Skull bones of four Proceratophrys Miranda-Ribeiro, 1920 species sharing long dermal appendages on eyelids - P. boiei (Wied-Neuwied, 1825), P. appendiculata (Günther, 1873), P. melanopogon (Miranda-Ribeiro, 1926), and P. laticeps Izecksohn & Peixoto, 1981 - are herein studied. Proceratophrys boiei, P. appendiculata and P. melanopogon share higher lateral crests on the frontoparietals, quadratojugal corners similarly positioned in relation to the vertical level of the occipital condiles, cranial bones with granules and tubercles, and maxillaries with ventro-posterior pits, hence being considered members of a single group; P. laticeps, given the presence of temporal arcades (similar to Ceratophrys Wied-Neuwied, 1824), quadratojugal corners posterior to the vertical level of occipital condiles, wrinkled skull bones, and maxilaries without ventro-posterior pits, is nonetheless considered as a member of a distinct group.
Anatomy; frogs; skulls; Southeastern Brazil; taxonomy
