Tyrannomimus Explained

Tyrannomimus (meaning "tyrant mimic") is an extinct genus of ornithomimosaurian theropod dinosaurs from the Kitadani Formation of Japan. The type species is Tyrannomimus fukuiensis.[1]

Discovery and naming

Tyrannomimus is based on the holotype FPDM-V-11311, a partial postrcranial skeleton. Multiple referred specimens are also known.

They were named as a new genus and species of ornithomimosaur in 2023. The generic name, "Tyrannomimus", is a reference to its morphological similarities with tyrannosauroids, particularly the vertical ridge of the ilium previously believed to be a synapomorphy of that clade and shared with Aviatyrannis. The specific name, "fukuiensis", refers to Fukui Prefecture where the fossils were found.

Classification

Tyrannomimus was entered in a phylogenetic analysis by Hattori et al. (2023) and placed within the family Deinocheiridae, as the sister taxon to Harpymimus. Their cladogram is shown below:

Although it wasn't included in the dataset, Hattori et al. also consider Aviatyrannis to be a basal ornithomimosaur due to its similarities with Tyrannomimus.

Paleoenvironment

Tyrannomimus lived alongside a diverse assemblage of animals, most of which are named after Fukui Prefecture. These include the sauropod Fukuititan, the ornithopods Fukuisaurus and Koshisaurus, and the theropods Fukuiraptor, Fukuivenator, and Fukuipteryx.[2] [3] [4]

Notes and References

  1. Hattori . S. . Shibata . M. . Kawabe . S. . Imai . T. . Nishi . H. . Azuma . Y. . New theropod dinosaur from the Lower Cretaceous of Japan provides critical implications for the early evolution of ornithomimosaurs . 2023 . Scientific Reports . 13 . 13842 . 10.1038/s41598-023-40804-3 . free . 10484975 .
  2. Azuma, Y. . Shibata, M. . 2010 . Fukuititan nipponensis, a new titanosauriform sauropod from the Early Cretaceous Tetori Group of Fukui Prefecture, Japan . Acta Geologica Sinica - English Edition . 84 . 3 . 454–462 . 10.1111/j.1755-6724.2010.00268.x.
  3. Shibaba . Masateru . Azuma . Yoichi . 2015 . New basal hadrosauroid (Dinosauria: Ornithopoda) from the Lower Cretaceous Kitadani Formation, Fukui, central Japan. . Zootaxa . 10.11646/zootaxa.3914.4.3 . 3914 . 4 . 421–440 . 25661952. |
  4. Imai, T., Azuma, Y., Kawabe, S., Shibata, M., Miyata, K., Wang, M., & Zhou, Z. (2019). An unusual bird (Theropoda, Avialae) from the Early Cretaceous of Japan suggests complex evolutionary history of basal birds. Communications Biology, 2(1). doi: 10.1038/s42003-019-0639-4