Euthecosomatous gastropods (Mollusca: Heterobranchia) from Buton (SE Sulawesi, Indonesia), with notes on species from Viti Levo, Fiji; systematics, biostratigraphy

Abstract

Pteropoda (Mollusca, Gastropoda, Euthecosomata) described by Beets (1943, 1950,1953) from the alleged Late Miocene/Early Pliocene asphaltic deposits of Buton (SE Sulawesi, Indonesia) are revised. The following species are distinguished: Styliola subula (Quoy & Gaimard, 1827), Cavolinia bituminara (Beets, 1953), Cavolinia mexicana(Collins, 1934), Cavolinia vendryesiana (Guppy, 1873)and Diacria mbaensis Ladd, 1934. A comparison with the Fiji pteropod associations suggests a Miocene (Tortonian to Messinian) age for the Indonesian faunules. Pteropod species described by Ladd (1934) from Viti Levu (Fiji Islands), are revised in an appendix. Five species are distinguished, viz. Creseis acicula (Rang, 1828) (?), Cavolinia gypsorum (Bellardi, 1873), C. mexicana, C. rewaensis (Ladd, 1934) and Diacria mbaensis Ladd, 1934. The presence of Cavolina gypsorum dates this association as Miocene (Tortonian-Messinian).