Phylogeny of Carditidae (Bivalvia: Archiheterodonta): Revisting the subfamiliar systematic scheme

PEREZ DAMIAN; DEL RIO, CLAUDIA JULIA

Buenos Aires

Congreso; 35º Annual Meeting of the Willi Hennig Society y 12º Reunión Argentina de Cladística y Biogeografía; 2016

Carditidae comprises a large family of bivalves distributed worldwide with a high diversification during the Paleogene but their phylogenetic relationships are scarcely studied and only one subfamiliar systematic classification was suggested. This scheme includes seven subfamilies based on shell outlineand hinge configuration. Some authors proposed the presence of two lineages named as "alticostastes" and "planicostates", but these were not considered in the subfamiliar classification. We performed a cladistic phylogenetic analysis including 74 fossil and recent species belonging to all known subfamilies, using 137 morphological shell-characters. The obtained results differ from the previously proposed systematic scheme. The Thecalinae subfamily is nested within Carditinae, and the Carditamerinae shows a lower diversity than before, only including the genera Carditamera, Byssomera, Glans and Centrocardita.These both subfamilies had shared a common ancestor. The remaining Carditamerines are placed in different locations over the tree. Venericardiinae is splitted into two different clades, one including Venericardia and the other one the "planicostate" taxa such as Leuroactis, Venericor, Pacificor, Megacardita and Neovenericor. The former Carditesinae, with the exception of Cardites, are placed along with Venericardia into a new clade that contains all alticostate carditids. Miodomeridinae is not recovered and Paleocarditinae is placed in a basal position from the rest of carditids. The genera Vimentum, Scalaricardita and Coripia comprise a new and previously unrecognized clade. The use of phylogenetic tools provides a new systematic approach of the family and allows to discard the previous subfamiliar scheme.