Molecular phylogeny of Ischnocnema (Anura: Brachycephalidae) with the redefinition of its series and the description of two new species

[Display omitted] •We propose a new phylogenetic hypothesis for Ischnocnema.•We recover I. nanahallux outside the I. parva series with high support.•I. nanahallux, I. manezinho, and I. sambaqui are not assigned to species series.•We describe the new I. venancioi series and two new species within the series.•We designate a lectotype for I. venancioi. We present a new phylogenetic hypothesis for Ischnocnema, a Neotropical brachycephaloid genus of ground-dwelling direct-developing frogs. We performed Bayesian inference, maximum likelihood, and maximum parsimony analyses using two nuclear (RAG1 and Tyr) and three mitochondrial genes (12S rRNA, tRNA-Val, and 16S rRNA) in a matrix comprising more than 80% of the described species. We recover Ischnocnema nanahallux outside the Ischnocnema parva series, and it is now unassigned to any species series, nor are Ischnocnema manezinho and Ischnocnema sambaqui. We propose the Ischnocnema venancioi species series to comprise Ischnocnema venancioi, Ischnocnema hoehnei, and two new species described herein (Ischnocnema parnaso sp. nov. and Ischnocnema colibri sp. nov.). Furthermore, we designate a lectotype for I. venancioi. The nuptial pad present in males is an important character in the genus, and having a large, conspicuous, and glandular-appearing nuptial pad seems to be a synapomorphy for the clade composed of the I. parva, Ischnocnema guentheri, and the newly proposed I. venancioi series.