Were dinosaurs doomed to extinction? New insights from phylodynamic models

Dinosaur diversity is a topic of significant interest due to its implications for understanding evolutionary history. The accompanying phylogeny illustrates the evolutionary process of archosaurs, which first emerged just before the end-Permian mass extinction, approximately 252 million years ago. Over millions of years, archosaurs diversified into various forms, including modern crocodiles, which remain abundant today, as well as several extinct clades such as pterosaurs.

The phylogeny also highlights the emergence of the Dinosauria group, which encompasses ornithischian dinosaurs, sauropodomorphs, and theropod dinosaurs. Notably, theropods eventually led to the evolution of modern birds. A critical event in this evolutionary timeline occurred around 66 million years ago, marked by an asteroid impact that resulted in widespread extinction. This event caused significant atmospheric changes, leading to a catastrophic environment for many species.

A key question arises from this context: Would non-avian dinosaurs have faced extinction if the asteroid had not struck? Prior to this event, it is essential to consider whether dinosaurs were thriving or already in decline. Understanding these dynamics can provide insights into their evolution and the factors contributing to their eventual extinction.