Groovy Bones: Mammalian ear structure evolved more than once
By Sid Perkins
Fossils of an ancient egg-laying mammal indicate that the configuration of the bones in all living mammals’ ears arose at least twice along independent evolutionary pathways, paleontologists say.
The tiniest mammalian bones—the middle ear’s sound-transducing trio of the stapes, incus, and malleus—most distinctively distinguish mammals from other vertebrates.