Asiatyrannus xui, new tyrannosaurid from Late Cretaceous of southeastern China

[VD231991]

A new Asian tyrannosaurid-related paper:

Zheng, W., Jin, X., Xie, J., and Du, T., 2024. The first deep-snouted tyrannosaur from Upper Cretaceous Ganzhou City of southeastern China. Scientific Reports 14 16276. doi:10.1038/s41598-024-66278-5.

Although its holotype specimen is not mature, the deep snout of Asiatyrannus xui demonstrates that deep-snouted tyrannosaurines co-existed with the long-snouted alioramin tyrannosaurine Qianzhousaurus in southeastern China. Newly discovered tyrannosaurid material from the Prince Creek Formation reported by Druckenmiller et al. (2021) indicates that the derived tyrannosaurine Nanuqsaurus is much larger than previously suggested, even though the estimated skull length of the Asiatyrannus xui is shorter than that for Nanuqsaurus. The recovery of Nanotyrannus lancensis in polytomy with Alioramini and other tyrannosaurines by Zheng et al. is not surprising because even though CMNH 7541 and Jane are immature, Currie (2003) took issue with differences in maxillary tooth count between CMNH 7541 and adult Tyrannosaurus rex being the result of ontogeny despite agreeing with Tom Carr that CMNH 7541 is a juvenile (the juvenile T. rex specimen KUVP 156375 is still waiting publication despite having a maxillary tooth count different from that of CMNH 7541 and Jane). I respectfully disagreed with the opinion of Longrich and Saitta (2024) about CMNH 7541 and Jane being small-bodied adults, and it'd be interesting to see whether the holotype of Nanotyrannus lancensis and Jane could constitute an alioramin or a taxon of Tyrannosaurini which convergently evolved a long snout with alioramins irrespective of the immature status of CMNH 7541 and Jane.

Currie, P.J., 2003. Cranial anatomy of tyrannosaurid dinosaurs from the Late Cretaceous of Alberta, Canada. Acta Palaeontologica Polonica 48 (2): 191–226.

Druckenmiller, P. S., Erickson, G. M., Brinkman, D., Brown, C. M., and Eberle, J. J., 2021. Nesting at extreme polar latitudes by non-avian dinosaurs. Current Biology 31: 3469–3478. https://doi.org/10.1016/j.cub.2021.05.041.

Longrich, N.R., and Saitta, E.T., 2024. Taxonomic Status of Nanotyrannus lancensis (Dinosauria: Tyrannosauroidea)—A Distinct Taxon of Small-Bodied Tyrannosaur. Fossil Studies 2 (1): 1–65. doi:10.3390/fossils2010001

[Sim]

I'm surprised to see basically all of its skull is preserved.  Also that it's a relatively small species, deduced by how tyrannosauroids of a similar age to this specimen were much larger.  And it appears its contemporary Qianzhousaurus was larger.  Also, despite its young age, it already had a deep snout, that's surprising to me too!

[Faelrin]

Wonder if PNSO will roll out a figure of this one? Nice find though.

[Sim]

Wonder if PNSO will roll out a figure of this one? Nice find though.

I thought so too, until I realised how small it is and how PNSO seems to want to avoid making small animals.

[Faelrin]

@Sim Oh good point about that.

[DefinitelyNOTDilo]

I decided to speedrun some art of the boi lol. Definitely much too small for a pnso figure.

[Sim]

Wow, you're very good at drawing, and quick too.

[DefinitelyNOTDilo]

Thank you very much!