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New Miocene Caribbean gavialoids and patterns of longirostry in crocodylians

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dc.contributor.author Salas-Gismondi, R.
dc.contributor.author Moreno-Bernal, J.W.
dc.contributor.author Scheyer, T.M.
dc.contributor.author Sánchez-Villagra, M.R.
dc.contributor.author Jaramillo, C.
dc.date.accessioned 2019-04-24T18:23:54Z
dc.date.available 2019-04-24T18:23:54Z
dc.date.issued 2018
dc.identifier.uri https://hdl.handle.net/20.500.12866/6478
dc.description.abstract Gavialoidea is a clade of slender- and long-snouted crocodylomorphs with a single living species, the Indian gharial Gavialis gangeticus. Because elongated snouts (longirostry) have evolved independently in several crocodylomorph clades, this head shape has been interpreted as an ecological adaptation. How this condition affected patterns of diversification and how longirostrine-associated cranial features changed through adaptive radiations remain poorly understood. Two new small gryposuchine gavialoids, Dadagavialis gunai gen. et sp. nov. (early Miocene, Panama) and Aktiogavialis caribesi sp. nov. (late Miocene, Venezuela), evidence remarkable Miocene diversification of longirostrine forms in the Neotropics and support transmarine biogeographical relations between northern South America, the Caribbean, and southernmost North America before the Isthmus of Panama was fully established. By integrating phylogenetics and geometric morphometrics, we focus on this gavialoid diversity to investigate patterns of longirostry across the crown group of crocodylomorphs (Crocodylia). Analyses revealed that the snout shape of gavialoids has occupied a small, distinct and almost invariable morphospace since the Cretaceous, in contrast with the morphologically labile snout shape of other crocodylians (crocodyloids and alligatoroids). Our results suggest iterative environmental shift occupations throughout gavialoid evolution without major changes in snout proportions, but involving conspicuous rearrangements of the circumorbital bones. The longirostrine gavialoid morphotype is a distinct adaptation for seizing small prey and typically includes short and wide premaxillae and enlarged ‘caniniform’ teeth only at the tip of the snout. In longirostrine crocodyloids (Tomistoma, Crocodylus intermedius), the conservation of powerful bites and ‘caniniforms’ closer to the jaw joints allowed them to exploit a wider range of prey sizes, which could explain their snout shape plasticity. Therefore, the Mio–Pliocene extirpation of gryposuchine gavialoids from the Caribbean by the arrival of Crocodylus is quite unlikely. The last gryposuchine survived throughout the Pliocene in the south-eastern Pacific, where Crocodylus has never been documented. en_US
dc.language.iso eng
dc.publisher Taylor and Francis
dc.relation.ispartofseries Journal of Systematic Palaeontology
dc.rights info:eu-repo/semantics/restrictedAccess
dc.rights.uri https://creativecommons.org/licenses/by-nc-nd/4.0/deed.es
dc.subject evolution en_US
dc.subject Pacific Ocean en_US
dc.subject Pacific Ocean (Southeast) en_US
dc.subject Miocene en_US
dc.subject adaptation en_US
dc.subject morphology en_US
dc.subject phylogenetics en_US
dc.subject adaptive radiation en_US
dc.subject Alligatoroidea en_US
dc.subject conservation status en_US
dc.subject Cretaceous en_US
dc.subject crocodilian en_US
dc.subject Crocodylidae (all crocodiles) en_US
dc.subject Crocodylomorpha en_US
dc.subject Crocodylus en_US
dc.subject Crocodylus intermedius en_US
dc.subject Gavialinae en_US
dc.subject Gavialis gangeticus en_US
dc.subject Gavialoidea en_US
dc.subject Isthmus of Panama en_US
dc.subject morphometrics en_US
dc.subject morphometry en_US
dc.subject morphotype en_US
dc.subject Neotropical Region en_US
dc.subject Neotropics en_US
dc.subject North America en_US
dc.subject Panama [Central America] en_US
dc.subject Pliocene en_US
dc.subject reptile en_US
dc.subject Tomistoma en_US
dc.subject Venezuela en_US
dc.title New Miocene Caribbean gavialoids and patterns of longirostry in crocodylians en_US
dc.type info:eu-repo/semantics/article
dc.identifier.doi https://doi.org/10.1080/14772019.2018.1495275
dc.subject.ocde https://purl.org/pe-repo/ocde/ford#1.05.03
dc.relation.issn 1478-0941


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