Discovery of the smallest mammal, the holocephalon

Dr. Zhexi Luo, a Chinese-American paleontologist, recently published a latest research result in the American magazine Science, reporting that a species as small as the tip of a little finger was discovered in Lufeng, Yunnan, China in 1985 and lived among 190 million A mammal from the early Jurassic period years ago, it was named "holocephalon", meaning "complete head". The holocephalon is the smallest mammal known to mankind. Its discovery has given paleontologists a better understanding of early mammals.

We know that dinosaurs became extinct from the earth 65 million years ago. Since then, mammals have become the rulers of the earth and eventually evolved into us humans. The most important characteristics of mammals are that their bodies are covered with hair, their body temperature is constant, and their young are fed by breast milk. In addition, mammals also have the ability to learn survival experiences from their elders.

Although the full-headed beast is less than 12 mm long and weighs only 2 grams, it already has the characteristics of the above-mentioned mammals. This speculation is based on the study of its skull. The middle ear bone and mandible of the holocephalon are separated, which is an important link in the evolution from reptiles to mammals. In addition, compared with other animals of the same era, the relative brain capacity of the holocephalon is larger, which means that its brain is more developed, which is of great significance in terms of animal evolution.

Luo Zhexi believes that the enlargement of the brain is likely to be an important reason for the separation of the middle ear bone and the mandible. He pointed out: "Certain changes in the ear bones and jaw bones of mammals are likely to have been completed before the emergence of holocephalians, and the emergence of holocephalians means the final separation of ear bones and jaw bones. Holocephalus is related to A primitive mammal that existed at the same time as the ancestors of modern mammals, it can be said to be a distant relative of humans. Of course, the holocephalous beast is not our direct ancestor."

In the early Jurassic period 190 million years ago, the behemoths of the dinosaur family may not have noticed the existence of the whole-headed beasts as big as fingertips. However, more than 100 million years later, the extinction of the dinosaur family has marked the world. The family of mammals to which the alpha beast belongs opened the door to explosive evolution.

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