Researchers from CIM lead a study published in the journal ‘Current Biology’. Findings highlight the possible link between climate and the evolution of these prehistoric animals
Unlike their closest reptilian relatives, such as crocodiles, dinosaurs developed the ability to regulate their body temperature. But how and when these adaptations appeared are two unanswered questions in the evolution of these prehistoric animals. Some answers are provided by an article published in the journal Current Biology, resulting from the work of an international group led by Alfio Chiarenza and Sara Varela, researchers at the Marine Research Center of the University of Vigo (CIM-UVigo).
Thermoregulation is an important biological feature inherited by the only group of living dinosaurs: birds, and thanks to it, they constitute the large animal group that best adapts to the different climatic conditions of the Earth today. As scientists recount, some dinosaurs developed the ability to live and breed in cold polar regions, which raised the intriguing question about the origins of their warm-bloodedness. “Homeothermy (maintenance of a constant body temperature) and endothermy (generation of body heat) must have evolved, at least, in two groups of dinosaurs that inhabited those harsher cold regions: herbivorous ornithischians (among which are the Stegosaurus and the Triceratops) and mostly carnivorous theropods (such as the Tyrannosaurus rex and the Velociraptor), among which birds are also found”, explain Alfio Chiarenza and Sara Varela, researchers from the Mapas Lab team.
In the article published in Current Biology, and as a result of combining fossil data with phylogenetic trees and paleoclimatic models, the research team demonstrated that ornithischians and theropods diversified in a wide range of climates, also occupying colder environments, while long-necked herbivorous sauropodomorphs showed prolonged climatic conservatism associated with warmer environments. According to the authors of the study, this fact suggests that the latter maintained a more strongly temperature-dependent cold-blooded physiology.
A link between climate and dinosaur evolution
The results obtained in this research provide new insights into the origin of birds’ unique thermal regulation, suggesting that the evolution of their active metabolism probably began in the early Jurassic, a crucial period for the evolution of small feathered dinosaurs. An active metabolism could provide an advantage for speeding up the development of species with smaller feathers, which would find it easier to survive than their larger, slower-developing ancestors, especially after environmental crises like the Jenkyns.
“These findings highlight a possible link between climate and the evolution of dinosaurs, offering new clues about the dinosaurian origins of birds and the wide diversity of thermo-physiological strategies adopted by Mesozoic dinosaurs”, points out Sara Varela, Oportunius researcher and coordinator of the UVigo Mapas Lab team. Thus, this study, involving researchers from University College London, the University of Vigo, the University of Bristol, and the National Museum of Natural Sciences in Madrid (MNCN-CSIC), “contributes to a more nuanced understanding of dinosaur evolution and the interaction between the planet and its diverse ecology”, concludes Alfio Chiarenza, lead author of the article.
Source: DUVI
