Paleo-ecology, ethology, & physiology

The mystery of stegosaur ‘armor’

A model for the evolution and function of stegosaur plates, spikes, and ossicles is proposed, involving calcium storage, defense, thermoregulation, and sexual display and combat.

Preprint: bioRxiv

Spinosaurus might not have dove underwater

Did Spinosaurus dive underwater to chase fish? Bone density as a proxy for ballast possibly lacks the statistical predictive power to make such an inference. Instead, its sail was likely under sexual selection for display rather than a propulsive fin.

Study: Myhrvold et al. 2024. PLoS One

Press Release: University of Chicago

Media: New York Times, Newsweek, Discover Magazine, Science

Tiny tyrants alongside T. rex

Decelerating growth rates measured from bone tissue, along with other lines of evidence, suggest that the latest Cretaceous of western North America probably had a much smaller species of tyrannosaur alongside the giant Tyrannosaurus rex.

Study: Longrich & Saitta 2024. Fossil Studies

Press Release: University of Bath

Media: New York Times, Smithsonian, New Scientist, Cosmos, Live Science, IFLScience, USA Today, Sky News, Discover Magazine, Cowboy State Daily, I Know Dino, briefly discussed by Joël Ignasse (2025) Sur les traces du nouveau T. rex Eyrolles (French)