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Deep time diversity and the early radiations of birds. (1 Viewer)

Fred Ruhe

Well-known member
Netherlands
Yilun Yu, Chi Zhang, and Xing Xu ,2021

Deep time diversity and the early radiations of birds.

Proceedings of the National Academy of Sciences 118(10): e2019865118
doi: https://doi.org/10.1073/pnas.2019865118
https://www.pnas.org/content/118/10/e2019865118

Significance​

Our lineage diversification rate through time analyses of three supertrees combining the published phylogenies of both stem and crown group birds reveal three distinct large-scale increases in the diversification rate across bird evolutionary history. The first two increases also are associated with rapid morphological evolution pertaining to the locomotory and cranial systems, respectively. The third increase needs further support from morphological data. Our study demonstrates that the bird biodiversity evolution was influenced mainly by long-term climatic changes and also by the Cretaceous–Paleogene extinction.

Abstract​

Reconstructing the history of biodiversity has been hindered by often-separate analyses of stem and crown groups of the clades in question that are not easily understood within the same unified evolutionary framework. Here, we investigate the evolutionary history of birds by analyzing three supertrees that combine published phylogenies of both stem and crown birds. Our analyses reveal three distinct large-scale increases in the diversification rate across bird evolutionary history. The first increase, which began between 160 and 170 Ma and reached its peak between 130 and 135 Ma, corresponds to an accelerated morphological evolutionary rate associated with the locomotory systems among early stem birds. This radiation resulted in morphospace occupation that is larger and different from their close dinosaurian relatives, demonstrating the occurrence of a radiation among early stem birds. The second increase, which started ∼90 Ma and reached its peak between 65 and 55 Ma, is associated with rapid evolution of the cranial skeleton among early crown birds, driven differently from the first radiation. The third increase, which occurred after ∼40 to 45 Ma, has yet to be supported by quantitative morphological data but gains some support from the fossil record. Our analyses indicate that the bird biodiversity evolution was influenced mainly by long-term climatic changes and also by major paleobiological events such as the Cretaceous–Paleogene (K–Pg) extinction.

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Fred
 

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