The skull of the Miocene Spheniscus urbinai (Aves, Sphenisciformes): osteology, brain morphology, and the cranial pneumatic systems

Abstract Spheniscus urbinai represents one of four extinct Spheniscus species from the Cenozoic of southern South America, known from several poorly described diversely complete skulls and postcranial elements. Here, we present a review of the cranial osteology of all known specimens (collected in A...

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Bibliographic Details
Published in:Journal of Anatomy
Main Authors: Acosta Hospitaleche, Carolina, Paulina‐Carabajal, Ariana, Yury‐Yáñez, Roberto
Other Authors: Universidad Nacional de La Plata, Fondo para la Investigación Científica y Tecnológica
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2021
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Online Access:http://dx.doi.org/10.1111/joa.13403
https://onlinelibrary.wiley.com/doi/pdf/10.1111/joa.13403
https://onlinelibrary.wiley.com/doi/full-xml/10.1111/joa.13403
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Summary:Abstract Spheniscus urbinai represents one of four extinct Spheniscus species from the Cenozoic of southern South America, known from several poorly described diversely complete skulls and postcranial elements. Here, we present a review of the cranial osteology of all known specimens (collected in Argentina, Chile, and Peru), including a paleoneurological analysis using CT scans, and an exploration of its cranial pneumaticity compared to other extinct and living seabirds. Our results show that among Spheniscus species, S. urbinai exhibits slightly greater cranial pneumaticity than the living species. Additionally, we confirm previous findings which indicate that the marked reduction of cranial pneumaticity—which is characteristic of living penguins—occurred early during the Eocene (as observed in the Antarctic penguin MLP 12‐I‐20‐1, but not in the coeval Anthropornis ).