Oreophrynella

Oreophryne Boulenger, 1895 — junior homonym of Oreophryne Boettger, 1895 Oreophrynella, commonly known as bush toads, is a genus of true toads native to the tepuis of southern Venezuela and adjacent Guyana.

[3] Species of the genus Oreophrynella are small frogs, less than 26 mm (1.0 in) in snout–vent length.

They are characterized by opposable digits of the foot, dorsal skin that bears tubercules, and direct development[3] (i.e., there is no free-living larval stage[4]).

The presence of opposable digits, unique among bufonids, in combination with an extension of the interdigital integument and the relative length/orientation of the digits, is likely to be an adaptation to facilitate life on rocky tepui summits and an exaptation to arboreality[5] The genus also displays cranial simplification in the form of cranial fontanelles and absence of the quadratojugal, which may be driven by a reduction of developmental costs, increase in flexibility, and reduction of body weight.

[5] The cranial simplification combined with the shortening of the vertebral column and shift towards a partly firmisternal girdle may be adaptations to the peculiar tumbling behaviour displayed by Oreophrynella.