Re: [dinosaur] Dzharatitanis, new rebbachisaurid sauropod from Upper Cretaceous of Uzbekistan (free pdf).

I don't find the case for this taxon being a rebbachisaurid all that convincing. Dzharatitanis is based on a specimen previously described as a titanosaur by Sues et al. (2015) and Averianov and Sues (2017). In the previous descriptions, the authors noted several similarities to the approximately contemporaneous Chinese titanosaurs Baotianmansaurus and Dongyangosaurus. The lack of any mention of either genus in this paper is perplexing and raises the question of whether Dzharatitanis is actually more similar to rebbachisaurids than to those genera. My impression is that it is not; the "intricate lamination and extensive pneumatization of the neural arch" said here to be inconsistent with a position in Titanosauria looks very similar to the condition in Dongyangosaurus. Aside from a phylogenetic analysis that does not include any of the titanosaurs Dzharatitanis has been previously said to be similar to, this paper doesn't seem to contain much of an argument against the inclusion of Dzharatitanis in Titanosauria, only comparisons to rebbachisaurids. Thankfully, the specimen is well-described, which should facilitate comparisons to both titanosaurs and rebbachisauridsâsadly, the same cannot be said of Dongyangosaurus as of yet.

I have to wonder if the authors came up with the name before conducting their phylogenetic analysis, as the name Dzharatitanis certainly seems more in line with their previous view that it was a titanosaur. Coincidentally, this is the second time the rarely-used form "-titanis" has been associated with a titanosaur later reidentified as a diplodocoid, after Amargatitanis.

On Wed, Feb 24, 2021 at 1:12 PM Ben Creisler <bcreisler@gmail.com> wrote:

Ben Creisler
bcreisler@gmail.com

A new paper with free pdf:

Free pdf:

Dzharatitanis kingi gen. et sp. nov.
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Alexander Averianov & Hans-Dieter Sues (2021)
First rebbachisaurid sauropod dinosaur from Asia.
PLoS ONE 16(2): e0246620
doi: https://doi.org/10.1371/journal.pone.0246620
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0246620

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, âwing-likeâ 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.

News:

https://www.eurekalert.org/pub_releases/2021-02/p-ndd021721.php

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