The cochlea of the enigmatic pygmy right whale Caperea marginata informs mysticete phylogeny

• Published in: Journal of Morphology
• Main Authors: Park, Travis, Marx, Felix G., Fitzgerald, Erich M.G., Evans, Alistair R.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2017
• Subjects: Recess; Fitzgerald; baleen whale
• Online Access: https://zenodo.org/record/1137761; https://doi.org/10.1002/jmor.20674

The pygmy right whale, Caperea marginata, is the least understood extant baleen whale (Cetacea, Mysticeti). Knowledge on its basic anatomy, ecology, and fossil record is limited, even though its singular position outside both balaenids (right whales) and balaenopteroids (rorquals1grey whales) gives Caperea a pivotal role in mysticete evolution. Recent investigations of the cetacean cochlea have provided new insights into sensory capabilities and phylogeny. Here, we extend this advance to Caperea by describing, for the first time, the inner ear of this enigmatic species. The cochlea is large and appears to be sensitive to low-frequency sounds, but its hearing limit is relatively high. The presence of a well-developed tympanal recess links Caperea with cetotheriids and balaenopteroids, rather than balaenids, contrary to the traditional morphological view of a close Caperea-balaenid relationship. Nevertheless, a broader sample of the cetotheriid Herpetocetus demonstrates that the presence of a tympanal recess can be variable at the specific and possibly even the intraspecific level. This is the peer reviewed version of the following article: Park T, Marx FG, Fitzgerald EMG, Evans 1 AR (2017) The cochlea of the enigmatic pygmy right whale Caperea marginata informs mysticete phylogeny. Journal of Morphology, 278, 801-809, which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1002/jmor.20674/full. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.