Supplementary Discussion for Fig. 2.
Moving models explaining sound transmission through the middle ear in land mammals, and in cetaceans can be founds at:
The model for cetacean hearing is based on studies of odontocetes (ref. S12). Here, we use this model to explain certain features of the evolution of middle ear transmission in archaeocetes. Sound transmission through the mysticete middle ear is poorly understood, and no working model is available. The odontocete middle ear transmission system appears to be more plesiomorphic than that of mysticetes, and can thus be used to study archaeocete sound transmission. Further research on mysticete sound transmission is necessary to clarify this.
Supplementary Discussion for Fig. 4
Phylogeny and sister group relations are discussed in refs S2-S4, S15-S16.
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