Composition and distribution of the inoceramid bivalve genus Anopaea
Anopaea is a distinctive Late Jurassic-Early Cretaceous inoceramid bivalve genus. Traditionally recognized by its elongate-pyriform outline and impressed antero-ventral sulcus, it is now apparent that it also has a distinctive hingeline. In each valve the thickened shell material of the hinge region terminates in a prominent fold, the anterior buttress; this often takes on the appearance of a small anterior ‘ear’. Some fifteen taxa are now assigned to the genus and a further seven are probable members. The bulk of these forms fall within the Late Tithonian-Early Albian. A. callistoensis sp. nov., from the Late Tithonian-?Early Berriasian of the Antarctic Peninsula, and a probable new species from the Berriasian of the South Shetland Islands, are described. Inoceramus constrictus, from the Early Albian of Queensland Australia, can now be referred to the genus. It can be confirmed that, with only a very small number of exceptions, Anopaea was restricted to Late Jurassic-Early Cretaceous extra-Tethyan localities. In this sense it may be regarded as a genuine bipolar taxon, although amphitropical is perhaps a more accurate term.