A NEW GENUS AND SPECIES OF SARCOGLANIDINAE (SILURIFORMES, TRICHOMYCTERIDAE) FROM SOUTHEASTERN BRAZIL, WITH A REEXAMINATION OF SUBFAMILIAL PHYLOGENY

Microcambeva barbata, n. gen. et sp., is described from rio Sao Joao, Estado do Rio de Janeiro. It is proposed as the sister group of Malacoglanis and Sarcoglanis, on the basis of three characters: pectoral fin longer than the head, pectoral fin rays projecting well beyond the fin membrane, and a forked caudal fin. Monophyly of the Sarcoglanidinae is confirmed by the unique possession of a long lateral process on the premaxilla and a separate anterior ossification on the palatine. A sister group relationship between the Sarcoglanidinae and the Glanapteryginae is supported by four synapomorphies: a posteriorly directed dorsal process on the quadrate, a large dorsal anteriorly directed process on the hyomandibula, vomer reduced and generalized miniaturization. A more inclusive group composed of Sarcoglanidinae, Glanapteryginae, Tridentinae, Vandeliinae and Stegophilinae is considered monophyletic, since they all exhibit a reduced interopercular patch of odontodes, a reduced or absent metapterygoid, reduction in the number of pleural ribs, and lack an elongate process on the parasphenoid.