Sauropods from Mongolia and the former Soviet Union TI:KC< \ \[\I<\ \U<k\ Introduction Subsequently, many Cretaceous localities on the terri- tory of Kazakhstan, Uzbekistan, Kirgizstan, Sauropods, a spectacular group of gigantic sauris- 'I'adzhikistan (cf Rozhdcstvenskii and Khozatskii, chians, are knoan from the F:arl>lJurassic to the end of 1067; liozhdestvenskii, 1070, 1977) and Russia the Cretaceous from all continents, except Antarctica. (Dmitriev and Rozhdestvenskii, 1968) have yielded :\n enormous numl~erof genera (ahout 00) and species sauropod remains, but most of them are represented (over 1-50) of sauropods have been named and l)!~ isolated bones. .ln exception is an undescribed, described, hut most of them are tmed on imperfect, fragmentarily prcser\.ed postcranial skeleton of a fragmentary material. Complete skulls and skclctons Jurassic sauropocl found I)y Russian palaeontologists are rare, and this makes comparisons hetween difercnt in 1066 near .l'ashkumyr town in Kirgizstan sauropod species dithcult or impossi0le. For the same (Rozhdestvenskii, 0)and housed in the reason, the number of sauropod fi~miliesvaries over I'aleontological Institute in hloscow. The most con- time. plete anci comprehensive information on dir~osnur In contrast to the long history of discovery and remains from the territory ofthe former Soviet Union, study of sauropods in Europe and North .\merica Lvith a list of localities, and some data on lithology and which started in the nineteenth century, the first docu- the age of local svitas, was recently published by mented, undoubted sauropod material from Mongolia Nesov (1995). ..\ccortiing to him, isolateti bones of as fi~undin 1922 by inernhers of the Central Asiatic Jurassic sauropods were discovered in five localities in Expedition, organized hy the :\merican hluseum of Kirgizstan and one in Uzl)ekistan, bones of Early Natural History in New IJork. 'lhe first Mongolian Cretaceous sauropods \\.ere recognized in four local- sauropod genus and species, ,.lsi~s.ruuru.rmot~;,llinr.ri.r, ities in Russia anci Late Cretaceous sauropod remains was described by Oshorn (1924). 1;rorn that time, sau- are knoan tiom six localities on the territory of ropod remains, primarily represented I)y isolated Uzbekistan, six in Kazakilstan, three in Kirgizstan, t\vo bones, have been discovered in many sites on the terri- in 'I'adzhikistan and one in Russia. In general, sauro- tory of Mongolia (cf Kalandadze and Kurzanov, 1074; pods from Mongolia and the territory of the former Gradzinski et dl., 1077; heishampel, 1900). The most Soviet Union are relatively poorly known, most of important sauropod material fro111hlongolia was dis- them are represented by incomplete and nondiagnos- covered by the Polish-hlongolian Paleontological tic hones, and there arc no mass accumulations. Expedition in I965 and by the Soviet-Mongolian Among the five Cretaceous forms listed belo\\, only Expedition in 1971 (see below). The first information three monospecific genera are represented by rela- on sauropod bones from the territory of the former tively well preserved and diagnostic material. They Soviet Union was published by .l.N. Kyahinin in the are: Opisthocoelicuu~liu Rorsuk-Bialynicka, 1077; 1930s, and the first sauropod species from Kazakhstan, ,Ycnrcgo.murus Nowinski, 197 1 , and Qlr/li.sitosnurrr.r Antnrcto.r~~urus,ju.u/luticus, was named by him in 1 9 38. Rannikov and Kurzanov, 1083. Sauropods from hlongolia tcr the fi~rn~erSoviet Union Figure 23.1. Rcconsc~.uccionof clic skclecon of O~~il-tl,o~uclici~~~di~~~-k/~~-~y~~~kii.Redrann from Borsuk-Biaiynich (1077). Scale bar - l 111. Institutional ahbre\~iationsare as h,llo\vs: :\htNH, (Campanian-hlaastrichtian) Nemept Fornlation of :\merican h'tuseum of Natural tlistory, New York; the locality of ;\Itan Uul I\.: (Gradxiriski et al., 1069; PIN, Paleontological Institute, Russian .Icadernj, of Gradzi~iski,1Y70), in the Ncmept Basin, Gohi Desert, Sciences, htoscow; %P.iI., Institute of Paleobiology, h'longolia. 'fhe holotype is presently housed in the Polish :\cademy of Sciences, n'arsaw. Institute of Geology, hlonpolian ;\cade~ny of Sciences, Ulaanhaatar. Rc;/i,n*l~vltt~/~rc~i~d. TO 0. ~.kal~?..~/r.skii is also assigned a Systematic survey scapl~locoracoidof a young individual (ZI';\L MgD- 'The phylogenetic relationships of sauropods are not 1/2.5c). yet stabilized or generally accepted. 1:or this reason, in De.rcl<iptiog. 'The most outstanding anatomical features this chapter, the conscr\.ativc and hasicallv [r-ln~iliar of this sauropod are the relatively long vertebral taxonomy of' sauropods proposed by hlcl~~tosh centra of the dorsal and caudal vertehrae, the opistho- (OO is utilized, and the assignment of coelous caudal vertehrae and short tail. 'The dorsal OpirtL~ocnelic./~uJiuto the fi~~n~ilyCamarasauridae, and vertel~raeare characterized by distinctly opisthocoe- L\'c~trrt~/o.r/~u~~~.rand Q~/~c~sito~/~~t~~~s to the diplodocid lous centra, comparatively low neural arches, and subf;~~nilyI)icraeosaurinae, as proposed t~yMclntosh heavy transverse processes that are directed outwards. (lOOOh), arc also accepted. -l'he neural spines do not form single elements, hut along the dorsal region of the ~ertehralcolumn they Sal~ropodomorphafiuene, 1032 arc divided into two stout elements, separated hy a ti- Sauropoda hlarsh, 1887 shaped cleft. The centra of the sacrals are coossified liamily Camarasauridae (:ope, 1887 and bear low neural spines. 'l'he transverse process of Subfanlily Opisthocoelicaudiir~;~~hlclntosh, 1000b. the last sacral (caudosacral) ~ertehrais fused \vith the Genus Opi.rtL~ncor~licn~~~li~~13orsnk-Kiatynicka, 19 77 ilium and ischiurn. The cent]-a of the perfectl!. pre- r.I.j,p(, /llrd 0111)~ktrnm~? .rpccic~. O~~i~rL~ocor~lic~~~rJil~skal~.j~irs- served caudals are strongly opisthocoelol~sin the kii Rorsl~k-Biatyuicka,1077 cranial half of the tail and none of the caudal centra Ilolo~~pf:/,P:\ I. hlgl)-T,l-l.H, an almost complete post- have pleurocoels. Caudals 16 to 27 are a~~~phiplat!lan, cranial skeleton (lacking skull and cervicals) discov- and the more distal ones arc biconvex. The cattdal ered in I065 hy the Polish-hlongolian Paleontological ceutra fiom 20 to 27 were probably coossified. The Expedition to the (;obi Ilesert (Figure 23.1). 'The caudal neural arches are I-obust.'l'he uniramous chev- specimen \vas found in the Upper Cretaceous rons are not present beyond caudal 10. 'l'he pectoral girdle is massive and the forelimbs are also relatively glenoid axis and the long axis of the scapular hlatle. stout and massive. kletacarl,als I and I1 arc almost of ?I > he opisthocoelous caudal vertel~raeand i.ery short the same length and are longer- than metacarpal Ill. tail distinguish this gcnns horn all other memhers of The pelvis is characterized hy a strong lateral flexure the Camarasauridae ant1 the structure of the limbs of of the anterior wings ofthe iliac hlade and hy a large Opi.rthocoelic/~u//i~~suggest a possil)le association ~ith contribution of the ischiurn to the acetabnlun~.The the Titanosauridae. 'fhe assignment of 0pi.rthococli- hind li~nhsare robi~st.'l'he fourth trochanter on the cau//i~~to the Camarasauridae lvaa accepted by femur is siti~atedhcloiv the middle length of the shaft. McIntosh (1 YOOa, h), hladse11 ct ill. (1')05), and Hunt et 'I'he stout, reduced pedal phalanges arc present onl17 al. (1991). '1'11~ presence of opisthococlons caudal in four digits ant1 the phalangeal formula is 2:2:2:1:0. vertehrae was the Imis for the proposal I)!, hlclntosh Such reduction of the pedal phalanges is not ol)served (1990b), of a new camarasaurid sul~l'amily - in other sauropods. 'l'hc total height of the forelimb of Opisthocoelicaudiinae fix this h'longolian genus. 0. .rk/~v?yj~.skiiis 1.87 m. The height of the hind limb is Subsequently, horvever, Upchurch (1094) removed 2.46 m, and the hu111erus:femurratio = 0.72. this genus from the Camarasauridae and placed it as Comn?c.jrt.c. 'l'he main anatoniical teatures of the sister taxon to the family l'itanosauridae within Opi.rt/~ocoeli~~~~t~~/inare shown in the reconstrr~ction the 'l'itanosauroidea'. (1:igure 23.1). 'l'he neck of' this sauropod was probal~ly rather short, as is documented by a reconstruction of Family Iliplotlocidae hlarsh, 1881 the nnchal ligament presented by Borsuk-Biaiynicka SubLilmil~,DicraeosaurinaeJanensch, 1014 (1077). 'The tail was held in a horizontal position Genus .~c~t)2egto.r~zt~~~t~,s~ow~i1jski,1971 during terrestrial locomotion, as is evidencetl by the '1,jpc am/ ojrly kknowr .sprzzcs. .2i~iilcgtow1~1-tl.ci~o~/pli~~/.r~.r structure of the caudals: there are no wedge-shaped or Nowi~iski,1971 dolvnwardly flexed centra in the tail vertebrae, and the Holo[ypc. %I';\L MgI)-119, an al~nostcomplete sLr~ll haemapophyses are firmly fused with the centra in associated with tlie lower jaw, discovered in 1065 1))' caudals 6-1 7. 'l'he presence of opisthocoelous centra the Polish-hlongolia~> Paleontological Lxpedition in in the cranial half of the tail and some characters of the Upper (:retaceous (Ca~npanian-hlaastrichtian) the pelvis, such as the strongly deepened iliac section Nemegt Formation at the Nemegt locality, (;obi of the acetabulum, the outward bend of the ilia, and Desert, Mongolia (Figure 23.2). the fused pubic symphysis suggest, according to Kefivved matcvinl. .I second, u~ldescrihedskull, proh- Borsuk-Biaiynicka (1077), that the tail in al~lyof the sanie genus, is housed in the (;eological Opirthc~coelic~~t~di~~could have served as a prop during Institute of the Mongolian .Icademy of Sciences, occasional I~ipedalposture. If this posture was really Ulaanhaatar, possible for Opi~thococ~lic/~udin,it may have bee11 con- D~.rct-i/)tion. In its general characters the skull of .I: nected with some important part of its life activity, nto~qlic~zsi~exhibits a diplodocid type of structure, most probably with feeding.