Occurrence of a young elasmosaurid plesiosaur skeleton from the Late Cretaceous (Maastrichtian) of Antarctica

The most completely articulated fossil skeleton heretofore found on the continent of Antarctica is
represented by a juvenile plesiosaur. The specimen was found in the Sandwich Bluff area of Vega Island east of the
Antarctic Peninsula from Late Cretaceous (Maastrichtian) marine deposits from the upper Snow Hill Island Formation.
The plesiosaur skeleton is represented by a nearly complete torso, partial paddles, and neck and tail sections. Along the
ventral margin of the torso are articulated gastralia, some that are unusual in being forked. Numerous small gastroliths
are associated within the trunk cavity, indicating that even juveniles ingest gastroliths. Coupled with other known
specimens, the skeleton indicates shallow marine environment may have been an area where marine reptiles had their
young, and the young remained until reaching maturity prior to facing open marine environments. The morphology of
the specimen suggests the skeleton represents a juvenile Mauisaurus, an elasmosaurid plesiosaur taxon originally
described from New Zealand and endemic to the Weddellian Province of the austral region.