First marine Triassic fauna from the Antarctic Peninsula

The fauna reported here was obtained from the Legoupil Formation in the north-western part of the Antarctic Peninsula (Fig. 1), which has been assigned a Cretaceous age on the basis of radiometric data1,2. Among the first collection of poorly preserved fossils from this formation were two bivalves tentatively referred to the Cretaceous genus Platopis, an identification which substantiated the radiometric evidence. The study of a more recent collection, by members of the British Antarctic Survey, shows, however, that the bivalves have strong Triassic affinities and, since there is no reason to suspect that they are derived, indicates that the Legoupil Formation is of the same age.