LATE CAMPANIAN-EARLY MAASTRICHTIAN VERTEBRATES FROM THE JAMES ROSS BASIN, WEST ANTARCTICA: UPDATED SYNTHESIS, BIOSTRATIGRAPHY, AND PALEOBIOGEOGRAPHY

REGUERO, M.A.; GASPARINI, Z; OLIVERO, E.B.; CORIA, RODOLFO A.; FERNANDEZ, M.; O'GORMAN, J. P.; GOUIRIC-CAVALLI, S.; ACOSTA-HOSPITALECHE, C; BONA, PAULA; 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: 2021

0001-3765

Abstract. - The Snow Hill Island Formation (SHIF; late Campanian - earlyMaastrichtian) crops out in the northeast of the Antarctic Peninsula and constitutes thebasal part of the NG Sequence being part of the transgressive sedimentation cycle of theJames Ross Basin. Its major exposures occur at the James Ross and Vega islands.Several fossil-bearing localities have been identified in the SHIF providing a valuablefauna of invertebrates and vertebrates, and flora. Our study focuses on the vertebratefauna recovered at Gamma and Cape Lamb members of the SHIF. The marinevertebrate assemblages include fishes (chondrichthyans, and actinopterygians) andmarine reptiles (elasmosaurid plesiosaurs and mosasaurs). A diverse terrestrialvertebrate assemblage has been reported being characterized by dinosaurs (sauropod,elasmarian ornithopods, nodosaurid ankylosaur, and a paravian theropod), pterosaursand birds. Most SHIF dinosaurs share close affinities with penecontemporaneous taxafrom southern South America, indicating that at least some continental vertebrates coulddisperse between southern South America and Antarctica during the Late Cretaceous.The Snow Hill Island Formation provides the most diverse Late Cretaceous marine andcontinental faunas from Antarctica. The present study summarizes previous vertebratefindings with the best actualized stratigraphical position, provides new recordsproviding a more complete fauna association, and analyzes further perspectives.