r a m b u l a c r a l p l a t e s in each cu m n . T h e r e are 14 or 15 p l a t e s in an i n t e r a m b uc r u m as o p p o s e d to o n l y 7 in the s p e c i m e n ofsubsimilis of s i m i l a r s i z e . F u r t h e r m o r e , in T. giausis a d j a c e n t a m b u l a c r a l p l a t e s are of the same sand each p l a t e bea rs a s e c o n d a r y t u b e r c l e . Insubsimilis eve ry o t he r p l a t e (or in some cases evt h i r d ) n e a r the a m b i t u s is w i d e r n e a r the p e r r a ds u t u r e . A s e c o n d a r y t u b e r c l e is a b s e n t on the nrower p l a t e s . F i na l l y , in T. giauensis the i n t e r r a d(medi a l ) zones of the i n t e r a m b u l a c r a are w iw i t h m o r e s e c o n d a r y t u b e r c l e s .

    OCCURRENCE.Force l l a G i a u .F a m il y C I D A R I D A E G r a y

    G e n u s Mikrocidaris D o d e r l e i nMikrocidaris pentagona ( M u n s t e r )

    FIGURE 4, P LATE 2: FIGURES 3-6, P LATE 3, P LATE 4: FIGURES 1Cidaris pentagona Munster, in Wissmann and Muns

    1841:42, pl. 3: fig. 8.D'Orbigny, 1849:206.Gie1853:316.Desor, 1855:4.Laube, 1865a:280, pl. 9: fig1865b:325.

    Microcidaris pentagona (Munster).Doderlein, 1887:39Lambert and Thiry, 1910:140.Mortensen, 1928:64,34.Zardini, 1973a:9, pl. 5: figs. 18-19.Kier, 1974:17,79.Cidaris subpentagona B r a u n , in Wissmann and Muns1841:42, pl. 3: fig. 9.D'Orbigny, 1849:206.Gie1853:316.Desor, 1855:4.Laube, 1865a:282, pl. 9: fig1865b:325. [Not Zardini, 1973a:13, pl. 5: figs. 16-17.]

    Mikrocidaris subpentagona (Braun).Doderlein, 1887:3Lambert and Thhhry, 1910:140.Mortensen, 1928:64.K1974:17.D r . V o l k e r F a h l b u s h in M u n i c h v e ry k i n d l y p

    m i t t e d me to c l ean an d p h o t o g r a p h the h o l o t y(A S VII 392, in B S P G ) . T h r o u g h the k i n d n e s s

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    14 SMITHSONIAN CONTRIBUTIONS TO PALEOBIOLO

    FIGURE 4.Mikrocidaris pentagona (Munster): A, B, adapicalviews of portion of test showing separation of ambulacrafrom ocular plates; c, adapical; D, side views of test. (SeePlate 3 for photographs of this specimen; X 10).

    Dr. A. W. Ruttner in Vienna I was able to do thesame with Laube's figured specimen. Munster's an dLaube's specimens are clearly conspecific, bu tLaube's figures are so erroneous that his specimenappears to be quite different. His drawings showfar too many ambulacral an d interambulacralplates, to o small an apical system, an d also imperforate tubercles. Neither Munster nor Laube notedthat the ambulacra do not reach the apical systemin this species.

    M A T E R I A L . T h i s description is based on fourspecimens, the holotype (Plate 2: figure 3), Laube'sfigured specimen (Plate 3), and two specimens figured by Zardini (Plate 2: figures 4-6).

    S H A P E AND SIZE . The marginal outline is pentagonal with apices in the interambulacra. All the

    specimens are small, 4.6-5.3 mm in diameter (Dwith a height 58-63 percent D.

    A P I C A L S Y S T E M . T h e system is small, diame24-28 percent D. The ocular plates are small adeeply inserted into the interambulacra (Fig4 A - C ) . T he genital plates and the rest of the apisystem are absent on all specimens. T he outlof the apical system is pentagonal with the apiin the ambulacra.

    A MB U LA C R A . Ea c h ambulacrum is composedtwo columns of narrow, high, hexagonal pla(Figure 4 D ; Plate 3: figure 3) with large pores. Tinner pore of a pair is more adoral than the outThe ambulacra are 33 percent as wide as the terambulacra an d 14-16 percent D. T he ambulacdo not reach the apical system, being separafrom the ocular plates (Figure 4 A - C ) by the juntion of one or two interambulacral plates. Thare 18 plates in each ambulacrum (both columin the smallest specimen 4.6 mm in diameter a23-24 in the largest (the holotype) 5.3 mm in ameter. One node on each plate occurs adapicatowards the perradial suture (Plate 3: figure 3).

    I N T E R A M B U L A C R A . E a c h interambulacrum h12-13 plates with very large tubercles (Platefigure 6), occupying most of the surface of eaplate. T he mamelons are strongly developed, pforate, and slightly undercut. T he parapet is ncrenulate, and the boss has gently sloping sidThe scrobicular ring of nodes is complete on sotubercles, but confluent on a few of the larger; ttubercles are largest at the ambitus an d juadapical to the ambitus.

    P E R I S T O M E . T h e peristome is subpentagon(Plate 2: figure 5) with it s apices in the interabulacra. It is very large, with it s greatest wid50-59 percent of the diameter of the test. Thare no gill slits.

    O CCU RRE N CE . Z a r d in i ' s specimens came froForcella Giau an d Milieres.R E M A R K S . A l t h o u g h these specimens are vsmall, they are evidently mature specimens. Tfact that the ambulacra are separated from tocular plates indicates that no further ambulacplates would have been produced. Kier (1956) hshown that the separation of the interambulacrufrom the ocular plates indicates a cessation of pduction of new plates for the interambulacrum, apresumably the same applies for the separation

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    NUMBER 30the ambulacrum. This echinoid exhibi ts manycharacters found in the immature of Recent cidaroids such as a large peristome, few plates, largeinterambulacral plates with large tubercles, andlarge, high ambulacral plates. Its resemblance insome of these characters and in its general appearance is evident in a comparison (Figure 5) of itstest with that of an immature Austrocidaris canali-culata (A. Agassiz), a Recent cidaroid from theAntarctic.

    FIGURE 5. Austrocidaris canaliculata (A . Agassiz), side viewof an imm atur e specimen (1.45 mm in d iame ter) now l iv ingin the Antarct ic showing i ts resemblance for Mikrocidarispentagona (Munster) . Both have a large peris tome, fewplates, l a rge in te rambu lacra l pla tes, a n d la rge , h igh ambu lacral plates. (Photocopied from Loven, 1892, p l. 2: fig. 8.)

    I have cleaned and studied the holotype ofCidaris subpentagona Braun and cannot dist inguish it from M. pentagona. The two species aresimilar in having their primary tubercles decreasein size adorally with 12 plates in each area, in having high ambulacral plates which do not extend tothe apical system and which have very large pore-pairs occupying most of the ambulacra, and inhaving a very large peristome. Cidaris subpentagonais, therefore, considered here to be a jun ior (itfollows M. pentagona in the original description)subjective synonym of M. pentagona. The holotypeof C. subpentagona is figured h ere o n Pla te 4: figures 1, 2.

    Zardini (1973a: 13, pl. 5: figs. 16, 17) referredtwo specimens to M. subpentagona, but one of them(figured on his plate 5: figs. 17a, b, c) is consideredhere a holotype of Megaporocidaris mariana, newspecies. I have not studied the other specimen, butit appears to be too low to be a M. pentagona. Oneof the two specimens Zardini (1973a:9, p l. 5: fig.18) referred to M. pentagona is il lustrated here(Plate 2: figures 4-6).Fell (1966a:U321) provisionally referred Mikro

    cidaris to the family Miocidaridae but considethe assignment doubtful because of the lack imbricating test plates. Probably the genus shobe referred to the family Cidaridae and subfamCidarinae.

    Genus Polycidaris QuenstedtPolycidaris regularis (Munster)

    PLA TE 8: FIGURES 3-6Cidaris regularis Munster, in Wissmann and Munster, 1841

    pl. 3: fig. 6.Bather, 1909:101-102.Hemicidaris regularis (Munster).Agassiz and Desor, 18339.D'Orbigny, 1849:206.Hypodiadema regularis (Munster).Desor, 1858:61.La

    1865a:295, pl . 9: fig. 8; 1865b:326.Eodiadema regulare (Munster).Lambert, 1900:34.Lam

    a n d T h t e r y , 1910:177.This description is based on the holotype (V II 435, in BS PG), which is a slightly crushspecimen that was originally about 30 mm in hozontal diameter a nd 17 mm high.APICAL SYSTEM.The apical system is missibut its diameter is estimated to have been 13 mor 43 percent of the diam eter of the test.AMBULACRA.Each ambulacrum is s t raight , arcuate, and narrow with a width of 3.4 mm the ambitus (24 percent width of an interambucrum), narrowing slightly adorally with a wiof 3.0 mm at the peristomial margin. The plaare all simple primaries without any indication compounding even adoral ly nearing the peristomA single column has 43 plates (86 in a single abulacrum) with 5 plates at the ambitus adjacenta single interambulacrum plate. The interporifous zone is narrow, 1.3 mm wide at the ambitus35 percent width of ambulacrum. The pore-paare in a straight vertical series; the outer pore each pair is slightly more elongated transversthan the inner. The pores are not conjugate, hing a slight protuberance rising between the poof a pair. A single node occurs on each plate tween the inner pore of a pair and the perradsuture forming two vertical rows of nodes in eaambulacrum. The ambulacra do not bevel undthe interambulacra. The adradial sutures betwethe ambulacra and interambulacra are nearly vtical.INTERAMBULACRA.The interambulacral pla

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    16 S M I T H S O N I A N C O N T R I B U T I O N S T O P A L E O B I O L Oa re low. A p l a t e at the a m b i t u s is 7.9 m m w i d ea n d 2.5 m m h i g h ( h e i g h t 32 p e r c e n t of w i d t h ) .E a c h i n t e r a m b u l a c r u m has 2 0 - 2 4 p l a t e s . A pr i m a r y t u b e r c l e is p r e s e n t on each p l a t e excep t themos t adap i ca l p l a t e s whe re it is a b s e n t or s l ight lyd e v e l o p e d . The t u b e r c l e is deepl y pe r fora t e wi t h ac i rcu l a r pe r fora t i on as v i e w e d f r o m a b o v e an ds t r o n g l y c r e n u l a t e w i t h a p p r o x i m a t e l y 14 c renul a t i ons on each t ube rc l e at the a m b i t u s . T he scrobi cules are deepl y depre s sed be l ow the gene ra l sur face of the test and are s t rongl y conf l uen t . A p l a t ea t the a m b i t u s has a sc rob i cu l e 4.3 m m w i d e ona p l a t e 7.5 m m w i d e (57 p e r c e n t w i d t h of p l a t e ) .T h e s u r f a c e of a p l a t e o u t s i d e the sc rob i cu l e hasn o d e s i r r e g u l a r l y a r r a n g e d and of i r r e g u l a r s h a p e .

    P E RI S T O M E . T h e p e r i s t o m e was a p p r o x i m a t e l y14 mm in d i a m e t e r or 46 p e r c e n t of the h o r i z o n t a ld i a m e t e r of the test . N o gil l sl i ts ar e p r e s e n t .

    L A N T E R N SUPPORTS.The interambulacral apophyses are low and i n c l i n e d . N o p r o j e c t i o n s arep r e s e n t on the a m b u l a c r a l b a s i c o r o n a l p l a t e s .

    R E M A R K S . O n l y one s p e c i m e n is k n o w n of thi sspec ies . La ub e 's (1865b, p l . 9: fig. 8) figure is ofM u n s t e r s hol o t ype . Thi s spec i e s has e r r o n e o u s l ybeen re fe r red to seve ra l nonc i da ro i d gene ra , p re s u m a b l y b e c a u s e of its sma l l e r p r i ma ry t ube rc l e s .H o w e v e r , it lacks gi l l sl i ts and has a m b u l a c r a lp l a t e s t ha t are all p r i m a r i e s , i n c l u d i n g t h o s e n e a rt h e p e r i s t o m e . I h a v e e x c a v a t e d the l a n t e r n s u p p o r t s . T h e y are a p o p h y s e s , i n t e r a m b u l a c r a l in pos i t i o n , w i t h o u t any p r o j e c t i o n s on the b a s i c o r o n a lambul ac ra l p l a t e s , whi ch sugges t s t ha t t h i s spec i e sis a c i d a r o i d . Its r i g i d t es t wi t h pe r fora t e t ube rc l e splaces it in the f a m i l y C i d a r i d a e ; its c r e n u l a t e tu berc les an d n o n c o n j u g a t e p o r e - p a i r s , in the subf a m i l y H i s t o c i d a r i n a e ; and its n u m e r o u s i n t e r a m bu l ac ra l p l a t e s , conf l uen t s c rob i cu l e s , an d s t r a i g h ta m b u l a c r a , in Polycidaris. It is so s i mi l a r to thetype-spec ies of t h i s genus , P multiceps ( Q u e n s t e d t )from the O x f o r d i a n of G e r m a n y , t h a t I suspec tt ha t t h i s supposed l y Tr i a s s i c spec i men of M u n s t e r ' smay rea l l y be conspec i f ic wi th P. multiceps an dm ay be f rom the O x f o r d i a n . Q u e n s t e d t ' s ( 1 8 7 2 -1875, p l . 79: fig. 69) figures are no t a d e q u a t e fora c o m p a r i s o n . His figure of his O x f o r d i a n s p e c i m e n s s h o w a w i d e r a d r a d i a l t r a c t (the z o n e bet w e e n the p r i m a r y t u b e r c l e and the a m b u l a c r a ) .T h i s may s i mpl y be an e r r o r of the a r t i s t . Unfor t u n a t e l y , the l o c a t i o n is u n k n o w n of Q u e n s t e d t ' st ype spec i mens of P. midticeps. A c c o r d i n g to Dr.

    F. W est p ha l (pe r s . com m. , 1973) , it is n ot w i t h to t h e r Q u e n s t e d t t y p e s at the I n s t i t u t u n d M u s efi i r Geologie u n d P a l a o n t o l o g i e de r UniversT u b i n g e n nor is it at S t u t t g a r t .

    Zardinechinus, ne w g e n u sTYPE-SPECIES.Cidaris lancedelli Z a r d i n i f r

    t he La t e T r i a s s i c , e a r l y Ka rn i an , St . C ass i an B eI t a l y .

    T h e t e s t is s m a l l an d r i g id w i t h n o n i m b r i cp l a t e s . T he a m b u l a c r a are c o m p o s e d of p r i m ap l a t e s t h r o u g h o u t t h e i r l e n g t h . T h e p o r e s are c o n j u g a t e . M o s t a m b u l a c r a l p l a t e s b e a r a s i nseconda ry t ube rc l e ; an d m o s t i n t e r a m b u l a cp l a t e s bea r a p e r f o r a t e , n o n c r e n u l a t e p r i m a r y tbe rc l e .

    R E M A R K S . T h i s g e n u s has a r i g i d t e s t wi t h nb e v e l i n g of the a m b u l a c r a u n d e r the i n t e r a m bl ac ra , and, t he re fore , it c a n n o t be r e f e r r e d to ag e n e r a of the M i o c i d a r i d a e , and m u s t b e l o n g a m ot h e C i d a r i d a e . H a v i n g n o n c r e n u l a t e t u b e r c l e s , noconj uga t e pore s , and no s u t u r a l p i t s or g r o o vt h i s genus is re fe r red to the s u b f a m i l y C i d a r i n aOf all the g e n e r a in t h i s subfami l y , it r e s e m b lm o s t Plegiocidaris in h a v i n g s i m p l e a m b u l a c rb u t it differs in h a v i n g n o n c r e n u l a t e t u b e r c l e s ann a r r o w e r a m b u l a c r a .

    Zardinechinus lancedelli ( Z a r d i n i ) ,n e w c o m b i n a t i o n

    P L A T E S 9, 10, P L A T E 11: F I G U R E S 1-8Cidaris lancedelli Z a r d i n i , 1 9 7 3 a : 12 , p l . 5: f igs. 24a,b.Cidaris admeto.Zardini, 1973a: 12, p l . 5: figs. 34a [ a d a p i c

    v i e w ] , 34b [not B r a u n ] .Cidaris cfr. admeto.Zardini, 1 9 7 3 a : 1 2 , p l . 6: figs. 11

    [ a d a p i c a l v i e w ] , l i b [ u p s i d e d o w n ] , [not B r a u n ] .M A T E R I A L . T h e f o l l o w i n g d e s c r i p t i o n is b a s

    o n m a n y f r a g m e n t s and on the h o l o t y p e (172-Mi-k i n d l y l e n t by Mr. R i n a l d o Z a r d i n i , w h i c h is dpos i t ed at the M u s e o di C o r t i n a d ' A m p e z z o . T hh o l o t y p e is ve ry we l l p re se rved , l a ck i ng on l y iapica l sys tem. T h e test is no t c r u s h e d or d i s t o r t ea n d is l i t t l e w e a t h e r e d .

    SIZE AND SHAPE.The test is 10.0 m m in di ame ta n d is re l a t i ve l y h i gh , 5.9 m m or 59 p e r c e n t thd i a m e t e r of the t es t (D). T he t e s t appea rs r i gb u t the i n t e r a m b u l a c r a s t r o n g l y b e v e l o v e r tha m b u l a c r a .

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    N U M B E R SO

    A P I C A L S Y S T E M . N o plates are preserved. Thediameter of the system in the holotype is 4.4 mmor 44 percent D.

    A M B U L A C R A . I n the holotype an ambulacrum(Plate 9: figure 5) attains its greatest width adoralto the ambitus where its width is 1.47 mm or 14.7percent D. The plates are all primaries with 56plates in each ambulacrum. Five or six plates abutan interambulacral plate at the ambitus. T he poresare not conjugate; each pore is separated by aprominent, thick, vertical ridge. The pore-pairs aresituated in slightly developed peripodia. A ridgeruns along the adapical edge of the pore-pair joining it with the vertical ridge that lies between thepores of a pair. T he pore-pairs at the ambitus occupy 60 percent of the width of the ambulacrum.The outer pore of a pore-pair (the pore nearer theadradial suture) is situated more adapically thanthe inner. Each plate curves slightly adapically toward the perradial suture of the ambulacrum. T heplates bear a single, secondary tubercle betweenthe inner pore of a pore-pair and the perradialsuture. An exception is the first 3 or 4 adoral platesat the peristome, which have a smaller tuberclebetween the larger tubercle and the perradial suture.

    The ambulacra are far wider than appears in anintact specimen. T he adjacent interambulacralplates bevel in a low angle over almost one-half thewidth of an ambulacra. When the interambulacraare in place, they extend almost to the edge of theouter pore of a pore-pair (Plate 10: figure 1, leftside of ambulacrum). When an interambulacrum isremoved (Plate 10: figure 1, right side of ambulacrum), it can be seen that the width of the ambulacrum is almost twice that visible when theinterambulacra are in place. Each ambulacral plate,where it is overlapped by an interambulacral plate,bears a transverse groove ex ten din g from outsidethe outer pore to the edge of the plate (Plate 10:figure 1, ri ght side of photograph; figure 2).

    INTERAMBULACRA.Each interambulacrum in theholotype is approximately 4.05 mm wide (40.5 percent D) and is composed of 14 plates. Each bears alarge tubercle except the first plate in one of thecolumns at the apical system which lacks a tubercle.The tubercles are largest adapically, decreasing continuously in size adorally. T he mamelons are prominent with deep circular to longitudinally slit per

    forations. Most of the mamelons are slightly undcut. T he parapets are generally not crenulate, bin a few specimens crenulations occur on the adoside of some tubercles (Plate 10: figure 9). Tscrobicules are distinct an d slightly depressedlow the general surface of the test. Adapically,scrobicules are complete; but at the ambitus aadorally, they are confluent (Plate 9: figures 3,with no scrobicular tubercles transversely sepaing the tubercles. T he dimensions of a platemediately above the ambitus are: width of pl2.20 mm, height 1.62 mm, diameter of scrobicuring 1.47 mm, and diameter of mamelon 0.91 m

    The adradial edge of the interambulacral pla(Plate 10: figure 1) are thin where they bevela low angle over the ambulacra. Denticulatiare present along the inside of the adradial ed(Plate 10: figure 6). These denticulations are described by Bather (1909:73) in Triadocidwith their ridges corresponding in position to transverse sutures of the ambulacra.

    P E R I S T O M E . D i a m e t e r 5.0 mm (50 percentNo gill slits are present.

    LANTERN S U P P O R T S . F o r t u n a t e l y , many frments have their lantern supports intact. Thsupports are small and are situated at the marof the ambulacra and interambulacra. T he sports are formed by a thickening of the interabulacral plates at their adradial margin at peristome (Plate 10: figure 6) and by a greathickening of the ambulacral where they bevelder the interambulacral. This thickening involtwo or three of the plates in each half ambu lacrnear the peristome (Plate 10: figure 3).

    INSIDE O F T E S T . T h e interambulacral plates tto thicken medially an d thin out towards the addial and interradial sutures. T he result is a dgroove that runs longitudinally along the med(interradial) suture (Plate 10: figure 6). The plaalso thicken at the transverse sutures productransverse ridges.

    R E M A R K S . Z a r d i n i ' s specimens, referred todaris admeto Braun (Zardini, 1973a, pl. 5: figs. 3b) and Cidaris cfr. admeto (Zardini, 1973a, pl.figs. 11a, b) , appear conspecific with the holotypeZardinechinus lancedelli. Their shape, ambulactuberculation, relative dimensions, an d numberplates are indistinguishable from the holotype. Tlarger specimen (Zardini, 1973a, pi . 6: figs. 11a

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    18 S MIT H S O N IA N C O N T R IB U T IO N S T O PALEOBIOLOmy Pla t e 11 : f igures 1-4) i s 10 m m in dia m ete r( e s t i m a t e d ) a n d h a s 5 6 p l a t e s i n e a c h a m b u l a c r u ma n d 14 p l a t e s i n e a c h i n t e r a m b u l a c r u m . T h e o t h e rspec i men (Za rd i n i , 1973a , p l . 5: figs. 34a, b; myPla te 1 1: f igures 5-8) i s 7 .5 m m in dia m ete r (es t im a t e d ) a n d h a s 5 2 p l a t e s i n e a c h a m b u l a c r u m a n d12 i n e a c h i n t e r a m b u l a c r u m .As no t ed e l sewhe re , t he t ype spec i men of Cidarisadmeto B r a u n h a s b e e n l o s t . B r a u n ' s ( i n W i s s m a n na n d M u n s t e r 1 8 4 1 , p l . 3: fig. 3) figure is so inadequa t e t ha t i t i s i mposs i b l e t o know t he gene r i c o rspec i f ic charac ters of thi s spec ies . Al though Zardinechinus lancedelli appea rs t o be s i mi l a r t o B raun ' sfigure of his Cidaris admeto, i t seems bes t to maint a i n Za rd i n i ' s spec i e s un t i l t he t ype spec i men ha sb e e n f o u n d .

    O v e r 100 f r a g m e n t s , m a i n l y i n t e r a m b u l a c r a , h a v ebeen co l l e c t ed by Mr . Za rd i n i a t C ampo. Some ofthese pieces di ffe r f rom the holo typ e by the i r tube rc l e s , ha v i n g s l it - li ke ra t he r t ha n rou nd pe r fora t ions , a few c renul a t i ons on t he adora l s i de o f sometube rc les , an d a br oa de r field of secon dary tube rc le s a l on g t he me di a l i n t e r rad i a l su t u re (P l a t e 10 :figure 8). At f i r s t I t hought t ha t t he se mi ght r epre sent another spec ies of Zardinechinus; b u t t h e r e a r es o m e f r a g m e n t s w h i c h h a v e e lo n g a t e d p e r f o r a t i o n sand na r row seconda ry f i e l ds l a ck i ng c renu l a t i ons(P late 10: figure 9). Bec aus e of the prese nc e of thes et ran s i t i on a l fo rms , i t s e ems adv i sab l e no t t o e rec ta s epa ra t e spec i e s . Onl y when compl e t e t e s t s havebeen found of spec i mens wi t h t he se cha rac t e r s c ani t be dec i ded , wi t h some degree o f c e r t a i n t y ,wh e t he r o r no t a s econd spec ie s i s p re sen t .

    OCCURRENCES.Fragment s of this species arem o s t c o m m o n a t C a m p o . T h e h o l o t y p e is f r omM il ie res , w hi le the oth er f igured in tac t s pec im ensare f rom Alpe di Spec i e and C i anzope \ Ot he r spec i m e n s a n d f r a g m e n t s a re f ro m R u m e r l o , M i s u r i n a ,M i l ie r es , a n d T a m a r i n .

    Paurocidaris, n e w g e n u sTYPE-SPECIES. Cidaris rinbianchi Zard i n i f rom

    t he La t e T r i a s s i c , e a r l y Ka rn i an , S t . C ass i an B eds ,I t a l y .

    T h e t es t i s sma l l and r i g i d wi t h no ni m br i ca t ep l a t e s . T h e a m b u l a c r a a r e w i d e a n d c o m p o s e d ofp r i m a r y p l a t e s t h r o u g h o u t t h e i r l e n g t h . T h e p o r e sa re no t con j uga t e . Each ambul ac ra l p l a t e bea rs a

    s i ng l e , l a rge , s econda ry t ube rc l e whi ch , because t he adap i c a l curv i n g of t he p l a t e , i s s i t ua t ed adac a l o f t h e p o r e - p a i r . T h e i n t e r a m b u l a c r a a r e c oposed of a few, la rge pla tes each bear ing a la rp e r f o r a t e , c r e n u l a t e t u b e r c l e .

    R E M A R K S . T h i s gen us ha s a r i g i d t e s t wi t h b e v e l i n g o f t h e a m b u l a c r a u n d e r t h e i n t e r a m b uc ra . Th e re for e , i t c an no t be re fe r red t o any g eneof t he Mi oc i da r i dae and mus t be l ong t o t he da r i da e . B ecause it s sp i ne s and p ed i ce l l a r i a e anot known, the ass ignment to a subfami ly i s di fc u l t . I t h a s n o n c o n j u g a t e p o r e s a n d n o s u t u r a l por g rooves and cou l d be l ong e i t he r t o t he Hi s t oda r i nae o r t he C i da r i nae . B ot h of t he subfami la re ma i n l y d i s t i ngu i shed by t he cha rac t e r o f t hsp i ne s and ped i ce l l a r i a e . I f compared t o t he Hi sc idar inae , i t di f fe rs f rom the Jurass ic Polycidaa n d Procidaris i n hav i ng a sma l l e r , l ower t e s t af a r l a r g e r a n d f e w e r i n t e r a m b u l a c r a l p l a t e s . A m ot he C i da r i nae , i t r e sembl e s mos t Plegiocidaris in s i m p l e a m b u l a c r a a n d c r e n u l a t e t u b e r c l e s b u t dfe r s i n i t s sma l l e r t e s t wi t h b roade r ambul accomposed of f a r f ewer p l a t e s i n e ach co l umn.

    Paurocidaris rinbianchi re sembl e s i n gene ra l ap e a r a n c e Triadocidaris venusta (Muns t e r ) a l so f rothe St . Cass ian Beds . Both spec ies have smal l , lt e st s wi t h few i n t e ra m bu l ac r a l p l a t e s , l a rge p ro mn e n t p r i m a r y t u b e r c le s , a n d s i m i l a r a m b u l a cPaurocidaris rinbianchi di f fe r s i n hav i ng c renu lt ube rc l e s and a r i g i d t e st i n wh i ch t he am bu l acd o n o t b e v e l u n d e r t h e i n t e r a m b u l a c r a .

    Paurocidaris rinbianchi ( Z a r d i n i ) ,n e w c o m b i n a t i o n

    FIGURE 6, PLATE 11 : FIGURES 9, 10, PLATE 12 : FIGURES \-4Cidaris rinbianchi Zardini, 1973a:ll, pl. 5: figs. 1 2 pl

    fig. 12.M A T E R I A L . Z a r d i n i based t h i s spec i e s on t h r

    spec i m ens : t wo te s ts an d a po r t i o n of an i n t e rab u l a c r u m . T h e s e s p e c i m e n s w e r e k i n d l y l e n t m e by Za rd i n i and a re de sc r i bed be l ow .

    T h e h o l o t y p e ( 1 2 5 - M - Z , i n M C A ) , f ig ure d Zardini (1973a , pl . 5: f ig . l a , b) , i s a wel l -preservspec i men wi t h on l y t he ap i ca l sys t em and a smpor t i on of some of t he adora l p l a t e s absen t . ho r i zon t a l d i am e t e r i s 7 .7 m m an d i t s he i g h t 3m m ( 49 p e r c e n t t h e d i a m e t e r o f t h e t es t ) . A l t h o u

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    NUMBER 30the test is slightly crushed, it may have originallybeen only slightly higher. The apical system islarge, 3.25 mm wide or 42 percent the diameterof the test. The peristome is also large with adiameter of 3.75 mm or 49 percent of the diameterof the test.

    FIGURE 6.Paurocidaris rinbianchi (Zardini), portion of anambulacrum of the holotype a t the ambi tus showing theadapical curving of the plates near the median suture, X 40.(For photographs of this specimen, see Plate 9; Plate 12:figures I, 2.)

    An ambulacrum is 1.27 mm wide at the ambitusor 16.5 percent of the diameter of the test. Theambulacral plates are all primaries with 56 platesin each ambulacrum and 6-8 plates abutt ing aninterambulacral plate at the ambitus. The poresare not conjugate. Each pore is separated by avertical ridge. The pore-pairs are situated in peri-podia in which a high ridge runs along the adapicaledge (Plate 12: figure 2) of the pore-pair with avertical ridge extending down between and separating the pores of a pore-pair. The pore-pairs occupylittle more than one-half the width of the ambulacra. T h e oute r pore of a pore-pair (the porenearer the adradial suture) is situated more adapically than the inner. Each plate curves sharplyadapically (Figure 6) nearing the perradial or median suture of the ambulacrum. Each plate, including those nearest the peristome, bears a single,large, secondary tubercle. Because of this adapicalcurving of the plate, it is situated adapical of thepore-pair.The interambulacra are composed of a few, largeplates with 9 or 10 plates in each interambulacrum.An interambulacrum is 3.15 mm wide at the ambitus or 41 percent of the diameter of the test. Theplates are largest adapically except for the adapicalplate in the right column (as viewed from above)of each interambulacrum. This is small and lacksa tube rcle. Th e tub ercles (Plate 12: figures 1, 2)are large, covering most of the surface of each

    plate. The mamelons are prominent with dperforations, which are slightly elongated dorventrally. Most of the mamelons are slightly undcut. The parapets are distinctly crenulate with proxim ately 14 crenu lations on a tubercle at ambitus. A slight basal terrace is present on larger, more adapical tubercles. The scrobicuare flush or slightly below the general surface the test. The scrobicular tubercles are larger ththe secondary tubercles outside of the scrobicuring and form a circle occupying most of each plaThe adapical plates (Plate 11: figure 9) have scbicular r ings which are complete. The more adoplates (Plate 12: figure 2) have confluent rings alotheir transverse sutures in which only a single rof scrobicular tubercles separate the scrobicules vertically adjacent plates. Each scrobicular rabove the ambitus has 16-18 tubercles.The test appears to have been rigid. None of plates have shifted over each other along thsutures. In part icular the interambulacra hanot shifted over the ambulacra at any place on ttest. At the peristome the plane of the suture btween the ambulacra and interambulacra appearsbe nearly vertical, but one is uncertain because the difficulty of distinguishing sutures frofractures.The figured paratype (Zardini, 1973a, pl. 5: fi

    2a, b; my Plate 12: figures 3, 4) is a smaller spemen (diameter 3.6 mm), which is not as well pserved as the holotype. Its apical system is missinand the test is we athere d an d fractured . It shoenough characters, however, to determine that itconspecific with the holotype. Its tuberculation similar. Its ambulacral plates are like those in tholotype in that each bears a single large secondatubercle situated perradially where the plate curvadapically. As in the holotype, its interambulacare composed of a small number (8-10) of larplates. It only differs from the holotype in havithe small, nontuberculate, adapical plate on tleft instead of on the right in each area. Beingsmaller specimen, it has fewer plates in eaambulacrum (28), a slightly larger (relative to tsize of the test) apical system (diameter 45 perceof diameter of the test), larger peristome (55 pcent), but approximately the same height (47 pcent diameter of test). This specimen like tholotype appea rs no t ' to have had a flexible te

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    20 S M I T H S O N I A N C O N T R I B U T I O N S T O P A L E O B I O L ON o n e of the pl a t e s have s l i pped ove r e ach o t he ra t t he i r su t ure s .

    The t h i rd f i gured pa ra t ype (Za rd i n i , 1973a , p l .6 : fig. 12 ; my P l a t e 12: figure 5), is a p o r t i o n of ani n t e r a m b u l a c r u m l a c k i n g it s a d a p i c a l or a d o r a le x t r e m i t i e s . It is c o m p o s e d of 6 pl a t e s . T he m a m e l ons are b r o k e n off; and, t h e r e f o r e , it is n o t k n o w nw h e t h e r t h e y w e r e p e r f o r a t e or w h e t h e r the tube rc l e s we re c renu l a t e . Th i s spec i men does n o ta p p e a r to b e l o n g to thi s spec ies . Its i n t e r a m b u l a c r u m is l e s s curved t han in the h o l o t y p e s u g g e s t i n gt h a t it s test was far h i g h e r . F u r t h e r m o r e , it s scrobi cules are more conf l uen t wi t h fewer sc rob i cu l a rt ube rc l e s t r ansve rse l y sepa ra t i ng ad j acen t t ube rc l e sof the same ver t ica l se r ies .

    Leurocidaris, ne w g e n u sTYPE-SPECIES.Cidaris montanaro Zard i n i f rom

    t he La t e T r i a s s i c , e a r l y Ka rn i an , St. C ass i an B eds ,I t a l y .

    T h e t e s t is s m a l l an d r i g i d w i t h n o n i m b r i c a t ep l a t e s . The a m b u l a c r a are n a r r o w and are c o m p o s e do f p r i m a r y p l a t e s t h r o u g h o u t t h e i r e n t i r e l e n g t h .T h e p o r e s are no t conj uga t e . Each p l a t e bea rs atl e a s t t h ree sma l l , equa l s i z ed , i r r egu l a r l y a r ranged ,seconda ry t ube rc l e s . T he i n t e r a m b u l a c r a are composed of a few, l a rge p l a t e s e ach bea r i ng a p r o m i n e n t t u b e r c l e t h a t is p e r f o r a t e on the a d a p i c a lp l a t e s b u t i m p e r f o r a t e a d o r a l to the a m b i t u s . T hep a r a p e t s are c r e n u l a t e ; and the sc rob i cu l e s aresma l l , l a ck i ng a s c r o b i c u l a r r i n g of t ube rc l e s . Sma l l ,i r r egu l a r l y a r ranged , s econda ry t ube rc l e s cove r allt he a rea ou t s i de the s c r o b i c u l e s . T h e r e are nodi s t i nc t g i l l s l i t s . Lan t e rn suppor t s are p r e s e n t ont he f i r s t i n t e rambul ac ra l p l a t e s .

    R EMA R K S . I t is difficult to ass ign thi s genus toany fami l y wi t h ce r t a i n t y because no t h i ng is k n o w nof it s sp i ne s , ped i ce l l a r i a e , or pe r i s t omi a l p l a t e s .H a v i n g a rigid test , it c a n n o t b e l o n g to the Mi oc i d a r i d a e . It is e x c l u d e d f r o m the D i p l o c i d a r i d a e byi t s un i se r i a l pore s .

    A m o n g the C i d a r i d a e , Leurocidaris montanarore sembl e s Paracidaris caumonti (C ot t eau) f rom theMi ddl e Jura s s i c (B a j oc i an) . B ot h spec i e s have sec o n d a r y t u b e r c u l a t i o n c o n s i s ti n g m a i n l y of i r regu l a r l y a r r a n g e d g r a n u l e s . In L. montanaro a scrobi cu l a r r i ng of t ube rc l e s is a b s e n t ; in P. caumonti iti s s l i gh t l y deve l oped on some p l a t e s an d a b s e n t on

    o t h e r s a c c o r d i n g to Co t tea u 's f igures (1875 : pl . 15figs. 9, 12; 1880: p l . 153: fig. 6). B ot h spec i e s hai r regu l a r l y a r ranged t ube rc l e s on the a m b u l a cp l a t e s . L a m b e r t an d Thi e ry (1910: 135) p l aced tBajoc ian spec ies in Paracidaris, a genus t hey de fa s h a v i n g e n l a r g e d , s e c o n d a ry , a m b u l a c r a l t u b e r cadora l l y wi t h an e n l a r g e d


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Silicified Eocene molluscs from the Lower Murchison ...museum.wa.gov.au/sites/default/files/SILICIFIED... · corals, brachiopods, echinoids and molluscs. The known molluscan fauna

Silicified Eocene molluscs from the Lower Murchison ...museum.wa.gov.au/sites/default/files/SILICIFIED... · corals, brachiopods, echinoids and molluscs. The known molluscan fauna

Tertiary Stratigraphic Map, Correlation and Cross Section ... · Nummulites. sp., and fragments of mollusks and echinoids. In the study area, the maximum thickness of the Darnah Formation

Tertiary Stratigraphic Map, Correlation and Cross Section ... · Nummulites. sp., and fragments of mollusks and echinoids. In the study area, the maximum thickness of the Darnah Formation