A pair of 160-million-year-old fossils recently discovered in China are believed to belong to the oldest known “winged” mammals, suggesting that the Jurassic Period creatures had the ability to glide between trees, according to new research published this week in the journal Nature.
According to BBC News, the creatures apparently possess adaptations such as long limbs, long hand and foot fingers, and wing-like membranes that would have allowed them to climb up trees, roost in branches and glide from one tree to another – meaning that ancient mammals developed these abilities far earlier than experts previously believed.
Indentified as Maiopatagium furculiferum and Vilevolodon diplomylos, the species are believed to be the oldest known gliding mammals, the study authors explained in a statement. In fact, the discovery suggests that ancient mammals evolved the volant (or flying) way of life roughly 100 million years earlier than the first modern flying mammals.
“In a way, they got the first wings among all mammals,” said study co-author Zhe-Xi Luo, a professor of anatomy and biology from the University of Chicago. “We continue to be surprised by how diverse mammalian forerunners were in both feeding and locomotor adaptations. The groundwork for mammals’ successful diversification today appears to have been laid long ago.”
“It’s amazing that the aerial adaptions occurred so early in the history of mammals,” added co-author David Grossnickle, a graduate student at the University of Chicago. “Not only did these fossils show exquisite fossilization of gliding membranes, their limb, hand and foot proportion also suggests a new gliding locomotion and behavior.”
Findings reveal that early mammals thrived, despite dinosaurs
The new species, Maiopatagium furculiferum and Vilevolodon diplomyl, belong to an extinct branch of the mammalian evolutionary tree known as the haramiyidans – creatures though to be the predecessors of the modern mammal, according to BBC News. They possessed a membrane made of skin that stretched from their fore and hind limbs and allowed them to glide.
In addition to the wing membrane, Maiopatagium had fused wishbones similar to those found in modern birds, and the creatures’ skeletons resembled the platypus, the UK media outlet reported. The fossils were discovered in the Tiaojishan Formation, northeast of Beijing, and they probably were herbivores that dined on ferns, conifers and other gymnosperms, since flowering plants had not yet started becoming prevalent (that happened during the Cretaceous Period).
For a long time, experts believed that mammals from this era had little opportunity to evolve and adapt to different environments, due primarily to competition from dinosaurs. Recently, though, a series of new discoveries – including these two gliding mammals – serve as evidence that there was actually far more variation in mammalian lifestyles at this time than previously thought.
“We think of the Jurassic as ‘dinosaur world’. But fossils keep showing us the great diversity of small mammals doing many of the ecological jobs they do today,” Oxford University vertebrate paleontologist Dr. Roger Benson, who was not involved in the study, said in an interview with BBC News.
“Mammals are more diverse in lifestyles than other modern land vertebrates, but we wanted to find out whether early forerunners to mammals had diversified in the same way,” added Luo. “These new fossil gliders… demonstrate that early mammals did indeed have a wide range of ecological diversity, which means dinosaurs likely did not dominate the Mesozoic landscape as much as previously thought.”
Image credit: April I. Neander/UChicago