Prolonged morphological expansion of spiny-rayed fishes following the end-Cretaceous

• Published in: Nature ecology & evolution Vol. 6; no. 8; pp. 1211 - 1220
• Main Authors: Ghezelayagh, Ava, Harrington, Richard C., Burress, Edward D., Campbell, Matthew A., Buckner, Janet C., Chakrabarty, Prosanta, Glass, Jessica R., McCraney, W. Tyler, Unmack, Peter J., Thacker, Christine E., Alfaro, Michael E., Friedman, Sarah T., Ludt, William B., Cowman, Peter F., Friedman, Matt, Price, Samantha A., Dornburg, Alex, Faircloth, Brant C., Wainwright, Peter C., Near, Thomas J.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.08.2022; Nature Publishing Group
• Subjects: 45; 631/181/2480; 631/181/757; 631/601/2722; Aquatic habitats; Biological and Physical Anthropology; Biomedical and Life Sciences; Calibration; Cenozoic; Cretaceous; Ecological conditions; Ecology; Evolutionary Biology; Fossils; Life Sciences; Mass extinctions; Morphology; Paleogene; Paleontology; Phylogeny; Predators; Swimming; Vertebrates; Zoology
• ISSN: 2397-334X; 2397-334X
• DOI: 10.1038/s41559-022-01801-3

Spiny-rayed fishes (Acanthomorpha) dominate modern marine habitats and account for more than a quarter of all living vertebrate species. Previous time-calibrated phylogenies and patterns from the fossil record explain this dominance by correlating the origin of major acanthomorph lineages with the Cretaceous–Palaeogene mass extinction. Here we infer a time-calibrated phylogeny using ultraconserved elements that samples 91.4% of all acanthomorph families and investigate patterns of body shape disparity. Our results show that acanthomorph lineages steadily accumulated throughout the Cenozoic and underwent a significant expansion of among-clade morphological disparity several million years after the end-Cretaceous. These acanthomorph lineages radiated into and diversified within distinct regions of morphospace that characterize iconic lineages, including fast-swimming open-ocean predators, laterally compressed reef fishes, bottom-dwelling flatfishes, seahorses and pufferfishes. The evolutionary success of spiny-rayed fishes is the culmination of multiple species-rich and phenotypically disparate lineages independently diversifying across the globe under a wide range of ecological conditions. The authors construct a time-calibrated phylogeny spanning >90% of spiny-rayed fishes to explore patterns of body shape disparity within acanthomorphs. They find a trend of steady accumulation of lineages from the Cenozoic, with an increase in morphological disparity following the Cretaceous–Palaeogene event, facilitating the radiation of diverse morphotypes that characterize acanthomorphs’ widespread ecological success today.