Footprints in China show dinosaurs came in from the cold to rule the world, say scientists
- A feathery coat and adaptation to extreme cold helped the animals survive the end-Triassic mass extinction that wiped out reptiles: paper
- Team says evidence unearthed in Junggar Basin, Xinjiang, indicates Triassic dinosaurs regularly endured freezing conditions
Non-avian dinosaurs, including the Tyrannosaurus, were protected against cold volcanic winters during the late Triassic and early Jurassic periods, by feathers, or a primitive feather-like covering, and could live on evergreen Arctic vegetation, even during a deadly chill, the team of researchers in Britain, China, Sweden and the United States said.
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180-million-year-old nearly intact dinosaur fossil unearthed in China
After surviving the end-Triassic mass extinction, which killed three-quarters of marine and land species, insulated dinosaurs expanded their territory during the Jurassic period and took over regions that had been dominated by large reptiles, said the team that included experts in palaeontology and earth sciences.
For example, the long-necked basal sauropodomorphs spread to the tropics from mid- and higher latitudes, definitive ornithischian “bird-hipped” dinosaurs appeared for the first time, and “the maximum size of theropods (at least in the tropics) increased by 20 per cent, equating to nearly a doubling of mass”, they said.
“Traditionally, dinosaurs have been viewed as thriving in the warm and equable early Mesozoic climates, but our results indicate that they also endured freezing winters,” the researchers wrote in an article published on Saturday in the peer-reviewed journal Science Advances.
“We argue that the rich plant resources of the high latitudes were key for the survival of early herbivorous dinosaurs and that insulated dinosaurs were well adapted to these cold conditions.
“Through their adaptation to cold temperatures, dinosaurs were able to survive … volcanic winters and thereby expand to dominate terrestrial communities for the next 135 [million years], and, as birds, remain two to three times more speciose than mammals to this day.”