An inventory of molluscs recorded from mid-Cretaceous Burmese amber, with the description of a land snail, Euthema annae sp. nov. (Caenogastropoda, Cyclophoroidea, Diplommatinidae)

Abstract

A new species of Euthema of mid-Cretaceous age (Cenomanian, ca. 99–98 Ma), E. annae sp. nov., is described on the basis of two shells in Burmese amber (northern Myanmar). It differs by the presence of a parietal inclusion in the aperture and by the weakly convex whorls with dense, diagonally aligned ribs on the last whorl. The genus Euthema is redescribed, and a new synonym recognised, Paleodiplommatina. A list of all currently described molluscan species from Burmese amber is provided. Lagocheilus electrospira is reassigned to the genus Eotrichophorus. The taxonomic diversity and abundance of molluscs in Burmese amber are discussed on the basis of 198 observed snail inclusions from amber trading exchange and published data. Apparently, molluscs are much more common in Burmese amber than in any other deposit of amber, with a notable predominance of Cyclophoroidea. There are no specimens that could indicate the presence of Stylommatophora, Ellobioidea or other “pulmonates”.