Systematics of minute strabomantid frogs allocated to the genus Noblella (Amphibia: Anura) with description of a new genus, seven new species, and insights into historical biogeography

Noblella is a genus of 17 recognized nominal species of ground-dwelling, direct-developing frogs. It consists of two clades that do not form a monophyletic group: a northern clade from northern Peru, Ecuador, Colombia, and Brazil and a southern clade from southern Peru and Bolivia. Herein, we present a systematic review of Noblella with emphasis on the northern clade, including a new phylogeny based on DNA sequences of mitochondrial and nuclear genes. We also describe the osteology of five species from the northern clade using X-ray computed tomography. Based on our results, we resurrect the genus Phyllonastes for species of the northern clade (i.e. eight described species plus six new species described herein) and restrict the genus Noblella to the southern clade. We describe a new genus of Holoadeninae, sister to Phyllonastes: Urkuphryne gen. nov., from northern Ecuador. The new genus is distinguished by unique morphological characteristics that are diagnostic of different genera in Strabomantidae. We describe seven new species diagnosable based on morphology. Phyllonastes has five morphological synapomorphies, including the absence of vomerine teeth. Phyllonastes originated in the Pacific basin, Chocó region, ∼21 Mya.