China News Service, Beijing, November 3 (Reporter Sun Zifa) Springer Nature's international professional academic journal "Nature-Ecology and Evolution" recently published a paleontology research paper, which passed the rat that dates back to 75.5 million years ago. Fossil samples of polymammoid mammals, studies have found that the fossils include multiple individual skeletons in the same crypt, suggesting that mammals may have social behaviors since the Mesozoic.
Although a large number of placental mammals today have social behaviors, the relative lack of sociality of oviparous and marsupial mammals has led researchers to believe that the ancestors of mammals lived alone until the dinosaurs lived in about 66 million It changed after the extinction a year ago.
The corresponding author of the latest research paper, Lucas Weaver (Lucas Weaver) of the University of Washington in the United States, and his colleagues described the small mammalian bone deposits found in Montana, the bones from multiple intergenerational individuals buried together. The time can be traced back to the Late Cretaceous.
These skeletons represent a new genus of murine-shaped polynodon mammals, and the authors of the paper named it Filikomys primaevus.
This genus name comes from the Greek filikós, which means friendly or cordial, and describes the behavior that the author reads from these fossils.
According to reports, Filikomys primaevus has strong legs and is very suitable for digging, which allows them to form a cross-generation digging group of up to 5 individuals.
Based on the behavior of mammals in the existing burrowing community (such as rabbits), the author of the paper believes that the individuals in the fossil are related to them.
The author of the paper concluded that the evidence provided by these fossils showed that mammals had social behavior more than 75 million years ago.
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