Craniofacial development illuminates the evolution of nightbirds (Strisores)

Navalón, Guillermo; Nebreda, Sergio M.; Bright, Jen A.; Fabbri, Matteo; Benson, Roger B. J.; Bhullar, Bhart Anjan; Marugán-Lobón, Jesús; Rayfield, Emily J.

Abstract

Evolutionary variation in ontogeny played a central role in the origin of the avian skull. However, its influence in subsequent bird evolution is largely unexplored. We assess the links between ontogenetic and evolutionary variation of skull morphology in Strisores (nightbirds). Nightbirds span an exceptional range of ecologies, sizes, life-history traits and craniofacial morphologies constituting an ideal test for evo-devo hypotheses of avian craniofacial evolution. These morphologies include superficially 'juvenile-like' broad, flat skulls with short rostra and large orbits in swifts, nightjars and allied lineages, and the elongate, narrow rostra and globular skulls of hummingbirds. Here, we show that nightbird skulls undergo large ontogenetic shape changes that differ strongly from widespread avian patterns. While the superficially juvenile-like skull morphology of many adult nightbirds results from convergent evolution, rather than paedomorphosis, the divergent cranial morphology of hummingbirds originates from an evolutionary reversal to a more typical avian ontogenetic trajectory combined with accelerated ontogenetic shape change. Our findings underscore the evolutionary lability of cranial growth and development in birds, and the underappreciated role of this aspect of phenotypic variability in the macroevolutionary diversification of the amniote skull.

Citation

Navalón, G., Nebreda, S. M., Bright, J. A., Fabbri, M., Benson, R. B. J., Bhullar, B. A., …Rayfield, E. J. (2021). Craniofacial development illuminates the evolution of nightbirds (Strisores). Proceedings of the Royal Society B: Biological Sciences, 288(1948), Article 20210181. https://doi.org/10.1098/rspb.2021.0181

• Journal Article Type: Article
• Acceptance Date: Mar 17, 2021
• Online Publication Date: Apr 14, 2021
• Publication Date: Apr 14, 2021
• Deposit Date: Apr 14, 2021
• Publicly Available Date: Apr 15, 2021
• Journal: Proceedings of the Royal Society B: Biological Sciences
• Print ISSN: 0962-8452
• Electronic ISSN: 1471-2954
• Publisher: The Royal Society
• Peer Reviewed: Peer Reviewed
• Volume: 288
• Issue: 1948
• Article Number: 20210181
• DOI: https://doi.org/10.1098/rspb.2021.0181
• Keywords: Skull; Birds; Ontogeny; Shape; Morphometrics; Macroevolution
• Public URL: https://hull-repository.worktribe.com/output/3751593