Paleopathology in Late Triassic phytosaurs as a window to early archosauriform paleoecology

Paleopathology, i.e., the study of ancient disease and injury, plays an important role in understanding the physiology and paleoecology of long-extinct animals. Phytosaurs, a species-rich group of carnivorous archosauriforms, are well suited for large-scale paleopathological research because thousands of specimens are housed in museums in Europe and the United States. Although not closely related, they can be compared with crocodilians, which are often regarded as their closest ecological analogs.

This project investigates the lifestyle and behavior of phytosaurs through a broad analysis of the types and frequencies of their skeletal pathologies. Particular attention are given to injuries associated with active lifestyles, including those resulting from trophic interactions (e.g., struggling prey), intraspecific aggression, and repetitive stress on bones and tendons. Differences in pathology type and frequency will be evaluated across taxonomic groups, inferred trophic positions, and ontogenetic stages.

The near-global distribution of phytosaurs in Late Triassic continental ecosystems provides a rare opportunity to study pathologies in relation to paleoenvironmental changes across time and regions. This project combines classical morphology with medical and micro-CT imaging, as well as histological thin-sectioning. 

Comparing phytosaur pathologies with those of extant crocodylians (whose ecology and behavior are well understood) will test whether similar pathologies reflect analogous lifestyles and morphology. The results will provide independent insights into phytosaur paleobiology, contribute to understanding early archosauriform evolution, and clarify trophic interactions in Late Triassic ecosystems. 

Collaborating partners

• Kyla Beguesse (veterinarian; Comparative Zoological Osteological and Paleontological Pathology (CZOPP), LLC, Durham, North Carolina, USA)

• Ewan Wolff (veterinarian; Mountainside Animal Emergency & Speciality (MAES), North Vancouver,

• British Columbia, Canada)

• Patrick Asbach (radiologist; Charité—Universitätsmedizin Berlin, Department of Radiology, Berlin,

• Germany)

• François Clarac (archosaur expert; CR2P, Sorbonne Université, Muséum National d'Histoire Naturelle, Centre National de la Recherche Scientifique, Centre de Recherche en Paléontologie—

• Paris (CR2P, UMR 7207), Paris, France