The Pipidae are a family of primitive, tongueless frogs. There are 41 species in the family, found in tropical South America (genus Pipa) and sub-Saharan Africa (the three other genera).
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 system is present in adults.[1] 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 4 to 19 cm (1.6 to 7.5 in) in body length.[2]
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 oldest known crown group pipids are Oumtkoutia and Pachycentrata from the Upper Cretaceous of Morocco and Niger, respectively.[5]