A new fossil genus of the family Strombidae (Gastropoda: Caenogastropoda: Stromboidea) from the Middle Miocene of Java

Abstract

A new genus of the family Strombidae (Caenogastropoda: Stromboidea) is described: Javastrombus n. gen., from the Middle Miocene of Western Java (Indonesia). It is considered to be phylogenetically close toPersististrombus, from which it probably derived. It is distinguished by its small size and delicate structure, the notable development of the apertural sinuses, a supracolumellar keel, and the delicate spiral sculpture. Six new species are included therein: J. praegracilis n. sp. (type species), J. pinguis n. sp., J. cylindratus n. sp., J. kecil n. sp., J. subinermis n. sp, and J. sondaicus n. sp. The new genus occupies a geographical position distant from both Afristrombus, currently limited to the tropical West African shores (but extending during the Neogene throughout the Paratethys and the Mediterranean), and Persististrombus, distributed throughout the Mediterranean area during the Oligocene and Miocene, as well as the tropical Atlantic and Pacific coasts of America since the Miocene. The new genus represents a branch of the group it constitutes together with Persististrombus and Afristrombus diversified in isolation in a favorable, stable and complex environment during the Middle Miocene (Langhian and Serravalliian, between 16.0 i 11.6 Ma).