Recent research suggests that some dinosaurs may have developed the ability to internally regulate their body temperature during the Early Jurassic period, which allowed them to adapt to colder climates and survive environmental challenges. The artist’s depiction shows a dromaeosaur, a type of feathered theropod, in the snow. This group of dinosaurs is popularly known as birds of prey. A well-known dromaeosaur is Velociraptordepicted in the film Jurassic Park. Photo credit: Davide Bonadonna/Universidade de Vigo/UCL
A new study led by researchers at UCL and the University of Vigo suggests that the ability to regulate body temperature, a trait common to all modern mammals and birds, may have first evolved in certain early dinosaurs law Period, about 180 million years ago.
A new study led by researchers at UCL and the University of Vigo suggests that the ability to regulate body temperature, a trait common to all mammals and birds, may have first appeared in some dinosaurs in the early Jurassic period, around 180 years ago millions of years ago.
In the early 20th centuryTh In the 19th century, dinosaurs were considered slow-moving, “cold-blooded” animals like modern reptiles, relying on the sun’s warmth to regulate their temperature. Recent discoveries suggest that some dinosaur species were likely capable of generating their own body heat, but when this adaptation occurred is unknown.
Research methods and results
The new study, published in the journal Current Biologystudied the spread of dinosaurs in different climates on Earth over the course of the year Mesozoic era (the dinosaur age, 230 to 66 million years ago), based on 1,000 fossils, climate models and geography of the period, as well as dinosaur evolutionary trees.
The research team found that two of the three main groups of dinosaurs, theropods (such as T Rex And Velociraptor) and ornithischians (including relatives of herbivores). Stegosaurus And Triceratops), moved to colder climates in the Early Jurassic, suggesting that they may have developed endothermy (the ability to generate heat internally) by that time. In contrast, the other major group, which includes the sauropods, is the sauropods brontosaurus and that Diplodocuskept in warmer areas of the planet.
Previous research has found traits associated with warm-bloodedness in ornithischians and theropods, with some known to have had feathers or protofeathers that insulated internal heat.
Evolutionary implications
First author Dr. Alfio Alessandro Chiarenza, from UCL Earth Sciences, said: “Our analyzes show that different climate preferences evolved among the main dinosaur groups around the time of the Jenkyns event 183 million years ago, when intense volcanic activity led to global warming.” Extinction of plant groups .
“Many new dinosaur groups emerged at this time. The introduction of endothermy, possibly a consequence of this environmental crisis, may have allowed theropods and ornithischians to thrive in colder environments, allowing them to be highly active and sustain their activity for longer periods of time, to develop and grow more rapidly, and to produce more offspring.”
Co-author Dr. Sara Varela from the Universidade de Vigo, Spain, said: “Theropods also include birds and our study suggests that the unique temperature regulation of birds may have its origins in this early Jurassic period.” Sauropods, on the other hand, which live in warmer Climate zones reached gigantic sizes around this time – another possible adaptation due to environmental pressure. Their smaller surface area to volume ratio would have meant that these larger creatures would lose less heat, allowing them to remain active longer.”
Further implications of the research
In the paper, the researchers also examined whether sauropods may have remained at lower latitudes to eat richer foliage not available in colder polar regions. Instead, they found that sauropods appear to thrive in dry, savanna-like environments, supporting the idea that their restriction to warmer climates is more related to higher temperatures and then to colder physiology. At this time, the polar regions were warmer and had lush 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 in Madrid, Spain, said: “This research suggests a close connection between climate and the evolution of dinosaurs.” It sheds new light on how birds may have a unique biological trait Dinosaur ancestors inherited and the different ways in which dinosaurs adapted to complex and long-term environmental changes.”
Reference: “Origin of avian endothermy and thermophysiological diversity in dinosaurs in the Early Jurassic” by Alfio Alessandro Chiarenza, Juan L. Cantalapiedra, Lewis A. Jones, Sara Gamboa, Sofía Galván, Alexander J. Farnsworth, Paul J. Valdes, Graciela Sotelo, and Sara Varela, May 15, 2024, Current 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.
Researchers from UCL at the University of Vigo were involved 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.