Phylogeny, systematics, and evolution of the family Costellariidae (Gastropoda: Neogastropoda)

The neogastropod family Costellariidae is a large and successful group of carnivorous marine mollusks that encompasses about 475 living species. Costellariids are most diverse in the tropical Indo-Pacific at a depth interval of 0-200 m, where they are largely represented by numerous species commonly assigned to the genus Vexillum. The present work expands the taxon sampling of a previous phylogeny of the mitriform gastropods to resolve earlier problematic relationships, and thus establish a robust framework of the family, revise its taxonomy, and uncover major trends in the evolution of costellariid morphology. A multicuspidate rachidian is shown to have appeared at least twice in the evolutionary history of the family: it is regarded as an apomorphy of the primarily Indo-Pacific Vexillum-Austromitra-Atlantilux lineage, and has evolved independently in the Nodicostellaria-Mitromica lineage of the western hemisphere. The genera Ceratoxancus and Latiromitra are transferred from the Ptychatractidae to the Costellariidae. Tosapusia, Protoelongata, and Pusia are ranked as full genera, the latter with the three subgenera Pusia, Ebenomitra, and Vexillena. Vexillum ( Costellaria) and Zierliana are treated as synonyms of Vexillum. The replacement name Suluspira is proposed for Visaya Poppe, Guillot de Suduiraut & Tagaro, 2006, non Ahyong, 2004 ( Crustacea). We introduce four new genera, Alisimitra, Costapex, Turriplicifer, and Orphanopusia, and characterize their anatomy; 14 new species, mostly from deep water in the Indo-Pacific, are described in the genera Tosapusia, Alisimitra, Costapex, and Pusia. At least two species of Costapex gen. nov. have been collected from sunken wood. (C) 2017 The Linnean Society of London, Zoological Journal of the Linnean Society, 2017