TY - JOUR
T1 - The tempo of cetacean cranial evolution
AU - Coombs, Ellen J.
AU - Felice, Ryan N.
AU - Clavel, Julien
AU - Park, Travis
AU - Bennion, Rebecca F.
AU - Churchill, Morgan
AU - Geisler, Jonathan H.
AU - Beatty, Brian
AU - Goswami, Anjali
N1 - Funding Information:
This research was funded by the Natural Environment Research Council Doctoral Training Partnership training grant NE/L002485/1 to E.J.C. E.J.C.’s data collection was also supported by the UCL Bogue Fellowship and the Palaeontological Association Stan Wood Award. This research was also supported by National Science Foundation NSF-EAR 1349607 to J.G., B.B., A.G., and M.C., and University of Wisconsin-Oshkosh Faculty Development Grant to M.C. J.C. was funded by a Marie Skłodowska-Curie Individual Fellowship ( IF 797373-EVOTOOLS ), T.P. was funded by L everhulme Research Project Grant ( RPG-2019-323 ), and R.B. was funded by a FRIA fellowship from the F.R.S.-FNRS (grant FC 23645). Special thanks go to Richard Sabin for his help and support throughout and to Erich Fitzgerald for his helpful comments on improving the manuscript and analyses. We would like to thank Anne-Claire Fabre, Carla Bardua, Andrew Knapp, Eve Noirault, Heather White, João Vasco Leite, and Sandra Alvarez-Carretero for their comments, discussion, and help with code and Olivier Lambert, Felix Marx, and Robert Boessenecker for their helpful insights and discussion throughout E.J.C.'s research. Further thanks go to Eve Noirault for help with data collection and digitization of scans. Thanks also go to the many curators and museum staff who helped E.J.C., R.F.B., and M.C. collect scan data. Please see the list of institutions visited in the Github supplemental information. Final thanks go to the anonymous reviewers who helped us to improve the study.
Funding Information:
This research was funded by the Natural Environment Research Council Doctoral Training Partnership training grant NE/L002485/1 to E.J.C. E.J.C.’s data collection was also supported by the UCL Bogue Fellowship and the Palaeontological Association Stan Wood Award. This research was also supported by National Science Foundation NSF-EAR 1349607 to J.G. B.B. A.G. and M.C. and University of Wisconsin-Oshkosh Faculty Development Grant to M.C. J.C. was funded by a Marie Skłodowska-Curie Individual Fellowship (IF 797373-EVOTOOLS), T.P. was funded by Leverhulme Research Project Grant (RPG-2019-323), and R.B. was funded by a FRIA fellowship from the F.R.S.-FNRS (grant FC 23645). Special thanks go to Richard Sabin for his help and support throughout and to Erich Fitzgerald for his helpful comments on improving the manuscript and analyses. We would like to thank Anne-Claire Fabre, Carla Bardua, Andrew Knapp, Eve Noirault, Heather White, João Vasco Leite, and Sandra Alvarez-Carretero for their comments, discussion, and help with code and Olivier Lambert, Felix Marx, and Robert Boessenecker for their helpful insights and discussion throughout E.J.C.'s research. Further thanks go to Eve Noirault for help with data collection and digitization of scans. Thanks also go to the many curators and museum staff who helped E.J.C. R.F.B. and M.C. collect scan data. Please see the list of institutions visited in the Github supplemental information. Final thanks go to the anonymous reviewers who helped us to improve the study. Conceptualization, E.J.C. A.G. R.N.F. and J.C.; formal analysis, E.J.C. A.G. R.N.F. J.C. and T.P.; investigation, E.J.C. A.G. R.N.F. J.C. and T.P.; methodology, R.N.F. J.C. A.G. and E.J.C.; data acquisition, E.J.C. M.C. R.F.B. J.H.G. and B.B.; writing – review & editing, all authors. The authors declare no competing interests.
Publisher Copyright:
© 2022 The Authors
PY - 2022/5/23
Y1 - 2022/5/23
N2 - The evolution of cetaceans (whales and dolphins) represents one of the most extreme adaptive transitions known, from terrestrial mammals to a highly specialized aquatic radiation that includes the largest animals alive today. Many anatomical shifts in this transition involve the feeding, respiratory, and sensory structures of the cranium, which we quantified with a high-density, three-dimensional geometric morphometric analysis of 201 living and extinct cetacean species spanning the entirety of their ∼50-million-year evolutionary history. Our analyses demonstrate that cetacean suborders occupy distinct areas of cranial morphospace, with extinct, transitional taxa bridging the gap between archaeocetes (stem whales) and modern mysticetes (baleen whales) and odontocetes (toothed whales). This diversity was obtained through three key periods of rapid evolution: first, the initial evolution of archaeocetes in the early to mid-Eocene produced the highest evolutionary rates seen in cetaceans, concentrated in the maxilla, frontal, premaxilla, and nasal; second, the late Eocene divergence of the mysticetes and odontocetes drives a second peak in rates, with high rates and disparity sustained through the Oligocene; and third, the diversification of odontocetes, particularly sperm whales, in the Miocene (∼18–10 Mya) propels a final peak in the tempo of cetacean morphological evolution. Archaeocetes show the fastest evolutionary rates but the lowest disparity. Odontocetes exhibit the highest disparity, while mysticetes evolve at the slowest pace, particularly in the Neogene. Diet and echolocation have the strongest influence on cranial morphology, with habitat, size, dentition, and feeding method also significant factors impacting shape, disparity, and the pace of cetacean cranial evolution.
AB - The evolution of cetaceans (whales and dolphins) represents one of the most extreme adaptive transitions known, from terrestrial mammals to a highly specialized aquatic radiation that includes the largest animals alive today. Many anatomical shifts in this transition involve the feeding, respiratory, and sensory structures of the cranium, which we quantified with a high-density, three-dimensional geometric morphometric analysis of 201 living and extinct cetacean species spanning the entirety of their ∼50-million-year evolutionary history. Our analyses demonstrate that cetacean suborders occupy distinct areas of cranial morphospace, with extinct, transitional taxa bridging the gap between archaeocetes (stem whales) and modern mysticetes (baleen whales) and odontocetes (toothed whales). This diversity was obtained through three key periods of rapid evolution: first, the initial evolution of archaeocetes in the early to mid-Eocene produced the highest evolutionary rates seen in cetaceans, concentrated in the maxilla, frontal, premaxilla, and nasal; second, the late Eocene divergence of the mysticetes and odontocetes drives a second peak in rates, with high rates and disparity sustained through the Oligocene; and third, the diversification of odontocetes, particularly sperm whales, in the Miocene (∼18–10 Mya) propels a final peak in the tempo of cetacean morphological evolution. Archaeocetes show the fastest evolutionary rates but the lowest disparity. Odontocetes exhibit the highest disparity, while mysticetes evolve at the slowest pace, particularly in the Neogene. Diet and echolocation have the strongest influence on cranial morphology, with habitat, size, dentition, and feeding method also significant factors impacting shape, disparity, and the pace of cetacean cranial evolution.
KW - cranium
KW - diversity
KW - ecology cetaceans
KW - evolutionary rates
KW - morphology
UR - http://www.scopus.com/inward/record.url?scp=85130812186&partnerID=8YFLogxK
U2 - 10.1016/j.cub.2022.04.060
DO - 10.1016/j.cub.2022.04.060
M3 - Article
C2 - 35537454
AN - SCOPUS:85130812186
SN - 0960-9822
VL - 32
SP - 2233-2247.e4
JO - Current Biology
JF - Current Biology
IS - 10
ER -