Introduction:
Tyrannomimus is an extinct ornithomimosaurian theropod from the Kitadani Formation of Japan. This dinosaur’s name translates to ‘Tyrant Mimic‘ because of its similarities with the bone structure of tyrannosauroids. This is because both Tyrannosauroids and Ornithomimosaurian are part of the same Clade, Theropod.
What is Tyrannomimus Fukuiensis?
Tyrannomimus is one of the only ornithomimosaurian discovered in Japan and even in ornithomimosaurian group, it is was the earliest ever species of the family, Deinocheiridae which gave rise to the gigantic Deinocheirus. Tyrannomimus was a very important discovery in filling up the gaps in the evolution of Deinocheiridae and answers how to its lineage evolved into larger sizes. Now, that we know some of the preliminary details, let move on to some more in-depth knowledge for this amazing ornithomimosaurian!!
Discovery:
Tyrannomimus was found from the Kitadani Formation by many different paleontologists as isolated remains. Later on Dr. Soki Hattori and colleagues wrote a paper where they analyzed the phylogenetics and described it as Tyrannomimus fukuiensis. Tyrannomimus is a very recent discovery and thus the studies and research on this species is a lot lower than some other, older species but this discovery helped in filling the gaps in Deinocheiridae and showed that the species started to rise from Early Cretaceous.
Tyrannomimus is a part of the Deinocheiridae family but the ancestor of it created 2 different families. One tree led to Harpymimus and Tyrannomimus while the other tree led to Deinocheirus, Garudimimus and Paraxenisaurus. The ancestor for both of the family trees are known as the common ancestor and if we go further back, the common ancestor came from another common ancestor who also had 1 or more family trees. This is usually how classification work in the case of biology. While Tyrannomimus is a member of the Deinocheiridae family, you think of it more as a cousin instead of it directly evolving into Deinocheirus, I wanted to clear that up!
Surprisingly, this dinosaur was just described in 2023, very recent although the fossils are very fragmentary and not even remotely completely but the fossils are very different and clear that we can accurately categorize where the dinosaur belonged and that is a blessing for this very new dinosaur!!
Biology:
While the name must sound gigantic but in actuality, Tyrannomimus was fairly small when compared with other, more larger ornithomimosaurian. It being only 1 meter (3.3 feet) in height and 2.5 meters (8.2 feet) in length, it is definitely one of the more smaller ornithomimosaurian but this dinosaur’s lineage would evolve into much greater, and larger dinosaur ever.
What was the diet of the Tyrannomimus?
Most people think that all theropods are carnivores but that is exactly not true. It would have most probably been on a diet of plants and insects and maybe, very occasionally, carcass meat in smaller quantities. It’s like all carnivores are theropods but not all theropods are carnivores.
Tyrannomimus lived in the Early Cretaceous Period which is around 121 – 113 million years ago. Most of the bones found in the Kitadani Formation is of Early Cretaceous rocks. Early Cretaceous Japan was not separate from most of the huge landmasses like today, rather it was connected to the main landmass at that time which had connections with the continent Africa as well as North and South America.
The reason I am saying this is because you know how I said Tyrannomimus is basal Deinocheiridae and you might be wondering how did a Japanese dinosaur move over to Mongolia. This is why because Japan was connected at that time and the first ancestor of Tyrannomimus traveled to Japan while the other traveled to Mongolia and then 2 different family trees were created where they become more like cousins. One ancestor evolved into Tyrannomimus while the other evolved into more larger forms and with millions of years in between them, Deinocheirus came right at the Late Cretaceous Period.
The fossil record, honestly, is full of missing links and empty places where we know someone is supposed to be here but we did not either find them at the right place or the fossils may have been destroyed by the forces of nature and man-made changes. Some may not even see the light of day and be forgotten in the stream of time and which is why I find paleontology to be a very important field of science which helps us to understand the diversity of life before humanity and how Earth spent millions of years with varied forms of life.
As for ecology in prehistoric Japan at that time was a lot warmer and drier than modern day and it would have lived alongside sauropods like Fukuititan, ornithopods like Fukuisaurus and Koshisaurus, and theropods like Fukuiraptor, Fukuivenator and Fukuipteryx and also undescribed Spinosauridae. Surprisingly, Tyrannomimus has yet to gain more popularity as it is the kid on the block but hopefully it will become more popular in time.
Merchandise:
Unfortunately, the merch side of Tyrannomimus is non-existent but I believe in few years time, somewhere or someplace or someone might release a figure of it, who knows! I hope that Takara Tomy’s, a toy brand like Hasbro or Mattel, ANIA line of animal and dinosaur toys release a Tyrannomimus soon because they have been dabbling in some Japanese dinosaur genera like Fukuiraptor, Fukuisaurus, Futabasaurus, and Fukuivenator for now. They have to make some more Japanese dinosaurs and I really wonder what’s next in the line. After Pachycephalosaurus, I thought they would release a Fukuititan but they released a relative of it, Argentinosaurus, so I was not quite wrong or not quite right. They later released a Dilong and Dracorex. I should make a list blog post about Ania at this point. Let me know in the comments what else you might wanna know.
And that is all there is to know about Tyrannomimus, as this is a new dinosaur, I have not been able to find any merch of it. I also posted a whole list of Dinosaurs in Japan, make sure to check out that post too. I hope to see you again soon on other posts in Prehistoric Pedia!!!
References:
- Hattori, S.; Shibata, M.; Kawabe, S.; Imai, T.; Nishi, H.; Azuma, Y. (2023). “New theropod dinosaur from the Lower Cretaceous of Japan provides critical implications for the early evolution of ornithomimosaurs”. Scientific Reports. 13. 13842. doi:10.1038/s41598-023-40804-3. PMC10484975.
- 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. doi:10.1111/j.1755-6724.2010.00268.x.
- Shibaba, Masateru; Azuma, Yoichi (2015). “New basal hadrosauroid (Dinosauria: Ornithopoda) from the Lower Cretaceous Kitadani Formation, Fukui, central Japan” (PDF). Zootaxa. 3914 (4): 421–440. doi:10.11646/zootaxa.3914.4.3. PMID25661952.
- 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
