Field Guide
Geography & Distribution

Dozens of oviraptorosaur specimens have been found in Asia, particularly in Mongolia and China. On the other hand, decades of searching for these dinosaurs on other continents were almost fruitless - until the fall of 1998, when two skeletons of the new oviraptorosaur were discovered only 165 feet (50 meters) apart in the fossil-rich Hell Creek badlands of northwestern South Dakota. Carnegie Museum of Natural History's new skeletons are the most complete oviraptorosaur specimens known outside of Asia, and firmly establish the presence of this group in western North America. But how can this be? How can oviraptorosaurs, which were land-dwelling animals (and probably poor swimmers), be found on two continents that today are separated by the Pacific Ocean?

Eurasia
in the Late Cretaceous

The majority of oviraptorosaurs are from this general location.

North and South America
in the Late Cretaceous

Discovery site of the new Carnegie Museum of Natural History oviraptorosaur.

Click maps for larger images

The answer to this puzzle lies in the arrangement of the Northern Hemisphere continents during the Cretaceous Period. Based on multiple lines of geologic and paleontologic evidence, scientists believe that northwestern North America (what is now Alaska) and northeastern Asia were connected by a "land bridge" for at least part of the Cretaceous. Along with many other kinds of dinosaurs, oviraptorosaurs seemingly used this land bridge to move between the two continents.

But where did oviraptorosaurs come from in the first place? Asia, North America, or someplace else? The most ancient and primitive oviraptorosaurs we know of (Incisivosaurus and Caudipteryx) both hail from China. Consequently, it seems that oviraptorosaurs originated in Asia before they colonized North America. However, if an even earlier oviraptorosaur were to be discovered outside of Asia, it would cast serious doubt on this idea. Therefore, a single fossil could completely overturn our current thinking on the birthplace of oviraptorosaurs!

Appearance & Behavior Evolutionary History Ancient Environments Research at CMNH
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