Discovery of Six Fossil Egg Types Reveals Utah’s Ancient Biodiversity

Scientists uncover diverse dinosaur and reptile eggshells in Utah's Mussentuchit Member, reshaping understanding of Cretaceous ecosystems.

Researchers analyzed over 4,000 fossil eggshell fragments from Utah's Cedar Mountain Formation, identifying six distinct types of eggshells.
The eggshells were linked to three oviraptorosaur dinosaurs, two ornithopod dinosaurs, and one crocodylomorph reptile species.
Several eggshell types, including Mycomorphoolithus kohringi, were identified for the first time in North America, with some previously only known from Europe.
The findings suggest a more complex Cretaceous ecosystem with multiple coexisting species and diverse nesting behaviors.
This study provides the earliest evidence of multiple oviraptorosaurs cohabiting in North America, offering new insights into dinosaur diversity and interactions.