Mount Duida frogs (''Dischidodactylus'') form a genus of brachycephaloid
frog
A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order (biology), order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough ski ...
s
endemic
Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...
Venezuela
Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...
. The scientific name is derived from the Greek ''dischidos'', meaning divided, and ''dactylos'', meaning finger or toe, in reference to the divided ungual flap (see below).
Taxonomy
The family in which ''Dischidodactylus'' should be placed is currently uncertain.Amphibian Species of the World currently places it in superfamily
Brachycephaloidea
Brachycephaloidea (or Terrarana) is a large Monophyly, monophyletic unranked clade of Direct development, direct-developing frogs including more than 1,100 species, comprising about 15% of named frog species. Brachycephaloids inhabit the New Worl ...
with family incertae sedis, while AmphibiaWeb places it in
Ceuthomantidae
''Ceuthomantis'' is a small genus of Craugastoridae, craugastorid frogs, also treated as comprising their own monogeneric family Ceuthomantidae. They are found in the southern and eastern parts of the Guiana Highlands in Venezuela, Guyana, and Bra ...
. It had been placed in subfamily Ceuthomantinae within family Craugastoridae based on morphology because no DNA sequence data was available. ''Dischidodactylus'' was considered closely related to ''
Ceuthomantis
''Ceuthomantis'' is a small genus of craugastorid frogs, also treated as comprising their own monogeneric family Ceuthomantidae. They are found in the southern and eastern parts of the Guiana Highlands in Venezuela, Guyana, and Brazil. The gene ...
'' because they share a
synapomorphy
In phylogenetics, an apomorphy (or derived trait) is a novel Phenotypic trait, character or character state that has evolution, evolved from its ancestral form (or Plesiomorphy and symplesiomorphy, plesiomorphy). A synapomorphy is an apomorphy sh ...
(completely or almost completely divided ungual flaps) and both genera also have dorsal skin composed of small, flat, pliable (not keratinized) warts, and lack nuptial pads in adult males; they differ in that ''Dischidodactylus'' possess a dentigerous process of the
vomer
The vomer (; ) is one of the unpaired facial bones of the skull. It is located in the midsagittal line, and articulates with the sphenoid, the ethmoid, the left and right palatine bones, and the left and right maxillary bones. The vomer forms ...
, and in that ''Ceuthomantis'' lack basal toe webbing.
Description
''Dischidodactylus'' are smallish frogs that reach a maximum snout–vent length of in females. Their head is not as wide as body. Tympanic membrane is not differentiated and tympanic annulus is visible below skin. Cranial crests are absent. Vomers have small, oblique dentigerous processes. Terminal discs are expanded, rounded, and bifurcate; circumferential groove is present and terminal phalanges are T-shaped. Dorsum is granular and venter is areolate.