Alioramus

genus of Late Cretaceous tyrannosaurids

Alioramus is a genus of tyrannosaurid dinosaur. It was about 20 feet long. It lived during the Upper Cretaceous period in what is now Mongolia.

Alioramus
Temporal range: Maastrichtian
~70 Ma
Skeleton mount at Texas A&M University-Commerce
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Family: Tyrannosauridae
Tribe: Alioramini
Genus: Alioramus
Kurzanov 1976
Type species
Alioramus remotus
Kurzanov 1976
Species
  • A. altai Brusatte et al. 2009
  • A. remotus Kurzanov 1976
Synonyms

The type species, A. remotus, is known from a partial skull and three foot bones. They were got from Mongolian sediments which were deposited in a humid floodplain about 70 million years ago.[2] A second species, A. altai, known from a much more complete skeleton, was named and described in 2009.[3] Its relationships to other tyrannosaurid genera are unclear. Some evidence suggests that Alioramus is closely related to the contemporary species Tarbosaurus bataar.

Wetter climate

change

The Maastrichtian stage in Mongolia had a wetter and more humid climate than the previous stages. Sediments show there were floodplains, large river channels and soil deposits, with periodic droughts.[4]

This animal had many teeth, which were smaller than usual in the Tyrannosauridae, and a narrow, lower skull. It may have been a sub-adult (teenager), and must have eaten different prey than Tyrannosaurus. Since the general area was a riverine delta, the prey may have been fish.

References

change
  1. Carr, Thomas D.; Varricchio, David J.; Sedlmayr, Jayc C.; Roberts, Eric M.; Moore, Jason R. (2017). "A new tyrannosaur with evidence for anagenesis and crocodile-like facial sensory system". Scientific Reports. 7: 44942. Bibcode:2017NatSR...744942C. doi:10.1038/srep44942. PMC 5372470. PMID 28358353.
  2. Kurzanov, Sergei M. A new carnosaur from the Late Cretaceous of Nogon-Tsav, Mongolia". The Joint Soviet-Mongolian Paleontological Expedition Transactions (in Russian) 3: 93–104.
  3. Brusatte, Stephen L. et al 2009. A long-snouted, multihorned tyrannosaurid from the late Cretaceous of Mongolia. Proceedings of the National Academy of Sciences of the United States of America. online preprint (41): 17261–6. [1]
  4. Osmólska, Halszka (1997). "Nemegt Formation". In Currie, Philip J.; Kevin Padian (eds.). The Encyclopedia of Dinosaurs. San Diego: Academic Press. pp. 471–472. ISBN 978-0-12-226810-6.