Recent research suggests that some dinosaurs may have developed the ability to internally regulate their body temperature during the early Jurassic period, allowing them to adapt to colder climates and survive environmental challenges. An artist’s impression shows a dromaeosaurus, a type of feathered theropod, in the snow. This group of dinosaurs is popularly known as a predator. The dromaeosaurus is known Velociraptordepicted in the film Jurassic Park. Credit: Davide Bonadonna/Universidade de Vigo/UCL
A new study led by researchers from UCL and the University of Vigo suggests that the ability to regulate body temperature, a trait shared by all modern mammals and birds, may have first evolved in some early dinosaurs Jurassic period approximately 180 million years ago.
A new study led by scientists from UCL and the University of Vigo suggests that the ability to regulate body temperature, a trait shared by all mammals and birds, may have first evolved in some dinosaurs during the early Jurassic period, around 180 million years ago.
At the beginning of the 20Thursday In the 20th century, dinosaurs were thought of as slow-moving, “cold-blooded” animals, like modern reptiles that rely on heat from the sun to regulate their temperature. More recent discoveries suggest that some types of dinosaurs were probably capable of generating their own body heat, but when this adaptation occurred is unknown.
Research methods and findings
A new study published in the journal Contemporary Biologylooked at the spread of dinosaurs in different climates on Earth around the world mesozoic Era (the dinosaur era spanning 230 to 66 million years ago), drawing on 1,000 fossils, climate models and geography of the period, and dinosaur evolutionary trees.
The research team found that two of the three main groups of dinosaurs, theropods (such as T rex and Velociraptor) and ornithians (including related herbivores). Stegosaurus and Triceratops), moved to cooler climates during the Early Jurassic, suggesting that they may have developed endothermy (the ability to generate heat internally) at this time. In contrast, the sauropods, another major group that includes Brontosaurus and Diplodocusheld in the warmer regions of the planet.
Previous research has found traits associated with warm-bloodedness among ornithians and theropods, with some known to have had feathers, or protofeathers, to insulate internal heat.
Evolutionary implications
First author Dr. Alfio Alessandro Chiarenza from UCL Earth Sciences said: “Our analyzes show that different climatic preferences emerged between the main groups of dinosaurs at the time of the Jenkyns Event 183 million years ago, when intense volcanic activity led to global warming and the extinction of plant groups.
“Many new groups of dinosaurs appeared during this time. The adoption of endothermy, perhaps a consequence of this environmental crisis, may have allowed theropods and ornithischians to thrive in colder environments, allowing them to be highly active and maintain activity for longer periods, develop and grow faster, and produce more offspring.
Co-author Dr. Sara Varela from the Universidade de Vigo in Spain said: “Theropods also include birds, and our study suggests that the unique temperature regulation of birds may have originated in this early Jurassic period. On the other hand, sauropods that lived in warmer climates grew to gigantic proportions at this time—another possible adaptation due to environmental pressure. Their smaller surface-to-volume ratio would mean that these larger creatures would lose heat at a reduced rate, allowing them to stay active for longer.”
Broader implications of the research
In the paper, the researchers also investigated whether sauropods might have stayed at lower latitudes to eat richer leaves unavailable in colder polar regions. Instead, they found that sauropods appeared to thrive in dry, savanna-like environments, supporting the idea that their limitation to warmer climates was more related to higher temperature and then more cold-blooded physiology. During that time, the polar regions were warmer, with abundant vegetation.
The Jenkyns event occurred after lava and volcanic gases erupted from long fissures in the Earth’s surface, covering large areas of the planet.
Co-author Dr Juan L. Cantalapiedra of the Museo Nacional de Ciencias Naturales, Madrid, Spain, said: “This research suggests a close link between climate and how dinosaurs evolved. It sheds new light on how birds might have inherited a unique biological trait from dinosaur ancestors and the different ways dinosaurs adapted to complex and long-term environmental changes.
Reference: “Early Jurassic origin of avian endothermy and thermophysiological diversity in dinosaurs” by Alfio Alessandro Chiarenza, Juan L. Cantalapiedro, Lewis A. Jones, Sara Gamboa, SofÃa Galván, Alexander J. Farnsworth, Paul J. Valdes, Graciela Sotelo, and Sara Varela , May 15, 2024, Contemporary Biology.
DOI: 10.1016/j.cub.2024.04.051
The study was funded by the European Research Council, the Royal Society, the Natural Environment Research Council and the Spanish Ministry of Research.
Scientists from UCL, University of Vigo, USA participated in the study University of Bristoland the Museo Nacional de Ciencias Naturales in Madrid and has received funding from the European Research Council, the Spanish Ministry of Research, the Natural Environment Research Council and the Royal Society.