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| Youngolepis praecursor Chang & Yu, 1981 in Cui, Friedman, Qiao, et al., 2022. artwork by Brian Choo |
Abstract
Innovations relating to the consumption of hard prey are implicated in ecological shifts in marine ecosystems as early as the mid-Paleozoic. Lungfishes represent the first and longest-ranging lineage of durophagous vertebrates, but how and when the various feeding specializations of this group arose remain unclear. Two exceptionally preserved fossils of the Early Devonian lobe-finned fish Youngolepis reveal the origin of the specialized lungfish feeding mechanism. Youngolepis has a radically restructured palate, reorienting jaw muscles for optimal force transition, coupled with radiating entopterygoid tooth rows like those of lungfish toothplates. This triturating surface occurs in conjunction with marginal dentition and blunt coronoid fangs, suggesting a role in crushing rather than piercing prey. Bayesian tip-dating analyses incorporating these morphological data indicate that the complete suite of lungfish feeding specializations may have arisen in as little as 7 million years, representing one of the most striking episodes of innovation during the initial evolutionary radiations of bony fishes.
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| Youngolepis praecursor, specimen IVPP V28375 in dorsal view. |
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| The palate and dorsal portion of the hyoid arch of Youngolepis praecursor. |
Youngolepis praecursor Chang & Yu, 1981
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| Timing of divergences and rates of trait evolution in lungfishes and their close relatives. |
Xindong Cui, Matt Friedman, Tuo Qiao, Yilun Yu and Min Zhu. 2022. The Rapid Evolution of Lungfish Durophagy. Nature Communications. 13: 2390. DOI: 10.1038/s41467-022-30091-3
highlighting feeding innovations in Youngolepis, an Early Devonian stem lungfish from China (art: Brian Choo) @NatureComms @Friedman_Lab
