Late Campanian-Early Maastrichtian Vertebrates from The James Ross Basin, West Antarctica: Updated Synthesis, Biostratigraphy, And Paleobiogeography

REGUERO, M.A.; GASPARINI, Z.; OLIVERO, E.; CORIA, R.; FERNANDEZ, MARTA S.; O'GORMAN, JOSÉ P.; GOURIC-CAVALLI, S.; ACOSTA HOSPITALECHE, C. ; BONA, P.; IGLESIAS, A.; GELFO, J.; RAFFI, M.E.; MOLY, J.J.; SANTILLANA, S.; CARDENAS, M

ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS.

ACAD BRASILEIRA DE CIENCIAS

Lugar: Rio de Janeiro; Año: 2022

0001-3765

The Snow Hill Island Formation (SHIF; late Campanian – early Maastrichtian)crops out in the northeast of the Antarctic Peninsula and constitutes the basal partof the late Campanian-early Maastrichtian sedimentary succession of the JamesRoss Basin (NG Sequence). Its major exposures occur at the James Ross and Vegaislands. Several fossil-bearing localities have been identifi ed in the SHIF providing avaluable fauna of invertebrates and vertebrates, and fl ora. Our study focuses on thevertebrate fauna recovered at Gamma and Cape Lamb members of the SHIF. The marinevertebrate assemblages include chondrichthyans, actinopterygians, and marine reptiles(elasmosaurid plesiosaurs and mosasaurs). A diverse terrestrial vertebrate as semblagehas been reported being characterized by dinosaurs (sauropod, elasmarian ornithopods,nodosaurid ankylosaur, and a paravian theropod), pterosaurs and birds. Most SHIFdinosaurs share close affi nities with penecontemporaneous taxa from southern SouthAmerica, indicating that at least some continental vertebrates could disperse betweensouthern South America and Antarctica during the Late Cretaceous. The Snow Hill IslandFormation provides the most diverse Late Cretaceous marine and continental faunasfrom Antarctica. The present study summarizes previous and new vertebrate fi ndingswith the best actualized stratigraphical framework, providing a more complete faunaassociation and analyzing further perspectives.