A huge caseid pelycosaur from north−western Sardinia … · and its bearing on European Permian...

A huge caseid pelycosaur from northminuswestern Sardiniaand its bearing on European Permian stratigraphy andpalaeobiogeography

AUSONIO RONCHI EVA SACCHI MARCO ROMANO and UMBERTO NICOSIA

Ronchi A Sacchi E Romano M and Nicosia U 2011 A huge caseid pelycosaur from northminuswestern Sardinia and itsbearing on European Permian stratigraphy and palaeobiogeography Acta Palaeontologica Polonica 56 (4) 723ndash738

Skeletal remains some loose on the surface and others still embedded have been recovered from the uppermost part of anoutcrop of the Permian Cala del Vino Formation located near Torre del Porticciolo (Alghero Nurra NW Sardinia)Taphonomic analysis suggests that all the elements pertain to a single individual ongoing studies indicate the fossil repreminussents a large caseid close (or referable) to Cotylorhynchus otherwise restricted to a narrow geographic and stratigraphiczone of the central USA The new finding the first of a caseid in Italy and one of few in Europe enlarges the known distriminusbution of the family and provides a significant and key chronostratigraphic constraint for the continental succession ofthis area and in turn helps establish a stratigraphic framework for the Permian units cropping out in Italy and southernFrance

Key words Synapsida Pelycosauria Caseidae taphonomy stratigraphy Permian Italy

Ausonio Ronchi [ausonioronchidstunipvit] Dipartimento di Scienze della Terra Universitagrave di Pavia v Ferrata 127100 Pavia ItalyEva Sacchi [evasacchiuniroma1it] Marco Romano [marcoromanouniroma1it] and Umberto Nicosia [umbertonicosiauniroma1it] Dipartimento di Scienze della Terra ldquoSapienzardquo Universitagrave di Roma P le A Moro 5 00185Roma Italy

Received 3 September 2010 accepted 2 February 2011 available online 7 February 2011

IntroductionSkeletal remains of a large tetrapod have been recoveredfrom a level of the Permian Cala del Vino Formation cropminusping out near Torre del Porticciolo (Alghero Nurra NWSardinia) (Ronchi et al 2008a) The boneminusbearing bed liesnearly 30 m below the lower boundary of the Conglomeratodel Porticciolo an easily recognizable lithostratigraphicunit that locally marks the beginning of the Triassic seminusquence (Cassinis et al 2003) No large vertebrate has yetbeen reported from the Late Palaeozoic of Italy In Sardiniathe only relevant discovery of fossil vertebrates is that ofsome small branchiosaurid amphibians from the AutunianPerdasdefogu Basin (Ronchi and Tintori 1997 Werneburget al 2007)

The discovery reported herein provides an important newage constraint on the fossil bearing unit and forms the basisfor improvement in knowledge of stratigraphy and palaeominusbiogeography of Permian deposits in the central Mediterraminusnean area

Institutional abbreviationsmdashFMNH Field Museum of Natminusural History of Chicago MPUR (NS) Museum of Paleontolminusogy University of Rome (New Series)

Geological setting

In Sardinia postminusldquoAutunianrdquo continental deposits (fluvial andvolcanoclastic) crop out extensively only in its northminuswesternregion of Nurra (Fig 1) ldquoAutunianrdquo is a traditional Europeanterm previously considered an age which now indicates acharacteristic flora In any case as stated by Broutin et al(1999) and by Ronchi et al (2008b) referring to the Internaminustional Stratigraphic Chart by IUGS it spans from the latestGhzelian to the early Sakmarian Significant Autunian succesminussions characterize small basins (Perdasdefogu EscalaplanominusMulargia SeuiminusSeulo and Montarbu) in the central to southminuseastern part of Sardinia (see Ronchi et al 2008b for a review)

In contrast scattered Early Permian outcrops occur in thesouthminuswestern portion of the island (see Cassinis and Ronchi2000 Cassinis et al 2000 Ronchi et al 2008b) ConcerningNurra the Late PalaeozoicndashEarly Mesozoic continental sucminuscession ranges discontinuously from Early Permian to theAnisian (Neri et al in Cassinis et al 2000 Fontana et al 2001Cassinis et al 2002b Cassinis et al 2003) From the base tothe top it includes six named units most with unconformablerelationships Punta Lu Caparoni Formation Pedru Siligu Forminusmation Porto Ferro Formation Cala del Vino Formation

httpdxdoiorg104202app20100087Acta Palaeontol Pol 56 (4) 723ndash738 2011

Conglomerato del Porticciolo and Arenarie di Cala ViolaThese units some of which contain interbedded volcanicproducts are ascribed to three major sequences (Cassinis et al2002b 2003 Ronchi et al 2008b) as summarized in Fig 2

Up to the present only two biochronological constraintsare available for this entire Permian and Triassic continentalsuccession

(1) At its base in the Punta Lu Caparoni Formation (firstsequence) Pecorini (1962) recorded a rich ldquolate Autunianrdquomacroflora assemblage This ageminusattribution was confirmedby other findings by Gasperi and Gelmini (1980) Broutin etal (1996) and Broutin et al (2000) The sporomorph assominusciation found by the same authors also confirms the lateldquoAutunianrdquo attribution of the formation (Broutin et al 2000)

(2) At the uppermost levels the presence of Equisetummougeotii in the Arenarie di Cala Viola (third sequence) ledPecorini (1962) to assign these siliciclastic deposits to the

Lower Triassic Two different sporomorph assemblages fromsimilar units in the subsurface (Cugiareddu well PomesanoCherchi 1968) led Pittau (in Cassinis et al 2000) and Pittauand Del Rio (2002) to tentatively ascribe the Arenarie di CalaViola respectively to the late Induanndashearly Olenekian andlate Anisian

The second sequence here informally named the ldquoNurraGrouprdquo and where the osteological material was recoveredattains a thickness of about 600 m and has hitherto yielded alminusmost no stratigraphically meaningful fossils

In the fluvial deposits only the abundance of rhizolitesand various kinds of bioturbations testify to paleoenvironminusments rich in life and subjected to alternately wet and dry tosubminusarid climatic conditions Therefore as said above theage attribution of this alluvial megacycle which representsthe bulk of the Permian and Triassic clastic deposition isconstrained only by the presence of ldquoAutunianrdquo floras at thebase of the first sequence (ie Punta Lu Caparoni Formaminustion) and of Anisian microfloral remains in its uppermost unit(ie Arenarie di Cala Viola third sequence)

Radiometric datings and previous age attribution of thesecond Permian sequencemdashIn northern Nurra at the baseof the Permian and Triassic clastics (previously ldquoBuntsandminussteinrdquo after Pecorini 1962) of Mt Santa Giusta (Fontana et al2001) a volcanic unit crops out These volcanic rocks whichhave already been tentatively correlated to those lying at thetop of the Pedru Siligu Formation (cropping out at Casa Sattaand named as V2 in Fig 2) were first isotopically dated byLombardi et al (1974) and Edel et al (1981) Only the latterauthor gave reliable ages these being 296 plusmn 8 Ma and 297 plusmn 9Ma More recently the same volcanic unit was investigatedby Buzzi et al (2008) who gave an isotopic age of 2915 plusmn15 Ma (40Arminus39Ar step heating technique on biotite) correminussponding to the earlyndashmiddle Sakmarian Tominusdate the pertiminusnence of Casa Satta volcanics to a second magmatic episodeand also its correlation with the Santa Giusta ignimbrites apminuspears debatable

Previously different ages have been ascribed to the boneminusbearing unit (Cala del Vino Formation) In particular on thebasis of regional stratigraphic correlations the top of the Permminusian portion was referred to the Late Permian by Pecorini(1962) Vardabasso (1966) agreed with this interpretation anddistinguished in the whole clastic succession a Permian and aTriassic (ldquoBuntsandsteinrdquo) parts in the former envisaging beminuslow ldquoSaxonianrdquo facies and upper nonminusevaporitic Zechsteinfacies of Late Permian age Gasperi and Gelmini (1980) subminusdivided the ldquoPermotriassicrdquo continental deposits of Nurra intofour informal units also hypothesizing a large gap (rangingfrom Autunian to the PermominusTriassic boundary) between thesecond and the third one Subsequently a generic Early Triassicage was suggested for the third and fourth units (sensu Gasperiand Gelmini 1980) by Sciunnach (2001 2002) on the base ofdata that seem to us weak and debatable Before Cassinis et al(1996) had also ascribed the third unit of Gasperi and Gelmini(1980) to a generic Buntsandstein but with not a precise ageminusatminus

724 ACTA PALAEONTOLOGICA POLONICA 56 (4) 2011

Fig 1 Location of Permian and Triassic outcrops in the Nurra area (northminuswestern Sardinia)

tribution Costamagna and Barca (2002 82) stating that ldquoitwas not possible to establish a boundary between lsquoBuntsandminusstein Triassic facies and lsquoRotliegendes faciesrdquo even ascribedto the Triassic all the clastic deposits overlying the AutunianPunta Lu Caparoni Formation

Recently a detailed lithostratigraphic correlation betweenPermian and Triassic successions of Nurra and southern Prominusvence France (Cassinis et al 2002b 2003) has confirmed thecontiguity of the two regions during that timeminusinterval andfixed unambiguously the paleoposition of at least this part ofthe SardiniaminusCorsica block before its Cenozoic counterminusclockminus

wise drift to the southest Consistently on the base of the samelithostratigraphic correlation with the StminusMandrier Formationof the ToulonminusCuers Basin in Provence unit 3 (correspondingto the Cala del Vino Formation of this paper) has been asminuscribed to ldquoundefined Late Permian (Tatarian) timesrdquo accordminusing to the bipartite subdivision of the Permian system (Casminussinis et al 2003 119)

The Torre del Porticciolo sectionmdashThe Cala del Vino Forminusmation consists of an alternating dark red poorly cementedmudstoneminussiltstone deposit and greyminusgreenish sandstone

httpdxdoiorg104202app20100087

RONCHI ET ALmdashPERMIAN CASEID PELYCOSAUR FROM SARDINIA 725

Syste

m-P

erio

d

Se

rie

s-E

po

ch

Stage age(ISC 2008)

Age(Ma)

Litho-stratigraphic

units

Th

ikn

ess

(m)

Ma

jor

cycle

s

Fossil recordT

ria

ssic

Mid

dle

Lo

we

r

Pe

rmia

n

Cis

ura

lian

Ca

rbo

nife

rou

s

Nu

rra

gro

up

Variscan basement

Lo

pin

gia

nG

ua

da

lup

ian

Lithologies and relationshipsamong the units

continental successionof the Permian

to Triassic

Fig 2 Stratigraphy of the three major Permian and Triassic sequences of Nurra BC basal conglomerate


bodies characterized by different geometries and sizes Theformer alluvial plain fine sediments appear homogeneousand deeply bioturbated while the latter bodies often havelenticular shape and erosive bases and where not amalgamminusated with internal trough crossminus to plane parallelminusstratificaminustion Laminations also occur in the medium to fine ripplecrossminuslaminated sandstone Many of these sandstone bodiesshow lateral accretion and are thought to represent pointbarsThe lenticular sandstone at the top of these bars could repreminussent the infill of small chuteminuschannels cut at the bar top durminusing the main floods Such lithologies and fluvial architectureare typical of a meanderingminuschannel alluvial system (Fontanaet al 2001 Ghinassi et al 2009) These deposits were laiddown by mediumminusscale bedminusload streams under a relativelymild semiminusarid climate This is confirmed also by carbonatepalaeosols which repeatedly drape the top of bars (Fig 3F)Nodular caliches and tubular rhizolites are very frequent inminusside both the coarseminusgrained sand bodies (Fig 3E) and the alminusluvial plain muds Waterminusescape structures can be also obminusserved in some sandstone horizons (Fig 3G)

The vertebrate remains were found in an alluvial plainmudstoneminussiltstone layer on top of the promontory which sepminusarates the Porticciolo Gulf from the northern coast (Fig 3A)characterized by other small gulfs (eg Cala del Vino Caladel Turco etc) They were recovered in the Cala del VinoFormation in a level about 30 m below the unconformablecontact with the Conglomerato del Porticciolo which repreminussents the basal unit of the Triassic (third) sequence (Fig 3C)

The entire PermianndashTriassic succession of Nurra isstrongly affected by brittle to ductile compressive tectonics reminusferable to different Pyrenean orogenic phases in particular inthe Porticciolo area a double fold occurs with further refoldingof the axis A subsequent extensional tectonic phase led to thedevelopment of a number of normal faults with limited offsetThese complex tectonics phases which affected the wholesuccession are the principal reasons why we can not yet give adefinitive and exact stratigraphic position of the vertebrateminusbearing level within the Cala del Vino Formation It is neverminustheless clear that in this sector of the coast it is a lower part ofthe formation that is covered by the basal conglomerate of theTriassic (Marc Durand personal communication 2009) Tothe NNE up Porto Ferro cliffs offer a long section through theCala del Vino Formation with good exposure practically conminustinuous for more than 300 m and without significant tectonicdisturbance its monoclinal structure (dipping to the north) alminuslows to show a marked coarseningminusupward trend from sandminusstone (as at Porticciolo) to conglomerate the correspondingangular unconformity below the subhorizontal Triassic can

be seen 500 m south of the Tower Nevertheless a detailedstratigraphic section which includes the bones bearing deminusposit was measured and is hereafter described (Fig 4) Thelog starts approximately at seaminuslevel at the base of the smallcliff of the promontory on which lies the Porticciolo Araminusgonese tower and consists of the following units

Unit 1 5 m thick body of wineminusred micaceous siltstone andmudstone beds with scattered very fine sandstone lenses (Fig



me

tre

s

un

its

Ca

lad

elV

ino

Fo

rma

tio

nC

on

glo

me

rato

de

lP

ort

iccio

lo

Fig 4 Columnar section of the Torre del Porticciolo outcrop

Fig 3 A The Torre del Porticciolo promontory B Meniscate burrowswithin silty shalemudstone (coin diameter 22 mm) C The Conglomeratodel Porticciolo the basal unit of the Triassic (T) unconformably resting onthe Permian Cala del Vino Formation (P) (in the circle a hammer for scale)D Wineminusred micaceous siltstone and mudstone beds with sandstone lenses(in the circle a booklet for scale 20 cm wide asterisk marks the exact locationof the find) E Rhizolithes (r) (hammer for scale) F Palaeosol (p) draping abar (hammer for scale) G Water escape structures (white scale bar 6 cm)

3D) these fine sediments appear deeply amalgamated bybioturbation and rippleminuslaminations rarely occur Rhizolitesand small caliche nodules frequently occur throughout theunit Root traces are developed at the topmost part of this unitand mottling structures frequently occur

Unit 2 a fineminustominusmedium sandstone body with scatteredquartz pebbles about 045 m thick with through crossminusbedminusding yellowminusorange rhizolite concretions occur in its midminusdleminusupper portion

Unit 3 015 m thick red siltstone intervalUnit 4 a large mediumminusgrained fairly cemented quartz

sandstone bar 190 m thick characterized by large throughcrossminusstratification and coarsening upward yellowish smallto largeminussized rhizolitic concretions with elongated to noduminuslar shape are frequently developed all throughout the unit Aparallel lamination is poorly preserved at its top As for unit2 lateral persistence of such sandstone bars is very variable

Unit 5 a homogeneous poorly cemented grey fine sandminusstone horizon 020 m thick

Unit 6 110 m thick micaceous siltstone layer with no

sedimentary structures these fine sediments appear verypoorly cemented This is the horizon which hosted the verteminusbrate remains

Unit 7 115 m thick grayminusgreenish and poorly cementedbut well sorted sandstone body with very subtle crossminuslminusaminae The section continues about 30 m to the west in thedirection of the tower

Unit 8 150 m thick interval showing an alternation ofreddish fine sandstone lenticular bodies with shaley siltminusstoneminusmudstone beds those last are pervasively affected bymeniscate burrows (Scoyenia type Fig 3B)

Unit 9 020 m thin mediumminusgrained greyish well ceminusmented sandstone body

Unit 10 130 m thick homogeneous mudstone intervalwith mmminustominuscm sized carbonate nodules and rhizolites Thinoversize clast horizons are not rare inside these overbank finesediments

Unit 11 060 m thick body of micaceous mudstone interminuslayered with fineminusgrained sandstone Upwards the section isoffset and complicated by small faults and folding


Fig 5 Map of recovered bones White embedded bones grey bones displaced on the ground surface

Taphonomy

Even taking into account the rarity of Paleozoic vertebrates(Reisz and Laurin 2001) and the consistent high probabilitythat all the bones pertained to the same individual most of thebones were found disarticulated For this reason an initialphase of study was to determine whether the remains representone or more individuals In order to address this question thelocation of each bone was mapped (Fig 5) data on the state ofpreservation were carefully collected and the material was anminusalyzed mostly in the framework of the taphonomic schemesof Behrensmeyer (1978) and Voorhies (1969)

All the bones were found in a confined area a belt meaminussuring nearly 2 m in width and 850 m in length Some boneswere recovered loose on the ground surface and others stillembedded Those found still in place did not lie on the samebedding plane but were embedded flat lying at differentdepths in a thickness of around 40 cm of homogeneous redsiltstone lacking sedimentary structures The final position ofbones could have resulted at least in part from sediment comminuspaction

Some of the embedded bones were still articulated (twopedal elements and eight caudal vertebrae reclined on the rightside and grossly parallel to the bedding plane with three proximinusmal portions of haemal arch) (Fig 6) whereas others were disminusplaced in the sedimentary matrix ie the distal portion of theleft ulna (MPUR 15163) and two large fragments of the badlycrushed right scapulocoracoid (MPUR 15170minus71) Amongthese displaced bones some were fragmentary Analysis offracture surfaces indicates that these bones were broken beforebeing buried In this case the fractures are angular and mostlyperpendicular to the bone shaft (Fig 7) Frequently rib fragminusments show fractures (Fig 8) that are perpendicular to theirlong axes parallel to each other straight and clean We interminuspret such breaks as occurring after permineralization This

fracturing phase must be related to tectonic activity that tookplace much later than burial (Gonzalez Riga and Astini 2007)Thus both compression and fracturing have been consideredmeaningless as biostratinomic characters (Lee Lyman 2010)



50 mm

Fig 6 Caseid pelycosaur cf Cotylorhynchus sp from Cala del Vino Formation Permian Late KungurianndashRoadian NW Sardinia Italy Articulated porminustion of the axial skeleton (MPUR 15119minus28)

20 mm

Fig 7 Caseid pelycosaur cf Cotylorhynchus sp from Cala del Vino Forminusmation Permian Late KungurianndashRoadian NW Sardinia Italy Distal porminustion of the left ulna crushed before burial (MPUR 15163) The fractures areangular and mostly perpendicular to the bone shaft

The nonminusembedded elements including some caudal verminustebrae a few pedal elements and rib fragments resulted fromrecent erosion of the same sedimentary body which embedsthe other fossil bones Study of the isolated vertebrae showsthat they are caudals and that they are comparable in shapeand preservation to those that were found in articulationMoreover some of them fit each other and with the mostproximal articulated vertebra (both in size and deformationpattern) indicating they were also articulated before the reminuscent erosion

Because surrounding rock matrix is poorly cemented andonly lightly indurated we were able to completely free skeleminustal elements from the rock allowing threeminusdimensional obminusservation of the material Some bones show a slight degree ofcompression (for the caudal centra around 20) probablyby the overlying sediment weight

Taking into account the ablation order suggested by Voorminushies (1969) the preservation in the same place of long bonesvertebrae ribs and foot elements suggest short transportationof the body and relatively speedy burial Nevertheless thepresence of the distal portions of the foot among the first thatare usually displaced far from the body during the decay prominuscesses may be related to the presence of particularly robusttendons connecting the pedal elements suggested as peculiaradaptations of the huge caseids (Olson 1968)

The presence of bones that were buried after having beenbroken (ie ulna ribs haemal arches etc) suggests that thetransportation phase was energetic and violent

The bone material is in general quite well preserved sothat most of the recovered bones show an almost completecover of periosteal tissue Also present and irregularly distribminusuted on the surface of many bones are the ldquorugosity and thestrong tuberclesrdquo considered by Romer (1956 226) as eviminus

dence of the ldquohellip firm union with the fibrous tissue of thedermisrdquo In the recently fragmented bones where the observaminustion of internal structure is allowed the cavities of the canminuscellous tissue are free both from sediments and recrystallizedminerals Neither flaking nor mosaic surface fractures orcracking are apparent and no scavenging traces have been obminusserved though the good surface preservation could have alminuslowed perfect observation of such features (Holz and Barminusberena 1994) Thus weathering evidences fall in Behrensminusmeyerrsquos (1978) stage ldquo0rdquo suggesting a very short interval ofpreminusburial exposition Accordingly the biostratinomic prominuscesses were concluded when the collagen was still abundantlypresent within the bones and a relatively early entombment isindicated (Holz and Barberena 1994 Peacuterez et al 2009)

The most parsimonious explanation of this set of phenomminusena seems a complex and multiphase biostratinomic processIn order to explain all the evidence and excluding from conminussideration diagenetic deformation we must hypothesize thatsoon after death the body was subjected first to a transportphase from the place of death to a second deposition place asfor instance ending stranded on a river bank This first phase oftransport was probably due to a short and high energy flowstrong enough to break some bones Thereafter the body stillon sediment surface and partially crushed was subject to a furminusther short phase of decay a phase to which we ascribe the abminuslation of some portions of the fragile haemal arches brokendown during the phase of violent transport Subsequently allthe remains could have been loaded with a large amount offine grained sediment (probably in a flashminusflood) transportedpacked within sediments and ultimately deposited all tominusgether in a third place not too far from the previous one Thiswould explain why the bones lie at different depths within thesedimentary body


20 mm

Fig 8 Caseid pelycosaur cf Cotylorhynchus sp from Cala del vino Formation Permian Late KungurianndashRoadianNW Sardinia Italy Fragmentary rib (MPUR 15169) showing syndiagenetic fractures perpendicular to its long axis

In conclusion although most of remains were found isominuslated if we accept the foregoing sequence of taphonomicprocesses and take into consideration the nonminusrepetitive naminusture of the skeletal elements the fact that dimensions of theelements are congruent with each other the identical kind ofpreservation the confined area of discovery and the nonminusrandom distribution of body parts we must refer all the reminuscovered bones and fragments to the same individual The ocminuscurrence of such isolated individuals indicates according toBandyopadhyay et al (2002) a normal attritional deathmoreover in agreement with the studies of Behrensmeyer(1978) Holz and Barberena (1994) and Peacuterez et al (2009)the time of subaerial exposure of the Sardinian specimencould have been limited to a short interval spanning betweenseveral days and a few tens of days

Systematic palaeontologySynapsida Osborn 1903Caseasauria Williston 1912Caseidae Williston 1912Cotylorhynchus sp Stovall 1937Taxonomic background of CaseidaemdashThe Caseidae monominusphyletic according to Maddin et al (2008) includes a comminuspact small group of genera of pelycosaurminusgrade synapsidsMembers of this group were first described by Williston(1910 1913) and Stovall (1937) and subsequently studiedby Olson (1954 1955 1962 1968) Olson and Beerbower(1953) Olson and Barghusen (1962) Stovall et al (1966)and Reisz (1986 2005) As many as nine genera (and 16 speminus

cies) have been placed in the family namely Casea (thefamily nameminusbearing genus) Cotylorhynchus Angelosauminusrus Ennatosaurus Oromycter Caseoides PhreatophasmaTrichasaurus and Caseopsis

Caseoides was later considered as a caseid of uncertainposition because ldquonothing is known of the skull and the fewpostcranial elements are poorly preservedrdquo (Reisz 1986 62)

Phreatophasma was considered a therapsid ldquoincertaesedisrdquo in Romer (1956) and ascribed to Caseidae by Olson(1962 1968) based on a single femur it was assigned onlytentatively to the family by Reisz (1986) as well as byCarroll (1988) Subsequently it was excluded from caseidsand moved to an indeterminate family by Ivakhnenko et al(1997) Maddin et al (2008) retained the classification ofIvakhnenko et al (1997)

Trichasaurus has been considered ldquoprobably a caseidrdquo byRomer and Price (1940) and a caseid by Romer (1956) Subminussequently it was transferred to Labidosauridae by Stovall etal (1966) and finally was considered among the ldquopelycominussaurs incertae sedisrdquo by Reisz (1986) Carroll (1988) andMaddin et al (2008)

Maddin et al (2008) considered Caseopsis a doubtfultaxon and for this reason excluded it from their phylogeneticanalysis even though it was not formally excluded from thefamily

At present the family groups six genera (and one uncerminustain taxon) including 13 formalized species moreover threeasminusyet undescribed taxa are known (see below)

MaterialmdashAt present the material includes more than 180complete bones or fragments ranging in size from more than40 cm to a few mmminuslong minute fragments Some bones stillarticulated were moulded in place before removing to preminus



20 mm

Fig 9 Caseid pelycosaur cf Cotylorhynchus sp from Cala del vino Formation Permian Late KungurianndashRoadian NW Sardinia Italy Caudal vertebra(MPUR 15127) in lateral (A) anterior (B) and posterior (C) views

serve their original relative positions and some fragmentedandor incomplete bones have been restored Every completeor fragmentary bone has been labelled with the acronymMPUR NS followed by 151 (specimen number) and by aslash and a serial number starting at 1 (for simplicity belowwill be reported only MPUR 151 and the serial number)

Among the recovered material a number of elementshave been identified as follows 15 well preserved caudalvertebrae and numerous large fragments clearly referable toat least eight other vertebrae seven proximal portions ofhaemal arches three proximal segments of dorsal ribs andten undetermined fragmentary ribs distal portion of a leftulna right scapula and badly crushed right coracoid plate12 pedal elements Comparisons were made with materialhoused at the FMNH

DescriptionmdashThe available taxonomically meaningful eleminusments are few the skull of the Sardinian specimen was notfound so the most diagnostic elements are lacking Thismade difficult the attribution of the specimen mostly takinginto consideration the absolutely prevailing ldquocraniocentricrdquotaxonomy widespread in the concerned literature So wewere obliged to base our study on the few available elementsthat nevertheless early steered our attention to particularmembers of the Caseidae

The vertebrae are amphicoelous with the centrum as longas wide (Fig 9) Their maximum length ranges from 25 to50 mm The centra are half as high as the complete vertebraeand show the typical pelycosaurian subminuscylindrical shape(ldquospoolminusshapedrdquo according to Romer and Price 1940) Preserminusvation does not allow us to observe if the notochord was reallyinterrupted (discontinuous) In the ventral part the bevellingsfor the insertion of the proximal portion of the haemal arches(intercentra) are apparent Bevellings are small and more apminusparent on the posterior margin of the centra On some centraa narrow groove is present ventrally The neural arch widthnever exceeds the centrum width and thus the vertebrae can

be considered ldquonarrowrdquo (sensu Sumida and Modesto 2001)Zygapophyseals facets are gently sloping (ca 30) The neuralspines are posteriorly inclined and gradually decrease inheight posteriorly The neural canals show a circular sectionwith a diameter of around 7ndash9 mm (Fig 9B C) The shape andproportions of the vertebrae of the Sardinian specimen are typminusical of caseid pelycosaurs Vertebra MPUR 15128 is verysimilar to the caudal FMNH UR 894 labeled as Cotylominusrhynchus hancocki particularly in having a well preservedlongitudinal groove on the ventral surface of the centrum TheSardinian vertebrae are comparable in size and morphology tothose described by Olson (1962) for Cotylorhynchus hanminuscocki and can be tentatively referred to the postsacral verteminusbrae starting at the 12th

The ribs are massive and elliptical to concavominusconvex incrossminussection Some of them show a shallow longitudinalgroove Among the recovered material three wellminuspreservedproximal portions (MPUR 15113 MPUR 15162 MPUR15169) show a wellminusdeveloped capitulum and a tuberculumreduced to an oval area facing upward and inward typical ofthe ldquorounded bodied barrel shaped edaphosaursrdquo (Romer1956 292) (Fig 10) Specimen MPUR 15113 is closely comminusparable to ribs of Cotylorhynchus romeri and is particularlysimilar to one illustrated as rib 13ndash14 by Stovall et al (1966) intheir fig 5 specimen MPUR 15162 corresponds to their ribillustrated as no 17 while MPUR 15169 is closely similar torib 19 of the same published illustration Specimen MPUR15162 is comparable in known details to FMNH UR 266 asminuscribed to C hancocki These ribs also permit us to estimate thedimensions of the corresponding presacral vertebrae at around10 cm in length well corresponding to or slightly longer thanpreminussacral vertebrae 9ndash12 of C hancocki (Olson 1962 42 taminusble 19) or dimensionally comparable to the vertebra FMNHUR 566 labeled as C hancocki

Two scapulocoracoid portions were found close eachother lying flat in the same bedding plane One of the twoportions is a right scapular blade a sheet of bone thin and


20 mm

Fig 10 Caseid pelycosaur cf Cotylorhynchus sp from Cala del vino Formation Permian Late KungurianndashRoadianNW Sardinia Italy Proximal portion of a dorsal rib (MPUR 15162)

high The bone is characterized by the typical narrowing justabove the supraglenoid buttress while the dorsal terminationis anterominusposteriorly expanded with an unfinished edge Itprobably continued with a cartilaginous suprascapula asgenerally found in early amniotes (early reptile sensu Romer1956) The expanded upper portion of the scapular blade hasa gently hollow surface on the lateral side and the bone axisshows dorsally the typical gently inward bending Belowthe maximum narrowing of the scapular blade the boneshows a thickened posterior edge that probably representsthe dorsal portion of the supraglenoid buttress There is nosupraglenoid foramen as in all known caseid scapulocoraminuscoid in which this portion is preserved (Olson 1968) Thesecond portion of the scapulocoracoid is a badly crushed parminustial coracoid plate In the upper part of the bone there is a longand low depression which could be the glenoid fossa Thepreserved portion of the coracoid plate is somewhat deminusformed showing a concave surface instead of the typicalconvex structure The ventral portion of coracoid plate beminuslow the glenoid cavity is badly crushed and hard to prepareso at the moment is not possible to determine the presence ofa supracoracoid foramen This foramen carrying nerve andvessels in living forms (Romer 1956) is present in all knownscapulocoracoids of caseids (Olson 1968) and probably is afamilial plesiomorphy Because of poor preservation the suminusture between the scapula and the coracoid plate can not beobserved Moreover it is impossible to check for the presenceof one or two coracoids Nevertheless wellminuspreserved caseidspecimens lack sutures between the elements of the scapulominuscoracoid The presence of two coracoids is only hypotheticalas already recognized by Olson (1968 258) who stated ldquotheexistence of the two coracoids thus is merely conjecturalbased on the condition of other pelycosaursrdquo

Concerning the partial left ulna only its distal head and thedistal portion of the axis are preserved The head with asubminuscrescentic distal outline is somewhat flattened and widein a typical pelycosaurian fashion (Reisz 1986) The dorsalsurface is better preserved compared to the ventral one andshows rugosity and strong tubercles that probably indicate theorigins of ligamentous connections to the forefoot elements(Olson 1968) The articular surface for the pisisform ulnareand intermedium is wide and deep with only the interminusmediumrsquos portion of the surface visible in dorsal view Thepreserved bone shows the greatest thickness at the level of thearticular surface and thins proximally The lateral margin ofthe preserved axis is nearly straight while the medial margin isgently concave in outline to face inwardly the left radius

The preserved foot bones are one mesopodial fragmentthree metapodials five nonminusungual and three ungual phalanminusges Taken as a whole the foot was very large and formed bybulky elements The mesopodial is flat subminusdiscoid in shapeand shows a particularly cancellous internal structure Metaminuspodials distally and proximally expanded show large andsloping articular surfaces One phalanx (the one found articuminuslated with the metapodial) is wider proximally than distallywhere it is characterized by a crescentic termination The other

nonminusungual phalanges are as long as wide and bear proximinusmally and distally strongly developed accessory scars for thetendon insertion (Fig 11) All the nonminusungual phalanges arecharacterized by sloping articular surfaces The best preservedungual (MPUR 15141) is triangular in outline and clawminusshaped (Fig 12) gently curved downward with a strongflexor tubercle and a longitudinal groove for blood vessel oneach side The massive construction the sloping articular surminusfaces and the strong tubercle on the ungual phalanges are typiminuscal of caseids (Reisz 2005) The protruding and massive flexortubercle on the ventral surface of the ungual phalanx permitsgood morphological comparison with Cotylorhynchus (Madminusdin and Reisz 2007) Casea and to a lesser extent withOromycter In particular ungual MPUR 15141 is strikinglysimilar in shape to FMNH PR 272 (catalogued as Cotylominusrhynchus romeri) even though their dimensions are quite difminusferent and the nonminusungual MPUR 1512 is comparable to IV 1and III 1 of FMNH UR 836 (catalogued as Cotylorhynchusbransoni) although the latter are a little more slender



20 mm

Fig 11 Caseid pelycosaur cf Cotylorhynchus sp from Cala del vino Forminusmation Permian Late KungurianndashRoadian NW Sardinia Italy Nonminusungual phalanx (MPUR 1514) in dorsal (A) and left lateral (B) views

Metapodial MPUR 1511 resembles Mt IV of FMNH UR988 UR 836 and UR 905 catalogued as Cotylorhynchusbransoni and also resembles that of FMNH PR 272 (cataminuslogued as C romeri) even if more medially compressedwhile is completely unlike that of the other bones of the carminuspus and tarsus If MPUR 1511 actually is a Mt IV the obminusserved differences suggest unexpectedly high variability ofthe genus or a still unknown new taxon

In conclusion preserved characteristics of specimenMPUR 151 in particular the unique morphology of thepedal bones are completely sufficient for its identificationas a caseid Caseids phalangeal elements are highly apominusmorphic differing radically from those observed in otherpelycosaurs (Romer and Price 1940) The massive and shortphalanges in MPUR 151 their proximal and distal expanminussion the presence of distal accessories scars for tendon inminussertion and the strongly tilted articular surfaces not perpenminusdicular to the bone axis represent certain exclusive synapominusmorphies of Caseidae (see Reisz 2005 909) The very largeand bulky skeletal elements of the Sardinian specimen preminusclude reference to the small and lightly built caseids CaseaCaseoides Oromycter and Ennatosaurus which are lessthan half as large in linear dimensions Among Caseidaeonly Cotylorhynchus and Angelosaurus are morphologiminuscally and dimensionally comparable to the specimen understudy However the short wide and smooth unguals of

Angelosaurus which are hoofminuslike rather than clawminusshapedsuggest that Angelosaurus can be excluded as well

Based on foregoing consideration the Sardinian speciminusmen a gigantic pelycosaur with a total extimated length ofnearly 6 m could be ascribed either to one of the known speminuscies of Cotylorhynchus or to a closely related new taxon

Stratigraphic andpalaeobiogeographic inferencesAge attributionmdashIt is worth noting as a prefatory comminusment that both SigogneauminusRussell and Russell (1974) andReisz (1986) commented on the need to reminusevaluate the speminuscies of caseids Indeed SigogneauminusRussell and Russell(1974) in establishing Casea rutena reviewed literature andcast grave doubt on the validity of some caseid taxa (particuminuslarly the ones established only on the basis of dimensionaldifferences) indirectly suggesting that significant lumpingor synonymization is called for More or less the same opinminusion was shared by Reisz (1986 60) who stated ldquoThese speminuscies [of Cotylorhynchus] should be restudied thoroughly rdquoand that ldquoIt is likely that further studies of this importanttaxon will result in the synonymy of the three speciesrdquoReminusexamination of all fossils ascribed to Caseidae is thusstrongly in need though there is general agreement as tocomposition of the family and the validity of most genera

Regardless of the validity of individual species speciminusmens referred to Caseidae have been reported from a smallnumber of horizons in North America in Western and Cenminustral Europe and in Russia Among caseids the taxa that canbe compared to the Sardinian one are presently limited tothe known North American large caseids (Cotylorhynchus)which are important constituents of the Redtankian LVF andof the Littlecrotonian LVF in the North American Land Verminustebrate faunochrons (Lucas 2006) The occurrence of largecaseids can be either ascribed to the Sakmarian to Wordianinterval (in agreement with Reisz and Laurin 2001) or to theKungurian (pro parte) and Roadian (Lucas 2006) or reminusstricted to the interval Sakmarian to Kungurian according toLucas (2002) Kemp (2006) and Maddin et al (2008) Thesedifferent interpretations seem to depend at least partially onthe questioned age of the Chickasha Formation consideredlate Kazanian (Roadian Wordian pro parte) in Reisz andLaurin (2001 2002) but ldquobase Guadalupianrdquo (Roadian) inLucas (2002) and uppermost Lower Permian in Modesto etal (2001)

Only four caseids are currently known from the WesternEurope

(1) A still undescribed caseid (Maddin et al 2008) is presminusent at the Early Permian site of Bromacker (Tambach Formaminustion central Germany)

(2) The small Casea rutena comes from the ldquoSaxonianrdquobeds of the Rodez Basin (southern France SigogneauminusRusminussell and Russell 1974) and a second larger taxon from the


20 mm

Fig 12 Caseid pelycosaur cf Cotylorhynchus sp from Cala del vino Forminusmation Permian Late KungurianndashRoadian NW Sardinia Italy Clawminusshaped phalanx (MPUR 15141) in dorsal (A) and right lateral (B) views

same basin is presently under study (Seacutebastien J Steyer perminussonal communication 2009) their stratigraphic position isstill unclear

(3) A taxon described only as a ldquo3minusmminuslong caseid pelycominussaur similar to Cotylorhynchusrdquo (Lucas et al 2006 4) thusdefinitely smaller than the Sardinian specimen was recentlyfound at the classic site of Lodegraveve (Heacuterault southern France)ldquohigher in that section (in respect to the La Lieude tracksite)rdquo(Lucas et al 2006 4) The deposits in question are definitelypostminus Cisuralian but still below the Illawarra reversal (MarcDurand personal communication 2009)

All that considered a late KungurianndashRoadian age is sugminusgested as the most probable for the Sardinian specimenwhich thus assumes great relevance in constraining the ageof the fossil bearing level at the Torre del Porticciolo sectionto a time interval not younger than Roadian

Regional correlationmdashAssuming a late KungurianndashRoaminusdian time interval for the Cala del Vino Formation and conminussidering the late InduanndashOlenekian age attributed to thebasal conglomerate of the succeeding Triassic cycle (Casminussinis et al 2003) a very long gap is thus evidenced betweenthe sediments of the Permian cycle and the overlying Triassicdeposits

At this juncture it is worth briefly reviewing the chronominusstratigraphic framework of the terrigenous Permian rocks ofItaly and southern France which comprise the entire Alpineand Central Mediterranean area

As a whole few reliable calibration points are availablefrom the Late Paleozoic continental deposits cropping out inthe Alpine and Central Mediterranean areas In the Alpine reminusgion stratigraphically meaningful data consist of scatteredsporomorphs associations and a few invertebrate and verteminusbrate fossils In particular land vertebrates are quite rare(Nicosia et al 2005) and we can only list a beautiful butbiochronologically useless specimen of which only the outminusline of the soft tissues is well preserved (Tridentinosaurusantiquus Dal Piaz in Leonardi 1959) from a tuffaceous bedinside the Athesian Porphyric Complex (Nicosia et al 2005)some tetrapod footprintminusbearing levels within the Collio Forminusmation from different basins in the Central and SouthernAlps (Ceoloni et al 1987 Nicosia et al 2000 Avanzini et al2008) and the well known tetrapod footprint associationfrom the Arenaria di Val Gardena (Conti et al 1977 Nicosiaet al 2005)

The Early Permian footprintminusbearing levels well caliminusbrated by isotopic dating of the interdigitating and overlyingvolcanic units were formed in a time interval between about283 Ma and 277 Ma (Avanzini et al 2008) and up to 274 Ma(Marocchi et al 2008) These levels thus range from Sakminusmarian (pro parte) to Kungurian

The Late Permian tetrapod ichnoassociation of the Areminusnaria di Val Gardena comes from sedimentary units laiddown after the Illawarra Reversal Event ( 265 Ma) and reminusferred by sporomorphs by the overlying fusulinid bearingbeds and by sequence stratigraphy to the Wuchiapingian

(Massari et al 1988 Nicosia et al 2005 Valentini et al2009) Thus a gap of variable but significant extent (approxminusimately between 274 and 258 Ma) is present in the fossil reminuscord of the Alpine region as a whole (Cassinis et al 2000Cassinis and Perotti 2007)

In Sardinia Late Paleozoic calibration elements are alsofew tetrapod footprints were found from the Upper Carbonifminuserous (Stephanian) sediments of the San Giorgio basin (Contiet al 2004) and Early Permian ldquobranchiosaursrdquo are knownfrom the Rio su Luda Formation in the Perdasdefogu basin(Ronchi and Tintori 1997 Ronchi et al 1998 Werneburg etal 2007) The latter fossils formed the basis for significantbiostratigraphic and paleobiogeographic correlations with theThuringian Forest Basin (Germany) The already cited ldquoAutuminusnianrdquo plant remains were reported from the Nurra deposits andfrom many other continental basins in the central SE and SWpart of the island (see the review of Broutin and Ronchi inCassinis et al 2000 and Ronchi et al 2008b)

From the basins of Southern France palaeogeographiminuscally and lithostratigraphically correlated to northern Sarminusdinia two occurrences are critical to chronostratigraphicalassessment both concerning ages estimated on the basis ofichnological data

According to Durand (2006 2008) an ichnoassemblagefrom the Les Pradineaux Formation (in literature tentativelycorrelated to the SaintminusMandrier Formation which is correminuslated in turn to the Cala del Vino Formation) from a site nearthe town of SaintminusRaphaeumll reveals a stage of evolution moreadvanced than the Early Permian (Cisuralian) ones (Gand andDurand 2006) of the Lodegraveve Basin which have been studiedin detail (Gand et al 2000) Through the occurrence of sometracks ascribed to therapsids (ie Lunaepes and Planipes)the ichnoassociation could be referred to the ldquotapinocephalidstagerdquo corresponding to the North American Roadian andWordian (Cassinis et al 2002a) From the revision of all theprevious age determinations Durand (2006 2008) taking intoaccount also palaeobotanical and palynological data as wellas an ostracod association concluded that the Pradineaux Forminusmation as a whole could be of Wordian age A Middle Permminusian age was also ascribed to that ichnoassociation by Valentiniet al (2009) by correlation with similar tracks from the SouthAfrican Tapinocephalus Assemblage Zone

A second ichnoassemblage was uncovered from the Gonminusfaron site within the La Motte Formation the uppermost unitin the BasminusArgens basin (also called the Fabregas FormationGonfaron Formation or Pelitic Formation in the other Prominusvence basins) This track assemblage has been consideredMiddle Permian in age by Gand and Durand (2006) and by(Durand 2006) A Roadian age was ascribed to the tentativelycorrelated SaintminusMandrier Formation by Durand (2008)

As stated above on the base of the specimen reportedherein a late Kungurian to Roadian age could be ascribed tothe Cala del Vino Formation Thus accepting the lithostratiminusgraphic correlation between the fossil bearing unit and theSaintminusMandrier Formation (correlated in turn to the Pradiminusneaux Formation from the BasminusArgens and Esteacuterel Permian



basins) a Wordian age has to be considered as doubtful for thedeposits cropping out in basins of southern France

Durand (2006 2008) stated that the subminusTriassic unconminusformity represents in Provence a hiatus probably as long as10ndash15 Ma encompassing at least the entire Lopingian and themajority of the Induan In the light of the new discovery thisgap must be increased (at least in NW Sardinia) to include themost of the Middle Permian

Taking into consideration all the data the same large gapbelow the Triassic cycle sediments signaled by Cassinis etal (2000) in the Alps and by Durand (2006) in Provencenow seems to be also present in Sardinia and in most of thesuccessions in the western Mediterranean area It includes atleast a large part of the Middle Permian and the entire LatePermian ranging from around 270 Ma to nearly 248 Ma Atpresent the only known exception is represented by theWuchiapingian Arenaria di Val Gardena of the SouthernAlps (Valentini et al 2009)

PalaeobiogeographymdashThe new discovery is importantpalaeobiogeographically because it expands known range ofcaseids to the Mediterranean area Thus a land connectionbetween North America and southern Europe during the lateKungurianndashRoadian is suggested The existence of such aroute for faunal interchange has already been proposed bySumida et al (1996) for the Sakmarian and by Reisz andLaurin (2001) for the Wordian Consistently the structuraland environmental continuity between these land areas alminusready suggested on the base of shared ichnoassociations(Avanzini et al 2001) is substantiated for the whole EarlyPermian and for most of the Middle Permian

ConclusionsThe presence of a huge caseid in the Nurra Permian depositsthe first uncovered in Italy and the fifth in all of the WesternEurope (considering also the much smaller forms) repreminussents an important source of information and allows some inminusferences with respect to the generally poor fossil vertebraterecord in Palaeozoic continental sediments (Reisz and Laurin2001) The new finding represents in fact a decisive biostratiminusgraphic constraint to fix the age of Cala Del Vino Formationpreviously referred to ldquoundefined Late Permian (Tatarian)timesrdquo (Cassinis et al 2003) and even to an Early TriassicldquoBuntsandsteinrdquo (Sciunnach 2001 Costamagna and Barca2002) as being late KungurianndashRoadian This age is consisminustent with biostratigraphic results gathered in the Permianrocks of the Provence basins and confirms the validity of thecorrelations proposed by Cassinis et al (2003) on purelysedimentological criteria

The new discovery allows also to better define the time ofoccurrence of caseids in Western Europe and to confirm conminustinuity in the terrestrial environment between North Americaand Europe for the whole Early Permian and for the most ofthe Middle Permian a continuity necessary for migration ofland dwelling animals

AcknowledgementsWe are grateful to Marco Morandotti and Enrico Bortoluzzi (students ofPavia University Pavia Italy) for bringing the vertebrate remains to ourattention We are deeply indebted to Luciano A Trebini (SoprintendenzaArcheologica per la Sardegna Sassari Italy) for its assistance both in thefield and in the sea of bureaucracy The Soprintendenza Archeologica diSassari kindly gave us the authorization to the study Francesco BattistaPaolo Citton Teresa Coppola Giovanni Gaglianone Claudia LeonciniRiccardo Manni and Massimo Santantonio of ldquoSapienzardquo (University ofRome Rome Italy) are acknowledged for their help during field workKenneth D Angielczyk Olivier C Rieppel and William F Simpson arewarmly acknowledged for the kind reception of some of us (ES MR) atthe Field Museum (Chicago USA) ES and MR are grateful to RichardL Cifelli and Kyle L Davies for the help during their visit to the Sam Nominusble Oklahoma Museum Seacutebastien J Steyer actively supported our visitto the specimens at the Museum national drsquoHistoire naturelle Paris SeanModesto (Cape Breton University Sydney Nova Scotia) and Stuart SSumida (California State University S Bernardino USA) gave us theirinvaluable help with suggestions literature and showing more than a norminusmal interest Simone Maganuco (Museo di Storia Naturale MilanoItaly) is also acknowledged for his suggestions and Giacomo Oggiano(Universitagrave degli Studi di Sassari Sassari Italy) for sharing his fundaminusmental knowledge of the geology of the area This manuscript wasgreatly improved by the constructive reviews of Giuseppe Cassinis (Uniminusversity of Pavia Pavia Italy) and Marc Durand (Universiteacute Henri Poinminuscareacute Nancy France) ES was partially supported by a scholarship of theField Museum of Natural History of Chicago The research was partiallysupported by MIUR funds (PRIN 2008 resp Giacomo Oggiano)

ReferencesAvanzini M Ceoloni P Conti MA Leonardi G Manni R Mariotti

N Mietto P Muraro C Nicosia U Sacchi E Santi G andSpezzamonte M 2001 Permian and Triassic tetrapod ichnofaunalunits of northern Italy their potential contribution to continental biominuschronology Natura Bresciana Monografia 25 89ndash107

Avanzini M Neri C Nicosia U and Conti MA 008 A new Early Permminusian ichnocoenosis from the ldquoGruppo Vulcanico Atesinordquo (Mt Lucosouthern Alps Italy) Studi Trentini Scienze Naturali Acta Geologica 83213ndash236

Bandyopadhyay S Roy Chowdhury TK and Sengupta DP 2002Taphonomy of some Gondwana vertebrate assemblages of India Sediminusmentary Geology 147 219ndash245

Behrensmeyer AK 1978 Taphonomic and ecologic information frombone weathering Paleobiology 4 150ndash162

Broutin J Calsia P and Ronchi A 2000 Paleontological data In GCassinis L Cortesogno L Gaggero P Pittau A Ronchi and E Sarria(eds) Late Paleozoic Continental Basin of Sardinia Field Trip Guideminusbook 15ndash25 Sept 1999 90 Pavia University Brescia

Broutin J Cassinis G Cortesogno L Gaggero L Ronchi A andSarria E 1996 Research in progress on the Permian deposits of Sarminusdinia (Italy) Permophiles 28 45ndash48

Broutin J Chacircteauneuf JJ Galtier J and Ronchi A 1999 LrsquoAutuniendrsquoAutun resteminustminusil une reacutefeacuterence pour les deacutepocircts continentaux du Permieninfeacuterieur drsquoEurope Geacuteologie de la France 2 17ndash31

Buzzi L Gaggero L and Oggiano G 2008 The Santa Giusta ignimbrite(NW Sardinia) a clue for the magmatic structural and sedimentary evominuslution of a Variscan segment between Early Permian and TriassicBollettino della Societagrave Geologica Italiana 127 683ndash695

Carroll RL 1988 Vertebrate Paleontology and Evolution 698 pp WHFreeman and Company New York

Cassinis G and Perotti C R 2007 A stratigraphic and tectonic review of


the Italian Southern Alpine Permian In Q Yang and DH Ervin (eds)Contributions to Permian and Carboniferous Stratigraphy BrachiopodPalaeontology and EndminusPermian Mass Extinction in Memory of Profesminussor YuminusGan Jin Paleoworld (Special Issue) 16 140ndash172

Cassinis G and Ronchi A 2000 General stratigraphy In G Cassinis LCortesogno L Gaggero P Pittau A Ronchi and E Sarria (eds) LatePaleozoic Continental Basin of Sardinia Field Trip Guidebook 15ndash25Sept 1999 25ndash26 Pavia University Brescia

Cassinis G Cortesogno L Gaggero L and Ronchi A 2000 PermianSardinian BasinmdashAn overview In G Cassinis L Cortesogno LGaggiero P Pittau A Ronchi and E Sarria (eds) Late PaleozoicContinental Basin of Sardinia Field Trip Guidebook 15ndash25 Sept1999 19ndash20 Pavia University Brescia

Cassinis G Cortesogno L Gaggero L Ronchi A and Valloni R 1996Stratigraphic and petrographic investigations into the PermianndashTriassiccontinental sequences of Nurra (NW Sardinia) Cuadernos de GeologiacuteaIbeacuterica (Special Issue) 21 149ndash169

Cassinis G Durand M and Ronchi A 2002b The Permian and Triassiccontinental framework of Nurra (NW Sardinia) Rendiconti della SocietagravePaleontologica Italiana 1 297ndash305

Cassinis G Durand M and Ronchi A 2003 PermianndashTriassic contiminusnental sequences of Northwest Sardinia and South Provence stratiminusgraphic correlations and palaeogeographical implications Bollettinodella Societagrave Geologica Italiana (Volume speciale) 2 119ndash129

Cassinis G Nicosia U Lozovsky VR and Gubin YM 2002a A viewof the Permian continental stratigraphy of the Southern Alps Italy andgeneral correlation with the Permian of Russia Permophiles 40 4ndash16

Costamagna LG and Barca S 2002 The ldquoGermanicrdquo Triassic of Sardinia(Italy) a stratigraphical depositional and palaeogeographic reviewRivista Italiana di Paleontologia e Stratigrafia 108 67ndash100

Ceoloni P Conti MA Mariotti N Mietto P and Nicosia U 1987Tetrapod footprints from Collio Fm (Lombardy Northern Italy)Memorie di Scienze Geologiche 39 213ndash233

Conti MA Leonardi G Mariotti N and Nicosia U 1977 Tetrapod footminusprints from the ldquoArenarie di Val Gardenardquo (North Italy) Their paleontominuslogical stratigraphic and palaeoenvironmental meaning PaleontographiaItalica 70 1ndash91

Conti MA Nicosia U Petti FM Pillola GL Piras S Sacchi E andZoboli D 2004 Italyrsquos earliest tetrapod footprints the Sardinian UpperCarboniferous ichnofaunas 32nd International Geological CongressFlorence Italy 20ndash28 August 2004 599 Nuova Cesat Florence

Durand M 2006 The problem of transition from the Permian to the Triassicseries in southeastern France comparison with other Peritethyan reminusgions In SG Lucas G Cassinis and JW Schneider (eds) Nonminusmaminusrine Permian Biostratigraphy and Biochronology Geological SocietySpecial Publication London 265 281ndash296

Durand M 2008 Permian to Triassic continental successions in southernProvence (France) an overview Bollettino della Societagrave GeologicaItaliana 127 697ndash716

Edel JB Montigny R and Thuizat R 1981 Late Palaeozoic rotations ofCorsica and Sardinia new evidence from paleomagnetic and KminusAr studminusies Tectonophysics 79 201ndash223

Fontana D Neri C Ronchi A and Stefani C 2001 Stratigraphic archiminustecture and composition of the Permian and Triassic siliciclastic succesminussion of Nurra (northminuswestern Sardinia) In G Cassinis (ed) PermianContinental Deposits of Europe and Other Areas Regional Reports andCorrelations laquoNatura Brescianaraquo Annali del Museo Civico di ScienzeNaturali di Brescia Monografia 25 149ndash161

Gand G and Durand M 2006 Tetrapod footprint ichnominusassociations fromFrench Permian basins Comparisons with other Euramerican ichnominusfaunas In SG Lucas G Cassinis and JW Schneider (eds) NonminusMaminusrine Permian Biostratigraphy and Biochronology Geological SocietySpecial Publications London 265 157ndash177

Gand G Garric J Demathieu G and Ellenberger P 2000 La palichnominusfaune de verteacutebreacutes teacutetrapodes du Permien supeacuterieur du bassin de Lodegraveve(Languedoc France) Paleovertebrata 29 1ndash82

Gasperi G and Gelmini R 1980 Ricerche sul Verrucano 4 Il Verrucano

della Nurra (Sardegna nordminusoccidentale) Memorie della Societagrave Geominuslogica Italiana 20 (for 1979) 215ndash231

Ghinassi M Durand M Ronchi A and Stefani C 2009 PermianndashMidminusdle Triassic continental succession of NW Sardinia In V Pascucci andS Andreucci (eds) Fieldminustrip Guidebook 27th IAS Meeting of Sediminusmentology Alghero Italy 20ndash23 Sept 2009 37ndash50 Edes Sassari

GonzalezminusRiga BJ and Astini RA 2007 Preservation of large titanosaursauropods in overbank fluvial facies A case study in the Cretaceous ofArgentina Journal of South American Earth Sciences 23 290ndash303

Holz M and Barberena MC 1994 Taphonomy of the south Brazilian Triminusassic paleoherpetofauna pattern of death transport and burial Palaeominusgeography Palaeoclimatology Palaeoecology 107 179ndash197

Ivakhneneko MF Golubev VK Gubin YM Kalandadze NN Noviminuskov IV Sennikov AG and Rautian AS 1997 Permian and Triasminussic Tetrapods of Eastern Europe 216 pp GEOS Moscow

Kemp TS 2006 The origin and early radiation of the therapsid mamminusmalminuslike reptiles a palaeobiological hypothesis Journal of Evolutionminusary Biology 19 1231ndash1247

Lee Lyman R 2010 What taphonomy is what it isnrsquot and why taphonomistsshould care about the difference Journal of Taphonomy 8 (1) 1ndash16

Leonardi P 1959 Tridentinosaurus antiquus Gb Dal Piaz rettile protorominussauro permiano del Trentino orientale Memorie di Scienze Geologiche21 3ndash15

Lombardi G Cozzupoli D and Nicoletti M 1974 Notizie geopetrominusgrafiche e dati sulla cronologia KminusAr del vulcanismo tardopaleozoicosardo Periodico di Mineralogia 43 221ndash312

Lucas SG 2002 The reptile Macroleter First vertebrate evidence for correlaminustion of Upper Permian continental strata of North America and RussiaDiscussion Geological Society of American Bulletin 114 1174ndash1175

Lucas SG 2006 Global Permian tetrapod biostratigraphy and biochronominuslogy In SG Lucas G Cassinis and JW Schneider (eds) NonminusMarinePermian Biostratigraphy and Biochronology Geological Society SpecialPublications London 265 65ndash93

Lucas SG Cassinis G and Schneider JW 2006 Nonminusmarine Permianbiostratigraphy and biochronology an introduction In SG Lucas GCassinis and JW Schneider (eds) NonminusMarine Permian Biostratiminusgraphy and Biochronology Geological Society Special PublicationsLondon 265 1ndash14

Maddin H and Reisz RR 2007 The morphology of the terminal phalanminusges in PermominusCarboniferous synapsids an evolutionary perspectiveCanadian Journal of Earth Sciences 44 267ndash274

Maddin H Sidor CA and Reisz RR 2008 Cranial anatomy of Ennatominussaurus tecton (Synapsida Caseidae) from the Middle Permian of Russiaand the evolutionary relationships of Caseidae Journal of VertebratePaleontology 28 160ndash180

Marocchi M Morelli C Mair V Klotzli U and Bargossi GM 2008Evolution of large silicic magma systems New UminusPb zircon data on theNW Permian Athesian Volcanic Group (Southern Alps Italy) Journalof Geology 116 480ndash498

Massari F Conti MA Fontana D Helmold K Mariotti N Neri CNicosia U Ori GG Pasini M and Pittau P 1988 The Val GardenaSandstone and Bellerophon Formation in the Bletterbach Gorge (AltoAdige Italy) biostratigraphy and sedimentology Memorie di ScienzeGeologiche 40 229ndash273

Modesto S Sidor CA Rubidge BS and Welman J 2001 A secondvaranopseid skull from the Upper Permian of South Africa implicaminustions for Late Permian ldquopelycosaurrdquo evolution Lethaia 34 249ndash259

Nicosia U Avanzini M Barbera C Conti MA Dalla Vecchia FMDal Sasso C Delfino M Gianolla P Leonardi G Loi M MiettoP Morsilli M Paganoni A Petti FM Piubelli D Raia PRenesto S Ronchi A Sacchi E Santi G and Signore M 2005 Ivertebrati continentali del Paleozoico e del Mesozoico In L Bonfiglio(ed) Paleontologia dei Vertebrati in Italia 41ndash66 Museo Civico diStoria naturale di VeronaVerona

Nicosia U Ronchi A and Santi G 2000 Permian tetrapod footprintsfrom W Orobic Basin (Northern Italy) Biochronological and evolutionminusary remarks Geobios 33 (6) 753ndash768



Olson EC 1954 Fauna of the Vale and Choza 7 Pelycosauria FamilyCaseidae Fieldiana Geology 10 193ndash204

Olson EC 1955 Parallelism in the evolution of the Permian reptilian faunaof the Old and New Worlds Fieldiana Zoology 37 385ndash401

Olson EC 1962 Late Permian terrestrial vertebrates USA and USSRAmerican Philosophical Society Transaction (new series) 52 1ndash224

Olson EC 1968 The family Caseidae Fieldiana Geology 17 225ndash349Olson EC and Barghusen H 1962 Permian vertebrates from Oklahoma

and Texas Oklahoma Geological Survey Circular 59 5ndash48Olson EC and Beerbower JR Jr 1953 The San Angelo Formation

Permian of Texas and its vertebrates Journal of Geology 61 381ndash423Osborn HF 1903 The reptilian subclasses Diapsida and Synapsida and the

early history of the Diaptosauria Memoirs of the American Museum ofNatural History 1 449ndash507

Pecorini G 1962 Nuove osservazioni sul Permico della Nurra (Sardegnanordminusoccidentale) Atti Accademia Nazionale dei Lincei RendicontiClasse di Scienze Fisiche Matematiche e Naturali 32 377ndash380

Peacuterez LM Otero A Apesteguiacutea S and Gallina PA 2009 Estratigrafiacuteay anaacutelisis tafonoacutemico de Bonitasaura salgadoi Apesteguiacutea en el sitioldquoLa Bonitardquo (Cretaacutecico superior Riacuteo Negro Argentina) Revista MuseoArgentino Ciencias Naturales (new series) 11 39ndash48

Pittau P and Del Rio M 2002 Palynofloral biostratigraphy of the Permianand Triassic sequences of Sardinia Rendiconti della Societagrave Paleontominuslogica Italiana 1 93ndash109

Pomesano Cherchi A 1968 Studio biominusstratigrafico del sondaggio Cugiaminusreddu nel Trias e Permico della Nurra (Sardegna nordminusoccidentale)Pubblicazione dellrsquo Istituto di Geologia e Paleontologia dellrsquoUniversitagrave diCagliari 61 7ndash51

Reisz RR 1986 Pelycosauria In P Wellnhofer (ed) Handbuch derPalaumloherpetologie 17A 102 pp Gustav Fischer Verlag Stuttgart

Reisz RR 2005 Oromycter a new caseid from the Lower Permian ofOklahoma Journal of Vertebrate Paleontology 25 905ndash910

Reisz RR and Laurin M 2001 The reptile Macroleter First vertebrate eviminusdence for correlation of Upper Permian continental strata of North Amerminusica and Russia Geological Society of America Bulletin 113 1229ndash1233

Reisz RR and Laurin M 2002 Reply Geological Society of America Bulminusletin 114 1176ndash1177

Romer AS 1956 Osteology of the Reptiles 772 pp The University of Chiminuscago Press Chicago

Romer AS and Price LI 1940 Review of the Pelycosauria GeologicalSociety of America (Special Paper) 28 1ndash538

Ronchi A and Tintori A 1997 First amphibian find in Early Permian fromSardinia (Italy) Rivista Italiana di Paleontologia e Stratigrafia 103 (1)29ndash38

Ronchi A Broutin J Diez JminusB Freytet P Galtier J and Lethiers F 1998New paleontological discoveries in some Early Permian sequences ofSardinia Biostratigraphic and paleogeographic implications ComptesRendus de lrsquoAcadeacutemie des Sciences Paris 327 713ndash718

Ronchi A Manni R Sacchi E Nicosia U Citton P Coppola TRomano M Bortoluzzi E and Trebini LA 2008a First large verteminusbrate find in the Permian deposits of Nurra (NW Sardinia) 84 CongressoSocietagrave Geologica Italiana Sassari September 15ndash17 2008 RendicontiOnline Societagrave Geologica Italiana 3 689

Ronchi A Sarria E and Broutin J 2008b The ldquoAutuniano Sardordquo basicfeatures for a correlation through the Western Mediterranean and Paleominuseurope Bollettino della Societagrave Geologica Italiana 127 655ndash681

Sciunnach D 2001 Heavy mineral provinces as a tool for palaeogeominusgraphic reconstruction A case study from the Buntsandstein of Nurra(NW Sardinia Italy) Eclogae Geologicae Helvetiae 94 197ndash211

Sciunnach D 2002 The PermominusTriassic clastics of Nurra sedimentologyheavy mineral provinces and palaeogeography Rendiconti della SocietagravePaleontologica Italiana 1 177ndash184

SigogneauminusRussell D and Russell DE 1974 Eacutetude du premier Caseacuteideacute(Reptilia Pelycosauria) drsquoEurope occidentale Bulletin du Museacuteum Naminustional drsquoHistoire Naturelle 230 145ndash215

Stovall JW 1937 Cotylorhynchus romeri a new genus and species ofpelycosaurian reptile from Oklahoma American Journal of Science 34308ndash313

Stovall JW Price LI and Romer AS 1966 The postcranial skeleton ofthe giant Permian pelycosaur Cotylorhynchus romeri Bulletin of theMuseum of Comparative Zoology 135 1ndash30

Sumida S and Modesto S 2001 A phylogenetic perspective on locomotorystrategies in early amniotes American Zoologist 41 568ndash597

Sumida S Berman D and Martens T 1996 Biostratigraphic correlationsbetween the Lower Permian of North America and Central Europe usminusing the first record of an assemblage of terrestrial tetrapods from Germinusmany PaleoBios 17 (2ndash4) 1ndash12

Valentini M Nicosia U and Conti MA 2009 A reminusevaluation of Pachyminuspes a pareiasaurian track from the Late Permian Neues Jahrbuch fuumlrGeologie und Palaumlontologie Abhandlungen 251 71ndash94

Vardabasso S 1966 Il Verrucano sardo Atti del Symposium sul VerrucanoPisa settembre 1965 293ndash310 Societagrave Toscana di Scienze NaturaliPisa

Voorhies M 1969 Taphonomy and population dynamics of an early Pliominuscene vertebrate fauna Knox County Nebraska Contributions to Geolminusogy (Special Paper) 1 1ndash69

Werneburg R Ronchi A and Schneider JW 2007 The Early Permianbranchiosaurids (Amphibia) of Sardinia Systematic palaeontologypalaeoecology biostratigraphy and palaeobiogeographic problemsPalaeogeography Palaeoclimatology Palaeoecology 252 383ndash404

Williston SW 1910 New Permian reptiles rhachitomous vertebrae Jourminusnal of Geology 18 585ndash600

Williston SW 1912 Primitive reptiles Journal of Morphology 23 637ndash666Williston SW 1913 The skulls of Araeoscelis and Casea Permian repminus

tiles Journal of Geology 21 743ndash747


Conglomerato del Porticciolo and Arenarie di Cala ViolaThese units some of which contain interbedded volcanicproducts are ascribed to three major sequences (Cassinis et al2002b 2003 Ronchi et al 2008b) as summarized in Fig 2

Up to the present only two biochronological constraintsare available for this entire Permian and Triassic continentalsuccession

(1) At its base in the Punta Lu Caparoni Formation (firstsequence) Pecorini (1962) recorded a rich ldquolate Autunianrdquomacroflora assemblage This ageminusattribution was confirmedby other findings by Gasperi and Gelmini (1980) Broutin etal (1996) and Broutin et al (2000) The sporomorph assominusciation found by the same authors also confirms the lateldquoAutunianrdquo attribution of the formation (Broutin et al 2000)

(2) At the uppermost levels the presence of Equisetummougeotii in the Arenarie di Cala Viola (third sequence) ledPecorini (1962) to assign these siliciclastic deposits to the

Lower Triassic Two different sporomorph assemblages fromsimilar units in the subsurface (Cugiareddu well PomesanoCherchi 1968) led Pittau (in Cassinis et al 2000) and Pittauand Del Rio (2002) to tentatively ascribe the Arenarie di CalaViola respectively to the late Induanndashearly Olenekian andlate Anisian

The second sequence here informally named the ldquoNurraGrouprdquo and where the osteological material was recoveredattains a thickness of about 600 m and has hitherto yielded alminusmost no stratigraphically meaningful fossils

In the fluvial deposits only the abundance of rhizolitesand various kinds of bioturbations testify to paleoenvironminusments rich in life and subjected to alternately wet and dry tosubminusarid climatic conditions Therefore as said above theage attribution of this alluvial megacycle which representsthe bulk of the Permian and Triassic clastic deposition isconstrained only by the presence of ldquoAutunianrdquo floras at thebase of the first sequence (ie Punta Lu Caparoni Formaminustion) and of Anisian microfloral remains in its uppermost unit(ie Arenarie di Cala Viola third sequence)

Radiometric datings and previous age attribution of thesecond Permian sequencemdashIn northern Nurra at the baseof the Permian and Triassic clastics (previously ldquoBuntsandminussteinrdquo after Pecorini 1962) of Mt Santa Giusta (Fontana et al2001) a volcanic unit crops out These volcanic rocks whichhave already been tentatively correlated to those lying at thetop of the Pedru Siligu Formation (cropping out at Casa Sattaand named as V2 in Fig 2) were first isotopically dated byLombardi et al (1974) and Edel et al (1981) Only the latterauthor gave reliable ages these being 296 plusmn 8 Ma and 297 plusmn 9Ma More recently the same volcanic unit was investigatedby Buzzi et al (2008) who gave an isotopic age of 2915 plusmn15 Ma (40Arminus39Ar step heating technique on biotite) correminussponding to the earlyndashmiddle Sakmarian Tominusdate the pertiminusnence of Casa Satta volcanics to a second magmatic episodeand also its correlation with the Santa Giusta ignimbrites apminuspears debatable

Previously different ages have been ascribed to the boneminusbearing unit (Cala del Vino Formation) In particular on thebasis of regional stratigraphic correlations the top of the Permminusian portion was referred to the Late Permian by Pecorini(1962) Vardabasso (1966) agreed with this interpretation anddistinguished in the whole clastic succession a Permian and aTriassic (ldquoBuntsandsteinrdquo) parts in the former envisaging beminuslow ldquoSaxonianrdquo facies and upper nonminusevaporitic Zechsteinfacies of Late Permian age Gasperi and Gelmini (1980) subminusdivided the ldquoPermotriassicrdquo continental deposits of Nurra intofour informal units also hypothesizing a large gap (rangingfrom Autunian to the PermominusTriassic boundary) between thesecond and the third one Subsequently a generic Early Triassicage was suggested for the third and fourth units (sensu Gasperiand Gelmini 1980) by Sciunnach (2001 2002) on the base ofdata that seem to us weak and debatable Before Cassinis et al(1996) had also ascribed the third unit of Gasperi and Gelmini(1980) to a generic Buntsandstein but with not a precise ageminusatminus


Fig 1 Location of Permian and Triassic outcrops in the Nurra area (northminuswestern Sardinia)







Syste

m-P

erio

d

Se

rie

s-E

po

ch

Stage age(ISC 2008)

Age(Ma)

Litho-stratigraphic

units

Th

ikn

ess

(m)

Ma

jor

cycle

s

Fossil recordT

ria

ssic

Mid

dle

Lo

we

r

Pe

rmia

n

Cis

ura

lian

Ca

rbo

nife

rou

s

Nu

rra

gro

up

Variscan basement

Lo

pin

gia

nG

ua

da

lup

ian



to Triassic










me

tre

s

un

its

Ca

lad

elV

ino

Fo

rma

tio

nC

on

glo

me

rato

de

lP

ort

iccio

lo

















Taphonomy







50 mm


20 mm










20 mm













20 mm










20 mm








20 mm












20 mm






















































































































Syste

m-P

erio

d

Se

rie

s-E

po

ch

Stage age(ISC 2008)

Age(Ma)

Litho-stratigraphic

units

Th

ikn

ess

(m)

Ma

jor

cycle

s

Fossil recordT

ria

ssic

Mid

dle

Lo

we

r

Pe

rmia

n

Cis

ura

lian

Ca

rbo

nife

rou

s

Nu

rra

gro

up

Variscan basement

Lo

pin

gia

nG

ua

da

lup

ian



to Triassic










me

tre

s

un

its

Ca

lad

elV

ino

Fo

rma

tio

nC

on

glo

me

rato

de

lP

ort

iccio

lo

















Taphonomy







50 mm


20 mm










20 mm













20 mm










20 mm








20 mm












20 mm
























































































































me

tre

s

un

its

Ca

lad

elV

ino

Fo

rma

tio

nC

on

glo

me

rato

de

lP

ort

iccio

lo

















Taphonomy







50 mm


20 mm










20 mm













20 mm










20 mm








20 mm












20 mm






























































































































Taphonomy







50 mm


20 mm










20 mm













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20 mm








20 mm












20 mm
























































































































20 mm













20 mm










20 mm








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A huge caseid pelycosaur from north−western Sardinia … · and its bearing on European Permian...

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Transcript of A huge caseid pelycosaur from north−western Sardinia … · and its bearing on European Permian...