New fossil rewrites history of mammals

Paleontologists have discovered the fossil of a mouse-like animal that is the earliest example of a mammal that fed its unborn young with its placenta. According to Nature magazine, the discovery of the 160-million-year-old specimen indicates that marsupial mammals and placental mammals took up separate lines earlier than scientists originally thought. Scientists say the discovery is important as 90 per cent of mammals today are placental, and knowing when the two types of mammals split is necessary to understanding the evolution of mammals. Paleontologists discovered the new specimen, called Juramaia sinensis, in China’s northeast Liaoning Province, the source of many recent important fossil discoveries.

BBC News