At the lower size limit for tetrapods, two new species of the miniaturized frog genus Paedophryne (Anura, Microhylidae)

Abstract. I describe two new species in the miniaturized microhylid frog genus Paedophryne from forests in southeastern Papua New Guinea. The first species is described on the basis of two specimens and exhibits female snout-vent length of 8.5–9.0 mm (no males known), whereas that of the second species, described on the basis of 12 specimens, is 8.8–9.3 mm, with males 8.1–8.9 mm. These frogs are smaller than the other two diminutive species described when the genus was recently erected, and they represent what are currently the smallest known species of tetrapods. The two species replace each other elevationally on the same mountain massif and occur in relative geographic proximity to the other named species of the genus. Females of both species contain only two enlarged ova, suggesting that they also possess clutch sizes at the extreme lower end of variation in frogs. All species of Paedophryne inhabit leaf litter, as seen for most other miniaturized anurans.