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Brachycephalidae :
The “Saddle-back” or “pumpkin toads,” as they are known due to the presence of bony shields above their vertebrae and the bright orange coloration of some of the members of this family. This family is an assemblage of tiny frogs composed of only two genera (Brachycephalus and Psyllophryne),. At first they were considered to be Bufonids, but an absence of a Bidder’s organ (ovarian tissue on the testes, a synapomorphy of Bufonidae) led to their recognition as an independent family. Recent molecular studies have placed Brachycephalidae within the Leptodactylid tribe Eleutherodactylini. Due to their small size and large genomes (an amphibian characteristic), these frogs have “lost” some of their digits (2 on the hand and 3 or 4 on the feet). These frogs are direct developers with inguinal and axillary amplexus. They are found in Southeastern Brazil. Brachycephalus ephippium is known to possess tetradotoxin, a strong toxin also found in newts of the genus Taricha and in puffer fish. The genera are united by the following morphological characters: 1) 7 presacral vertebrae; 2) ribs absent; 3) urostyle free with 2 condyles; 4) sternum and omosternum absent; 5) palatines and prevomers absent; 6) no teeth on premaxilla or maxilla; 7) pupil horizontal; 8) Bidder's organ absent; 9) direct developers; 10) complete ossification of epicoracoid cartilages with coracoids and clavicles; 11) have a dermal bony shield above each vertebrae (dorsally looking like a saddle, thus their vernacular name).
Genus : Brachycephalus (11 species) Psyllophryne |
