Anomalodesmata Dall, 1889

Lazo, Darío G., 2007, The bivalve Pholadomya gigantea in the Early Cretaceous of Argentina: Taxonomy, taphonomy, and paleogeographic implications, Acta Palaeontologica Polonica 52 (2), pp. 375-390 : 378

Subclass Anomalodesmata Dall, 1889 Order Pholadomyoida Newell, 1965 Superfamily Pholadomyoidea Gray, 1847 Family Pholadomyidae Gray, 1847 Genus Pholadomya G.B. Sowerby, 1823

Type species: Pholadomya candida G.B. Sowerby, 1823 ; Recent , Tortola Island, British Virgin Islands .

Diagnosis.—See Runnegar (1972).

Remarks.— Pholadomya candida is the only Recent species of the nominal genus. Since living specimens had not been found since the last century this species was considered extinct, but new discoveries of recently dead shells from the Colombian Caribbean provide further evidence that the species is not extinct ( Díaz and Borrero 1995). The records of these species are extremely scarce and the species is considered one of the rarest living bivalves ( Runnegar 1972). It is only known from a small number of shells housed at different institutions and only two specimens had soft parts. One of them was dissected by Richard Owen in about 1839, but his illustrations were lost and the manuscript never published. The second specimen was dissected and published by Morton (1980). The shell is aragonitic and consists of three layers: an outer prismatic layer, a middle nacreous layer, and an inner sheet nacre layer (Taylor et al. 1973).

Occurrences.—Late Triassic to Recent, cosmopolitan ( Cox 1969).