The orbital region has seven pairs of foramina, two on dorsal position: one for the trochlear nerve and another for the oculomotor nerve; two on median position: one for the orbitonasal
channel and another for the optic nerve; and two in ventral position: one for the interorbital vein and another for the efferent artery.
The medial orbitonasal foramen (Form, Figures 6-9) is larger in N.
Within the Neomorphinae, there are five characteristics that are shared by the group Geococcyx, Morococcyx and Neomorphus that differ from Tapera and Dromococcyx: the lateral length of the frontal is larger, the lateral process of the parasphenoid is reduced, the lateral orbitonasal foramen is larger, the bony lamella covering the nasal aperture is larger and the dorsal process of the nasal is absent.
Sphenethmoid well ossified; anterior terminus lying well behind anterior margins of nasals; margins of orbitonasal
foramina bony; posterior border of bony sphenethmoid laterally and ventrally reaching level of anterior third of optic foramina, dorsomedially reaching area above foramen magnum; overlain by frontoparietals dorsally; bony anterodorsal and lateral surfaces exposed; cartilaginous ventral element without alae over parasphenoid alae and extending caudally horseshoe-shaped with its rounded apex reaching level between columellae.
Difiere de las poblaciones de Rana vaillanti (Sistemas de poblaciones del Magdalena y Pacifico) por la presencia de un canal orbitonasal (Fig.
Difiere de Rana palmipes porque tiene una formula dentaria 4(3-5)/4, la ausencia de un canal orbitonasal (Fig.