Humeral

Humerus

The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....

 spines are ventrolateral extensions of the humeral

Humerus

The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....

 crista ventralis. This structures are present in the humerus of some frog

Frog

Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...

s (anurans). The majority of anuran species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 that present humeral spines are glassfrogs (family Centrolenidae) but humeral spines have been reported in various other species of different families of frogs, including Ceratophryidae

Leptodactylidae

Leptodactylidae is a diverse family of frogs that probably diverged from other hyloids during the Cenozoic era, or possibly at the end of the Mesozoic. There are roughly 50 genera, one of which is Eleutherodactylus, the largest vertebrate genus, with over 700 species...

 and Hylidae. In all cases, humeral spines are present in males but not in females.