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PALEONTOLOGY: Homoplasy in the Mammalian Ear
Science (New York, N.Y.)
|February 15, 2005
Abstract:
The separation of the middle ear bones from the mandible is considered a defining feature of all modern mammals. But did this event happen once in a primitive mammalian ancestor or independently in the monotreme lineage and therian (marsupial and placental) lineage? As Martin and Luo discuss in their Perspective, a new fossil-the dentary bone of an ancient toothed monotreme-suggests that the middle ear bones formed independently in these two mammalian lineages, providing a remarkable example of homoplastic evolution.
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01:13The Cochlea
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01:11The Auditory Ossicles
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The aptly named stapes look very much like a stirrup. The three ossicles are unique to mammals, and each plays a role in...
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