piiiio'v':.": P ii ii;iii P'i'ir" Si linn ili!fei!!!:!i;-^vv:n::ii;:i;im, llivv^il,v I ( illliilp:,,:.:,'!!;:'.! hliw.^:!', film I)' ' iaii!

lis'; ill! ! ' ! 1 )

H

l'\ 1? ii * ! 1 'ii'';'.;!-I 1 J

u

) 1 [! ) i Ih'i'

M

. *!

hi

!* •lliVV^il,V

iM

I( ti

piiiio'V':.":

1 'I!}

bH

'! 1 i t I )St

P'i'ir"

' I »• ill. ) !i. 1 1 * hliw.^:!', J iaii! film illliilP:,,:.:,'!!;:'.!

ili!fei!!|!:!i;-^Vv:n::ii;:i;iM,

P

ii|ii;iii ill.li''!'.'!::- ','•! -'..I'

The

_{person charging}thismaterial is

responsiblefor

Itsreturntothe

libraryfrom whichitwaswithdrawn on_{or before the Latest}

Date stamped below I^r;T*"'*"L"'""**""«'«^i"*"fl 01booksare reasonsfor

discipli-naryactionandmayresultin_{dismissal from the} University

TorenewcallTelephoneCenter,333-8400

UNIVERSITY OF ILLINOIS LIBRARY AT URBANA-CHAMPAIGN

NOVOy

/Rfii

ST.JRBAMa

C

PAIGN

FIELDIANA

Geology

NEW

SERIES,

NO.

32

Pachypleurosaurs

(Reptilia:

Sauropterygia)

from

the

Lower

Muschelkalk, and

a

Review

of the

Pachypleurosauroidea

Olivier

Rieppel

Lin

Kebang

December

29,

1995

Publication

1473

Fll

1

1

nil

Information

for

Contributors

to

Fieldiana

Generak Fieldiana is _{primarily a journal} for Field Museum staff members and research associates, although manuscriptsfromnonaffiliatedauthors_maybe_{considered as space permits.}

TheJournalcarriesa_{page charge}of $65.00perprintedpage orfraction thereof._Paymentofat least

50%

of_page chargesqualifiesapaperfor expedited processing,which_{reduces the publication time. Contributions}fromstaff,research

associates,andinvitedauthorswillbe_{considered for publication regardless ofability}to_{pay pagecharges,}however,thefull

chargeis_mandatoryfor nonaffiliatedauthorsof unsolicited_manuscripts.Three_{completecopies of the}text_(includingtitle

pageandabstract)andof theillustrationsshould_{be submitted (oneoriginalcopyplus}two_{review copies}which_maybe machine-copies).

No

manuscriptswill beconsidered for publicationor submitted to reviewers beforeallmaterials are complete andinthehands oftheScientificEditor.

Manuscripts should be submittedtoScientific_{Editor, Fieldiana, Field}

Museum

ofNatural_{History,Chicago,}Illinois

60605-24%,USA.

Text: _Manuscriptsmustbetypewrittendouble-spaced onstandard-weight,8Vi-_by11-inch _paperwith_{wide margins} on all four sides. If _typed on _{an IBM-compatible computer using MS-DOS,} also submit text on 5y4-inch diskette (WordPerfect4.1, 4.2, or5.0, MultiMate, Displaywrite 2, 3

&

4,

Wang

PC, Samna, Microsoft Word, Volkswriter, or WordStar_{programs or ASCII).}

For papers over100_{manuscriptpages, authors are requested to}submitaTable_{of Contents," a}"ListofIllustrations,"

anda"Listof Tables"_{immediatelyfollowing}title_page.Inmostcases,thetextshould_{be precededby}an"Abstract"and should concludewith_{"Acknowledgments"}(ifany)and"LiteratureCited."

Allmeasurementsshouldbeinthe metricsystem(periods are notusedafterabbreviatedmeasurements).Theformat and_styleof_{headings should}followthatof recentissuesof Fieldiana.

Formoredetailedstyle information, seeThe ChicagoManualofStyle(13thed.),publishedbyThe University of ChicagoPress,andalso recent issues of Fieldiana.

References: In "Literature Cited,"book and_journaltitlesshouldbe_giveninfull.Whereabbreviationsare desirable

(e.g.,in citationof synonymies), authorsconsistentlyshouldfoWowBotanico-Periodicum-Huntianum and TL-2 Taxonomic

Literature_byF.A.Stafleu«&

R

S.Cowan(1976et_{seq.)(botanical papers)}orSerial_{Sources for}theBiosisDataBase₍₁₉₈₃₎ publishedbytheBioSciences InformationService.Namesof botanicalauthorsshouldfollow the "DraftIndexofAuthor Abbreviations,Royal Botanic Gardens, Kew," 1984edition,or TL-2.

References shouldbetypedin_{the following form:}

Croat, T. B. 1978. Flora ofBarro ColoradoIsland._{Stanford University Press, Stanford,Calif.,}943_pp.

Grubb,P.J.,J._{R. Lloyd,}andT._{D. Pennington.}1963.

A

_comparisonofmontane andlowlandrainforest inEcuador.

I.The_{forest structure,physiognomy, and}floristics.Journal of Ecology,51:567-601. Langdon,E.J.M.1979._{Yageamongthe Siona: Cultural patterns}

in visions,pp.63-80.InBrowman,D.L.,and R.A. Schwarz,eds., Spirits,Shamans, andStars.MoutonPublishers,The_Hague,Netherlands.

Murra, J. 1946.The historic tribes_{of Ecuador,pp. 785-821. In Steward,}J. H.,ed.. HandbookofSouthAmerican Indians. Vol. 2,The Andean Civilizations. Bulletin 143, Bureau ofAmerican _{Ethnology, Smithsonian}

Institution,Washington, D.C.

Stolze,

R

G.1981.FernsandfernalliesofGuatemala.PartII._{Polypodiaceae. Fieldiana:Botany,}n.s., 6:1-522. Illustrations: Illustrationsare referred to as_{"figures" in}thetext_{(not as}

"plates").Figuresmustbe accompaniedby someindicationofscale, normallya referencebar.Statementsinfigurecaptions alone,suchas "x0.8,"are_{not acceptable.} Captions should betypeddouble-spaced andconsecutively.Seerecentissuesof Fieldiana fordetailsofstyle.

Allillustrationsshouldbemarked onthe reverse with author's_{name, figurenumber(s), and"top."}

Figures assubmittedshould,wheneverpracticable,be8V4x11_{inches (22}x_{28 cm),}andmaynotexceed W/tx16V4 inches (30x 42_cm).Illustrationsshouldbemounted onboardsinthe_arrangementtobe obtainedin_{the printed}work.This

original setshouldbesuitable for transmission to the_{printer as}follows:Pen andinkdrawingsmaybeoriginals(preferred) orphotostats;_{shaded drawings must beoriginals,}but within the_{size limitation;}and_photostatsmustbehigh-quality, glossy,

black-and-whiteprints.Originalillustrations willbereturnedtothe_{corresponding authoruponpublication unless otherwise}

specified.

Authors whowish _{to publish figures} that _{require costlyspecial}

paper or color reproduction must make prior arrangementswith theScientificEditor.

PageProofs: Fieldiana_{employsa two-step correction system.The}

corresponding authorwill_normallyreceive a_copy of the edited_manuscriptonwhichdeletions,additions,_{and changes can be}madeand_queriesanswered._{Only one}setof pageproofswillbesent.All desired corrections of_typemust bemadeonthesingle setofpageproofs.Changesin_page

proofs(asopposedto corrections) areveryexpensive.Author-generated changesin_pageproofscan_onlybe madeifthe author_agreesinadvanceto_payforthem.

aeOlOflY

UBRAI^fY

FIELDIANA

Geology

NEW

SERIES,

NO.

32

Pachypleurosaurs

(Reptilia:

Sauropterygia)

from

the

Lower

Muschelkalk, and

a

Review

of the

Pachypleurosauroidea

Olivier

Rieppel

Department of Geology

Field

Museum

ofNatural History Roosevelt

Road

atLakeShoreDrive Chicago,Illinois60605-2496 U.S.A.

Lin

Kebang

Redpath

Museum

McGillUniversity

Montreal, Quebec

H3A

2K6 Canada

Accepted

June

1,

1995

Published

December

29,

1995

Publication

1473

©

1995Field

Museum

ofNatural History LibraryofCongressCatalog

Card Number:

95-70458

ISSN

0096-2651

Table

of

Contents

Abstract

1

zusammenfassung

1

Introduction

1 Systematic

Paleontology

2 Phylogenetic Analysis 21 DefinitionofCharacters 24

Genera

and

Species

of

Pachypleuro-SAUROIDEA inTHE

MIDDLE

AND

UPPER

Triassic 34

Historical

Biogeography

of

the

Pachypleurosauroidea

36

The

Paleoeoology of Pachypleurosaurs .. 40

Acknowledgments

40

Literature Cited 41

Appendix:

Mateiual Included

and

Institutional Abbrevl\tions 43

List

of

Illustrations

1. Castsof_holotypeoi

Anarosaums

pumilio

Dames

3

2. Charitosaurustschudii

Meyer

4

3. Skullof Anarosaurus pumilio

Dames

(castofholotype) 5 4. Skullof Anarosaurus pumilio

Dames

... 5

5. GastralribsofAnarosaurus_pumilio

Dames

7

6. Pubis_{of Anarosaurus pumilio}

Dames

.. 7

7.

Humerus

and femurofAnarosaurus

pumilio

Dames

8. _{Holotype of Anarosaurus}heterodontus

n. sp 9

9. Leftpremaxillaof Anarosaurus hetero-dontusn. sp 9 10. SkullofAnarosaurusheterodontus

n. sp 10

1 1. _{Holotype ofDactylosaurusgracilis}

Giirich 12

12. _{Holotype ofDactylosaurus}schroederi

Nopcsa

13

13. DactylosaurusgracilisGiirichfrom the lower Muschelkalk ofGogolin,

Upper

Silesia

(Gomy

Slask, Poland) 14 14. Dactylosaurusgracilis Giirich,humerus,

fromthelower MuschelkalkofBobrek

near Beuthen 14

15. _{Right forelimb}ofDactylosaurusgracilis

Giirich 15

16. SVxAl ofDactylosaurusgracilisGurich

..16

17. _{Pectoral girdle}ofDactylosaurusgracilis

Giirich 17

18. PubisofDactylosaurusgracilisGurich

..18

19.

Humerus

ofDactylosaurusgracilis

Giirich 18

20.

Manus

andpesofDactylosaurusgracilis

Giirich 19

21. Sauropterygiaindet. fromthelower

Muschelkalk ofGogolin,

Upper

Silesia

(Gomy

Slask, Poland) 21

22. Strictconsensustreeofsauropterygian interrelationships 23

23. Unrooted networkforPlacodus,

Pachy-pleiu-osauroidea,

and

selected represen-tativesofEusauropterygia 31 24.

The

single

most

parsimonioustreefor

pachypleurosaurinterrelationships rooted

on

the_monophyletic

Eusau-ropterygia 32

25. Strictconsensustreefor pachypleuro-saursandselected_{eusauropterygians,} rooted

on

anall-0 ancestor 33

26. Strictconsensustreefor Placodus, pachy-pleurosaurs,andselected eusauroptery-gians,rooted

on

anall-0ancestor 33

27. Strictconsensustreefor pachypleuro-saurinterrelationships,rootingthe pachypleurosaursplus selected eusau-ropterygian taxaon Placodus 34

28. Reconstructionsof Anarosaurus_pumilio

and

Dactylosaurusgracilis 37

8 List

of

Tables

1. Measurements ofthe

humerus

of

Anaro-saurus pumilio

Dames

8 2. Measurements ofthefemur of

Anarosau-ruspumilio

Dames

8

3.

Body

_proportionsin

Pachypleurosauroi-dea 11

4. Measurements ofthe

humerus

of

DactylosaurusgracilisGiirich 18

5. Measurements ofthelimb bonesof

Dac-tylosaurusgracilis 19 6. Datamatrixfor 14 taxaand 50

Pachypleurosaurs

(Reptilia:

Sauropterygia)

from

the

Lower

Muschelkalk, and

a

Review

of the

Pachypleurosauroidea

Olivier

Rieppel

Lin

Kebang

Abstract

The

type material ofall pachypleurosaurs from thelower Muschelkalkis redescribedand

pachypleurosaur systematicsare reviewed. Three speciesoflower Muschelkalk pachypleuro-saursare_recognized,Anarosauruspumilio

Dames,

Anarosaurusheterodontusn. sp.,and

Dac-tylosaurnsgracilisGiirich.

A

cladisticanalysisbased

on

50charactersshowsKeichousaurusto

be the sister-taxon toall other pachypleurosaurs; Dactylosaurusis thesister-taxonto

Anaro-saurus plus the Serpianosaurus-Neusticosaurusclade; Anarosaurus is the sister-taxon to the Serpianosaurus-Neusticosaurusclade;Serpianosaurusmirigiolensisisthesister-taxon to

Neus-ticosaurus.

The

_genusNeusticosaurus includes fourspecies,A^. _edwardsii,N._peyeri,N.pusillus,

and

N. toeplitschi.

The

stratigraphic

and

biogeographicrelations ofpachypleurosaurs indicate thatpachypleurosaurs reachedtheEuropeanepicontinentalsea(MuschelkalkBasin)byinvasion

fromtheeast inAnisiantimes,andthata faunal interchangewas_possiblebetweenthe

Muschel-kalkBasin

and

the_{southern Alpine intraplatform basin}facies at leastduringlateAnisianand Ladiniantimes.

Zusammenfassung

Das

_{Typusmaterial} aller Pachypleurosaurier aus

dem

unteren Muschelkalk wird neu be-schrieben.DreiArten

von

Pachypleurosauriemlassen sich

im

unteren Muschelkalkfeststellen:

Anarosaurus_pumilio

Dames,

Anarosaurusheterodontusn.sp.,

und

Dactylosaurusgracilis Gur-ich. EinekladistischeAnalyseweist Keichousaurusals _{Schwestergruppe}alleranderen

Pachy-pleurosaurieraus;DactylosaurusistdieSchwestergruppe

von

Anarosaurus

und

der Serpiano-saurus-Neusticosaurus-Linie;Anarosaurus istdie_{Schwestergruppe der} Serpianosaurus-Neus-ticosaurus-lAme;Serpianosaurusmirigiolensisistdie_{Schwestergruppe}

von

Neusticosaurus.Die Gattung Neusticosaurus umfasst vierArten: A^. _edwardsii, N. peyeri, N. pusillus,

und

A^. toe-plitschi.Stratigraphische

und

biogeographischeBeziehungenzeigen,dassdiePachypleurosaurier das Germanische Becken

von

Ostenher

kommend

im

Unteren Aniserreichten.Zwischender

Germanischen

und

der_AlpinenTriasfandzumindestwarend

dem

spatenAnis

und

dem

Ladin einFaunenaustauschstatt.

Introduction

lesia(Dactylosaurusgracilis,Giirich, 1₈₈₄₎andin thelowerMiddleTriassicofChina (Young, 1958,

The

Pachypleurosauroidea (Pachypleurosauri- 1965).

The

clade has not been recorded beyond

dae) constitutea _monophyletic clade ofthe sau- the upperLadinian (upperMiddleTriassic), per-ropterygian radiation (Rieppel, 1987, 1989;Storrs, haps lower

Camian

(lower

Upper

Triassic), de-1991; Sues, 1987)thatfirstappears inthelower- posits in the southern_{Alps (Ca' del Frate,} Italy:

iswell

known

fortheMiddleTriassictaxa

abun-dantly represented in uppermost Anisian

and

lower Ladinian deposits at

Monte

San Giorgio, Switzerland (genera Neusticosaurus

and

Serpiano-saurus: Carroll

&

Gaskill, 1985; Rieppel, 1989; Sander, 1989), but the interrelationships of pa-chypleurosaursin general stillremainpoorly un-derstood. This results from the relatively poor knowledge ofearlierrepresentativesoftheclade.

Of

these,only aguttaperchacast oftheholotype of Dactylosaurusschroederi

Nopcsa

(1928)from theMuschelkalk ofGross-Stein,

Upper

Silesia,has recently been restudied (Sues

&

Carroll, 1985; Dactylosaurusschroederi

Nopcsa

is considered a

junior

synonym

oiDactylosaurusgracilisGiirich: see below).

A

second pachypleurosaur from the lowermiddle Muschelkalk, Anarosaurus pumilio

Dames,

1890,from Remkerslebenin_{Saxony, has} not been restudied since Arthaber's (1924) and Nopcsa's (1928) contradictory

comments on

its

morphology(areconstructionoftheskull

was

pub-lished_byCarroll, 1981,Fig. 32a).

Since the early original description of pachy-pleurosaurid taxa from the lower Muschelkalk

(lowerto middle Anisian),

new

material has

ac-cumulated in various

museum

collections, the identificationofwhich remainsproblematicuntil the diagnosesoftheoriginally described taxaare refined. Itisthe purpose ofthis_{paperto pull} to-gether all available information on the original type materialofpachypleurosaursfromthelower Muschelkalk.

A

redescriptionoftheoriginaltype material will alsoprovide the basis fora review

ofpachypleurosaurinterrelationshipsandthe re-constructionoftheir evolutionary

and

paleobio-geographichistory.

Systematic Paleontology

Sauropterygia

Owen,

1860

PachypleurosauroideaHuene, 1956

PachypleurosauridaeNopcsa, 1928

Definition—

A

_{monophyletic group including}

the

common

ancestor ofAnarosaurus, Dactylo-saurus, Keichousaurus,

and

allofitsdescendants.

Diagnosis—

Smalltomedium-sized

Sauropter-ygiawith thepreorbitalregion oftheskulllonger than _{the postorbital region; frontal}withconcave

lateral_{edge, entering}thedorsal_{margin of}the

or-bit; broad parietal skulltable; mandibular

artic-ulation at level with occipital condyle; quadrate withconcaveposteriormargin; ectopterygoid ab-sent;trough

on

dorsal surfaceofretroarticular pro-cess present; anterior teethnot _strongly procum-bent; posteriorprocess

on

interclavicle

rudimen-tary or absent; radius _{slightly longer than} ulna; iliacblade absent (i.e., reducedto narrowdorsal

process).

Distribution—

Middle Triassic ofChina

and

Europe (TethyanProvince).

Anarosaurus

Dames,

1890

Type

SPECIES—Aruirosaurus pumilio

Dames,

1890.

Generic Diagnosis—

A

small pachypleurosaur with aspatulateexpansion ofthetooth crown; a high dorsal vertebral count (25 or 26); an open obturatorforameninthe_pubis; pubis with a dis-tinct anteroventral spine;

and

a distinctly elon-gatedfemur(femur length/standardlength

=

1.55).

Distribution—

Lower and

middle

Muschelk-alk,centralEurope.

Anarosaurus pumilio

Dames,

1890

1890 Anarosauruspumilio.

Dames,

p. 74,PI. 1,

text_figs. 1,2.

1899 Anarosauruspumilio,

Schrammen,

p.408, PI. _25,Fig. 8.

1910 Anarosauruspumilio,Jaekel,pp.325, 335, textfig. 1.

1924 Anarosauruspumilio, Arthaber, pp.

480-483,textfigs. 12a,b, 13.

1928 Anarosauruspumilio, Nopcsa, pp. 30-31, 43,PI. 4, Figs. 1, 2.

1935 Anarosauruspumilio, Zangerl, pp. 64-65, 68.

1959 Anarosauruspumilio, Kuhn-Schnyder, p. 652.

1981 Anarosauruspumilio,Carroll, textfig.32a.

1985 Anarosauruspumilio. Sues

and

Carroll, p. 1349.

1987 Anarosauruspumilio, Rieppel, pp. 1110,

1115-1116.

1993 Anarosauruspumilio, Rieppel,p. 10.

Holotype—

The

holotypewasoriginallyhoused

attheInstitut

und

Museum

fiir_Geologic

und

Pa-laontologie, Georg-August-Universitat, Gottin-gen, butcan

no

longerbe located today(lost or

Fig.1. Castsofthe_{holotype o{}Anarosaurus_pumilioDames,_depositedbyNopcsainthe British

Museum

_(Natural

History).A, Dorsalview_(bmnhR-5691);B, ventralview(bmnhR-5866).Scalebar

=

20

mm.

destroyed during

World

War

II;H.Jahnke,inlitt.

1991).

Two

castsare available at this institution (Orig. Nr. 409-1).

The

specimen

came

from the orbicularis beds near _{Remkersleben,}

approxi-mately 15

km

westof Magdeburg.

The

orbicularis beds were _assigned to the top ofthe lower

Mu-schelkalk_by

Dames

(1890), but are

now

consid-ered the base ofthe middle Muschelkalk

(Hag-dom,

1991).

Arthaber(1924)describes_{a guttapercha}castof

the holotype in the Natural History

Museum,

Humboldt

University, Berlin(mbR. 57.1-3, dor-sal view;

mb

R. _{58, ventral view),} deposited by

Jaekel (1910)afterfurtherpreparationofthe ho-lotype.

Additional casts _{(Fig. 1)} were deposited by

Nopcsa

inthe British

Museum

_{(Natural History)}

(BMNH

R-5691, dorsal view;

bmnh

R-5866, ven-tral_view).Othercastsare keptattheInstitutfur Geowissenschaften, Martin-Luther-Universitat,

Fig. 2. CharitosaurustschudiiMeyer. A, Cast oftheEsperstadtspecimen(original of Meyer, 1851,PI. 31,Fig.

22;

MB

R. 62);B, castofthe_Querfurtspecimen(originalof Meyer, 1851,PI. 31,Fig.23;

mb

R.61).Scalebar

=

20

Halle _(M4/12, skull only),

and

at the Staatliches

Museum

fur_Naturkunde,Stuttgart(smns59073).

Diagnosis—

Same

as forgenus, butabout half the sizeofAnarosaurusheterodontus,

homodont

dentitionwitheight teethin_premaxilla,anda

weak

sculpturingofdermalskullbones.

Locus

Typicvs—

Orbicularis beds (middle

Muschelkalk) of Remkersleben, 15

km

west of Magdeburg,

Germany.

Distribution—

Lower

middle Muschelkalk,

Anisian, Europe.

Comments—

Anarosaurus pumilio was origi-nally described by

Dames

(1890).

Schrammen

(1899) found Anarosaurus to be closely

compa-rable to _{Cymatosaurus, perhaps because} of the spatulate expansion ofthe tooth crown. Jaekel (1910) reconstructed theskullof^4narosaurusafter furtherpreparationofthe holotype,

and

used

An-arosaurus (as well as Simosaurus) in support of

his_argumentthatsauropterygiansarea_subgroup

ofthe Diapsida. Arthaber (1924) criticized Jae-kel's (1910) reconstructionofthe skull, and pre-sented

new

vertebral counts_{in his redescription}

ofAnarosaurus.

He

alsonotedthesimilarityofthe pubisofAnarosaurusto other, isolated elements

from thelower Muschelkalkreferred to

'''Macro-tracheW

_by H.v.

Meyer

_(1847-1855).

Nopcsa

(1928)rejectedArthaber's(1₉₂₄₎vertebralcounts

inAnarosaurus,

and compared

thetaxonto

Dac-tylosaurus.

He

considered theskulltobevery sim-ilarin both genera, but found differences in the postcranial skeleton to support the generic dis-tinctionofthetwotaxa.

In1_958,

Huene

described asecond_species,

"^«-arosaurus"multidentatus,fromthelowerAnisian

of_{the Lechtaler Alps,}Austria.

The

specimen con-sistsofalower

jaw

characterizedby an elongate

symphysis

and

aheterodontdentition.Inarecent redescriptionofthe holotype, thespecieshasbeen referred to the genus Cymatosaurus (Rieppel,

1995).

In 1838,

Meyer

reported the collection oftwo

lower

jaw

_fragments(leftdentaries), onefromthe Saurierkalk (lowermiddle Muschelkalk) of Esper-stadt, the other from the orbicularis beds(lower

middle Muschelkalk) ofQuerfurt.

The

originalof the Esperstadtspecimen

was

keptin_Dresden,that

fromQuerfurt

was

kept in Jena. Both specimens

are

now

lost,butcastsof both specimensare pre-servedintheStaatliches

Museum

fiirNaturkunde

in Stuttgart (smns 80082-83), and in the

Hum-boldt

Museum

in Berlin _(mb R. _{61-62) (Fig.} 2).

The

specimensfirst reportedin 1838 were rede-scribed as lower_{jaws of}fishes by

Meyer

(1851),

who

renamed

them

Charitodon tschudii. Chari-todon {Charitosaurus) tschudii resembles

Anaro-saurusintoothstructure, with aconstrictedbase

and an expandedcrown, but thetooth crown of

Anarosaurusis

more

distinctly lanceolatethanthe ratherbulboustooth crown ofCharitosaurus.

At

the presenttime, Charitosaurustschudii

must

re-main

a

nomen

dubium.

Morphological Description— The

holotype

ofAnarosaurus pumiliois

known

fromcasts only.

The

original specimen consisted ofpart (dorsal view)

and

counterpart(ventralview).

The

Institute

and

Museum

of Geology andPaleontologyin

Got-tingen holdstwocastsofthedorsalviewthatdiffer in size; measurements of limb bones takenfrom

one cast

(Go

409-lb) beingconsistently smaller than those takenfromtheother

(Go

409-la).

Oth-er casts kept at the natural history

museums

in Berlin, London, and Stuttgart (see above) yield different values again, indicatingthe limited

Fig. 3. Cast ofthe skull ofAnarosauruspumilio

Dames

(holotype)(Institutfiir_{Geowissenschaften,} Mar-tin-Luther-Universitat, Halle, M4/12). Scale bar

=

20

mm.

curacyofthosecasts.Unlessnotedotherwise, the

measurementsgivenbelowarefromtheGottingen cast.

Go

409-la.

The

skull_{(Figs. 3,}4)is_{incompletely preserved,}

partially crushed,and (or)destroyed by prepara-tion. In dorsal view, both premaxillae, the right maxilla, right prefrontal,

and most

ofthe skull tableare wellexposed.

The

distancefromthetip

ofthe snout to the posterior margin ofthe skull table(aspreserved)is34.5

mm,

thedistancefrom

thetipofthesnouttotheposteriormargin ofthe supraoccipital(as preserved) is38

mm.

The

lon-gitudinaldiameterofthe (right)orbitis 13

mm,

the longitudinal diameterofthe upper temporal

fossa is 5

mm

_(right)

and

4.5

mm

(left), respec-tively.

The

premaxilla formstheanteriorand

antero-FiG.4. SkullofAnarosauruspumilio

Dames

(holotype).A,Drawingofthe castkeptattheInstitutund

Museum

fur_GeologicundPalaontologie,Georg-August-Universitat, Gottingen,Orig.Nr.409-1); B, reconstructionoftheskull

indorsal view. Scale bar

=

10

mm.

Abbreviations:ar,articular;f, frontal;m,maxilla;p, parietal;pm,premaxilla; po,i>ostorbital;pof,postfrontal;prf,prefrontal;so,supraoccipital;sq,squamosal.

dorsalmargin oftheexternalnaris.

A

slender pos-teriorprocess enteredbetweentheexternal nares, but its relation to the nasal

and

frontal remains

unknown. The

posteriorprocessofthepremaxilla

doesnotextend

beyond

theleveloftheposterior

margin oftheexternalnaris.Jaekel (1910)counted

four, Arthaber (1924) five premaxillary teeth,

numbers

that

seem

to refer to _{the incompletely} preserved left premaxilla.

The

exact tooth count

isdifficult toestablish

on

theavailablecasts, but the completely preserved right premaxilla shows a possible

maximum

ofeight teeth ortooth po-sitions.

Dames

(1890)

and

Jaekel (1910)

showed

acharacteristicleaflike_{expansion of}the

crown

of

the premaxillaryteeth,which cannot be confirmed

on the cast kept atthe Institute

and

Museum

of Geology and Paleontologyin Gottingen; a spatu-lateexpansion ofthetooth

crown

isdistinct inone

anteriorpremaxillary toothinthecastskeptatthe Staatliches

Museum

fiirNaturkunde _{in Stuttgart}

as well as in the castskeptattheNatural History

Museum

in Berlin.

The

remaining premaxillary teeth areabout3

mm

long,slightlyrecurved,

and

pointed.

The

exact structure of the maxilla

re-mainsobscure, asdoesthe

number

ofmaxillary teeth.Posteriorly,themaxillaformsashort slen-der_{process, underlying the prefrontal in} the an-teroventral_{margin of}theorbit.

The

prefrontalisa broad,

domed

element,asis

typical forpachypleurosaurs.Itremainedbroadly separated from the postfrontal along the dorsal

margin oftheorbit,whichisformed bytheslightly

concavelateralmargin ofthefrontal.

The

partially fused frontalsare longandslender elements, but theiranteriorportion is_{missing. Posteriorly,} the frontals form an _{interdigitating suture} with the parietalsinaratherforwardposition.Slender pos-terolateral lappetsofthefrontalsextendbackward

alongthemedialsideofthepostfrontals.

The

pa-rietals enclosea small parietal foramen that lies

midway

betweenthefrontoparietalsuture

and

the posterior margin ofthe parietals. Laterally, the parietalformsthe_{medial margin of}theupper

tem-poralfossa. Posteriorly, tapering processesofthe parietalextendlaterally

on

totheocciput.

The

upper temporal fossa inAnarosaurus has

rounded contours, and is smaller than the orbit but distinctly larger than the temporal fossa in

Serpianosaums andNeusticosaurus.

The

postfron-tal forms a considerable portion ofthe anterior

andanteromedial margin ofthe _{upper temporal} fossa, the triradiate postorbital forms the lateral margin, andthesquamosalborders the _temporal fossa posteriorly.

The

upper temporalarchis

nar-row, leaving the cheekdeeply "excavated."

The

ventralprocessoftheleft_{postorbital carries}afacet

on

itsanteriormarginthatreceivedthedorsalend ofthejugal. Details ofthe suspensorium

and

of

the occiputaredifficulttoascertainexceptforthe presenceofalarge supraoccipitalwith alow

sag-ittalcrest.

j

The

palate isdifficultto analyze. Littlecan be

'

seen

beyond

the generaloutlinesofthemajor

el-ements

and

thelocationofthe internalnares

(Car-roll, 1981). Inparticular, itisimpossibleto con-firm the presence or absenceofthe ectopterygoid.

A

distinct ventral ridge

marks

thelateral _edgeof

the pterygoid along the anteromedialand medial margin ofthesubtemporalfossa.

Lateral to the left _{suspensorium, the} articular facetofthelower

jaw

ispreservedinsitu,withthe retroarticular_{processextending}backward behind

themandibulararticulation.

A

distincttroughcan be identified

on

thedorsal surfaceofthe retroar-ticular process.

The

rightlower

jaw

is_exposedin ventralviewbutshowslittle_{morphological}detail. Its total length, including the retroarticular pro- i

cess, is47.5

mm.

1

Posteriorto theskull, 16 cervicalvertebraeare

preservedin articulation.Arthaber(1₉₂₄₎counted 15 cervicals, but obviouslyomitted_{counting the}

poorlyexposedatlas. In dorsalviewthe cervicals

j

show

pachyostotic neural arches with alowneural I

spine; theventral surfaceofthecentrumis

orna-mented

with pairedlongitudinalkeels.

The

sizeof

the cervical vertebrae _slightly and _gradually in-creasesfromfronttoback.

The

lengthofthe

cen-trum

is 4.2

mm

in the axis, 4

mm

in the 10th cervical,

and

4.8

mm

inthe16th_cervial;thewidth

ofthe corresponding elements, measuredacross the zygapophysealarticulations, is5

mm,

6

mm,

and

8

mm,

respectively. Three cervical ribs (an

incomplete

number)

can unequivocally be

iden-tified,theanteriormostone of whichliesadjacent tothe 15th cervicalvertebra

and

carriesadistinct freeanteriorprocessclose toits_proximalarticular head.

Separatedfromthecervicalvertebraebya_gap, atotal of14 dorsalvertebrae (13 complete, 1 in-complete) arepreserved inarticulation, followed

by the first sacral vertebra.

The

dorsal vertebrae

show

a

weak

constrictionofthecentruminventral view. Within the gap between the cervical and

dorsalvertebrae series, 10(left)ribs are exposed,

plusthe spaceforoneadditionalribthatwasnot completely prepared. Followingthe 16 _preserved

cervical vertebrae,thecontoursoffour additional elementscan beidentified (see alsoNopcsa,1928);

obt.f.

Fig.5. GastralribsofAnarosaurus_pumilio

Dames

(holotype)(drawnaftersmns59073).A, Anteriorgastral

ribs;B, posterior gastralribs. Scalebar

=

10

mm.

all liein frontofthefirstexposedOeft) rib.

With

a total of 15 vertebral_{elements bridging} thegap betweenthe preservedseriesofcervical

and

dorsal vertebrae,acountof45presacralvertebraeresults.

Dames

(1890) counted 43 presacrals, Arthaber

(1_{924) postulated}48_presacrals,and

Nopcsa

₍1928)

counted 39—40presacrals. Since theanteriormost ribexposedwithin the_{gap between}cervicals

and

dorsalsshowsthemorphology ofa holocephalous dorsal rib withoutfree_{anterior process,}

we

con-clude thatAnarosaunis had

no

more

than 19-20

cervical vertebrae (in agreement with _Nopcsa, 1928)

and

25-26 dorsal vertebrae.

The

standard length

was

defined as the length ofthe last four presacral centra(Rieppel, 1989;Sander, 1989),and

it is 23

mm

(the length of the second but last presacralcentrumis5.5

mm;

thestandardlength

isthe

same

inthecastsfrom_GottingenandBerlin, butitis21.3

mm

inthe castfrom _Stuttgart).

The

dorsal ribs lack pachyostosis.

The

gastral ribs are

composed

offive elements each (Peyer,

quotedin Zangerl, 1935),the angled medioventral

elementbearing adistinctanteriortipat leastin the anteriorand middlepartofthegastral region,

and

two lateral elements

on

either side _(Fig. 5).

The

ratio ofvertebral elements to gastral ribsis

1:2.

Of

the three sacral vertebrae, only the

anteri-ormost is preserved. However, three sacral ribs

canclearlybe identified,of whichthesecondone

(11.5

mm

long)is_{slightlylarger}thanthefirstone

(10,8

mm

long),whereasthethirdoneis_only in-completely preserved.

The

sacral ribs are slightly

expandedattheir_proximalend._Nothingis

known

ofthecaudalaxialskeleton.

The

pectoral girdle is _{poorly preserved} and/or

exposed,and dermalelementscannot beidentified unequivocally.

The

right scapulais preserved in ventral view,possibly in association witha

frag-FiG. 6. The pubis ofAnarosauruspumilio

Dames

(holotype). Scalebar

=

5

mm.

Abbreviation:obt.f, ob-turatorforamen.

mentaryclavicle.

The

rightcoracoidlacksitsdistal portion, but showsa rounded proximal head as wellasa_stronglyconcaveanteriormargin

oppos-ing the lessdistinctlyconcaveposteriormargin.

Of

the pelvic girdle,the ilium is not exposed.

The

twoischiaarepreservedinarticulation.

They

show

anarrow_{("rod-shaped" according}to

Nopcsa

[1928,p.31])acetabularportion, stronglyconvex anterior

and

posterior margins, anda widely

ex-panded

ventralportion with aconvexventral

mar-gin.

The

lengthoftheischiumis 19

mm,

its prox-imalwidthis6.5

mm,

theminimal widthis4

mm,

and

thewidth ofthe ventral partis 20

mm.

The

pubisoiAnarosaurusshows weakly concave an-terior

and

posteriormargins.

The

obturator

fora-men

is not closed, but rather forms an open slit

atthe _{posterior margin of}the pubisclose tothe acetabularmargin ofthe bone.

The

concavityof thecentral(medial)margin ofthepubisresultsin adistinctspine protrudingfromtheanteroventral edgeofthepubis(Fig.6).

A

largethyroidfenestra

was

developed between the pubis and ischium.

The

length ofthepubisis 19.5

mm,

its _proximal

widthis 10

mm,

itsminimal width is 7

mm,

the distal widthis9

mm

excludingtheanteroventral spine,but 13

mm

_{including the} latter.

The humerus

(Fig. 7A) is _{the only} elementof

the forelimb that is preserved.

The

element is

slightly curved with a concave medial(preaxial) margin, a well-developeddeltopectoralcrest,and a broadlyexpandeddistal_portion.

The

entepicon-dylarforameniswellsetofffromthedistal

artic-Table2. MeasurementsofthefemurofAnarosaurus pumilioDames,indifferentcastsofthe holotype.

ec.r

nt.f.

Fig.8. _{Holotype ofAnarosaurus}heterodontusn. sp.,

rightdentary (Institut fur Geowissenschaften, Martin-Luther-Universitat,Halle,M4/12).Scalebar

=

10

mm.

share theformdiagnosticofthe_genus

Anarosaums

(i.e.,aconstrictedtoothbaseandalanceolatetooth

crown).

Of

the preserved teeth, theanterior two

are distinctly larger (4.5

mm

high)than the suc-ceedingteeth (2.5

mm

high). Preparation ofthe dentaryfrom the ventral side revealed a narrow symphysisasischaracteristicofpachypleurosaurs. Overallsize,toothmorphology, andtheincreased sizeoftheanteriordentaryteethrender thefossil closely similar toa lower

jaw

reported from the lower Muschelkalk of Winterswijk, erroneously referred to Cymatosaurus(Oosterink, 1986, Foto 40).

A

perfectly preserved left premaxillafrom the

Schaumkalk

of _{Freyburg/Unstrut} (Fig. 9) has a dentition thatmatchesthemorphologydiagnostic

ofAnarosaurus.

The

premaxilla bears five teeth, if_{a posterolateraltrough} is_{interpreted as} afacet forthe maxillaratherthanas partofanalveolus forasixthtooth.Butevenwithsixfunctional teeth

on

the premaxilla the

number

islessthan_{the eight} teethobservedon the premaxillaof Anarosaurus

pumilio.

The

premaxillafromtheSchaumkalk of

Freyburg/Unstrutis_againabout twicethesizeof

the premaxilla in _{the holotype} of Anarosaurus

pumilio: thedistancefromthetipofthesnoutto the anterior _{margin of}the external naris is 25.7

mm

inthefirst, 13.2

mm

inthelatter.

Interms ofsize

and

morphology(fivetooth po-sitions), the premaxilla from the

Schaumkalk

of

Freyburg/Unstrut again comparesclosely to

ma-FiG. 9. Anarosaurus heterodontus n. sp., left pre-maxilla(Institutfur_{Geowissenschaften,} Martin-Luther-Universitat, Halle,M4/12).Scalebar

=

10

mm.

Abbre-viations:mf, maxillaryfacet;np, nasal process; vp, vo-merineprocess.

terialfromthelowerMuschelkalk ofWinterswijk,

which includesa skull depositedin the

Museum

Freriks, as well asa large

amount

ofundescribed material kept in _{private collections} (Oosterink, 1986,Foto 38).

The

skull in the

Museum

Freriks (#20778; Fig. 10) showsa

number

ofcharacters diagnostic ofpachypleurosaurs, suchasthe rela-tively shortandunconstrictedsnout,thelarge pre-frontal,the presenceofascleral ring,andthe rel-atively short postorbital portionoftheskull,

and

it shares with other pachypleurosaurs from the lower Muschelkalk the deep

embayment

ofthe

cheekregion

and

the relatively large upper

tem-poral fossa(as

compared

tothe Serpianosaurus-Neusticosaurus dade).Apart fromrelativesize

and

the heterodontdentition (enlargementofthe an-terior _dentary

and

premaxillary teeth), the skull differs fromthe holotypeofAnarosauruspumilio

bya closeapproximation ofprefrontaland post-frontal, restricting the frontal to _{a very} narrow

entryintothedorsalmargin oftheorbit.

Schaum-Fig.10.

A

narosaurus heterodontusn. sp.,skull inleft

lateralview,fromthelowerMuschelkalkof Winterswijk

(MuseumFreriks,#20778).Scalebar

=

20

mm.

kalk (upperlower Muschelkalk) of

Freyburg/Un-strutandthatfromthelowermost Muschelkalk of

Winterswijk represent a

new

speciesof Anarosau-rus thatis_geologically

somewhat

olderthan

An-arosaurus_{pumilio from} the lower middle

Mus-chelkalk. Morphological differences include ab-solutesize,the

number

ofpremaxillaryteeth,the relative sizeofthe anteriordentary

and

premax-illary teeth,

and

the configurationoftheprefrontal

and

postfrontal bones. It

may

be noted that the lowerMuschelkalkinthewestern_partofthe

Ger-manic

_{basin (Winterswijk)} is _geologically

some-what

_youngerthatthelowerMuschelkalkdeposits inthe_{eastern part}ofthebasin (Freyburg/Unstrut),

whichbringsthetwolocalititesclose in geological time.

Using Captorhiniis (Heaton, 1979)

Petrolaco-5aMms

(Reisz, 1981),C/aw^/osawms(Carroll,1981),

and Youngina (Gow, 1975) as successive

out-groups(Storrs, 1991, 1993a), v4narc>5aMrusshows the following plesiomorphiccharacters: relatively large upper temporal fossae with both the post-frontal

and

the parietal broadly entering the an-terior and anteromedial margin ofthe fenestra; postorbital distinctlytriradiate;

humerus

retaining

anectepicondylargrooveinadditiontoan entepi-condylar foramen, and a well-developed delto-pectoral crest; dorsal ribs without pachyostosis; gastralribs

composed

offiveelementseach.

Apomorphic

featuresof Anarosaurusincludethe spatulate expansion ofthe crown ofthe teeth, a character discussed

and

figured in detailby

Dames

(1890) but which is difficult to ascertain on the basisoftheavailable castsofthe holotypeof An-arosaumspumilio.

The

distinctionofcervicalfrom

dorsalvertebraeisdifficultin _{reptilesin general,} aproblemaggravatedbythefactthatthe transition

is _{very poorly preserved}in Anarosaurus.

Never-theless,acount of25-26dorsalvertebraeis

most

probable,anditisdistinctlyhigher thaninallother pachypleurosaursknown.

Both overallsize

and

the positionofthe ente-picondylarforamenat

some

distancefromthe dis-talarticularsurfaceofthe

humerus

indicatea

ma-ture individual, yetthe obturatorforamenin the pubis remains widely open.

The

pubis carriesa distinct_{anteroventral spineresulting}froma con-cavity ofits ventral (medial) margin, otherwise

known

onlyinSerpianosaurus

among

other

pachy-pleurosaurs(Rieppel, 1989). Isolatedelements with

an open obturatorforamen and ananteroventral spinehavealsobeenreportedfromthebaseofthe

middle Muschelkalk

(Hagdom

8l Simon, 1993),

and

aconcavelowermarginofthepubisisa gen-eral character for Simosaurus and Nothosaurus

among

eusauropterygians.

CarrollandGaskill(1985,p.349; see also

Kuhn-Schnyder, 1959; Rieppel, 1993) considered the elongatedfemurdiagnosticofAnarosaurus.

Mea-surements ofthe femurdiffer

on

different _casts, but inspectionof Table2indicates that35.75

mm

isan_{average estimate}ofthe_lengthofthefemur.

Using 23

mm

asstandardlength, the ratiofemur length/standard length is 1.55, an exceptionally high value

among

all other pachypleurosaurs

known

(Rieppel, 1993), corroboratingrelative

fe-mur

length asa diagnosticfeatureofAnarosaurus

(Table3).

The

corresponding valuesforother taxa are 0.86 for _{"Psilotrachelosaurus," 0.97-1.2} for Serpianosaurus(juvenilesandadults,bothsexes), 0.9 1-1.5forNeusticosaurus_{pusillus (juveniles}and

adults, bothsexes), 0.79-1.06 forNeusticosaurus peyeri(juveniles

and

adults,bothsexes),and 0.65-0.96 forNeusticosaurus edwardsii(juveniles and adults, bothsexes).

The

distinct striations

on

the surfaceof

humerus and

femurnearthe proximal

and

distal heads form anothercharacteristic fea-ture ofthis _{genus (sometimes} also observed on

well-preserved humeri and femora of Neustico-saurus: H.-D. Sues, pers. comm.). Ifthese stria-tions aretaken as indicatorsofadult individual age,they

document

that differences inoverall

body

size

and

degreeofbonesculpturing arenotmerely

ontogeneticvariations inAnarosaurus pumilio and Anarosaurusheterodontus.

DactylosaurusGiirich, 1884

Type

SvEdES—

Dactylosaurus gracilis Giirich,

1884.

Generic Diagnosis—

A

small pachypleurosaur with a narrow interorbital _{bridgeformed by} the frontals;acloseapproximation ofthe postfrontal

and

prefrontalalong thedorsal_{margin of}theorbit

due to_{a long}

and

slenderanteriorprocessofthe postfrontal (leavinga narrowentry ofthe frontal inthedorsal_{margin of}theorbit);long butnarrow (kidney-shaped)upper temporalfenestrae;

no

con-striction ofthe dorsal vertebral centra; clavicles withananterolateral expansion; preaxial margin ofthe radius with adistinctlyconcavemargin.

The

humerus

is _{plesiomorphic} at the level of the Pachypleurosauroidea butuniquewithinthegroup bythe retentionof anentepicondyledistinctlyset offfromthe shaft_(insexy).

Distribution—

Lower

Muschelkalk, central Europe.

DactylosaurusgracilisGiirich,1884

1884 Dactylosaurusgracilis, Giirich,p. 125,PI. 2, Figs. 1, 2.

1886 Dactylosaurus gracilis, Giirich, pp.

457-458, textfig. 1.

1886 Dactylosaurusgracilis, Deecke, p. 187.

1899 Dactylosaurusgracilis,

Schrammen,

PI.25, Fig. 10.

1924 Dactylosaurusgracilis, Arthaber,pp.

483-484, textfig. 14.

1928 Dactylosaurusschroederi, Nopcsa,pp. 3 1-37,PI. 3, Figs. 1-6.

1935 Dactylosaurusgracilis, Zangerl,p. 66.

1935 Dactylosaurusschroederi, Zangerl,p. 67.

1959 Dactylosaurusgracilis, Kuhn-Schnyder,p. 652.

1959 Dactylosaurusschroederi,Kuhn-Schnyder,

p. 652.

1985 Dactylosaurus gracilis. Sues

and

Carroll, pp. 1602, 1608.

1985 Dactylosaurusschroederi.Sues

and

Carroll, pp. 1602-1608, text_figs. 1-3.

1987 Dactylosaurusgracilis, Rieppel,pp. 1

109-1110.

1987 _{Dactylosaurus} schroederi, Rieppel, pp.

1109-1110.

1993 Dactylosaurusgracilis, Rieppel,p. 10.

1993 Dactylosaurusschroederi, Rieppel, p. 10.

HoLOTYPE.—

Dactylosaurus gracilis

was

de-scribed by Giirich (1884) on the basis ofa cast

made

froma natural

mold

(Fig. 1_1)depositedat

the InstituteofGeologicalSciences,University of

Wroclaw (mgu

Wr

3871s).

A

cast _{corresponding}

c

-a

S¥

3

Fig. 11. _{Holotypeof Dactylosaurus}gracilisGiirich(mgu

Wr

3871s). Scalebar

=

20

mm.

tothe figuregiven byGiirich (1884, PI. _{II, Figs.}

1

,2)iskeptattheNatural History

Museum,

Hum-boldt University,Berlin(mbR.63).

The

holotype

comes

from _{Michalkowitz,}

Upper

Silesia

(now

Michalowice, Poland), assignedtothelower

Mus-chelkalk.

The

holotype of Dactylosaurus schroederi

Nopcsa, 1928,

was

depositedinthecollectionsof

the Preussische Geologische Landesanstaltin Ber-lin_{(Kuhn, 1934),}and

now

isinthecollectionsof

the Bundesanstalt fur Geowissenschaften

und

Rohstoffe, Berlin(uncatalogued)(Fig. 1_2).

A

rubber

castofthe specimen, describedbySuesandCarroll (1985), iskeptatthe Forschungsinstitut

und

Na-turmuseum

Senckenberg, Frankfurt a.M. (smf

R-4097

a, b).

The

holotype

comes

from deposits assignedtothelowerMuschelkalk ofGross-Stein,

Upper

Silesia.

The

holotypesofDactylosaurusgracilisas well asD. schroederi arebothnaturalmoldspreserved in_yellowmatrix.

The

colorofthe matrix,as well as thepreservationofvertebratefossilsasnatural molds,ischaracteristicoftheupperBuntsandstein (Rot)whichunderliesthelowerGogolin Beds(H.

Hagdom,

pers.comm.).

Referred

Material—

Institut

und

Museum

fur Geologic

und

Palaontologie, University of Tii-bingen, uncatalogued (Fig. 13), lowermost

Mus-chelkalk_{of Gogolin(lowerGogolinbeds).}

A

poor-lypreserved specimenrepresentedbybarely vis-ibleimpressionsoftheskull,cervicalandanterior

dorsal regionofthevertebral

column

preservedin dorsalvieworasfaint_{impression(of}theventral aspect), right humerus, and left forelimb.

The

specimenisslightlylargerthan theonedescribed

by

Nopcsa

(1928).

Nopcsa

(1₉₂₈₎

and

SuesandCarroll₍1₉₈₅₎refer to

Meyer

_(1847-1855)

who

figuredhumericlosely similar tothoseofDactylosaurusgracilisfromthe

Muschelkalk ("Saurier-Kalk") from Jena. Other humeri ofthis _type are

known

from the lower

Muschelkalk ofBobreknear_Beuthen (Bundesan-staltfurGeowissenschaften

und

Rohstoffe, Berlin,

drawer S45/5 right) (Fig. 14),

and

fromthe

Mus-chelkalk of Gogolin

(Museum

fur _Naturkunde, Berlin,

mb

R. 772.1.,

MB

R. 769,anduncatalogued;

Institut

und

Museum

fur _Geologic

und

Palaon-tologie, University of Tubingen gpit 1744/1-10: Rieppel, 1993).

Diagnosis—

Same

as forgenus,ofwhichthisis

the only

known

species.

Locus

Typicus— Upper

Buntsandstein of

Michalowice,

Upper

Silesia

(Gomy

Slask, Po-land).

Distribution—

Upper

Buntsandsteinand low-er_{Muschelkalk, Europe.}

CoMMEt^TS—

Dactylosaurusgracilis is the type speciesofthegenus(Giirich,1_884).

The

cast avail-able in the_{Natural History}

Museum

in Berlinis

ofrather poorquality, and showslittle

morpho-logical detail.

The

following description of the

specimenisbased

on

a

new

siliconcast

made

from

Fig. 12. Holotypeof DactylosaurusschroederiNopcsa(bor,uncatalogued).

the holotypein 1994.Preserved_{are the posterior}

part ofthe skull, the cervical vertebral column,

thepectoralgirdle,andthe right forelimb,all

ex-posedindorsalviewon thecast.

The

posterior partofthe skull showsa deeply excavatedcheekandrelatively large,kidney-shaped

upper temporal fossae. Sutures are difficult to

identifyexceptforthe posteriorend ofthe post-frontal,whichdefinestheanteromedialmargin of

the upper temporal fossa. Sixteen cervical verte-brae_{(including the}atlas)arepreservedin articu-lation; an additional vertebra

would

have been

positionedattheleveloftheclavicles.Thiscount of17 cervical vertebrae correspondstothe

holo-Fig. 13. Dactylosaurus gracilis Giirich from the lower Muschelkalk of Gogolin, Upper Silesia

(Gomy

Slask, Poland)(gpit,uncatalogued).

Fig.14. _{Dactylosaurus}

gracilisGiirich,humerus,from thelower Muschelkalk ofBobrek near Beuthen (bgr, drawerS 45/5right).Scalebar

=

10

mm.

type ofDactylosaurus schroederi Nopcsa, 1928. Cervicalribscanonlybeidentifiedalongthe pos-terior part ofthe cervical vertebralcolumn, and

they are oftypical structurewith a freeanterior process.

The

centra offouranteriordorsal verte-braearepreserved

and

exposedinventralviewon

the actual specimen: they

show no

sign of con-striction, but slightly convex lateral margins in-stead.

The

proximalpartofthe dorsalribs_{(as far} as preserved)shows

no

pachyostosis.

In thepectoralgirdle,thedistalend ofthe clav-icleisseentooverlap with theanterior

and

medial

aspectofthe scapulainatypical pachypleurosau-roid pattern.

The

interclavicula cannot be

iden-tified.

The

clavicleshows expandedlateralcomers that arenotaspronouncedas inthe holotype of

Dactylosaurusschroederi,possibly ajuvenile char-acter.

The

coracoids are represented by impres-sions only.Theirlengthis7.4(8)

mm,

their

prox-imal widthis 3.6(3)

mm,

theirminimal widthis

3.4(3.4)

mm,

and

theirdistal width is 4.6 (5.3)

mm

(values inparentheses referto _{the right}

ele-ment;allmeasurements weretaken

on

the natural mold).

The

coracoidsof bothsidesmeetventrally in a well-defined suture, but their _proximal

ex-pansionis_{relativelyweak,}

and

the_proximal mar-ginshows

no

notchindicatingthepositionofthe

mc

hu

Fig.15. DactylosaurusgracilisGmich,holotype(mgu

Wr

387Is),rightforelimb.Scalebar

=

5

mm.

Abbreviations: dc4,distalcarpal4;hu,humerus;in,intermedium; mc,, metacarpal 1;mcj, metacarpal5; ra,radius;ul, ulna;uln,

ulnare.

coracoidforamen.This mightindicateincomplete ossificationofthecoracoidin_{a juvenilesi)ecimen.}

The

right frontlimbiswellpreserved(Fig. 1_5).

The

right

humerus

isa_slightlycurved elementthat

shows hardly any morphological differentiation, as is characteristic ofjuvenile pachypleurosaurs (Rieppel, 1989; Sander, 1989).

The

deltopectoral crest is hardly differentiated,

and

an entepicon-dylar foramen cannot be identified. In _juvenile pachypleurosaurs, the entepicondylarforamenlies

atthedistal_{margin of}theossified partofthe

hu-merus

or,inevenearlier stages,

beyond

that (Riep-pel, 1989;Sander, 1989).

The

total _length ofthe

humerus

is 11.9

mm,

its proximal width is 2.1

mm,

itsminimal widthis 1.85

mm,

and

itsdistal

widthis2

mm.

The

radiusis_{incompletelyexposed}

due to _{the overlapping}ulna,but appearsslightly longer than theulna. Total_lengthofthe radiusis

6.3

mm,

that ofthe ulnais 5.8

mm.

Some

con-troversy surrounds the structure of the carpus (Giirich, 1886), but the

new

casttaken from the holotype corroboratesGiirich's(1886)description

ofthree ossified carpalelements.

The

intermedium

is_elongatedandrectangularin_{shape;posterior to}

itlietheroundedulnareanddistal_carpal4.

The

phalanges are incompletely preserved, probably

due to _incompleteossification.

The

cast shows a

number

ofossified elements that correspond to Giirich's (1886) illustration of 2-3-3-4-3.

Un-guals areunequivocallyidentifiedondigits 1 and

2 only; the count for the _remaining digits

may

therefore be incomplete. Sander (1989)

docu-mented

aproximo-distal sequence ofossification

ofthephalangesinNeusticosauruspusillns.

The

overall sizeofDactylosaurusgracilis, and details_{of morphologythroughout}the skeleton, in-dicate that_{the holotype}ofthatsiieciesis_{a juvenile}

specimen.

The

only characterpotentially contra-dictingthisconclusion istheadvanceddegreeof ossification inthecarpus,butvariation in the tim-ingofossificationcan beextensiveinextant

rep-tiles_(Rieppel, 1_994a).

The

_relativelylow count of

cervicalvertebrae₍₁₇₎is_{shared with}

Dactylosau-rus schroederi _Nopcsa, 1928, and is otherwise

known

only from lower Ladinian

pachypleuro-saurs{Neusticosauruspeyeri:Sander, 1989;

Neus-ticosaurus edwardsii: Carroll

&

Gaskill,1_985).

The

lattertaxaarecharacterizedbyarelativelysmaller

upper temporal fossathan is observedin Dacty-losaurusgracilis

and

D. schroederi.

On

thebasis

ofthe limited data available,

we

conclude that Dactylosaurus gracilis Giirich, 1884 and

Dacty-losaurus schroederi_Nopcsa, 1_{928, are subjective}

synonyms

(see alsoSues

&

Carroll, 1_985);thefirst

name

has_priority.

Morphological

Descrifhon—

The

morpho-logicaldescriptionoiDactylosaurusgracilisisbased

on

new

latexcasts

made

from the original

speci-men

(natural mold) described by

Nopcsa

(1928, holotype ofDactylosaurusschroederi), as well as

on

therubbercasts_keptat theSenckenberg

Mu-seum, Frankfurt.

The

specimenisrepresentedby

natural molds of_part

and

coimterpart.

The

total lengthofthefossil

must

remain

unknown

because

ofthe incompletely preservedtail,butit

must

have

exceeded213

mm;

snout-ventlengthis 158

mm.

Skull length (the lengthoftheleftlowerjaw

ramus

in ventral view) is 27

mm;

_{glenoid-acetabulum}

length(measured on theright sideofthebody)is

68

mm;

standard _{length (length} ofthe last four dorsal vertebral centra)is 15.5

mm

(the lengthof thelastdorsal vertebralcentrumis3.5

mm).

In the skull (Fig. 1_6), thesnout_complexisnot wellexposed.

The

nasalprocessofthe premaxilla

remainsseparated from the frontal_by thebroad

nasals,whichmeetalong a middorsalsuture.

The

frontalformsa shortanteromedial process enter-ingbetween the nasals, as well as short anterolat-eral _processesthatmeet the maxilla

and

thereby separate the prefrontal from the nasal.

The

pre-frontal reaches high

up

along the anterodorsal

slen-Fig. 16. Skullof DactylosaunisgracilisGiirich (bgr, uncatalogued). A,Drawnafteranewcastmadefromthe originalofNopcsa(1928);B,reconstructionofthe skullindorsalview. Scalebar

=

5

mm.

Abbreviations:ar,articular,

f,frontal;m,maxilla;n,nasal;p,parietal;pm,premaxilla; po, postorbital; pof, postfrontal;prf,prefrontal;q,quadrate;

so,supraoccipital;sq,squamosal.

der anterior process running along the postero-dorsal _{margin of} the orbit.

The

prefrontal and postfrontal fail to meet, however, allowing the frontal toenterintothe dorsal_{margin of}theorbit forashort distance.

The

interorbital_bridgeformed bythepairedfrontalsisnarrow(2

mm

inthelatex casttakenfromtheoriginalspecimen).

The

fron-toparietal sutureis in a ratherforward position.

The

posterolateralprocessesofthefrontalsextend posteriorlybetweentheparietal

and

postfrontal.

The

skull tableiswellexposed.

The

upper

tem-poral fossae are relatively large

and

ofanelongated

kidney shape.

The

length ofthe upper temporal

fossais4.3

mm

_(right)

and

4.5

mm

(left), respec-tively;thewidth oftheupper temporalfossais 1.5

mm

(right) and 1.3

mm

(left), respectively.

The

postfrontal,thetriradiate postorbital, theparietal,

and

thesquamosalall_{participate in the}formation

ofthe margin ofthe upper temporal fossa.

The

pairedparietalsenclose thepinealforamen,which

ispositionedhalfway along the length ofthe pa-rietals.

The

occiputisdifficultto analyze.Inparticular, theoccipital exposure oftheparietal,

and

its re-lation tothe squamosal, remainunclear.

The

ventralview oftheskull displaysadermal

palateoftypicalpachypleurosauroidstructure;

lit-tlecan be addedtoits_description

and

illustration

bySues

and

Carroll (1985).

The

pterygoidshows a thickening (arudimentary "transverse flange")

along theanteriormargin ofthesubtemporal fos-sa.Thereis

no

positiveevidenceforthe presence or absenceofanectopterygoid.

A

ceratobranchial

elementispreserved, overlying theposterior part

oftheleft_pterygoid.

Dactylosaunisgracilisshowsa totalof 36 pre-sacral vertebrae, ofwhich 17 are countedas

cer-vical elements (Sues

&

Carroll, 1985), character-ized by a keeled ventral surface ofthe centrum.

The

ventral surfaceofthedorsalcentraissmooth,

and

the centra are not constricted.

The

neural archesare pachyostotic,

and

the neural spinesare consistentlylow.Based

on

the_Senckenbergcasts. Sues

and

Carroll(1985) believed the neurocentral sutures tobeclosedinDactylosaunisgracilis,but they are quite distinct in the cervical, posterior dorsal(wherethey passbelowthe transverse pro-cesses), sacral,

and

preserved caudal region (where they pass through the transverseprocesses).

The

material doesnot allow the presenceofa neuro-central suture in theanterior dorsal region tobe

ascertained.

Sues

and

Carroll(1985) describe atlantal ribs,

which aredifficultto identify, however.

The

cer-vical ribsbear adistinctfreeanterior process.

The

dorsalribs arenotpachyostotic,

and

thelastthree dorsal _("lumbar") ribs are distinctly reduced in length.

Dactylosaunis gracilis shows three sacral ver-tebrae.

The

sacral ribs are broad, stoutelements with a

weak

proximal expansion; theyarenot fused totherespective vertebrae.Caudalribs (againnot fusedtocaudalvertebrae)

and

chevron bonesare notwellexposed. Gastralribsare likewisepoorly preserved, but whatlittle is presentsuggests that theyare

composed

offiveelementseach,one

me-dioventraland twolateralones oneitherside.

Littlecan be addedtoSues

and

Carroll's(1985) descriptionofthe pectoralgirdle.

The

right clav-icleshowsarounded and

somewhat

expanded an-terolateral _{edge (Fig. 17).} This character is oth-erwise

known

from

A

narosaurtdsonly

among

other

pachypleurosaurs (undescribed material

from

Winterswijk), but is distinctly developed in the eusauropterygiangeneraNothosaurus and Simo-saurus (pers. obs.).

The

overlap ofthe clavicles with theanterior

and

medialsurfaceofthescapula

iswellexposedindorsalview

on

theright sideof the specimen.

The

shape ofthe interclavicle

re-mains

unknown. The

scapulaisofthetypical sau-ropterygian structure with a reduced and poste-riorlydirecteddorsalwing.

The

coracoidforamen

isdistinctandenclosedbetweenthenotched pos-teromedialmargin ofthe scapula

and

theopposing

Fig. 17. Pectoral girdle of Dactylosaunis gracilis

Giirich(bgr, uncatalogued),drawnafteranewcastmade

fromthe originalofNopcsa(1928). Scalebar

=

5

mm.

Abbreviations: cl,clavicle;co, coracoid;co.f.,coracoid

foramen;cr,cervicalrib;icl,interclavicle; sc,scapula.

posterolateral margin ofthe coracoid.

The

right coracoidmeasures 12.5

mm

in length. Inthe pel-vicgirdle, the pubisshowsacomplete enclosure

ofthe obturator foramen by bone (Fig. 18); the

bone

is _{completely fused} between the obturator

foramen andtheposterioredgeofthepubis.

The

pubis isa relativelybroad element with alength

of11

mm,

a_{proximal width of}6.8

mm,

aminimal

width of5

mm,

andadistalwidth of7.8

mm.

The

rightischiumiswellexposed,and showsa mark-edly thickenedproximal(acetabular) portion.

The

boneis12

mm

long,its_{proximal width}is4.5

mm,

itsminimal widthis3.5

mm,

itsdistalwidthis 13

mm.

Sues

and

Carroll (1985) describe a

well-de-veloped supra-acetabularbuttress, butin ventral

viewthe iliumdoesnot displayitsacetabular por-tion; indorsal view; theleftiliumisconcealedby

obt.f.

Fig.18. _{Right pubis of Z)ac/>'/o5aMrus^rac/7wGurich}

(bgr, uncatalogued),drawn aftersmns R-4907a. Scale bar

=

5

mm.

Abbreviations: il.f.,facetfor ilium; is.f.,

facetforischium;obt.f,obturatorforamen.

The humerus

of_{Dactylosaurus} gracilisis _very

distinctive_(Fig. 1_9),at leastinsex

y

{sensu Riep-pel, 1989, andSander, 1989; seealso the discus-sionin_{Rieppel, 1993).}

The

elementbears a

well-developeddeltopectoralcrest distinctly setofffrom

the waisteddiaphysis.

The

distal headisbroadly

expanded, with the entepicondyle forminga

me-dial _{process distinctly} set offfrom the articular head.

The

entepicondylar foramen lies at

some

distance from the distal articulation.

The

distal articular heads are level.

A

deep ectepicondylar ridgeis_present.

The

radiusofDactylosaurusgracilisappearsto

becharacterizedbyadistinctnotchinthemedial

(preaxial)margin oftheshaft(Fig.20A).Suesand Carroll(1985, p. 1607)attribute thisfeature toa preservationalartifact.Latexcaststakenfromthe originalspecimen

show

the concavity

on

the pre-axial _{margin of}the radius in both limbs,

more

distinctly in their ventralexposure(and asimilar concavityisalso observedin theradiusof

unde-scribedAnarosaurusmaterial fromWinterswijk).

ec

r

ec.r.

ent.f.

B

Fig. 19. Humerusof DactylosaurusgracilisGiirich (bgr,uncatalogued). A,Righthumerusinventralview, drawn after smns R-4907a; B, left humerus in dorsal view, drawnafter smns R-4907b. Scale bar

=

5

mm.

Abbreviations: ec.r., ectepicondylarridge; ent, entepi-condyle;ent.f,entepicondylar foramen.

The

ulnais

somewhat

shorterthan the radiusand

bears a _{weakly developed} olecranon on its

ex-panded proximalhead.

The

carpus (Fig.

20A)

comprises three

undis-putedossifiedelements,viz.theintermedium,the ulnare,

and

the fourth distal carpal.

The

inter-medium

is ofsubcircular_shape

and

lies distalto

thespatiuminterosseumbetweenradiusandulna.

A

pisiformisdistinct in_Nopcsa's(1_{928) retouched}

photograph ofthe specimen,

and

itspresence (or thatofa

neomorph

inits_position)

was

confirmed bySues

and

Carroll (1985).Latexcaststakenfrom

the original sp)ecimen indicate the presence ofa

minutestructurenexttotheulnareintheleftlimb

only. Ifthat structure represents a _carpal ossifi-cation, the pisiform (or a

neomorph) would

be

extremely small

and

presentinone limbonly. In extantreptiles,the pisiformgenerallyisthelastof

allcarpalelementsto ossify (Rieppel, 1992).

Ev-idencethatthisbone(ora

neomorph)

is, indeed.

mc

B

Fig. 20. Manus and pes ofDactylosaurusgracilisGiirich (bgr, uncatalogued). A,Left forelimb, dorsal view, drawnaftersmnsR-4907b;B,righthindlimb, ventralview,drawnaftersmnsR-4907a.Scalebar

=

5

mm.

Abbre-viations: as, astragalus;ca, calcaneum; dc4, distal _carpal 4; dt4, distal tarsal 4; fi, fibula; in, intermedium; mci, metacarpal 1;mcj, metacarpal5;mt,,metatarsal 1;mt,,metatarsal5;pi,pisiform;ra,radius;ti,tibia;ul,ulna; uln, ulnare.

present in _{Dactylosaurusgracilis} is here consid-ered equivocal.

The

phalangealcountinthe

manus

is 2-3—4-7-3.

The

presenceofeitherfourorfive phalangesinthefourthdigitcannot beascertained unequivocally.

Measurements

ofthe

humerus

are giveninTable 4.

Only

the proximal head ofthe left femur and

the distal head ofthe right femur are exposed.

Theseindicatea slenderbonewithtibialand

fib-ular articfib-ularheadslevel.

The

right fibulaisonly partiallyexposed.

The

righttibiaisalittlesturdier

thanthefibulabutitis stillaratherslenderbone

Table5. Measurementsofthelimbbones_{of Dactylosaurus}gracilis(holotype ofDactylosaurusschroederiNopcsa; BGR,uncatalogued).

with astraightmedial,

and

a_slightlyconcave lat-eral,margin.Threeossifiedelementscanbe iden-tifiedinthetarsus(Fig. 20B), viz. theastragalus,

calcaneum, andthe fourth distal tarsal.

The

pha-langealformulainthe pesis2-3-7-5—4,five pha-langes in the fourthdigit representingthe

plesio-morphic condition.

Measurements

of the limb bones ofthe specimen described by

Nopcsa

are givenin Table 5.

Discussion— The body

proportions of Dacty-losaurusgracilisfall squarely within therangeof variability ofthe

Monte

SanGiorgio pachypleu-rosaurs (Table 3).

The

upper temporal fenestrae

are distinctlysmallerthan theorbit,yet distinctly larger than the upper temporal fenestrae in Ser-pianosaurus

and

Neusticosaurus.

As

in

Anarosau-rus, the postfrontal, postorbital, and parietal broadly enter the margin ofthe upper temporal

fossa (unlike inSerpianosaurus

and

Neusticosau-rus), but the upper temporal fenestrae in Dacty-losaurusgracilisarerathernarrow

and

elongated asopposedtothesubcircularcontoursoftheupper temporal fenestra in Anarosaurus.

As

in

Anaro-saurus, theupper temporalarch_{of Dactylosaurm}

isnarrow

and

thecheekdeeply excavated, unlike Serpianosaurus

and

Neusticosaurus, which

show

abroadenedpostorbital

and

squamosal. Like oth-er_{pachypleurosaurs,Dactylosaurus}showsarather anterior positionofthe_{frontoparietal suture,}with distinct posterolateralprocessesofthefrontals ex-tendingbackward between the parietal and post-frontal. Dactylosaurusgracilis differs from other pachypleurosaurs exceptKeichousaurusinthe

nar-row

interorbitalbridgeformed bythefrontals;the close _{approximation of}the prefrontal

and

post-frontalbonesalong thedorsalmargin ofthe orbit

issharedwithundescribedAnarosaurusmaterial

from _Winterswijk.

The

lattercharacteris associ-atedwith thedevelopment ofa longandslender anteriorprocessofthe postfrontal.

The

cervical vertebral count in _{Dactylosaurus} gracilis is low

compared

to _other pachypleuro-saurs, particularlythoseofthelowerMuschelkalk

{Anarosaurus: 19-20[see above]; Keichousaurus: 26;Serpianosaurus:714-18[Rieppel,1_989];

Neus-ticosaurus: 15-20[Carroll&.Gaskill, 1985;

Sand-er, 1989],but the significanceofthis characteris

difficult to assessbecause ofthe lack ofdata

on

intraspecificvariability.Vertebrae aredifficultto

countintheTubingen specimen ofDactylosaurus gracilis,butthere

may

beas

many

as 19cervicals (and 17 _{preserveddorsals).}

The

_{morphology of}the

humerus

of Dactylosau-rusisquite distinctive.

Nopcsa

(1928;seealsoSues

&

Carroll, 1985,p. 1607)foundit similar to iso-latedhumeri fromthelowerMuschelkalkreferred to "Macrotracheli"by H.v.

Meyer

(1847-1855).

Huene

(1942, Fig. 11) figured a

humerus

from

much

youngerdeposits(lowermostLettenkohleof SchwabischHall,southern_{Germany), which}Sues

and

Carroll(1985,p. 1607) againfoundsimilar to that ofDactylosaurus, but the Lettenkohle

speci-men

appears

more

curved rather_{than angulated} as in the

humerus

ofDactylosaurus, andthe ent-epicondyleissetoff"fromtheshaft_byacrackrather than a notch. Indeed, the specimen figured by

Huene

(1942) closely resembles the

humerus

of Neusticosauruspusillus (Sander, 1989, Fig. 15c),

and

doesnotindicatethe extensionofthe strati-graphic occurrence ofDactylosaurus beyond the lower Muschelkalk.

The humerus

ofDactylosaurus gracilis (sex

y

sensu _Rieppel, 1989; Sander, 1989) is

plesio-morphicwithrespect toall_{other pachypleurosaurs}

intheretentionofawell-differentiated entepicon-dyleandadistinct_{ectepicondylar groove.}

The

ju-venile specimen described_by Giirich (1884) in-dicates similar ontogenetic changes in the

mor-phologicaldifferentiationasthose

known

inother pachypleurosaurs(Rieppel, 1989; Sander, 1989), while aseriesofhumeri fromthelower

Muschelk-alk of Goglin,

Upper

Silesia

(GPIT

1744/1-10) indicatesa similarsexual

dimorphism

in Dacty-losaurusgracilisasis

known

for_other pachypleu-rosaurs_(Rieppel, 1989; Sander, 1989).

As

inother pachypleurosaurs, the index of minimal width/ distalwidth is

most

informativewith _{respect to} ontogeneticchangesandsexual

dimorphism

inthe differentiationofthe humerus. Plottingall avail-ablematerial(seereferredmaterial above)results inanindexof0.53-0.67forsex

x

and/orjuveniles,

and0.40-0.57foradultspecimensofsexy.

Over-lapofthisratio(intherange of 0.54-0.57)between sexes isrestricted to three specimens (mb R. un-catalogued, gpit 1744/1-2), and

may

reflect nat-ural variability as well aswearoftheectepicondyle duringpostmortemtran