The discovery of two 160-million-year-old fossils from Tiaojishan Formation northeast of Beijing, China suggests that the precursors of mammals were evolved to live in trees. An international team of scientists from the University of Chicago and Beijing Museum of Natural History has brought out that these two species are the earliest known mammal species who used to glide for their transportation.

In the journal of Nature scientists explained, those mammal species were from Jurassic age and had long limbs, long hand and foot fingers, and wing-like membranes for tree-to-tree gliding. Scientists named those species as Maiopatagium furculiferum and Vilevolodon diplomylos.

Professor of organismal biology and anatomy at the University of Chicago Dr. Zhe-Xi Luo said in the paper,“These Jurassic mammals are true 'the first in glide. In a way, they got the first wings among all mammals”. he also explained, these two species were evolved 100-million-year earlier than the modern mammal fliers.

According to Phys, an ability to glide allowed them to find foods and keeps the safe from the risk of ground attacks. However, most of the mammals are evolved to live on land but there are also some volant animals like a sugar glider, bats, flying squirrels get to see in modern days. Discovery of the Jurassic Maiopatagium and Vilevolodon would help to understand the transition between land and aerial habitats, co-author David Grossnickle explained.

Both of the fossils belong to the haramiyidan family that is the long extinct branch of the modern mammalian evolutionary tree. In spite of having a long gap in the evolutionary calendar they still share similar ecology with modern gliders with some significant differences. Modern gliders usually diet on seeds, fruits and other soft parts of flowering plants as they are herbivorous but, in Jurassic period gymnosperm plants like cycads, gingkoes and conifers have the abundance.