First rebbachisaurid sauropod dinosaur from Asia

Abstract

Dzharatitanis kingi gen. et sp. nov. is based on an isolated anterior caudal vertebra (USNM 538127) from the Upper Cretaceous (Turonian) Bissekty Formation at Dzharakuduk, Uzbekistan. Phylogenetic analysis places the new taxon within the diplodocoid clade Rebbachisauridae. This is the first rebbachisaurid reported from Asia and one of the youngest rebbachisaurids in the known fossil record. The caudal is characterized by a slightly opisthocoelous centrum, ‘wing-like’ transverse processes with large but shallow PRCDF and POCDF, and the absence of a hyposphenal ridge and of TPRL and TPOL. The neural spine has high SPRL, SPDL, SPOL, and POSL and is pneumatized. The apex of neural spine is transversely expanded and bears triangular lateral processes. The new taxon shares with Demandasaurus and the Wessex rebbachisaurid a high SPDL on the lateral side of the neural spine, separated from SPRL and SPOL. This possibly suggests derivation of Dzharatitanis from European rebbachisaurids. This is the second sauropod group identified in the assemblage of non-avian dinosaurs from the Bissekty Formation, in addition to a previously identified indeterminate titanosaurian.

Sauropod dinosaur teeth from the lower Upper Cretaceous Winton Formation of Queensland, Australia and the global record of early titanosauriforms

“…Many narrow-crowned teeth (SI often greater than 5.0) attributed to titanosaurs have been recovered in Uzbekistan from uppermost Albian/lower Cenomanian deposits, as well as the middle–upper Turonian Bissekty Formation [93,418,419]. A caudal vertebra from the Bissekty Formation, originally described as titanosaurian [419], was reinterpreted as rebbachisaurid and named Dzharatitanis [420], but even more recently transferred back to Titanosauria by Lerzo et al . [421].…”

“…Many narrow-crowned teeth (SI often greater than 5.0) attributed to titanosaurs have been recovered in Uzbekistan from uppermost Albian/lower Cenomanian deposits, as well as the middle-upper Turonian Bissekty Formation [93,418,419]. A caudal vertebra from the Bissekty Formation, originally described as titanosaurian [419], was reinterpreted as rebbachisaurid and named Dzharatitanis [420], but even more recently transferred back to Titanosauria by Lerzo et al [421]. However, the latter authors made no comparisons with contemporaneous Asian sauropods, such as Dongyangosaurus (see [131,422]), the caudal vertebrae of which show a striking similarity to that of Dzharatitanis, as originally noted by Sues et al [419].…”

A new carcharodontosaurian theropod dinosaur occupies apex predator niche in the early Late Cretaceous of Uzbekistan

“…Within the rich and diverse dinosaur fauna of the Bissekty Formation (e.g. [12][13][14][15][16][17][18][19]), our discovery of this predatory theropod Ulughbegsaurus, at 7.5-8.0 m in length and greater than 1000 kg in mass, probably occupied the role of apex predator in this Turonian ecosystem. Although the remains of several predatory theropods are described from the formation (Itemirus medullaris, Paronychodon asiaticus, Richardoestesia asiatica, Timurlengia euotica and Urbacodon sp.…”

“…This well-studied formation has yielded a rich and diverse ecosystem with numerous dinosaurs (including Hadrosauroidea, Ceratopsia, Sauropodomorpha, Ornithomimidae, Dromaeosauridae and Tyrannosauroidea) and other vertebrates (e.g. [12][13][14][15][16][17][18][19]). Our discovery adds to few known Late Cretaceous carcharodontosaurian species from Asiamerica and reveals a previously unknown apex predator among mid-sized predatory tyrannosauroids and dromaeosaurids in the Turonian Bissekty ecosystem.…”

A possible brachiosaurid (Dinosauria, Sauropoda) from the mid-Cretaceous of northeastern China

“…Isolated teeth from the Barremian of Spain bearing a distolingual boss—a feature that is otherwise known only in some East Asian sauropods, including the Berriasian–Hauterivian Euhelopus ( Wiman, 1929 ; Wilson, 2002 ; Barrett & Wang, 2007 ; Suteethorn et al, 2013 ; Moore et al, 2020 )—would seem to suggest that a subclade of euhelopodids spread across both Asia and Europe in the Early Cretaceous ( Canudo et al, 2002 ). Recently, the discovery of an isolated anterior caudal vertebra of a rebbachisaurid in the Turonian Bissekty Formation of Uzbekistan, as well as possible rebbachisaurid teeth from the same formation, have been interpreted as evidence for dispersal of European rebbachisaurids into Central Asia sometime between the Barremian and Turonian ( Averianov & Sues, 2021 ). It should be noted, however, that the morphological basis for identifying the Bissekty Formation anterior caudal vertebra as a rebbachisaurid has been critically challenged by a reappraisal of the specimen by Lerzo, Carballido & Gallina (2021) , who rejected rebbachisaurid affinities and provided evidence in support of a titanosaurian identity, a hypothesis also previously favored by Sues et al (2015) and Averianov & Sues (2017) .…”