Presence of the elasmosaurid plesiosaur Mauisaurus in the Maastrichtian (Late Cretaceous) of central Chile

Abstract

The revision by Hiller et al. (2005) of the species Mauisaurus haasti Hector (Plesiosauroidea, Elasmosauridae) from the Late Cretaceous of New Zealand, has provided reliable postcranial characters that permit recognition of this taxon as distinct among Late Cretaceous elasmosaurid plesiosaurs from both the Northern and Southern hemispheres. Partic− ularly, in adult specimens, the femur displays a large, hemi− spherical capitulum that seems to be autapomorphic. This unique morphology is present in at least two specimens re− covered from Late Cretaceous (Maastrichtian) beds in cen− tral Chile, which these fossils may be referred to the same taxon with confidence. The Chilean fossils are considerably larger than those from New Zealand, suggesting either dif− ference in ontogenetic age or interspecific variation. The studied material constitutes the second accurate generic identification of elasmosaurid plesiosaurs from the eastern margin of the Pacific Ocean, thus complementing the known south−gondwanic paleodistribution of Mauisaurus during the Late Cretaceous.