How dinosaurs came to rule the planet

Dinosaurs, while they have long been extinct on our planet, are still part of our daily lives – from taking lead roles in some familiar and cherished movies and shows, like Jurassic Park and the Land Before Time, to even our dinner tables as chicken nuggets. While we have a good understanding of the lives of dinosaurs and how they became extinct nearly 65 million years ago, we know little about how they came about. Researchers from Europe have chipped away at this mystery and published their findings in November last year.

Two models to explain the rise of dinosaurs have been proposed: (1) they were able to out-compete other animals due to physiological advantages, like anatomy or eating habits, and (2) dinosaurs’ rise to the top was spontaneous and occurred in parallel to the extinction of other animals. However, no single model seems to fully explain the dinosaur dynasty. Over a 25 year period, Qvarnström et al. examined hundreds of bromalites, or fossil digestive products (essentially poop and vomit), to better understand the emergence of dinosaurs. The products’ contents offered clues about what dinosaurs were eating, and the researchers inferred the types of dinosaurs they came from based on the bromalites’ sizes and shapes. By integrating the bromalite data with climate and vegetation data, the researchers found that during the rise of dinosaurs, a change in climate bloomed the amount and variety of available vegetation. With this new and improved vegetarian menu, large and more diverse plant-eating dinosaurs rose. However, the uprising of these plant-eating dinosaurs then allowed for the evolution of giant meat-eating dinosaurs, much like the ones we commonly think of, like the T. Rex. The results of this paper suggest that the two models proposed earlier are not mutually exclusive; rather a combined model best explains the rise of dinosaurs millions of years ago.

By understanding the emergence and evolution of dinosaurs on our planet, we can better understand how current life may respond to environmental changes in the future. Additionally, the study by Qvarnstöm et al. is an amazing decades-long feat that demonstrates the truly remarkable discoveries we can make about our planet hundreds of millions of years ago; timescales that are not easily imaginable, yet, thanks to fossils and bromites, accessible.

This study was led by Martin Qvarnström from Uppsala University in Uppsala, Sweden.

Managing Correspondent: Olivia Sacco

Press Article: https://www.nature.com/articles/d41586-024-03889-y (Nature News) 

Original Journal Article: https://www.nature.com/articles/s41586-024-08265-4 (Nature) 
Image Credit: gettyimages