The Lystrosaurus is a mammal-like animal from the early Triassic period that roamed modern-day day areas these as India, South Africa and Antarctica in excess of 250 million years ago. It has tusks like an elephant and a beak equivalent to a turtle, and it was roughly the sizing of a pig.
Researchers at the College of Washington utilised fossils of the animal’s tusks to test for anxiety variances amongst the species dwelling in polar climates and warmer types, this kind of as in Africa. The tusks are vital due to the fact they can measure intervals of time in the animal’s lifetime, identical to rings on a tree.
They discovered prolonged anxiety consistent with animals that working experience torpor, or extended relaxation these kinds of as hibernation, and it is the oldest instance of torpor regarded in fossil information.
“To see the particular indicators of strain and strain brought on by hibernation, you require to glance at anything that can fossilize and was rising repeatedly for the duration of the animal’s daily life,” stated co-author Christian Sidor, a biology professor at the University of Washington. “Quite a few animals do not have that, but luckily Lystrosaurus did.”
The researchers also think that it may perhaps describe why the animal survived the mass extinction at the close of the Permian period, which wiped out 70% of vertebrate species on land.
The researchers said they can not definitively verify Lystrosaurus went into correct hibernation as we know it, but the stress could be triggered by another type of quick-phrase torpor.
“What we noticed in the Antarctic Lystrosaurus tusks matches a sample of little metabolic ‘reactivation events’ all through a time period of anxiety, which is most equivalent to what we see in heat-blooded hibernators today,” Whitney claimed.