A diminutive new tyrannosaur from the top of the world.

Tyrannosaurid theropods were dominant terrestrial predators in Asia and western North America during the last of the Cretaceous. The known diversity of the group has dramatically increased in recent years with new finds, but overall understanding of tyrannosaurid ecology and evolution is based almos...

Full description

Bibliographic Details
Published in:PLoS ONE
Main Authors: Anthony R Fiorillo, Ronald S Tykoski
Format: Article in Journal/Newspaper
Language:English
Published: Public Library of Science (PLoS) 2014
Subjects:
R
Q
Online Access:https://doi.org/10.1371/journal.pone.0091287
https://doaj.org/article/f3341e9ba67440eea924badcbe0a07bd
Description
Summary:Tyrannosaurid theropods were dominant terrestrial predators in Asia and western North America during the last of the Cretaceous. The known diversity of the group has dramatically increased in recent years with new finds, but overall understanding of tyrannosaurid ecology and evolution is based almost entirely on fossils from latitudes at or below southern Canada and central Asia. Remains of a new, relatively small tyrannosaurine were recovered from the earliest Late Maastrichtian (70-69Ma) of the Prince Creek Formation on Alaska's North Slope. Cladistic analyses show the material represents a new tyrannosaurine species closely related to the highly derived Tarbosaurus+Tyrannosaurus clade. The new taxon inhabited a seasonally extreme high-latitude continental environment on the northernmost edge of Cretaceous North America. The discovery of the new form provides new insights into tyrannosaurid adaptability, and evolution in an ancient greenhouse Arctic.