Ancestor types of humans and mammals

A large number of primitive mammal fossil skeletons discovered in the Triassic strata of South Wales, England, are representatives of the earliest mammals on the earth. Paleontologists named them Morganotherium and placed them in the subclass Eotherium and the order Stylodontia.

Morganantherium is petite and its slender lower jaw is clearly of the mammalian type - it is composed of a single tooth bone, rather than several bones such as the tooth bone and joint bone like reptiles. However, there is a groove on the inside of the lower jaw of Morganantherium, which still retains a little remnant of the joint bone, which reminds us that it originated from reptiles. One of the more primitive features of morganotheres than later mammals is that the connection between their mandibles and skulls is still double-jointed. This is somewhat similar to the last mammal-like reptiles, the Dicrognathos, but both There is a difference in which joint plays the main role.

Morganmon

The teeth of Morganus were mammalian, with small incisors, a single, large and sharp canine, and premolars and molars with two roots and many cusps on the upper surface. These cusps are aligned more or less in a line along the central axis of the tooth.

The entire family of mammals that developed through the "Long Night" in subsequent eras gradually differentiated and evolved based on physical characteristics like Morgan's. In this sense, morganotheres represent the ancestral type of the entire family of mammals, including us humans.

animal tags： morgan mammal