Attenuated evolution of mammals through the Cenozoic

2022/10/27 by Anjali Goswami, Eve Noirault, Ellen J. Coombs +11 · 1 citation
Earth and Planetary Sciences · Agricultural and Biological Sciences · Mathematics · #Evolution and Paleontology Studies #Bat Biology and Ecology Studies #Morphological variations and asymmetry

paper · doi:10.1126/science.abm7525

openalex publication_date 2022/10/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

The Cenozoic diversification of placental mammals is the archetypal adaptive radiation. Yet, discrepancies between molecular divergence estimates and the fossil record fuel ongoing debate around the timing, tempo, and drivers of this radiation. Analysis of a three-dimensional skull dataset for living and extinct placental mammals demonstrates that evolutionary rates peak early and attenuate quickly. This long-term decline in tempo is punctuated by bursts of innovation that decreased in amplitude over the past 66 million years. Social, precocial, aquatic, and herbivorous species evolve fastest, especially whales, elephants, sirenians, and extinct ungulates. Slow rates in rodents and bats indicate dissociation of taxonomic and morphological diversification. Frustratingly, highly similar ancestral shape estimates for placental mammal superorders suggest that their earliest representatives may continue to elude unequivocal identification.

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Cited by

• 2022 in paleomammalogy [wikipedia]