Miocene fossils from the southeastern Pacific shed light on the last radiation of marine crocodylians - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Proceedings of the Royal Society B: Biological Sciences Année : 2022

Miocene fossils from the southeastern Pacific shed light on the last radiation of marine crocodylians

Résumé

The evolution of crocodylians as sea dwellers remains obscure because living representatives are basically freshwater inhabitants and fossil evidence lacks crucial aspects about crocodylian occupation of marine ecosystems. New fossils from marine deposits of Peru reveal that crocodylians were habitual coastal residents of the southeastern Pacific (SEP) for approximately 14 million years within the Miocene ( ca 19 to 5 Ma), an epoch including the highest global peak of marine crocodylian diversity. The assemblage of the SEP comprised two long and slender-snouted (longirostrine) taxa of the Gavialidae: the giant Piscogavialis and a new early diverging species, Sacacosuchus cordovai . Although living gavialids ( Gavialis and Tomistoma ) are freshwater forms, this remarkable fossil record and a suite of evolutionary morphological analyses reveal that the whole evolution of marine crocodylians pertained to the gavialids and their stem relatives (Gavialoidea). This adaptive radiation produced two longirostrine ecomorphs with dissimilar trophic roles in seawaters and involved multiple transmarine dispersals to South America and most landmasses. Marine gavialoids were shallow sea dwellers, and their Cenozoic diversification was influenced by the availability of coastal habitats. Soon after the richness peak of the Miocene, gavialoid crocodylians disappeared from the sea, probably as part of the marine megafauna extinction of the Pliocene.
Fichier principal
Vignette du fichier
Salas_ProcB_preprint.pdf (2.58 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-03726573 , version 1 (13-10-2022)

Identifiants

Citer

Rodolfo Salas-Gismondi, Diana Ochoa, Stephane Jouve, Pedro Romero, Jorge Cardich, et al.. Miocene fossils from the southeastern Pacific shed light on the last radiation of marine crocodylians. Proceedings of the Royal Society B: Biological Sciences, 2022, 289, pp.20220380. ⟨10.1098/rspb.2022.0380⟩. ⟨hal-03726573⟩
83 Consultations
40 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More