A new limid bivalve from the La Meseta Formation (Eocene) of Seymour Island, Antarctic Peninsula

Abstract

Several specimens of an unusual limid bivalve were collected recently from basal transgressive facies (Telm 1) of the Eocene La Meseta Formation, Seymour (Marambio) Island, Antarctic Peninsula. This bivalve represents a new subgenus and species, described herein as Acesta (Antarcticesta) laticosa subgen. et sp. n. Acesta (Acesta) bibbyi STILWELL & ZINSMEISTER, 1992, and Acesta (Antarcticesta) laticosta subgen. et sp. n. are the only limid bivalves recorded from the Eocene of Antarctica, but the history of the family in Antarctica extends from Cretaceous to Recent. Acesta (Antarcticesta) subgen. n. is monotypic and endemic to Antarctica with no known close relative.