''Eodiscoglossus'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of prehistoric

frog A frog is any member of a diverse and largely Carnivore, carnivorous group of short-bodied, tailless amphibians composing the order (biology), order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-f ...

s. It is known from the type species ''E. santonjae'' from the

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

(

Barremian The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 129.4 ± 1.5 Ma (million years ago) and 121.4 ± 1.0 Ma). It is a subdivision of the Early Cretaceous Epoch (or Lower Cretaceous Series). It is preceded ...

) El Castellar Formation of

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , i ...

, as well as a referred species ''E. oxoniensis'' known from the Forest Marble Formation of the UK. It was a small primitive

, with a length of only from the

premaxilla The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has b ...

to the

ischium The ischium () form ...

. Formerly considered to be closely related to discoglossids, ''E. santonjae'' is now regarded as close to the root of the

crown group In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...

of modern frogs in a position more derived than New Zealand frogs and tailed frogs, but more basal than costatans like alytids and other more advanced frogs like neobatrachians. The morphology of ''E''. ''santonjae'' suggests a generalist and unspecialised movement habit. The referral of ''E. oxoniensis'' to ''Eodiscoglossus'' has been questioned, as it is much earlier than the type species and it is based on homoplasic and

plesiomorphic In phylogenetics, a plesiomorphy ("near form") and symplesiomorphy are synonyms for an ancestral character shared by all members of a clade, which does not distinguish the clade from other clades. Plesiomorphy, symplesiomorphy, apomorphy, and ...

characteristics inherited from a common ancestor, so there is no clear evidence of a close relation.

References

Prehistoric frogs Cretaceous amphibians of Europe Jurassic amphibians of Europe Fossil taxa described in 1957 {{paleo-anura-stub

See also

References