The Pipidae are a

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

of primitive,

tongue The tongue is a muscular organ in the mouth of a typical tetrapod. It manipulates food for mastication and swallowing as part of the digestive process, and is the primary organ of taste. The tongue's upper surface (dorsum) is covered by taste ...

less

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. The 41 species in the family Pipidae are found in tropical

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sou ...

(genus ''Pipa'') and sub-Saharan

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

(the three other genera).

Description

Pipid frogs are highly aquatic and have numerous morphological modifications befitting their habitat. For example, the feet are completely webbed, the body is flattened, and a

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial ...

system is present in adults. In addition, pipids possess highly modified ears for producing and receiving sound under water. They lack a tongue or vocal cords, instead having bony rods in the larynx that help produce sound. They range from in body length.

Taxonomy

Family Pipidae * '' Hymenochirus'' - dwarf clawed frogs (4 species) * '' Pipa'' - Surinam toads (7 species) * '' Pseudhymenochirus'' - Merlin's dwarf gray frog or Merlin's clawed frog (1 species) * ''

Xenopus ''Xenopus'' () (Gk., ξενος, ''xenos''=strange, πους, ''pous''=foot, commonly known as the clawed frog) is a genus of highly aquatic frogs native to sub-Saharan Africa. Twenty species are currently described within it. The two best-know ...

'' - clawed frogs (29 species)Evans et al., 2015 ** Subgenus ''( Silurana)'' - common clawed frogs ** Subgenus ''(

)'' - tropical clawed frogs

Fossil record

The oldest fossil records of frogs more closely related to pipid frogs than to other extant frog families ( Pipimorpha) extends into the

Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145& ...

. The oldest known

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 ...

pipids are '' Oumtkoutia'' and '' Pachycentrata'' from the Upper Cretaceous of Morocco and Niger, respectively. Included taxa after A. M. Aranciaga Rolando et al. 2019 * †'' Oumtkoutia'' Rage and Dutheil 2008

Aoufous Formation The Aoufous Formation is a geological formation that contains some of the vertebrate assemblage of the Kem Kem Group, of Late Cretaceous date.Cavin et al., 2010, p.391Dal Sasso, C., Maganuco, S., Buffetaut, E., Mendez, M.A., 2005. New information ...

, Morocco, Late Cretaceous (

Cenomanian The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in ...

) * †'' Llankibatrachus'' Báez and Pugener 2003 Huitrera Formation, Argentina,

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', ...

* †'' Pachycentrata'' Báez and Rage 2004 (= ''Pachybatrachus'' Báez and Rage, 1998) In Beceten Formation, Niger, Late Cretaceous (

Coniacian The Coniacian is an age or stage in the geologic timescale. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series and spans the time between 89.8 ± 1 Ma and 86.3 ± 0.7 Ma (million years ago). The Coniacian is preceded ...

) * †"'' Shelania" laurenti'' Baez and Pugener 1998 Argentina, Eocene * ''"Xenopus" romeri'' Estes 1975 Companhia National de Cimento Portland Quarry, Brazil,

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pala ...

* †'' Eoxenopoides'' Haughton 1931 South Africa, Late Cretaceous (

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the inte ...

) * †'' Singidella'' Báez and Harrison 2005 Tanzania, Eocene

References

Bibliography

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External links

* * {{Authority control Amphibian families Mesobatrachia Taxa named by John Edward Gray Extant Berriasian first appearances