Mammals had community behavior more than 75 million years ago

BEIJING, Nov. 2 (Xinhua Zhang Mengran) -- A team of U.S. scientists reported on the behavior of mammalian communities dating back 75.5 million years in a biological study published In the British journal Nature Ecology and Evolution on Monday. Scientists have discovered fossil samples of a new genus of mammals, the rat-shaped polymagosarcular beast, including several individual skeletons in the same cave, suggesting that mammals may have had community behavior from the Middle Generation.
so-called community behavior refers to the collective cooperative behavior between the same species of animals or exotic animals. The permanent community of animals has a more stable group structure and certain codes of conduct, as well as a clear division of labor and organization. Community sustainment depends on cooperative and mutually beneficial relationships, and the coordination of member behavior requires effective "communication" mechanisms. Generally speaking, it is usually required to have different levels between individuals, frequent interaction between members, certain goals and members of the division of labor, members have a sense of belonging and other basic characteristics.
Although a large number of placental mammals today have community behavior, the relative lack of community of eggs and bagged mammals has led researchers to believe that mammalian ancestors lived alone until the dinosaurs benexed about 66 million years ago.
this time, University of Washington researcher Lucas Weafu and colleagues described the small mammalian sedimentary bones found in Montana, USA, from multiple intergenerational individuals buried together, dating back to the late Cretaceous. These skeletons represent a new genus of rat-shaped polymatospheric animal mammals, which the authors name "F. primaevus".
researchers say the genus, which comes from Greek, means friendly or kind, describing the behavior scientists interpreted from the fossils. The legs of the "F. primaevus" species are particularly strong and well suited for digging holes, allowing them to form a cross-generational group of up to five individuals. Based on the behavior of existing cave community mammals, such as rabbits, the team believes that individuals in fossils are related to them.
researchers concluded that the fossils provide evidence that mammals had community behavior more than 75 million years ago.