Upper Cretaceous Plesiosaurs from James Ross Basin, Antarctic Peninsula

O'GORMAN, J.P; REGUERO, M.; MARENSSI, S; GASPARINI, Z; MOLY, J.J.

Congreso; 11th International Symposium on Antarctic Earth Sciences; 2011

As a result of 35 years of cooperative explorations and researches of the División Paleontología Vertebrados (Museo de La Plata, Argentina) and the Instituto Antártico Argentino (IAA, Argentina) has been formed the largest collection of plesiosaur specimens known from the James Ross Basin (NE of the Antarctic Peninsula). This collection is housed at the Museo de La Plata. The first remains of plesiosaurs from Antarctica were discovered and studied by Argentineans in 1976. Campanian and Maastrichtian plesiosaurs have been recovered from Santa Marta Formation (Campanian) on James Ross Island, Cape Lamb Member (Upper Campanian/Lower Maastrichtian) and Sandwich Bluff (Upper Maastrichtian) of the Snow Hill Formation onVega Island, and López de Bertodano Formation (Upper Maastrichtian) on Seymour (Marambio) Island. Preliminary results of the doctoral thesis carry out by one of the authors (J.P.O.) on systematic analysis on these specimens point out the predominant presence of plesiosaurs Elasmosauridae over Aristonectidae and Polycotylidae in Antarctica; however aristonectids plesiosaurs are not uncommon. Overall, the plesiosaurs from Antarctica, which can be identified al generic level, appear to be close related with those of the Late Cretaceous from Patagonia (South America) and New Zealand.