Flying was Evolutionary Parallel to Modern Mammal Gliders
Two 160 million-year-old mammal fossils discovered in China show that the forerunners of mammals in the Jurassic Period evolved to glide and live in trees. With long limbs, long hand and foot fingers, and wing-like membranes for tree-to-tree gliding, Maiopatagium furculiferum and Vilevolodon diplomylos are the oldest known gliders in the long history of early mammals. – University of Chicago.
The new discoveries suggest that the volant, or flying, way of life evolved among mammalian ancestors 100 million years earlier than the first modern mammal fliers. The fossils are described in two papers published this week in Nature by an international team of scientists from the University of Chicago and Beijing Museum of Natural History. – University of Chicago.
“These Jurassic mammals are truly ‘the first in glide,’” said Zhe-Xi Luo, professor of organismal biology and anatomy at the University of Chicago and an author on both papers. “In a way, they got the first wings among all mammals.” – University of Chicago.
“With every new mammal fossil from the Age of Dinosaurs, 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,” he said. – University of Chicago.
The two newly discovered creatures also share similar ecology with modern gliders, with some significant differences. Today, the hallmark of most mammal gliders is their herbivorous diet that typically consists of seeds, fruits and other soft parts of flowering plants.
But Maiopatagium and Vilevolodon lived in a Jurassic world in which the plant life was dominated by ferns and gymnosperm plants like cycads, gingkoes and conifers—long before flowering plants came to dominate in the Cretaceous Period. Their way of life also was associated with feeding on these entirely different plants. This distinct diet and lifestyle evolved again some 100 million years later among modern mammals, in examples of convergent evolution and ecology.
“It’s amazing that the aerial adaptions occurred so early in the history of mammals,” said study 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.”
Thriving among dinosaurs
Early mammals were once thought to have differences in anatomy from each other, with limited opportunities to inhabit different environments. The new glider fossils from the dinosaur-dominated Jurassic Period, along with numerous other fossils described by Luo and colleagues in the last 10 years, however, provide strong evidence that ancestral mammals adapted to their wide-ranging environments despite competition from dinosaurs.
“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,” Luo said. “These new fossil gliders are the first winged mammals, and they 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.”
Adjustments in life structures, way of life and eating regimen
The capacity to coast noticeable all around is one of the numerous wonderful adjustments in warm blooded animals. Most warm blooded creatures live ashore, yet volant well evolved creatures, including flying squirrels and bats that fold flying creature like wings, made an imperative progress amongst land and airborne territories. The capacity to float between trees enabled the antiquated creatures to discover sustenance that was unavailable to other land creatures. That developmental favorable position can at present be seen among the present warm blooded creatures, for example, flying squirrels in North America and Asia, flaky followed lightweight flyers of Africa, marsupial sugar lightweight flyers of Australia and colugos of Southeast Asia.
The Jurassic Maiopatagium and Vilevolodon are stem mammaliaforms, long-terminated relatives of living warm blooded animals. They are haramiyidans, an altogether terminated branch on the mammalian developmental tree, yet are thought to be among heralds to current warm blooded animals. The two fossils demonstrate the wonderfully fossilized, wing-like skin layers between their front and back appendages. They additionally indicate numerous skeletal components in their shoulder joints and forelimbs that gave the antiquated creatures the nimbleness to be competent lightweight flyers. Developmentally, the two fossils, found in the Tiaojishan Formation upper east of Beijing, China, speak to the most punctual cases of floating conduct among wiped out well evolved creature predecessors.
Luo, Z.-X., et al. (2017). “New evidence for mammaliaform ear evolution and feeding adaptation in a Jurassic ecosystem.” Nature advance online publication.