How to tell if something that died 250 million years ago hibernated when it was alive?
After all, hibernation — a state of reduced metabolism — is a good strategy for making it through long, harsh winters when food can be scarce. Biologists would not be surprised that evolution figured this out early in the history of life. But uncovering convincing evidence of that is hard.
“As a paleontologist, what you’re presented with is a pile of bones,” said Christian A. Sidor, a professor of biology at the University of Washington and curator of vertebrate paleontology at the Burke Museum in Seattle. “And that just tells you where the animal died. It doesn’t even tell you where the animal lived.”
But Sidor and Megan R. Whitney, a former graduate student who is now a postdoctoral researcher at Harvard, believe they have good evidence of hibernation behavior in an animal that lived in Antarctica a quarter of a billion years ago — before the age of dinosaurs.
This was a tumultuous time for life all around the planet, which was recovering from the largest mass extinction ever on Earth, marking the end of the Permian geologic period and the beginning of the Triassic. Antarctica, then as now, was near the South Pole, and might have provided something of a haven from the cataclysm, often called the Great Dying. (The cause of this extinction is still being debated.)
Whitney said this animal, Lystrosaurus, was about the size of a medium dog with a beak like a turtle and two small tusks, and it was one of the species to make it through the mass extinction