Two waves of colonization straddling the K-Pg boundary formed the modern reef fish fauna.
Living reef fishes are one of the most diverse vertebrate assemblages on Earth. Despite its prominence and ecological importance, the origins and assembly of the reef fish fauna is poorly described. A patchy fossil record suggests that the major colonization of reef habitats must have occurred in the Late Cretaceous and early Palaeogene, with the earliest known modern fossil coral reef fish assemblage dated to 50 Ma. Using a phylogenetic approach, we analysed the early evolutionary dynamics of modern reef fishes. We find that reef lineages successively colonized reef habitats throughout the Late Cretaceous and early Palaeogene. Two waves of invasion were accompanied by increasing morphological convergence: one in the Late Cretaceous from 90 to 72 Ma and the other immediately following the end-Cretaceous mass extinction. The surge in reef invasions after the Cretaceous-Palaeogene boundary continued for 10 Myr, after which the pace of transitions to reef habitats slowed. Combined, these patterns match a classic niche-filling scenario: early transitions to reefs were made rapidly by morphologically distinct lineages and were followed by a decrease in the rate of invasions and eventual saturation of morphospace. Major alterations in reef composition, distribution and abundance, along with shifts in climate and oceanic currents, occurred during the Late Cretaceous and early Palaeogene interval. A causal mechanism between these changes and concurrent episodes of reef invasion remains obscure, but what is clear is that the broad framework of the modern reef fish fauna was in place within 10 Myr of the end-Cretaceous extinction.
Department of Evolution and Ecology, University of California, , Davis, CA 95618, USA, W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges, , 925 North Mills Avenue, Claremont, CA 91711, USA, Department of Biological Science, Towson University, , Towson, MD 21252, USA, Department of Ecology and Evolutionary Biology and Peabody Museum of Natural History, Yale University, , New Haven, CT, USA, Department of Ecology and Evolutionary Biology and Biodiversity Institute, University of Kansas, , Lawrence, KS 66045, USA, Department of Earth Sciences, University of Oxford, , Oxford OX1 3AN, UK.
S A
SA
Price
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L
Schmitz
C E
CE
Oufiero
R I
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Eytan
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A
Dornburg
W L
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Smith
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M
Friedman
T J
TJ
Near
P C
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Wainwright
D000818:Animals; D044822:Biodiversity; D005075:Biological Evolution; D057894:Coral Reefs; D053476:Extinction, Biological; D005399:Fishes / Q000502:physiology*; D010802:Phylogeny
Cretaceous–Palaeogene mass extinction; macroevolution; niche-filling models; reef fishes