An elusive evolutionary “missing link” bridging the bones of the mammalian middle ear with the reptilian jawbones is discovered in a fossil of an early squirrel-like mammal.
One of the “knowns” in the evolutionary biology of mammals, including humans, is that the three little bones in their middle ear originated in the lower jaw of their reptilian predecessors. The link has been demonstrated in studies of developing mammalian embryos, and two of the three bones are found in the jaw of living reptiles…
But finding fossils of the transitional middle ear, considered a classic example of gradual evolution in vertebrates, had until now eluded paleontologists.
Scientists report in the current issue of the journal Nature the discovery in China of a 122 million-year-old fossil of a mammal the size of a small squirrel that lived in the shadow of the mighty Cretaceous dinosaurs…
Its well-preserved skeleton, the scientists said, bore “the first unambiguous paleontological evidence” showing the close relationship between the lower jaw and the middle ear, the ring-shaped area just inside the ear drum.
http://www.project-reason.org/newsf...:+Newsfeed&utm_content=Twitter#When:02:35:23Z
One of the “knowns” in the evolutionary biology of mammals, including humans, is that the three little bones in their middle ear originated in the lower jaw of their reptilian predecessors. The link has been demonstrated in studies of developing mammalian embryos, and two of the three bones are found in the jaw of living reptiles…
But finding fossils of the transitional middle ear, considered a classic example of gradual evolution in vertebrates, had until now eluded paleontologists.
Scientists report in the current issue of the journal Nature the discovery in China of a 122 million-year-old fossil of a mammal the size of a small squirrel that lived in the shadow of the mighty Cretaceous dinosaurs…
Its well-preserved skeleton, the scientists said, bore “the first unambiguous paleontological evidence” showing the close relationship between the lower jaw and the middle ear, the ring-shaped area just inside the ear drum.
http://www.project-reason.org/newsf...:+Newsfeed&utm_content=Twitter#When:02:35:23Z
