Home Society Strange 160-million-year-old fossils reveal that the earliest mammals could glide Our earliest mammal ancestors could glide from tree to tree on wing-like membranes, two Jurassic fossils suggest. April Neander/UChicago August 10, 2017 01:00 IST Close Our earliest mammal ancestors could glide from tree to tree on wing-like membranes, two Jurassic fossils suggest.