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.
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The tiniest mammalian bones—the middle ear’s sound-transducing trio of the stapes, incus, and malleus—most distinctively distinguish mammals from other vertebrates.