GEOL. CROAT. 51/2 105 . 134 23 Figs. ZAGREB 1998

Remains of (Reptilia, ) in the Lower (Upper Hauterivian/Lower ) Limestones of SW Istria (Croatia)

Fabio Marco DALLA VECCHIA

Key words: Dinosauria, Sauropoda, Titanosauriformes, eoenvironmental context (DALLA YECCHIA, 1994a. Diplodocimorpha, Upper Hauterivian- Lower Bar­ b; DALLA YECCHIA et a!., 1993; TUNIS et a!., 1994; remian, Cretaceous, Istria (Croatia). KOZARIC et aI., 1996). Some specimens were identi · fied as sauropod bones (DALLA YECCHIA, 1994b. 1997a. b, c; DALLA YECCHIA & TARLAO. 1995) Abstract Remains belonging 10 sauropod have recently been dis­ but never described in detail. This paper presents a deta­ covered in Upper Haut erivian/Lower Barremian (Lower Cretaceous) il ed description of the identifiable and attributable limestones of SW Istria (Croatia). The material consists of a complete remains of the sample. cervical vertebra, a nearly complete cervical centrum, fragmcnls of All of the material comes from the same outcrop, possibl e cervical ribs, three partial dorsa! and five more or less in­ complete caudal vertebrae, parts of caudal neural spines, a chevron, from the same stratigraphic level and, probably from the the distal pari of a femur, the proximal portion of a tibia and other same bed (see below). However, most were collected fragments of bones. The bones were collected randomly from the sea randomly as scattered fragments on the beach and on bottom, therefore despite the fact that they come from the same out­ the sea bottom, where the fossi liferous layer crops out. crop, the same level and probably the same bed, they cannot be assigned with certainty to the same taxon. Their vastly different sizes No systematic attempt had been made to collect the indicate the presence of several individuals while different morpholo­ numerous bones still embedded in the rock. Since the gies suggest the probable presence of more than one taxon. The com­ fossiliferous bed, which seems to be particularly laden plete cervical and the anterior 10 mid-caudal vertebrae present a more strict affinity with Brachiosauridae, a proximal cervical centrum rese­ with bony remains (D. BOSCAROLLI, pers. comm.). mbles those of "Cholldros(eosourtls", and a caudal neural spine is si­ lies below sea level, its excavation is difficult. Howev­ milar to those of the camarasaurids. The dorsal vertebrae have pecu­ er, this outcrop promises to be one of the most ri ch and liar features (a very tall neural arch, well developed laminar complex, interesting of present Europe. etc.) and characters suggesting their assignation to basal Titanosauri­ formes and, possibly, to Diplodocimorpha. A posterior dorsal verte­ bra testifies the presence of a new Diplodocimorph similar to Reh­ bachisollrlls but more primitive. 2. DEPOSITIONAL ENVIRONMENT AND AGE

The age and depositional environment of this depo­ sit are discussed in BOSCAROLLI e[ al. ( 1993), TU· NIS et a!. (1994) and DIN! e[ a!. (1998). The fossilifcr· 1. INTRODUCTION ous outcrop is characterized by the presence of beds of oncolitic rudstone with bone debris, and thinly laminat­ tracks of Cretaceous age are relatively ed limestones with plant, shrimp and fish remains. So­ common in the lstrian peninsula (NW Croatia), and me bones (for example, the complete cervical vertebra have recently been reviewed by DALLA YECCHIA et WN·YI, the small clorsal MPCM·YI , [he mid·caudal al. (1993), DALLA YECCHIA & TARLAO (1995) and Nos IG-I and other fragments) were preserved wholly DALLA YECCHIA (1997a, b. c). They are preserved in a yellow, thinly laminated limestone or with a side of in Upper Barremian, Upper Albian and Upper Ceno­ the fossil in this laminated limestone and the other side manian limestones at several sites along the coast of the in a grey, hard oncolitic rudstone. This seems to indi­ peninsula, and on the islands (Main Brijuni/Brioni catc that the preservation of complete bones is due to island, Fenoliga isle[, e[c.). deposition in a relatively protected, low energy environ­ The first discovery of dinosaur bones, on the Adriat­ ment (laminated limestones) and to the probably rapid ic sea bottom at the Kolone locality near Bale/Valle vil­ covering by the rudstone which testifies a high energy lage, south o/" Rovinj, was reported by BOSCAROLLl environment. However this should be confirmed by a e[ al. (1993), and was fo ll owcd by preliminary notes detailed sedimentological and taphol1omical study of concernin g the fossils and their stratigraphic and pala- the fossiliferous beds which is beyond the scope of this paper. The stratigraphic sequence of the OLilcrOP at Bale is Mu seo Pa[eontologico Cittadino, Via Valentinis 134, 1-34074 Mon­ composed of subtid al, intertidal and lacustrine limesto­ fa1eone (Gorizia), Italy. nes, The lower section is of Late Hauterivian/Early 106 Geologia Croatica 51n

Barremian age due to th e prese nce of th e foraminifer Acronyms: CD = caudal rib , CDL= centrodiapo­ Campanellll/a capllensis DE CASTRO; the upper scc­ physial lamina, CPR = centroprezygapophys ial lamina, tion is probably Lower Barremian (BOSCAROLLI ct CO=eondyle, COPR=condyloprezygapophysial lami­ aI., 1993; TUNIS et aI., 1994). Therefore the bones des­ na, DP=diapophysis, Has=articul ar surface for the hy­ cribed here arc the oldest record of dinosaurs curremly posphene, HL= horizon tal lamina (= diapo-prezygapo­ known in Istri a (DALLA VECCHIA & TARLAO, physial lamina, diapo-postzygapophys ial lamina), 1995) if possible sauropod tracks in the Berriasian of I-IPN = hyposphene, HYP = hypantrum, IDL = infradi­ Fantazija Quarry (LOCKLEY et aI. , 1994) arc exclud­ apophys ial lamina, IHPNL = infrahypos phellal lamina, ed. The bones arc approximately coeval with th e thero­ IPDL = infrapostdiapophys ial lam ina, lPDRL = infrapre­ pod pes and sa uropod manus prints found in a quarried diapophysial lamina, IPPLa = infraparapophysial anteri ­ limestone block from the Cansiglio Plateau (Northeast­ or lamina, IPPLb = infraparapophys ial posterior lamina, crn It aly, Pord enone) described by DALLA VECCHlA JPRL = infraprezygapophysial lamina, IPZL= infrapost­ & VENTURINI ( 1995). The sauropods of Bale are a zygapophysial lamina, ISPZL = inner suprapostzygapo­ rare case of dinosaur bone remain s that are dated in cor­ physial lamina, ITPZ= illtrapostzygapophysial lamina, relation w ith the marine biochronology. L1PPL = lateral in fraparapoph ys ial lam in a; L1PZL = lat­ eral infrapostzygapophysiaJ lamina, NA = neural arch, NC= neural canal, NS = neural spine, OSPZL= outer 3. DESCRIPTION AND COMPARISON suprapostzygapophys ial lamina, PL = pleurocoel, PP = parapophysis, PR = prezygapophysis, PRL= prezygapo­ The sample consists of more than 200 specimens, phys iallamina, PRSPL =prespin al lam in a, PSPL = post­ most of whi ch are just bone fragments. The coll ected spin al lamina, PZ= postzygapophysis, SCL = "core" la­ material was exposed to recent marine and shore weath­ mi na of the neural spine, SDL=supradiapophysiallam­ eri ng and was encru sted (and som etimes pierced) by ina, SIPRL=subinfraprezygapophysial lamina, SPRZ= living mar in e ani mals and al gae. It was cleaned and supraprezygapophysial lamina, SPZL = suprapostzyga­ prepared by the preparators of the Gmppo SpeJcologico pophysial lamina. Monfalconese A.D.F. at the Museo Paleontologico Cit ­ tadino of Monfalcone (Gorizia). Most of th e bones are AXIAL SKELETAL ELEMENTS crushed, sometim es strongly, but olh erwi se the state of preservation of th e bones still imbedded in the rocky Cervical vertebrae matri x is very good. Onl y bones attributable to sauro­ WN-Vl (Figs. I & 2; photographs in DALLA pods are describcd hcre; several specim ens are too frag­ VECCHIA, 1994b, fi g. 3, and DALLA VECCHIA, mented to identify th e skeletal element to which they 1997c, fi g. 2): two cervical vertebrae were preserved belonged, other fra gments belong obviously to long and nearl y in anatomical articulat ion. The posterior of the large bones which remain indetenninate. two is entire while onl y a posterior fr agment (with the The specimens wi ll finally be stored or exhibited in eotyle and th e left postzygapophysis) of th e other is a Museum dedicated to the local dinosaur rema ins in preserved. The following description concerns the com­ the vi ll age of Bale (Istria, Croatia). At present th ey are plete vertebra (Fi gs. I & 2). This is crushed laterall y, without the definitive number of this Mu seum therefore th e neural arch is bent to th e Icft sid e and the left J will report here the numbers used during prepara ti on diapophysis with th e corresponding ho ri zon tal lamina (MPCM-V = Museo Paleontologico Cittadino di Mon­ are crushed and bent to the centrum. Th e right side has falconc - Valle). The specimens that were nOl numbered been exposed to erosion on th e sea bOil om in recent durin g preparation and were at th e Mu seum in Ba le times and was strongly weathered. during the final version of thi s paper are identified with The centrum is opisthocoelous, very elongate and th e abbrev iat ion WN-V. Two bones are presentl y in the tubular. Its length is 350 mm , its height at th e posterior co ll ecti on of the Institute of Geology, Zagreb (Nos lG-I end is 50 mm, the length/height ratio is th erefore 7; and Nos IG-2). maximum depth of the neural arch as preserved is 100 Because of the way the specimens were collected it mm. The centrum has a cavernous, cancellate structure is im possible to be immediately sure that they belong to with thin external walls and relative ly smail, irregular the sa me taxon, or to a precise number of different taxa. internal cavities bordered by bone septa and ridges; the In some occurrences, for example in some levels of the septa and wall s are comparat ively thicker than in the Morrison Formati on (Upper ) of North Ameri ­ posterior cervical vertebra MPCM-V2 described below. ca, six sauropod genera were found together (see CUR­ The inner cavities are, at least in the ant erior part of the TICE & WILHITE, 1996). Therefore each bone is com­ centrum , antero-posteriorl y elongated. A small pleuro­ pared with the corresponding bones of described sauro ­ coel, al so antero-posteri orl y elongated, is identifiable pod taxa, in o rder to determine affiniti es particul arl y on the middle ventral part of the lateral side of the cen­ with th e better known forms (Brachiosaurus RIGGS , trum (Fig. 2). "Pleurocoels" are al so present anteriorly Haplocanfhosaurus HATCHER, Camarasaurus COPE, on the centrum, just above o r at the ba se of th e para­ Dip/odocll s MARSH , and Apatosallrus MARSH) and pophys is. They actuaIJy are deep depressions and do the Neocomian- Barremian ones. not appear to communicate with th e inner part of th e Dalla Vecchia: Remain s of Sauropoda (Reptilia, Saurischia) in the Lower Cretaceous .. 107

NS

COPR CPR CDL DP IPDL...: .. >,'. PZ ~ HL " ..1~/

PR "i<{t;'i, ;.:~~ ..'~~ ...·.:!.,.~tti"- .:.L.'~~;~ c PR~',h.. :· ~, - PP

NS

IPZL

lii!1T ~M~\- NC

Fig. J Cervical vertebra WN-VI . Views: A) left laleral. B) dor­ sal, C) ventral, D) posterior. E) Recon­ structi on in pos teri­ or view. Acronyms: ASPZ= additional su prapostzygapo­ DP PP phys ial lamina. 108 Geologia Crorllic(l 51n

~ ...... ··· ·· <:'?:' )"~; '('~"6~~;.,~;c,' ; ~;t'i ···I~jjKLii::.;-·:·· · .

Fig. 2 Ce rvical vertebra WN ­ V I. Pattern of pleurococls and small depressions. centrum (they do not pierce the external wall) and are well developed centroprezygapophysial lamina, crushed probably the Aussenkaverne reported in the ccrvicals of against the anterior horizontal lamina, with a wide basal Brachiosaurlls branca; JANENSCH by JANENSCH attachment on the dorsal-anterior part of the centrum, ( 1947, fig. I). Small , rounded or oval (4-10 mm) shal­ just caudal to the condyle. There is also a short condy­ low depressions arc present in the anterior part of the loprezygapophysial lamina. The supraprezygapophysial centrum, and are most prevalent on the lateral side of and suprapostzygapophysial laminae are thin, well the neural arc h. Ventral excavations arc not present. developed and separated (right from left) by very deep The " pJcurococls" and the depressions on the centrum infra-supraprezygapophysial and infra-suprapostzy­ are fi gured in Fig. 2. gapophysial cavities (Fig. I B). The supraprezygapo­ The cotylc (the posterior articular cavity on the cen­ physial laminae are thinner than the supraposlzygapo­ trum) is deep and oval (main verti cal diame ter;:::: 50 physial laminae. The ventra-posterior part of the medial mm) but the shape is probably biased by compression, side of the supraposlzygapophysial lamina presents a and the condyle is well developed, ball-like and small deep cavity bordercd medially by a very thin vertical (maximum diameter= 35 mm). lamina (ASPZ = additional suprapostzygapophys ial The neural arch occupies nearly the entire dorsal lamina). surface of the centrum. The neural spine is low and not There are two thin, parallel and short verlical lami­ bifid. The parapophysis lacks the distal part and is ori­ nae just above the bony arch surrounding the neural ented in the vertical plane; despite any compressional cavity. The intrapostzygapophysial lamina reaches the­ effects it is unlikely that this was originally oriented in se laminae medially fanning a Y -shaped structure. The the horizontal plane. The diapophys is is triangular in short verti cal lamina, infrapostzygapophys ial lamina dorso-Iateral view and tapers at the di stal tip, which is and intrapostzygapophys iaJ lamina surround a large, broken and shows a circular outline of the section and a deep cavit y (Fig. I E). Right infrapostzygapophysial hollow insidc. The tip of the diapophysis and the poste­ lamina and intrapostzygapophysial lamina arc crushed rior margin of the ant erior horizontal lamina are rough. against one another and the corresponding cavity bor­ From the diapophysis a well dcveloped wing-like hori­ dered by the two laminae is nearly closed. zontal lamina is directed anteriorly to the prezygapoph­ The prezygapophys is is long and projects we ll ysis and posteriorly to the poslzygapophysis. Where the beyond the anterior tip of the centrum. T he articular posterior horizontal lamina begins a strong infrapostdi­ surface is drop-shaped, facing medio-dorsally (orienta­ apophysial lamina is al so obvious (Fig. I C); this ends tion possibl y partly modified by crushing). The postzy­ as a lamina at the dorsal-posterior third of the centrum gapophysis is similar to th e prezygapophysis in that th e and continues as a ridge with the rel ief tapering caudal­ articular surface faces ventra-laterally. The well devel­ ly, ending before reaching the caudal margin of the cen­ oped, thin and wide (wing-like) horizontal lamina con­ trum. Where the infraposldiapophysiaJ lamina attaches nects the prezygapophysis and postzygapophys is to th e to the diapophysis, th e posterior side of the latter beco­ diapophysis. mes wider and presents a shallow depression (this part Comparisons - elongated , "tube-like" cervical cen­ has therefore a somewhat spoon-like aspect). There is a tra are present in Brachiosaurus brancai, Diplodocus double, V -shaped inner centradiapophysial lamina (Fig. and Barosallnts lellllls MARSH (MclNTOSH, 1990a, I C), with the point placed in correspondence to the nar­ b). Cervical centra of the camarasaurids are relative ly rowing of the tip of the diapophysis. The two branches short and wide (OSBORN & MOOK, 1921 ; MclN­ of the lamina end at the dorsal-lateral part of the cen­ TOSH, 1990a, b). Diplodoeids and Camarasallrus have trum; the anterior one is wider and very thin. There is a bifid neural spines in the cervical vertebrae (McIN- Dall:t Vecchi 3: ReJn3ins of S3uropoda (Replil i3. S3urischi3) in the Lower CrClaceous ... 109

Fig. 3 A) MPCM-VS poslerior part of a small cervical centrum, right lateral view; B) MPCM -V7 incomplete post zygapophys is of a A cerv ical vertebra, lateral view. The scale bar is in centi metres.

TOSH, 1990a, b; in Diplodocus and Camarasaurus M PC M-V2 (Figs. 4 & 5): a nearly complete cen­ they arc bifid from cervical 3 onwards) whereas they trum, rather short, wide and low (length = 300 mm, are single in Brachiosauru s . T he distribution of the height = 105 mm, and width = 175 mm at the posteri or "pl eurocoe ls" in WN-V I is similar, but not the same, as end) (Fig. 4). Its low profile is onl y partly due to dorso­ that of the ant erior ce rvica l vertebrae of Brachiosaurus ventral cru shing (the speci men, mainly in it s an terior brollcoi (JANENSCH, 1950, figs. 20, 23, 26, 29). In part, is crushed becau se of its ex tremely cavernous fact, the size of the posterior pl eurococ l of the cenlrum internal struclllre). A small pal1 of the base of the neural is much small er in the desc ri bed specimen. Also the arch is also preserved in th e posterior part. T he neural overall shape of the vertebra, the ante rior elongation of arch, the parapophyses, and the ext ern al bony wall in the prezygapophysis, and diapophysis distall y narrow­ the cranial hal f have all been weat hered away. in g in a bottleneck manner, are si milar to those of the The posterior cotyle is rather deep and probably had an ell ipt ical shape, wider than high, with a rat io Wjh = anterior cervical s of Brachiosaurus brancoi (JANEN­ SCI-!, 1950, ri gs. 20, 23, 26, 29). The internal cavities J.67. It s ventral side projects posteriorly more than the dorsal one. are probably the sa me as th e "longi tudinal pneumati c There are three large pleurocoels on both late ra l tubes" observed in a presumed specimen of Mamen­ sid es ( Fig, SA). T he ext ernal margins of the anterior chisourus YOUNG by RUS SELL & Z I-! ENG ( 1993, p. pleuroeoel (APL) arc weathered away, th erefore what 2089) and are prese nt also in "Chondrosleosaurus" we see now is probably slightly different to th e original (e.g. HULKE, 1879, p. 756) and in another cervical external shape. It is the shallowes t of the th ree ope ni ngs cenlmm described below. and is se parated [rom the posterior (PPL) and lower pleuroeoel (LPL) by thin bo ny laminae. M PCM-VS (Fig. 3A): thi s is the posterior part with T he posterior pleurocoel is the larges t and deepest th e co ty le of a small centrum, w ith a basal-posterior opening (about 40 mm), ell ipt ical, craniocaudall y elon­ fragment of the neural arch. The spec imen is stro ngly gate, extending along most of the caudal half of the crushed; it is 11 4 mm long and its height at the coty le is centru m. Though deep, the posterior pleurocoels do not 70mm. occupy the whole inner part of the centrum, and are not Comparisons - it is similar to the same reg ion of th e sepa rated from eac h ot her only by a medial lamina (as vertebra WN-V 1 and represents another cerv ica l verte­ in the dorsa ls of Camaras(JI.II"IIS or Brachiosaurus). In bra belonging to a relatively small sau ropod. faci the interio r of the cent rum of MPCM-V2 is wholl y composed of smal l, honeyco mb- like cham bers. T he MP CM-V6: th is speci men is probably the anterior dorsal and ven tral rims of the pl eurocoeJ are thi ck and portion (110 mm long) of a ri ght in frapostdiapophysial lip- like. T he anterior pl eurocoe l is elliptica l and also lam ina from a rather large vertebra : th e co rr es pond ing anteroposleriorly elongated. Th is pl eurocoel is deeper part on the complete ce rvi ca l WN-V 1 is no longe r th an posterio rl y and becomes more and mo re shallow ven­ 20mm. tro-ameriorly. It is separated from the posterior pl curo­ coe l by a thin lamina. T he lower pleurocoe l opens lat­ MPCM-V7 (Fig. 3B): an incomplete posterior part era-vent rally in th e mid-anterior part of the centrum of a postzygapophys is (48 mm long, 60 mm wide) cle­ and is more developed ventrally (Fig. 4D). Its true out ­ arly be long in g to a vertebra mu ch larger than the com­ line has probabl y bee n affec ted by weat hering on the plete cervical ve rtebra WN-V I. lateral side wh ere it po ss ibly ex tended on the pa ra- 110 Geologia Croa!ica 51/2

A

B

NC

c NA

o

PPL

Fig. 4 MPCM-V2, posterior cervical centrum. 10 em Views: A) right lateral, B) left lateral, C) dorsal, D) ventral, E) posterior. Acronyms: APL=antc­ E rior pleurocoel, LPL=iower plcufocoel. PPL= posterior pleurocoel. Dalla Veeehia: Remains of Sauropoda (Reptilia, Saurischia) in the Lower Cretaceous.. , 111

NA ,, ------

-', pp A

Fig. 5 MPCM-V2. posterior cervical centrum. A) Pattern of the pleu­ rococl s, B) cancellate structure of the condylar region (in the pic­ ture the vertebra is upside down and shows the ventral-anterior surface). Acronyms as in Fig. 4. pophyses. Its present shape is elliptical and antero-pos­ rasaurlls supremus COPE (OSBORN & MOOK, 1921, teriorly elongate. The left one is partly subdivided into figs. 7 & 32) and also the cervicals called C hondrosteo­ cells by thin bony septa. saUl·llS gigas by OWEN (1876, see Pis. II-V). The latter The weathered dorsal surface of the centrum shows are more or less coeval with MPCM-V2, being from the the cancellate structure of the inner vertebra. More or Barremian Wessex Fonnation (BLOWS, 1995) of Eng­ less irregularly shaped cells are separated by very thin land and have centra of the same proportions, overall septa; in some places (as in the left upper-mid part of outline, shape of articular surfaces, ventral aspect, very the centrum) these cells are regularly divided by verti ­ similar anterior pleurocoel and posterior pleurocoel and cal septa into a "honeycomb" pattern. A regular "hon­ the particular, regular cancellate, "honeycomb" bone eycomb" pattern, with antero-posteriorly elongated, texture, mainly in the condylar region (see Pis. II, IV tubular cells, is evident in the weathered anterior con­ and V of OWEN, 1876 and the description by HULKE, dylar part (Fig. 5B). 1879, p. 756-57). On the other hand, the cancellate tex­ The trace of the neural canal on the dorsal sid e of ture is not present in Camarasaurus (P. UPCHURCH, the centrum shows that it is very expanded at both pers. comm.). The size of MPCM-V2 is between that of extremities: maximum posterior (at the exit from th e the two specimens of C. gigas described by OWEN neuraJ arch) width is about 50 mm , maximum anterior (1876, sec PI. V). They could differ in the presence and width is 55 mm, minimum width is at midlenglh (about shape of the lower pleurocoel, but the shape and actual 25 mm); height in correspondence to the posterior exit position of this opening in MPCM-V2 is effected by from the neural arch is about 35 mm. The posterior weathering which rubbed out completely the para­ opening of the neural canal is therefore elliptical, wider pophyses, as reported above. Also variation of position of the posterior, lower and anterior pleurocoels may than high. account for the differences. Therefore MPCM -V2 at the The ventral side of th e centrum is very flat and present state of knowledge should be referred to this wi th out longitudinal depressions or rid ges. In the ante­ taxon, whose validity, however, is doubtful (see below). rior third the external, compact wall is weathered and C. gigas was based by OWEN (1876) on only a com­ the inner tubular, "honeycomb", cancell ate structure is plete and a weathered cervical centrum. HULKE (1 879) exposed (Fig. 5B). In the mid-anterior part there is a added at least another cervi cal centrum (n. 144, coli. H median, antcroposteri orl y elongate, large (length = 45 of HULKE, 1879) (actually he made a mistake in mm) and deep (about 40 mm) hole. In the mid-anterior reporting the name and attributed it to C. magnus). C. part of the centrum, the ventral external bony wall nar­ magnus (= Bothriospondylus mag nils OWEN, 1875 but rows because of the lower pleurocoel; here the medial type of hulkei of SEELEY, 1870) is repre­ margin of the opening is rimmed by the relatively thick sented by two dorsal centra found in the same forma­ wall. tion and locality of the cervicals called C. gigas Comparisons - the large pleurocoels are very differ­ (OWEN, 1876, p. 7). It appears plausible that C. mag­ ent [rom the titanosaurid condition, and are characteris­ nus belongs to the same taxon of C. gigas as partly real­ tic of brachiosaurids, camarasaurids and diplodocids ized by Owen himself, who referred them, "provisional­ (mainly Diplodocus). Brachiosaurids and Diplodocus­ ly", to distinct species on the base of the incorrect state­ like diplodocids seem to be excluded by the relative ment that they are both dorsal elements and that dorsals shortness and width of the centrum and its dorso-ven­ cannot be so different in the same species (p. 7). C. tral flatness (MciNTOSH, 1990b). The overall mor­ mag nus was based on a vertebra (BMNH 28632) which phology of MPCM-V2 and the size and position of the OWEN (1875) had call ed Bothriospondylus mag nus pleurocoels strongly resemble cervical 10 of Cama- before recognizing its resemblance to the vertebrae of 112 Geologia Croalica 51/2 c. gigas. Vertebrae of C. magnus (= Ornithopsis mation. S2 resembles a thick lamina, thicker posteriorly hulkei) have the same honeycomb-like texture in the than anteriorly, and holl ow inside. A large, oval pleuro­ condylar region as C. gigas (OWEN, 1875, PI. IX). coel opens in its present side surface, revealing the hol­ BMNH 28632 was indicated as one of the two types of low inside. S3 is the left sid e structure corresponding to Ornithopsis hulkei by SEELEY (1870) but OWEN S2 but was mostly weathered away. If so, SI, S2 and (1876) rejected the name as "misleading" because of its S3 originally formed an upside down Y or T-shaped Greek meaning which seems to suggest it is a stru cture. S4 is a lamina crushed against SI, with a bone. HULKE (1879) considered Eucamerotus HUL­ strong, rib-like upper margin (urn) and the remaining KE and Ornithopsis to be synonyms because the type of part (IS) whieh is a thin sheet of bone cru shed against il. the first (BMNH R2522, a partial neural arch), BMNH The rib-like upper margin um begins in the dorsal mar­ 28632 and a "mutilated centrum, reta ining enough of gin of S I where the latter becomes rib-li ke; th erefore the arch and superstructures" (p. 755) present an "extre­ th e two rib-like structures form (and formed before mely large-cell ed cancellous ti ssue" (p. 755). L YD­ cru shing) a V -shaped st ru cture with the acute part EKKER (1888) accepted the synonymy of Chol/dros­ po inting forward and downward. S4, now parall el to S 1 teosaurus (both species) and Omithopsis but suggested was originally divergin g from the latter posteriorly. that Pelorosaurus MANTELL should be synonimized. Comparisons Mthe shape of the structure S 1 resem­ In his recent review of Ornithopsis BLOWS (1995) bles one of a low neural spine of a cervical vertebra. does not include in O. hulkei the cervical vertebrae of However, the re lation with the stru cture S4 cannot be C. gigas but considers it, as SEELEY ( 1870) did, as a recogni zed exactly in any described vertebra of Hap/o­ lectotype of O. hulkei one of the two dorsal centra (the cantllosaurus, Diplodocus, Apatosaurus and Cama­ synt ype of SEELEY, 1870, BMNH28632 - see L YD­ rasaurus (pers. obs.). The shape of the specimen mostl y EKKER, 1888) called C. magI/us by OWEN (1876). C. resembles one of the bifid cervical neural spine of gigas was recently considered va lid and tentatively Apatosaurus (GILMORE, 1936). As reported above, in assigned to the Camarasauridae by McINTOSH (I990b, my opinion it is part of a complex laminar st ructure of a p. 387) because of its close resemblance with cervical neural arch of a rather large and bi zarre cervical or dor­ 10 of Camarasaurus. P. Upchurch, who is rev iewing sal sau ropod vertebra, but nothing more can be sa id th e British sauropod material, considers C. gigas a unti l a more complete part of this struc ture is found. 110m en dubium and probably a member of the Titano­ sauriformes (Brachiosaurus + Titanosauria) (P. UPCH­ Cervical ribs? (Fig. 7) URCH, pefS. comm.). Seven rod-like bone fragments (among them is MPCM-V4 (Fig. 6): thi s is a part of a larger bone MPCM-V8, the others now on exhibit at BaleNalle are and has a peculiar and somewhat puzzling shape and without number), with oval or elliptical cross sections stru cture. It s id entification is rather difficuil but it (about 10.5 x j 4.5 mm in the longest fragm ent, th e low­ appears to be part or a laminar system of th e neural arch er one in Fig. 7,195 mm long). They have the same of a cervica l or dorsal vertebra of a sauropod. In fact, transverse sizes for all their lengths and are straight or even if it is strongly clUshed and it s original shape was slightl y curved; they are not hollow and their surfaces deformed by compression, th e specimen is a ialt iceM present thin longitudinal stri ae. One surface is usually work of bone bridges and laminae, with pleurocoel-like flatter (less convex) than the other. openi ngs. This frame, linked to the extreme li ghtening Comparisons - They cou ld be segments of the distal of th e skeletal element s, is typical of sauropod cervical part of the shaft of long cervical ribs. They resemble the and dorsal vertebrae. very characteris tic, elongate rod-like shafts of the cervi­ I chose an arbitrary ori entation (see the caption of cal rib s of Camarasaurus, Brachiosaurus, Euheloplls Fig. 6) of the specimen to describe it and I identify the ROMER and Mamenchisaurus. On the other hand , main lamina-like struct ures which compose it with the MciNTOSH (1990a) indicates short cervical ribs as a acronyms S I, S2, etc. That which follows should be diagnosti c feature of Diplodocidae. The identification considered a tentative description. as part of rib shafts is supported by the presence in the S I is the upper, longitudinal, lamina-like structure outcrop of si milar bone fragments more than 500 mm which is strongly cru shed but not very derorm ed. Its long and perhaps as long as 1200 mm (D. BOSCA­ outline in the anterior part, where it is possibly fomled ROLLI and F. BACCHIA, pers. comm.). If the identifi­ by two thinner lami nae now strongly clUs hed one ca tion is correct, their large size excludes them from aga in st the oth er, is rec tangular in sid e view. At the belonging to a vertebra of the same size as the complete anterior third, S I becomes rib-like (ar), th e profile cervical vertebra WN-V I ; they belong to a much larger becomes inclined , the upper part enlarges and its dorsal vertebra of a large individual. Despite thi s, the frag­ margin is sharply acute. The back side of S I is nearly ments are very similar to the ossified tendons which vertical; here the stlUcture is divided inLO a ribMlike arch strengthen the tail and the back of iguanodontids. How­ (bs) which reaches S2 and a thin , centra l and inner lam M ever these skeletal elements are usually smaller and ina (i/). S2 was originally nearly perpendicular to SI flatter. If the described specim ens are ossified tendons but now is parallel to it because of crushing and defor- there are two possibilities: 1) also iguanodontids are Dalla Vecchia: Remains of Sauropoda (Reptilia, Saurischia) in the Lower Cretaceous ... II]

S1

®

S1

S2

S1 2cm

S2 Fig.6 MPCM -V4, possible frag­ ment of the laminar complex of a large cervical or dorsal vertebra. A-B) "side" views, C) "fronC view. Acronyms: a = "anlerior". p = "posterior", 5 I = lamina I . 52 = lamina 2, 53 = lamina 3, 54 = lamina 4. For the other abbreviations see lext.

represented in the fossiliferous outcrop but we do not original st ructures is not possible or at best very diffi­ have ot her evidence of this, 2) there arc sauropods with cult. ossifi ed tendons in the neck (calcified muscles are pre­ The centrum has a kidney-like outline in posterior served in Camarasallrlls - D. CHURE, pers. comm. III view, wider than high (about 80 x 55 mm) and the arti­ MclNTOSH, I 990b) or in the tail. cular fa ce is concave, It is a cylinder, therefore it has convex lateral sides. Dorsal vertebrae On both lateral sides there is ev idence of a very MPCM-Vl (Figs. 8 & 9): th e specimen consists of large pleurocoel, probably with an ovate outline (but a part ly preserved, small centrum and corresponding see below) occupying most of the lateral side of the neural arch without most of the spine. The neural arch centrum (Figs. 8D & 9C). The pleurocoel is not a hole is strongly crushed antero-posteriorly, due to the acti on piercing the lateral wall of the centrum and in connec­ of lithostatic pressure on th e extremely holl ow struc­ tion with its hollow inner part (Fig. 8B). It is just a deep ture. The whole vertebra is in fact just a very complex depression rimmed ve ntrally (lip-like ventral margin), latticework of thin bone laminae. After complete prepa­ opening dorsally and partially Uust in the ventral part) ration it seems clear that in previous papers I wrongly divided internally by a small, rib-like vertical septum identified the posterior part as the anterior (see DALLA (as in the dorsals of Ellcamerofu5 sensu BLOWS, 1995 VECCHIA, 1994b, fi g. 4b). The an terior side of the and many other sauropods). The inner structure of the vertebra was strongly weathered and to identify the centrum is ex tremely cavernous, cancellate, wi th thin Gculogia Cf()

rig. 7 Fragments of proba­ ble ccrvic

  • ve rti cal scpta (mainly antero-posteriorly oriented but directed (in front view) structure, possibly formed by a some smaller ones arc transversally oriented) and rein­ thick, rib-like infraprczygapophysi.aJ lamina at the later­ forc in g struts (Fig. 8B). The inner septa are as thi n as al margin and a thinner prezygapopbysial lamina a t. the less th an I mm, wh creas the external wall is thicker. dorsal one (Pigs. 8D & 9B). This apophysis is strongly The neural canal is oval, large, about 29.5 mm wide crushed against the other laminae which comprise the and 21 tlll1l high in posterior view, 25 and 16 mm neoral arch. Nothing is preserved of the part of the respect ive ly in ant erior view. prezygapophysis bearing the articular surface. A nother The neural arch is comparali vely very lall: the ratio triangular structure (indicated wi th the acronym AS in 11/h (H = distance between the base of the postzygapo­ Figs. 8B and 9B) seems LO start just above the neural physis and the top of Ihe centrum, and h =ccntrunl canal, tapers dorsally and ends against the presumed hcight ) is 1.83; the preserved part of the neural arch is prezygapophysial lamina. As in other vertebra this 2.8 timcs the height of the cenrrum. The neural arch is stru cture, whi ch has been vcry damaged by weathering. fo rm ed by very thin , long laminae whi ch arc difficult to is composed of a lalliccwork of very thin laminae. ident ify because of the strong crushing; thcir original Above these structures therc is the base of the neur­ position is tcntalively reconstructed in Figs. 9C and al spine. The rib-like trace of a possibly bif:i d (O-shaped lOll. in cross-section, Fig. 10) prespinal lam in a can be recog­ The ri ght post zygapophysis is nearly completely nized, with also the basal part of both supraprezy­ preserved. It is connected to the pedicels by a strong, gapophysial laminae. The latter taper toward the top straight, venieallamina (infrapostzygapophysial lami ­ and have a thickened margin in the upper half of the na). There is no suture between the basal pedi ccls and preserved part. the upper part of the arch. Between the two infrapostzy­ The pattern of lateral laminae is very complex (Figs. gapophysia! laminae the arch is depressed. Perhaps the 80, 9C & 10). two infrapos rzygapophysiallaminae were connected by A wide and very th in lateral infrapostzygapophysial a thin, horizonlal inlrapostzygapophysial lamina btll j(Jlllina starts from the lateral side o f the base of rhe cru shing preveilis furl her clarification. The cross-sec­ pedicel and rcaches the posteri or horizontal lamina just lion of the post zygapophysis shows pneumatic caviti es anterior to the postzygapophysis Wigs. 8D & 9C). inside; th e part with cavities is found dorsall y with The thi n infradiapophys ial lamin a seems (0 start respect 10 a 5 mm thi ck layer of spongy bone wh ich is from Ihe same point as the lat.eral infrapos(zygapo­ just above the articular surface. The latter faces ventro­ physial lamina (or a little above) and ends at the dia­ lateral ly and slighll y anteriorly. There is no hypo­ pophysial "knob". Most of the diapophysis is complele­ sphene: medially to the postzygapophyses th e (ITch is Iy weathered. and is recogni zable only as a knob or deeply depressed and in the middle of the concavity strut, composed in its proximal part by the confluence there is th e basal part of a rib-like (probably broken) of the laminae connected with it. The nat.ural, unbroken postspinallamina (Fig. SA). outer margin of the infradiapophysial lamina is pre­ The arti cular surface of the prezygapophysis was served in its basal part and shows that the infrad iapo­ probably borne by a large, triangular, dorso-Iatcrally physial1amina was upwardly and laterally directed; thi s Dalla Vecchia: Remains of Sauropoda (R eptilia, Saurischia) in the Lower Cretaceous .. . 115

    PRSPL PSPL

    PL

    PSPL SDL 2 em

    SPRZ PRSPL SDL? --I,~

    PR?

    .I--;c;f- I PD R L IPRL

    LlPZL PP

    I.",:: ~4- SIPRL

    IPLLa IPLLb

    PL

    c D

    Fig. 8 MPCM -VI, anterior dorsal vertebra. Views: A) posterior, B) anterior, C) len latera!, D) right lateral. Acronyms: AS=anterior structure between prezygapophyscs. 116 Geo logia Croatica 51!2

    PRSPL PSPL . ,, ,, -,\_- --,) PR? ' '\, ,ITPZ? 1 \ I ' I \ IPRL IDL -­ 1 lIPZL -­ IPZL - IPZL - '- l I \ .) --PP

    \ , I PL , A B / C

    Fig. 9 MPCM -V I, anterior dorsal vertebra. Simpl i fi ed drawing of the ve rtebra in A) pos terior and B) anterior vicw: C) reconstruction of lhe laminar paucrn in right lateral vicw.

    lamina appears 10 have been a wide, wing-like structure rapidly tapcrs to becomc a Ihi n, compact singlc shcet of projecting lalerally (Fi g. 9A). bonc. It was probably connectccl wi th the diapophysial Anteri or to th e desc ribed laminae there is evidence "knob", but this part of th e lamina is displaced because of a complcx, laterally projccting structure placed at the or strong c ru shing. There is a thin horizontal lamina b

    PRSPL

    PP PR -jl-.--.-

    HYP IHPNL HPN IHPNL

    Scm

    SPZL

    HL -Ir--~~.! pz --I-'~ HPN

    PR

    PR SPRL

    IPPL

    LlPP HL

    SDL PZ E SPZL PSPL SPZL PZ IHPNL PZ

    Fig. 11 MPCM-V3, part of a neural arch of a posterior dorsal vertebra. Views: A) anterior, B) posterior, C) right lateral, D) left lateral, E) dorsal. F) ventral, In these drawings broken surfaces are not showed by sloping lines. Acronyms: Has = art icular surface for the hyposphene. osseous tissue is a diagnostic character of Titanosauri ­ p. 26) consider that the "phylogenctic relcvance of the dac. ASTIBIA et al. (1990, p. 463) consider the "cellll­ relative development of cavernous osseous tissue is lar bony structure of the vertebrae" an "autapomorphic unclear", In the dorsal vertebrae of Brachiosaurus and titanosaurid feature". However SALGADO et al. (1997, Camarasaurus the inn er ccrtrum is camerate (large cav- Dalla Vecchia: Remains of Sauropoda (Reptilia, Saurischia) in th e Lower Cretaceou s ... 119

    spine. The bone was strongly crushed antero-posteriorly SPZL SOL SPRL / and this affected mainly the laminae visible in lateral view (i.e. horizontal lamina, infradiapophysiallamina, \ ~ supradiapophysial lamina, elc.) which are therefore de­ formed and artificially ap proached, PSPL - g'-L..-' .... _ PRSPL The specimen is composed of a latticework of thin lam inae, above all the axial part of the arch. Also the o thickest and strongest pal1s (i,e, zygapophyses) arc cav­ ernous. For example, a large deep cavity divided by a A o thick septum (Fig, lIF) opens medially at the base of the prezygapophysis, just below the articular surface for the hyposphene, The prezygapophyses are large, with wide articular surfaces facing dorso-medially. There is a wide, more or less quadrangular articular facet for the hyposphene bordering th e upper part of the hypantrum, and articu­ lating with the hyposphene, At the ventral end of thi s facet the prezygapophysis narrows fonning a step-like structure, (i.e. the articular surface for the hyposphene is on a low, ventro-medial projection of the prezygapo­ physis) and the prezygapophysis assumes a hammer­ like shape. A thin lamina starts from the base of the articular surface for the hypo sphene to reach the axis of HL the arch in the middle of the hypantrum, The hypan­ HPN trum is very wide, deep and with an isosceles trapezium outline. Has The postzygapophyses arc united to the hyposphene forming a very strong, Y -shaped articular structure IHPNL IO L (Fig, llB), The postzygapophysis articular surface is very wide and elongated. The hyposphene is triangular and dorsoventrally elongate, but unfortunately the pos­ terior portion is strongly weathered. The hyposphene originally was probably mu ch more developed posteri­ orly. In fact there is no clear indication of the presence Fig. 12 MPCM -V3, part of a neural arch of a posterior dorsal verte­ bra. A) reconstruction of the laminar pattern in dorsal view, B) of the accessory articulation, which should fit in the reconstruction of the preserved part of the basal neural arch in corresponding step-like structure of the prezygapoph­ right lateral view. The Has of the prezygapophysis is projected in ysis, nor a complete articular facet corresponding to the the corresponding position on the hyposplJene. articular facet in the prezygapophyses (Has, Figs, 11 & 12), The infrahyposphenallaminae start from the ven­ tral end of the hyposphene and arc ventrally and slight­ ly laterall y directed. The ventral cross-section of the iti es) rather than cancellate. Since the individual repre­ specimen shows that the axial core of the neural arch is sented by MPCM-VI is very small, the extreme li ght­ formed of a latticework of thin laminae (Fig, Il F), It is ening of the vertebrae cannot solely be an adaptation to possible th at there was something like an infrahypo­ large size. sphenal cavity entering the hyposphene from insi de the neural arch. MPCM-V3 (Figs, II & 12; figured in DALLA The parapophysis stalk is preserved but weathered VECCHIA, 1994b, fig, 4A, and DALLA VECCHIA & at the outer end, on the right side just behind the prezy­ TARLAO, 1995, fig, 2), This specimen represents th e gapophysis, On this side there is also a knob which is zygapophysial segment of the neural arch and the basal probably the proximal part of the "core" of the trans­ part of the neural spine of a dorsal element. The posi­ verse process (=diapophysis) since all laminae are con­ tion of the parapophysis and diapophysis suggests a fluent to it (Fig, 11C), On the left side, th e position of mid-posterior position. It is 220 mm high and 200 mm the parapophysis and diapophysis is shown only by wide, and therefore belongs to a large individual. Some convergence of the laminae, since the processes have parts have been weathered so that the present margins been completely removed by weathering (Fig, lID), seem to be the original margins of the bone but actually The position of the transverse process seems to be near are nol. Erosion destroyed the projecting part of the the post zygapophysis in the left side, while it is midway hyposphene, the complete transverse processes, most of between the postzygapophysis and parapophysis in the the processes fo r the capitulum and most of the neural right one. 120 Geologia Croat ica 51n

    Two laminae start from the base of the prezy­ sensu SALGADO et al. ( 1997) and its development gapophysis. The thin anterior lamina reaches the para­ down to the base of the neural arch is considered a pophysis an teriorl y or in the middle, and is therefore an character of deri ved titanosaurids. However, Titanosau­ infraparapophysia\ lamina. It borders posteriorly a very ridae sensu SALGADO et al. ( 1997) lack a hypantrum­ deep lateral depression excavated into the prczygapoph­ hyposphene complex in the posterior trunk vertebrae. A ysis. The poste ri or lamina is very thick, rib-like, reach­ prespi nal lamina in posterior dorsals is also present es the parapophysis posteri orly (Fig. I I C), and is here convergently in the Diplodoeidae (op. eit.). Ellcamero­ identifi ed as a lateral infraparapophysial lamina. The filS foxi BLOWS, considered a brachiosaurid by b LO­ presence of a very thin infradiapophysia\ lam ina is clear WS (1995), does not present a prespinal lamina in \he on the left side (Fig. II D) whil e th e ri ght one is very posterior dorsals (see HULKE, 1880, pI. IV, fig. 5). strongly cru shed. The development and morphology of the preserved The thin horizontal lamina was somewhat short­ supraprezygapophisial-prespinal laminae and supra­ ened, deformed and bellt to a S-shaped structure by postzygapophysial-postspinal laminae is similar to tho­ antcro-posterior compression (Figs. LI C-D). se of the Diplodocidae (sec posterior dorsals of Diplo­ The supraprczygapophysial lamina is a thick lami­ dOCIIS, HATCHER, 1901 ; Apatosaurus, GILMORE, na. It has a wide base (about 70 mm) in front view and 1936, pi s. XXV & XXXII; AlI1phieoelias COPE, OS­ tape rs quickly toward the top of th e preserved part, BORN & MOOK, 1921 , fi gs. 11 9 & 120) ancll-Japlo­ where it is at least 20 mm wide, and therefore does not eal1thosallrus prisells (HATCHER, 1903, pI. I). A nar­ end against the prespin al lamina. Interpretation of the row neural spine of the dorsal vertebrae is also a feature actual morphology of this lamina is difficult since the of the Diplodoeidae. ri ght one seems d i fferent from the left one, perhaps T he infrahyposphenal lamina and corresponding because of weathering and crushing. It was probably cavity arc structures which seem to be present only in antero-Iat erally directed (Fig. 12A), with a thick, lip­ the Diplodocidae (CURTICE et aI., 1996) but apparent­ like anterior margin wh ich rims the deep, axial depres­ ly th e posterior dorsals of Eucameratus faxi also have sion fo rm ed by the two sllpraprezygapophysiallaminae, them (see HULKE, 1880, pI. IV , fig. 7). at the bottom of which the prespinal lamina starts. No The step- like structure on the medial side of the bony strut s or laminae seem to connect the supraprezy­ prezygapophysis seems to be present also in the holo­ gapophysial lam ina to the supradiapophys ial lamina. type of EIlCOll1erotlls foxi (B LOWS, 1995, fig . I C). The The prespinal lamin a is weathered and appears more as whole prezygapophysis-hypantrum complex appears to a rib than a lamina. It probably did not project beyond be somewhat similar, on the basis of BLOWS (1995, the level of the supraprezygapophys ial lamina. It starts fi g. I C) to that of th e holotype of Eueal1lerotlls foxi. at the base or very ncar the base of the neural spine, However, the hypantrum-hyposphene articulation is becomes wider and stronger toward the lOp and perhaps al so similar to that of some basal litanosaurs, and in was bi fi d (but this aspect could be due to weathering), particular that of the an teri or dorsal of ArRentinosourus al least at the base. ituilleulellsis BONAPARTE & CORIA, where th e step­ The suprapostzygapophysial laminae, which are like structure has been called "accessory articul ati on of more a ffected by weathering, mimic the sup raprezy­ the hypantrum" (ef. BONAPARTE & CORIA, 1993, gapophys ial laminae but are thicker above all at the figs. 4 & 6), and is considered a diagnosti c feature of base where th ey arc connuent with the postzygapoph­ the genus (BONAPARTE & CORIA, 1993, p. 272). As ys is. The le ft one bifurcates just above the postzy­ suggested by the authors th emselves (p. 276, 280) th e gapophysis and becomes single again soon after (Fig. development of th ese structures is related to the large 11 D-E). A complex latti cework of transverse laminae, size of the individuals, and is therefore very probably a thin in the basal part of the neural spine, th icker and homoplastic character. strut-like above, connects the suprapostzygapophysial The presence, absence or shape of lesser laminae on lamina to the supradiapophysial lamin a. T he postspi nal the neural arch of sauropod dorsals probably lacks great lamina is similar and preserved like the prespinal lami­ taxonomic value because of th e variability existing in na but it s width is constant. The supradiapophysial lam­ the same individual (ef. Diplodoells in HATCHER, ina is thinner than th e suprapostzygapophysial and 190 J, and Apatosaurus in GILMORE, 1936). supraprezygapophysial laminae. There is a relatively sho rt "core" lam ina of the neural spine that means the WN-V6 (Fig. 13D-E), is a nearly complete dorsal spine was narrow in lateral view and roughly of rectan­ vertebra still under preparation, showing mainly its gular appearance in cross-section (Fig. 12A), at least at right and posterior side. The specimen will be stored at the apex of the preserved part. It seems narrow also in the Museum of the Municipality of Bale and is at pre­ antero-posteri or view but it is impossi bl e 10 know if it sent without number. It is less crushed than the other widened again above th e preserved part or not. presacral vertebrae found in the outcrop. The right pedi ­ Comparisons - Ih e presence of a medial prespinal cel of the neural arch is detached from the centrum and lamina in posterior dorsals is considered a synapomor­ thi s coul d mean that it was not completely fu sed to it phy of the T it anosaurifonnes [Brachiosaurus brancai + (but crushing should be considcred the main cause of (C/II/bu tisaurus ill si~lI i s DEL CaRRO + Titanosauria)] this detachment) and that the specimen does not belong Dalla Yecchia: Remains of Sauropoda (Reptil ia, Saurischia) in the Lower Cretaceous ... 121

    PSPL

    P PSPL -- .. DP

    , \ , \ A { ( \ I , '---/ I c

    P SP L --+-~; I

    ISPZL

    Fig. 13 Mid-postcrior dorsal vcrtebrae in posterior view. A) Dorsal 13 of HaplocanfllOsaurus priscu.\· (redrawn from HATCHER. 1903), B) dor­ sal 5 of Apatosall/"lls Imdsae (redrawn from GILMORE, 1936), C) mid-posterior dorsal of Rehhachi.murus fessonei (redrawn from CALVO & SALGADO, 1995), D) WN-V6, nearly complete posterior dorsal vertebra. E) postcro-lateral view of the neural arch of WN-V6.

    to a fu ll y mature individual. The overall morphology gapophysial laminae are wide and antero-posteriorly and th e relative position of the diapophysis and para­ directed. They run paraliel to the main axis of the spine, pophysis indicate that it is a posterior dorsal vertebra. Tt tapering upward, and abutting nearly perpendicularly is larger than MPCM -V 1 and smaller than MPCM -V3 the supradiapophyseal lamina (Fig. l3E). A similar and has a characteristic tall neural arch, with long suprapostzygapophysial laminar pattern is sometimes diapophysis extending sharply upward (the angle is present in the diplodocid Apatosaurus (see GILMORE, about 45'). There is a hyposphene-hypantrum complex 1936, PI. XXV; here Fig. 13B). The diapo-postzy­ and the neural spine is undivided (but only the lower gapophyseal lamina (= hori zontal lamina) ends in the part is preserved). The neural arch is a latticework of middle of the transverse process without reaching the thin and wide laminae. Each suprapostzygapophysial diapophysial articular surface. The centrum is relatively lamina is double. The relatively narrow inner supra­ small and elongate (its maximum dorso-ventral height postzygapophysial laminae taper rapidly, coming toge­ is about 150 mm , and length is more than 200 mm), the ther to [onn a postspinallamina. The outer suprapostzy- articular facets are circular and a large pleurocoel is 122 Geologia Croalica sin present antero-dorsall y on the lateral side. The inner Ihe spine and a high (aboul 45°) inclinalion of Ihe long structure of the centrum is not cancell ate (i. e. it is finely diapophyses. It is very probably re lated to Rebbachi­ spongy). SG urus but is less derived because of the presence of the Comparisons - the overall morphology is remines­ hyposphenc-hypantrum in dorsal vertebrae. The name cent of the mid-posterior dorsal vertebrae of HaplocGn­ Hislriasaurlls hoscarollii is proposed for this new tax­ lilosaIlrlls (Fig. 13A) and Rebbacilisallrlls LAVOCAT on, in honour of the discoverer o f the site, mr. Dario (reference is made mainly to R. lessonei CALVO & Boscarolli, and referring to the region where the speci­ SALGADO, Albian-Cenomani an of Argenlina (Fig. men was found (His/ria = Latin name of Istri a). 13C), because Ihe only prepared dorsal vertebra of R. Caudal vertebrae garasbae LA YOCAT, Aptian - ?Cenomanian of Moroc­ co, was never fi gured and was only poorly described by WN-V3 (Fig. 14). The specimen was fi gured in LAVOCAT , 1954). Reference 10 Dieraeosauridae is BOSCAROLLI el al. ( 1993, fi gs. 25-27). The cenlrum exclud ed by Ihe presence of Ihe plcuroeoel (I he absence is 100 mm long, 120 and 115 mm high respeeli vely al of pJcurocoels in the dorsal vertebrae is considered an the anterior and posteri or art icu lar side. The s hape of import ant apomorphy of dicraeosaurids, see MclN­ the art icular facets is roughl y ell ipt ical, with the longer TOST-I, 1990b). }-fap/ocamhosGurlls, which shares with axis ( 150 mm in the anterior facet) horizontal. The pos­ the vertebra LInder examination the hi gh in clination of terior is nearly flat, the anterior is a little weathcred and the diapoph ysis and the presence of the hyposphcnc­ was o ri ginally flat or shall owly concave. The vcntro­ hypantrum, has, on the other hand, a postspinal lam ina posterior part of the centrum projects downward and wi th a very different morphology, single suprapostzy­ sli ghlly backward; this projeeli on is relaled 10 Ihe gapophysial laminae, a taller subzygapophys ial portion chevron articulation, but th ere is no clear mark of th e of the neural arch, and is known presentl y only in the art icular facet, onl y a thin , transversall y fl at area. There Upper Jurassic of Norlh Ameri ca (McINTOSH, 1990b). are no plcurocoels and not even longitudinal ridges or Rebbachisaurlls does nol presel1l an out er supraposlzy­ grooves on the ventral sid e. The ventral side is slightl y gapophysial lamina (see CALVO & SALGADO, 1995, depressed but the cross-section o f the centrum is not rig. 9; here Fig. 13C) and, mosl imporlanl, docs nol pre­ "heart -shaped". The proximal parlor the coalesced cau­ sent a hyposphene-hypantrum complex in dorsal verte­ dal rib is placed hi gh on Ih e dorsal-Ialeral side of Ih e brae (CALVO & SALGADO, 1995). The neural spine cenlrum and is laterally and backwardly directed. The or R. lessoflei is more slender in antero-posterior view rib is spine-like and sli ghll y dorso-venlrall y n allened. Ihan that of the specimen here described. However, th e The neural arch is only partly preserved. II is lall and spine of R. garasbae is wider than that of the South placed anteriorl y on the centrum, so th e distal third of American species. The preserved part of the neural the latter is not covered by th e arch. The circular neural spinc of WN-V6 is most reminescent of th e neural canal is very large. The pedicels are slightly medi all y spin es of some dorsal vertebrae of Apatosaum s louisae inclined. The postzygapophysis is far above Ihe base of (Fig. 13B). the neural canal and is posteriorly elongate. The articu­ Characters present mainly in the Diplodocimorpha la r facet is a shallow depression, anterodorsall y-pos­ (sensu CALVO & SALGADO, 1995) indieale Ih al lhe lerovenlrally elongaled, faci ng lalerally and only slighl­ specimen belongs to this clade: 1) the neural arch is Iy venlrall y, placed on Ihe venl ral part of Ihe poslzy­ three times the dorso-ventral centrum height (the height gapophysis. The prezygapophyses are not preserved but of Ihe on ly partiall y preserved neural arch is 2.85 limes the posi ti on of the art icul ar facet in the poslzygapophy­ the dorso-vcntral centrum height), 2) th e suprapostzy­ ses s uggests it was anteriorly and upward ly directed. gapophysiaJ laminar pattcrn is relatively complex, wi th The neural spine is not preserved but its base was rather inner suprapostzygapophysial laminae whi ch are con­ far abovc the base of the neural canal. Shortness of the rIuent to form a postspinal lamina, and out er s upra­ centrum and the presence of a strong rib idcnt ify this as postzygapophysial laminae parall cl to the axis of the an ant erior caudal element. spine and tapering upward, 3) the tall neural spine is relat ively narrow in ant ero-posterior and lateral view. MPCM-VI4 (Fig. 15), is a eenlrum lacking the pos­ The dipJodocimorphs are repre­ terio r half and wi th the basal part of the neural arch. sented mainl y by a g roup of Gondwanian taxa (Reb­ The centrum is more broad than hi gh (about 11 5 x 70 bachisaurus garasbae, R. tessonei, and th e Neocomian mm), with a kidney-shaped, concave anterior articular Amargasallrus cazall; SALGADO & BONAPARTE surface. The left rib (only the ante ri or, basal part is pre­ from Argentina) wit h extremely tall neural spines and served) placed on the dorsal-Iatcral side of the centrum, upwardly directed diapophyses in th e dorsal vertebrae. is strong and probably latero-posteriorl y directed. T here T hi s suggests a Gondwan ian affinit y of the ISlrian is a s hall ow depression in the centrum just below the sauropod fauna. ri b. The neural canal is subc ircular to oval and very W N-V6 represents a new diplodocimorph taxon large, of greater heigh I Ihan w idlh (26 x 20 mm) in pos­ because of the combined presence of an hyposphene­ teri or vi ew, the opposite in front view. The neural arch hypantrum complex, a well developed outer supra­ is fu sed without suture to the centrum. The pedi ccls are poslzygapophysial lami na running parallel to the ax is of slrong and inclined mediall y. The prezygapophyses Dalla Vccchia: R emain~ of Sauropoda (Reptilia, Saurischia) in the Lower Cretaceous ... 123

    PZ

    B PZ A

    CD

    Fig. 14 WN- V3. anterior caudal vC l1ebra. Views: A) right lateral, B) dorsal, C) anterior, D) posterior.

    lack the distal part with the articu lar surfaces. They The evident shortness of the centrum and th e pres­ start at the base of th e neural arch and rise from the ence of a strong rib placed down on it identify it as an antcriormost part of the centrum, arc forwardly inclined anteri or caudal element. at about 45° in s id e view, and are flattened laterally with the outcr side which faces latera ll y, upward and MPCM-VlS (Fig. 16) compri ses most of a relative­ backward. Only th e basal anterior part of the neural ly short centrum with a fragment of the right basal part spine is preserved. II is not far above the base of the of the neural arch. The ri ght side of the centrum and, neural arch. The basal parts of the prcspinaJ and partly, the posterior articul ar surface are suffic iently supraprczygapophysial laminae are preserved. The preserved for description, The centrum is ellipti cal, of neural spine appears to be caudally inclined, at least in greater width than height (about 127 x 105 mm) in pos­ the basal part and it s base was antero-posleriorl y nar­ teri or vi ew, short (75-80 0101), and with a practi ca ll y row. flat posterior articular surface. It s shape was spool-like, 124 Geologia Croatica 51/2

    PRSPL

    LD

    SPRZ 2cm

    LD

    Fig. 15 MPCM -V 14, rragmentary anterior caudal vertebra. Views: A) anterior, B) left lateral, C) posterior, D) dorsal. Acronyms: LD = lateral depression. with a marked oval to semicircular depression in the trum is typically spool-shaped and relatively elongate dorsal lateral hai r just below the rib. The right rib (only (length 1= 120 mm; height h at the extremities = 90 mm; the basal segment is preserved) is placed in the upper­ l/h ratio = 1. 33), and amphicoelous with the anterior most, dorsa-lateral side of the centrum at the attach­ fac et shallow and the posterior one slightly deeper. ment of the ne ural arch. It is stron g, sli ghtly flattened These facets are elliptical and slightly greater in width dorsa-ventrally and directed latero-posteriorly. than height. There are moderately developed, separate The shortness of the centrum and the presence of a facets for the chevron on a relatively shallow ventro­ strong rib identify it as an anterior caudal element. posterior projection of the centrum. Pleurocoels, ventral ridges and grooves are absent. There is no true caudal Nos IG-l (Fig. 17 , photograph in DALLA VEC­ rib or transverse process, only an antero -posteri orly CHIA, 1997c, fig. 4). The centrum is nearl y complete elongate knob (LK in Fig. 17) at the base of the neural (the left side was weath ered) and there is part of the arch. The latter is placed on the anterior half of the cen­ neural arch without most of the neural spine. The ceo- trum and its base is 48 mm long. The zygapophyses are Dalla Vecchia: Remains of Sauropoda (Reptilia, Saurischia) in the Lower Cretaceous ... 125

    arch. Only the basal part of both pedicels are preserved; the neural canal is narrow (11 mm minimum width). The neural arch is placed decidedly on the anterior half of the centrum. The resemblance with Nos IG-l and its greater elongation and shorter base of neural arch (per­ haps related to a smaller and lower arch) suggest it is mid-caudal but more distal than the vertebra Nos IG-1. Comparisons - all five caudals present a centrum greater in width than in height, a feature also shared with the cervical MPCM-V2 and the dorsal MPCM-V!. This is not the most common state for sauropods even if it is present, for example, in Brachiosaurus brancai (JANENSCH, 19S0) , in the anterior dorsals of Diplodo­ cus cm'neg;; (HATCHER, 1901), sometimes in the dor­ sals of Andesaurus BONAPARTE & CALVO (BONA­ CD PARTE & CORIA, 1993), in the dorsals of Eucamero­ lusjoxi (BLOW, 1995). A ball-and-cup articulation is not present, and the centra are amphicoclous or amphiplatyan. Therefore Titanosauridae sensu SALGADO et al. (1997) are ex­ CD cluded, at least for the anterior elements sufficiently complete, since mid-caudals can be amphiplatyan or even gently amphicoelous in primitive forms of the Titanosauria. This is the case of Malawisaurus JAC­ OBS, WINKLER, DOWNS & GOMANI (amphicoe­ lous; JACOBS et aI., 1993), an undetermined genus from Argentina (SALGADO & CALVO, 1993), "an de­ saurid" titanosaurs (BONAPARTE & CORIA, 1993) and the Late Maastrichtian Magyarosaurus HUENE (pers. obs.). In the two mid-caudals, and in the most complete Fi g. 16 MPCM-V 15, fragmentary anterior caudal vertebra. Views: anterior caudal, the neural arch is displaced toward the A) right lateral, B) dorsal, C) posterior. anterior half of the centrum, a feature which was con­ si dered apomorphic for Titanosaurids (e.g McINTOSH, badly and in completely preserved. The postzygapoph­ 1990a), but is considered a synapomorphy of the wider ysis is far above the base of the neural canal, the articu­ clade Titanosatiriformes by SALGADO et al. (1997). lar region faces laterally and slightly ventrally. The There are no pleurocels, no ventral sulcus (excavation) prezygapophysis is lower on the arch and probably in the two mid~caudals and in the most complete anteri­ antero-dorsall y elongate. Only the basal part of thc or caudal; the ribs of the three anterior elements are not wing-like, and the centra are always short or moderate­ spine is preserved. ly elongated. This excludes the Diplodocidae as diag­ A relatively elongate centrum, lacking a caudal rib nosed by MciNTOSH (1990a, b). but possessing a knob at the base of the arch, together The shape of the centrum of WN-V3 and Nos IG-I, with a we ll developed neural arch, indicate that this is a and the postero-laterally directed ribs of WN-V3, mid-caudal vertebra (approximately posterior to the 15- MPCM-VI4 and MPCM-VIS, are more reminiscent of 16 caudal because of the absence of a rib, scc McIN­ the anterior to mid-tail vertebrae of Brachiosaurus TOSH,1990b). brancai (JANENSCH, 19S0). The anterior caudals of Camarasaurus are similar to the described anterior ver­ WN-V4 (Fig. 18). This vertebra consists of a ncarly tebrae but do not possess a posteriorly directed rib complete centrum. It is amphicoelous with shallow (OSTROM & McINTOSH, 1966; MciNTOSH, I 990a, articular facets, spool-shaped and more elongated than b). Also the position of the neural arch on the centrum, the centrum of Nos IG-I (lcngth = 116 mm, height at its overall morphology, the shape and position of the the extremities:::: 70.5 mm, I/h ratio:::: 1.55). The articu­ postzygapophysis, the orientation of the prezygapoph­ lar facets of the centrum are more or less elliptical, ysis and the shape of the caudal rib correspond to the slightly greater in width than in height. Pleurocoels, anterior and mid-caudals of Brachiosaurus brancai ventral ridges and grooves are absent. The face Is for the (JANENSCH, 19S0; McINTOSH, 1990b). chevron do not project. The only difference that may be The comparison with the caudals of this species found with the vertebra Nos IG-I, if we exclude elon­ (JANENSCH, 19S0, Pis. II-III) and the I/h ratio (0.87) gation, is a shorter (40 mm) basal part of the neural show that the vertebra WN-V3 might be the 6 - 8 cau- 126 Geologia Croatica 51/2

    A

    2cm

    Fig. 17 Nos JG-J, mid-caudal verte­ bra. Views: A) righl lateral, B) anterior, C) posterior. Acronyms: LK = lateral knob at the base of the neural arch.

    dal. The mid-caudals Nos IG-l and WN-V2 are compa­ probably corresponding small postzygapophysial lami­ rable, considering mainly the elongalion of the centra, nae which however, arc badly preserved. On the outer respectively, to the 18-20 and 22-25 caudal (JANEN­ (lateral) sides there is a stronger lamina (lateral spinal SCH, 1950, ibid.). lamina, LSL), antero-Iaterally directed, which tapers MPCM-V 14 differs from the anterior caudal WN­ and ends at the upper broken margin of the spine. V3 because the base of the spine is lower on the arch. Comparisons - it is very different from a brachio­ saurid spi ne. A vaguely similar laminar pattern is pre­ Isolated caudal neural spines sent in the proximal caudals of Apatosaurus (cL OST­ MPCM-V13 (Fig. 19), is the basal segment (95 mm ROM & MciNTOSH, 1966, pI. 35; pers. obs.). tall) of a neural spine probably from a small anterior caudal vertebra. It is rectangular in cross section, 30 MPCM-V9 (Fig. 20). This specimen is the upper mm wide in side view and narrow in front (12 mm) and portion (90 mm) of a neural spine. It is club-shaped, back (15 mm) view. The anterior and posterior sides are "triangular" in antcro-posterior view, rectangular in the wrinkled (rough). There seem to be very short (about ventral cross-section of the broken lower part, with flat, 30 mm), small supraprczygapophysial laminae, which smooth outer (lateral) sides and flat and wrinkled end just above a short prespinai lamina. There were (rough) anterior and posterior sides. The tip is rounded, Dalla Vecchia: Remains of Sauropoda (Reptilia, Saurischia) in the Lower Cretaceous ... 127

    chevron remains. It is Y -shaped, the proximal, articular part is not preserved, the distal shaft is straight and spatulate. Comparisons - haem apophyses are of poor taxo­ nomic value. Only Diplodocidae (Diplodocus) and some sauropods from China (Shunosaurinae) have haem apophyses with a characteristic shape on the mid­ dle segment of th e tail but this is not the case in our specimen which is similar to the mid-tail chevrons of •I both Camarasaurus (OSBORN & MOOK, 1921) and -- I .-..... /" -'..J Brachiosaurus (JANENSCH, 1950). No remains indi­ ". ~-~- ;. . cating the prcsence of thc typical diplodocid mid-caudal A chevrons have been collected up to now in the outcrop.

    APPENDICULAR SKELETON ELEMENTS

    Femur Nos IG-2 (Fig. 22), is the distal, condylar part (not the "proximal quarter" as reported by KOZARIC et aI., 1996, p. 745) of a quite large ri ght femur, 375 mm long and about 300 mm wide in antero-posterior view. The fragme ntary bone is partly very crushed and weathered. Its main recognizable feature is the presence of an 2cm undeform ed condyle with a lumpy surface which indi­ cales a well developed cartilaginous covering. This condyle is asymmetrical in side view (Fig. 22B), with an articular surface more developed posteriorly (cf. OSTROM & McINTOSH, 1966, pis. 71-73), and is slightly splayed outward in front view. The preserved condyle appears to occupy less than half the width of the femur in antero-posterior view and is identifiable as the tibial one (c f. OSTROM & McINTOSH, 1966, pis. 71-73). Latcral to the condyle (Fig. 22A) the bone is vcry crushed in correspondence with the sulcus infer­ condiloideus and the fibular condyle, which is nearly completely eroded. c Comparisons - the bone obviously belonged to a large , and is here attributed to a sauropod, beca­

    Fig. 18 WN-V4, mid-caudal venebra. Views: A) dorsal, B) posterior, use of its size and comparison with the femora illustrat­ C) left lateral. ed by GILMORE (1936), HATCHER ( 190 I), OSBO­ RN & MOOK (1921) and in OSTROM & McINTOSH (1966, pi s. 71-73). It is very similar to the femora of and is formed by the fus ion, represented by a suture, of Camarasaurus grandis figured in OSTROM & McIN­ a scmicylindrical element. The spine was inclined at TOSH ( 1966, pis. 72-73) and Camarasaurus in OSBO­ abou t 15° with respect to the vertical. RN & MOOK (1921, figs. 107-J09), but the preserved Comparisons - it is very similar to the neural spines part has no taxonomic value. of the anterior (2?) and mid-caudals (12-13?) of "Moro­ saurus grandis" (= Camarasaurus grandis) figured in Tibia OSTROM & McINTOSH (1966, pis. 37-38). Also the MPCM-V16 (Fig. 23): this is the proximal part of a anterior caudal vertebra of Aragosaurus ischiatiells left tibia. The specimen is 220 mm long. and is dam­ SANZ, BUSCALIONI, CASANOVAS & SANTAFE aged in the anterior part, therefore the cnemial crest is from the Hauterivian of Spain has a similar neural spine partly missing. The latter structure was proportionally (SANZ et aI., 1987). The tip of the spine is generally rather small (ef. SALGADO et aI. , 1997, fig. II). The rectangular in diplodocids. proximal articular part is spongy in aspect, and there is a moderate caudal projection in thi s region. In the later­ Haemapophyses al side there is a marked groove for the accomodation WN-VS (Fig. 21). The specimen (175 mm long) is of the proximal part of the fibula; there is also a small the only nearly complete element among the discovered and shallow depression on the medial side. The proxi- 128 Geologia Croalica 51/2

    0

    SPRZ

    LSL LSL

    LSL ® D

    SPZL Fig. 19 MPCM-VI 3, fragmentary neur- al spine. Views: A) le rt lateral, B) 2cm anterior, C) pos- terior, D) dorsal. Acronyms: L$L= lateral spinal lam- A B C ina, a = anterior, p = posterior,

    mal tibia is flallened medioanteriorly-posterolaterally of libia of the Latc Jurassic "GigantoSGllrUS megalo­ and expanded proximally, and narrows sensibly below nyx" (see GLUT, 1997, p, 439). the cnemial crest (the anterolateral-medioposterior width at the base of the cnem ial crest is only 75 mm). 4, DISCUSSION AND CONCLUSIONS This suggests that the tibia under examination had a shaft more slender than those of most sauropods (ef, Sauropod systematics are chaotic and in a state of McINTOSH, 1990, fi gs. 16-17, and SALGADO et aI., flux, as the very different classifications of JANEN­ 1997, fig. II). SCH (1929), MciNTOSH (1990a, b), BONAPARTE Comparisons - Diplodocids (Diplodocus carnegii (1986), UPCHURCH (1994,1997) and SALGADO et and Barosaums lenlus in McINTOSH, 1990, figs. 16- al. (1997) demonstrate. In most classifications the 17) have the most slender tibiae among sauropods, sauropod families are based mainly on just one more or probably because of the relative elongation of the hind less well known genus and the other members are tenta­ limbs. The specimen is very similar to the proximal end tively included, "weighting" the characters shared with

    Fig. 20 MPCM-V9, fragmentary neural spine. Views: A) anteri­ A B c or, B) posterior, C) right late­ ral . Dalla Vecchia: Remains of Sauropoda (Repti lia. Saurischia) in the Lower Cretaceous ... 129

    Fig.21 WN-V5. hacmapophys is. Vicws: A) anterior, B) left lateral. th ose well known forms, In thi s way Haplocalll!to­ sallrus, which is one of the best known sauropods, but lacks the skull and has "mixed" charac ters, is included in the Cetiosauridae by McINTOSH (1990b), in the Di­ craeosauridac by BONAPARTE (1986), in the Cam a­ rasaurid ae by UPCHURCH (1994) and finally consid­ ered, in a cladistic analysis, the sister-taxon of the Neo­ sauropoda (Brachi osauria + Diplodocoidea) by UPCH­ URCH (1997). Earl y Cretaceous sauropods appear to be wide­ spread and diversified but th ey are not well known since most species and genera are based on scarce or undi agnosti c remai ns. This was underlined by McIN­ TOSH (1992) who stated that most sauropod genera "mi ght be termed nomina dubia", "as they can be dis­ tinguished from the 12 well known genera but not from each other because they are based on frag ment ary post­ cranial skeletons or teeth" (HUNT et aI., 1994, p. 263). Therefore comparisons with th e Istri an remain s are in many cases prac ti cally impossible . This is clearly Fig. 22 Nos IG-2, distal end of a right femur in A) posterior view. B) ev id ent from th e ta xonomi c li st of Hauterivian - Bar­ medial view (tibial condyle), Acronyms: TC=tibial condy le. rem ian sauropods after McINTOSH (1990b; thi s li st of course follows McIn tosh's Li nn ean classification), completed here fo ll owin g JACOBS et al. (1993), HUNT et al. ( 1994), BLOWS ( 1995), and BONAPA­ Celiosollrlls conybeori MELVILLE (wrongly cited as RTE (1996). Most taxa are based on in complete, frag­ C. oxoniensis by HUNT et aI., 1994) (England, mentary remains. Valanginian - Barremian, vertebrae). Cetiosauridae (mentioned by HUNT et aI. , 1994, Cetiosaurus brevis OWEN (Eng land , Valang in ian­ but not in McINTOSH, 1990b). Probably none of these Barremi an) in LYDEKKER (1888) are reported ver­ taxa are actua lly "ceti osaurid s". tebrae, chevrons, metatarsals, phalanges and frag- 130 Geologia Croat ica 5112

    Titanosauridae Unnamed titanosaurid (="Titanosaurus" valdensis) (England, Valanginian- Barremian, several caudal vertebrae).

    Ma/aw;so ll!'IIS dixey; JACOBS, WINKLER, DOWNS & GOMANI (Malawi, Earl y Cretaceous, premaxil­ la, dentary teeth, cervical, dorsal and caud al vert e­ brae , sternal plates, ischium). This taxon could be more recent than the others reported in this list (JACOBS et aI. , 1993). MacrurosClurus semnus SEELEY (England, Valangin­ ian, isolated caudal vertebrae).

    Diplodocidac

    Amargasall!'lIs cazall; SA LGADO & BONAPARTE o ~:\~/!(t(~ ® (Argentina, Neocomian, a nearly complete skele­ Lon). C Incertae sedis Fi g.23 MPCM-V16. proximal pari of a left tibia. A) posterolateral view, B) anteromedial view. C) dislai cross-section. Acronyms: Mong%sall!'!ls /wp/odoll GILMORE (Mongolia, Berri­ CC =cnemial crest, a = anterior. p = posterior. asian - Albian, teeth , basioccipital , 3 cervical verte­ brae). Unn amed sauropod (England, Hauterivian - Barremi an, fo re limb, epidermal im pressions). ments of long bones from the Wealden and attrib­ utcd to this taxon; no other author mentions them. Following the list of HUNT et al. (1994) from thi s strat igraphi c interval there are indeterminate or unde­ Celiosourus sp. (S pain, Valangi nian - Barremian). scribed " brachiosaurids" also in Spain and Ihe USA, Brachiosauridae diplodocids in England and Argentina and indetenni­ nate sauropods in China, South Korea, Mongolia, Ja­ Or nifltopsis lIu/kei (England , Barremian, dorsal verte­ pan, Niger, Franee and England. bra, following BLOWS, 1995). It can be observed that the record comes mainly EucamerOlus taxi (England, Barremian, dorsal verte­ from the Wealden of England and th ere is little infor­ brae, foll owing BLOWS, 1995). mation about Gonci wani an sauropods and none UUS I undescribed bones from Niger) about northern African Pe/o!'osoll!'lIs cOllybea!'e; MANTELL (England, Valan­ wh ich are better known in the Albian- Cenomanian gi nian, following BLOWS, 1995, only a humerus is interval. considered to belong to thi s species). O f the abundant but scatt ered English remains a Pleurocoelus flal111S MARSH (USA, Hauterivian - Bar­ plethora of new taxa were created during th e 19th cen­ remian, isolated remain s of morc than 6 individuals, tu ry, and this led to inextricable confusion. Following including sku ll elements). BLOWS (1995) and P. UPCHURCH (pers. eomm.) the Wealden sauropod fa una is dominated by brachio­ P. a/tlls MARSH (USA, Hauterivian - Barremian, tibia and fibul a). saurids whereas camarasaurids are absent. T itanosauria and d ipJ odocids are scarcely represent ed, as seen above. P. va/dellsis L YDEKKER (England, Valanginian - Bar­ Unfortunately a sati sfying recent revision of the English remian, teeth, dorsal and caudal centra). matcrial has not been published yct and comparison Cr. Pleurocoelus sp. (Spain , Barremian). wi th Wealden sauropods is sti ll at best very difficult. The presencc of "Chondrosfeosaunls gigas" both in Camarasauridae Istria and Southern England could have palaeogeo­ graphic significance but the diplodocimorph similar to AraRosaurus ischiariclis (Spain , Earl y Barremian, cau­ Rebbachisaurus is more important under this point of dal vertebrae, scapul a, fore limb, ischium, pubis). view. This aspect should be investigated fU!1h er. Chondrosteosaurus gigas (England, Barremian, cervi­ cal vertebrae; nomen dubium following P. UPCHU­ The study of the described material suggests the fol­ RCH'S pers. comm .). lowing poin ts: Dalla Vecchia: Remains of Sauropoda (Reptilia, Saurischia) in The Lower Cretaceolls ... 131

    I) On the basis of size, at least two "forms" are pre­ 8) The anterior dorsal MPCM-V I is peculiar in being sent: a large form (fragments of cervical vertebrae, very small, with the relatively tallest neural arch ?cervical ribs, bony laminae MPCM-V4, part of the ever described in a sauropod, cancellate texture of neural arch of a dorsal vert ebra MPCM-V3, distal the centrum and with a very developed laminar part of the femur Nos IG-2) and a small one (cervi­ complex with peculiar structures. However, it can­ cal vertebra WN-Vl, fragmentary cervical vertebra not be stated with certainty that it does not belong to MPCM-V5, posterior cervical centrum MPCM-V2, the same taxon as MPCM-V2, and therefore possi­ anterior dorsal vertebra MPCM-VI, all the caudals bly to "Chondrosfeosaurus gigas". This suggests to and thc fragmentary neural spines, the proximal tib­ avoid the creation of a new taxon, pending the exca­ ia MPCM-V 16). There is too great a difference in vation of further materia1. size among some remains, and no evidence of 9) Thc developed prespi nallamina of MPCM-V3 sug­ immaturit y of small specimens (in all small verte­ gests that it belongs to the Titanosauriformes senS ll brae the neural arch is fused to the corrcsponding SALGADO et al. (1997) and most specifically to centrum), to support the idea thal all the specimens th e advanced Titanosauria, or to the Diplodocidae. belong to the same species. Even if we consider the Other features exclude the T itanosauria. Islrian sauropods as insular inhabitants with the typ­ ical intraspecific size variability of Pleistocenc in su­ 10) The anterior and mid-caudals resemble mostly the lar mammals (KOTSAKIS, 1985) the size differ­ Titanosauriformes sensu SALGADO et al. (1997) ence is sti ll too great. and Brachiosaurus brancai in particular, but they are not diplodocid or titanosaurid. 2) A new Diplodoeimorph similar to Rebbachisaurlfs but more primiti ve because it still retains a 11) Surprisingly, the fragmentary caudal neural spine hyposphene-hypanthrum, is represented by a poste­ MPCM-V9 is very similar to those of Camara­ rior dorsal vertebra. saurus and Aragosallrus. Since the other fragmen­ tary caudal neural spine MPCM-V 13, which has a 3) The posteri or cervical vertebra MPC-V2 is very relatively well developed system of lam in ae, repre­ similar to those of the coeval "Chondrosfeosaurus sents a different part of th e spine, these two speci­ gigas" of England, and in the shape an d pleurocoels mens could belong to the same taxon. Both broken but not the bone texture, to Camarasaurus of North spines are very different from the typically [ow Ameri can Late Jurassic. It is very different from the spines of Brachiosaurus brancai. cervical WN-V I and probably belongs to a different taxon. The latter cervical is most reminescent of the anterior ccrvicals of Brachiosaurus brancai. HUNT et al. (1994) suggested that "iso[ated, but di stin ct, postcrania may bc considcred valid type speci­ 4) Since long cervical ribs arc not known in diplo­ mens and disassociated specimens from the same bed docids (considering Mamenchisaurus does not be­ should be grouped as much as possible. These usuall y long to them, UPCHURCH, 1997) the fragments of questionable taxonomic procedures are only tolerated in rib shaft here reported, if correctly identified, sauropods bccause thesc immcnsc are so often belong most probably to a brachiosaurid or a cama­ represented by such fragmentary or jumbled speci­ rasaurid (the state in Titanosauria sensu SALGADO mens." (p. 266). The adoption here of this procedure is et aI., [997 is not known). prevented by the presence of individuals with very dif­ 5) All preserved cervical and dorsal vcrtcbral parts ferent sizes and bones with features suggesting that (excepted WN-V6) are extremely li ghtened having they belong to different families (sensu MciNTOSH, A) centra with a "honeycomb"-like, cancellate stru­ 1990b) (for example, all the caudals seem to be refer­ cturc, a feature considered by most specialists typi­ able to brachiosaurids while th e isolated caudal neural cal of the Brachiosauridae (scnsu MclNTOSH, spines are not brachiosaurid spines, cervicals seem to 1990b) or the most inclusive Titanosaurifonnes belong to different fami lies, etc.). (sensu SALGADO et aI., 1997), and B) neural arch­ However, most of the bones seem to come fro m es made by a complex network of thin laminae. non-Titanosauria Titanosaurifonnes (sensu SALGADO 6) The posterior cervical MPCM-V2, the anterior dor­ et aI., 1997) sauropods. sal MPCM-V [ and all the caudals present elliptical, Therefore both Titanosauriformes, Diplodocimor­ ki dney-shaped or, at least, wider than hi gh articular pha and, possibly, Camarasauridae are present in the faccts of the centra. site. 7) The arti cul ar facets of the anterior dorsal MPCM­ V I and the posterior ccrvical MPCM-V2 have a Acknowledgements great difference in size which suggests that they belongs to individuals of rather different size. I thank the Gruppo Spe[eo[ogico Monfa[conese Whether this is due to ontogeny, sexual dimorphism A.D.F. for its collaboration and the collecting of th e or because they belong to different taxa, is indeter­ specimens, Dr. Giorgio TUNIS of the Dipartimento di minated from the few remains coll ected. Scicnze Geologiche e Ambientali, University of Trieste 132 Geologia Croalica 51n and Dr. Sandro VENTURINI (Ravenna) for their coop­ Albian -Cenomanian of Argentina. New evidence on eration. I th ank Dr. John McINTOSH, Dr. Paul UP­ the origin of the Diplodocidae.- Gaia, II , 13-33. CHURCH and , above all , Dr. Brian CURTICE for thc CORIA , R.A. (1994): On a monospecific assemblage of di scuss ion, adv ice and critical review of thi s paper. r sauropod dinosaurs from Patagonia: implicati ons for am in debted to the discoverer of the fossiliferou s site. gregariou s behaviour.- In: LOCKLEY, M.G., DOS Mr. Dario BOSCAROLLI, for the precious informa­ SANTOS, V.F. , MEYER, C.A. & HUNT, A. (eds.): ti on. I thank Dr. Alexander KELLNER and Dr. Mary Aspects of sauropod pal eobiology. Gaia, 10, 209- DAWSON for their support respectively at the Ameri ­ 2 13. can Mu seum of Nat ural Hi story of New York City and th e Ca rn egie Museum of Pittsburgh. Without th e help CURTICE, B.D., STADTMAN, K.L. & CURTICE, of Igor VLAHOVIC, Institute of Geology, Zagreb, thi s L.J. (1996): A reassessment of Ultrasauros macill ­ paper could not have been publishcd and I th ank him toshi (JENSEN, 1985).- In: MORALES, M. (cd.): very mu ch. 1 thank also all th e Croatian In stitutions The continental Jurassic. Mu seum of Northern Ari­ which helped me in my study of the material. This work zo na Bull., 60, 87-95. was sponsored by a M.U.R.S.T. grant (40% Gi orgio CURTICE, B.D. & WILHITE, D. R. 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    Manuscript received June 29, 1998. Revised manuscript accepted November 23, 1998.