Morphological diversity of the cetacean mandibular symphysis coincides with novel modes of aquatic feeding
Published in Paleobiology, 2025
Recommended citation: Strauch, R. J., Berv, J. S., Fraser, D., Pyenson, N. D., & Peredo, C. M. (2025). Morphological diversity of the cetacean mandibular symphysis coincides with novel modes of aquatic feeding. Paleobiology. doi: 10.1017/pab.2025.10061 Student advisee https://www.cambridge.org/core/services/aop-cambridge-core/content/view/E26D07190859FF4B606098AACF19F246/S0094837325100614a.pdf/morphological-diversity-of-the-cetacean-mandibular-symphysis-coincides-with-novel-modes-of-aquatic-feeding.pdf
Abstract: The mandibular symphysis—the midline joint connecting the two halves of the lower jaw—is a key structure shaping feeding mechanics and prey capture in mammals. Cetaceans (whales, dolphins, and porpoises) exhibit exceptional diversity in this joint, ranging from tightly fused to highly kinetic forms. This study quantifies symphyseal morphology across 206 extant and fossil cetacean taxa, showing that shifts in fusion and length track major ecological transitions and the emergence of new feeding strategies, particularly during the middle–late Eocene and the Eocene–Oligocene boundary. Mysticetes evolved unfused, mobile mandibles, while several odontocete lineages independently converged on fully fused, elongated jaws in the Miocene. These patterns reveal strong correlations between symphyseal form, feeding strategy, dentition, and prey type, underscoring the joint’s pivotal role in cetacean trophic evolution.
Recommended citation: R. J. Strauch, J. S. Berv, D. Fraser, N. D. Pyenson, C. M. Peredo. 2025. Paleobiology, 1–10. https://doi.org/10.1017/pab.2025.10061