The strangest and first animal we know ... the shovel lizard practiced winter hibernation 250 million years ago

A new study shows that animals have been hibernating for a very long period of the life of living things on Earth.

In this study, researchers analyzed fossils of 250 million years old and found evidence that mammals of a genus called "Lystrosaurus" hibernated like bears and bats today.

And researchers from Harvard and Washington universities in the USA participated in this process. The results of the study were published in Communications Biology on 27 August.

Fangs Comparison 

The scoop lizard / Lystrosaurus - as indicated by the "wikipedia" encyclopedia - is a species that lived about 250 million years ago in what is now Antarctica, India and South Africa.

Currently about 6 species have been identified, although it was thought from 1930 to 1970 that the number of species may be much greater.

Listrosaurus had two years and two pairs of tusks, and it is believed that it had a horned beak that was used to bite off bits of vegetation.

This animal was growing big, and its size was about the size of a pig, and it was a herbivore.

Finding signs of a shift in metabolic rates in fossils is nearly impossible under normal circumstances.

The presence of tusks in Listrosaurus represented a record of activity not unlike that of tree trunks.

So, by comparing (and dissecting) cross-sections of tusks from 6 fossils of Lystrosaurus in Antarctica, to cross-sections of tusks from 4 fossils of Lystrosaurus from South Africa, the researchers were able to find lower growth periods and greater stress that were exclusive to samples of Antarctica.

The signs correspond to similar deposits in the teeth of modern-day animals that hibernate at certain times during the year.

It is not conclusive evidence of Lystrosaurus hibernating, but it is the oldest evidence discovered so far.

Marks in Lystrosaurus tusks coincide with similar deposits in the teeth of modern day animals that practice hibernation (Nobu Tamura - Wikipedia)

Adapt to extreme environments

In the published statement about the study, vertebrate paleontologist Megan Whitney of Harvard University commented on the University of Washington website.

"Animals that live in or near the poles have always had to adapt to the more extreme environments that are there," Whitney said. "These preliminary results indicate that entering a hibernation-like state is not a relatively new type of adaptation, it is an ancient species."

Hibernation was probably necessary for animals living near Antarctica at the time.

Although the area was much warmer in the Triassic period, there are still large seasonal differences in the number of daylight hours.

It is very likely that Lystrosaurus was not the only animal to hibernate at that time, as some dinosaurs that came after that may have gone into hibernation as well.

The problem is that most species at that time did not have tusks or even continuously growing teeth.

"To see the specific signs of stress and stress caused by hibernation, you have to look at something that could turn into a fossil, and it was constantly growing throughout the animal's life, and many animals don't have that, but fortunately Lystrosaurus has that," says biologist Christian Sidor of the University of Washington. .

It is possible that Listerosaurus was not the only animal to hibernate in the Triassic period (Wikipedia - Foreign Press)

A vital process of survival

There is much that the history of living species can teach us, supporting the idea that resilient physiology (the ability to adapt bodily functions to suit the seasons) may be vital to survival periods from mass extinctions.

More studies will be able to look in more detail at the question of whether Lystrosaurus is able to enter a deep state of hibernation or not, but this new analysis already charts some interesting similarities spanning hundreds of millions of years.

"Often cold-blooded animals stop their metabolism completely during the difficult season," Whitney says, "but many hibernating or hot-blooded animals that are in hibernation often reactivate their metabolism during hibernation."

"What we observed in the tusks of Listerosaurus in Antarctica fits into a pattern of small metabolic re-activation events during stress, which is very similar to what we see in warm-blooded hibernation today," she added.