How long have mammals been a social creature? According to a new study, at least since the Late Cretaceous period of the dinosaur era, gives the earliest evidence of behavior of about 10 million years.
Study of fossils of small rodents Filikomys primaevus (meaning “young, friendly mouse”) dating back about 75.5 million years ago, paleontologists uncovered evidence of animals hanging out and living in groups.
We’re not just talking about adults raising their kids – the site in Egg Mountain in western Montana shows adults and smaller animals choosing to burrow and nest together, perhaps one of the first social activities in history.
“I think it̵7;s really powerful to see how deeply social interactions originate in mammals,” said paleontologist Luke Weaver from the University of Washington.
“Because humans are such social animals, we tend to think that sociability is somehow unique to us, or at least to our closely evolved relatives, but now we can see that social behavior goes further in the mammal family tree. “
“Polygons are one of the oldest groups of mammals, and they’re extinct for 35 million years, but in the Late Cretaceous, they seem to have a group interaction similar to what you’d see in squirrels land today. “
It is thought that this kind of intentional social behavior developed after the extinction of the dinosaurs 66 million years ago, and mainly in the Placentalia class of mammals to which humans belong.
Not so, according to these fossils – the rocks in which they were found, how well they are preserved and the characteristics f is prime Sharing with today’s burrowing animals, all suggesting that these ancient creatures were very happy together.
Researchers were unable to find any evidence of fossil bites, so it is unlikely predators put these animals together, and if they were moved by the flow of an rivers fossils will not be as complete as they are. .
“These fossils are game changers,” says paleontologist Gregory Wilson Mantilla. “When paleontologists are working to reconstruct the biology of mammals around this time, we are often stuck in individual teeth and possibly a jaw rolling into the river. But here we have many of the almost complete skulls and skeletons preserved in the exact same place where the animals lived.
“Now we can reliably look at how mammals actually interact with dinosaurs and other animals that live at this point.”
Today, about half of all Mammals with the placenta or placenta integrate socially in this way (global pandemic allows), and this behavior is also seen in some marsupial species such as kangaroos.
Humans hang out together for all kinds of reasons other than breeding and parenting, but evolutionarily this behavior can help avoid predators, share resources, and stay warm.
Now it seems that behavior started a lot earlier than we thought it would. As much of the world continues to grapple with the limitations of group encounters, it’s a reminder that we are social animals – something the team is aware of.
“It’s crazy to complete this article as soon as the home order is in effect – here we are all doing our best to stay out of society and isolate, and I’m writing about how animals are. Mammals interacting with society when they were dinosaurs. Still wandering the Earth! “says Weaver.
Research has been published in Natural Ecology & Evolution.