About Nanotyrannus

About Nanotyrannus

Paleontology is riddled with many debates about the classifications of different species.  One hotly debate issue, is whether Nanotyrannus is a juvenile Tyrannosaurus rex  or a different genus of tyrannosaurid.

Lines of evidence supporting the hypothesis that Nanotyrannus was a different genus of tyrannosaurid:
• 16 laterally compressed teeth rather than 14
• wedge shaped skull
• narrow jaw
• large orbits
• forward pointing parasphenoid
• lacrimal horn

Lines of evidence supporting that Nanotyrannus is a juvenile T. rex:
• not all skull bones fused
• Slightly forward facing eyes due to expanded occupit relative to snout width
• presence of “juvenile features” seen in other juvenile T. rex
• share unique synapomorphies with T. rex

With only two specimen of Nanotyrannus having been found thus far, it is difficult to determine whether they are a juvenile T. rex or a completely different genus of tyrannosaurid.  Until more conclusive evidence is found, a decision cannot be drawn as to what exactly Nanotyrannus is.


This video is one of four created by students taking my class Vertebrate Paleontology in the Spring of 2014 at the University of Rochester. The text above was also prepared by those students.

The assignment was to create a two to three minute video focused on some important question or misconception in vertebrate paleontology.

This was an experimental assignment. I had no idea if it was going to work out.

It’s possible that there are factual errors and other problems with the videos. However, I think my students did great, and will probably continue to do this kind of class project.

1 Comment

  1. David says:

    When and where were the nanotyrannus found? I know one was found in eastern Wyoming in June, 2006. We have an upper and lower jaw, with teeth in both. One toe claw with toe bones, one finger claw and some other skull bones. There a a couple of vertebra and one rib.
    How many other claws have been found?


Leave a Comment

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s