Podocnemididae is a family of pleurodire (side-necked) turtles, once widely distributed. Most of its 41 genera and 57 species are now extinct. Seven of its eight surviving species are native to South America: the genus Peltocephalus, with two species, only one of which is extant ; and the genus Podocnemis, with six living species of South American side-necked river turtles and four extinct. There is also one genus native to Madagascar: Erymnochelys, the Madagascan big-headed turtle, whose single species E. madagascariensis.
The Pleurodira are one of the two living suborders of turtles, the other being the Cryptodira. The division between these two suborders represents a very deep evolutionary divide between two very different types of turtles. The physical differences between them, although anatomical and largely internal, are nonetheless significant, and the zoogeographic implications of them are substantial. The Pleurodira are known more commonly as the side-necked turtles and the name Pleurodira quite literally translates to side neck, whereas the Cryptodira are known as hidden-necked turtles. The Pleurodira turtles are currently restricted to freshwater habitats in the Southern Hemisphere, largely to Australia, South America, and Africa. Within the Pleurodira, three living families are represented: Chelidae, also known as the Austro-South American side-necked turtles, the Pelomedusidae, also known as the African mud terrapins, and the Podocnemididae, also known as the American side-neck river turtles. However, they were cosmopolitan clade during the Cretaceous and most of the Cenozoic, and even occurred in marine environments around the world.
Argiles et Grès à Reptiles Formation also known as the Argiles Rutilantes Formation is an early Maastrichtian French geologic formation in the département of Var preserving the remains of several types of dinosaurs and other extinct organisms.
Bothremydidae is an extinct family of side-necked turtles (Pleurodira) known from the Cretaceous and Cenozoic. They are closely related to Podocnemididae, and are amongst the most widely distributed pleurodire groups, with their fossils having been found in Africa, India, the Middle East, Europe, North America and South America. Bothremydids were aquatic turtles with a high morphological diversity, indicative of generalist, molluscivorous, piscivorous and possibly herbivorous grazing diets, with some probably capable of suction feeding. Unlike modern pleurodires, which are exclusively freshwater, bothremydids inhabited freshwater, marine and coastal environments. Their marine habits allowed bothremydids to disperse across oceanic barriers into Europe and North America during the early Late Cretaceous (Cenomanian). The youngest records of the group are indeterminate remains from Saudi Arabia and Oman, dating to the Miocene.
Cearachelys is an extinct genus of pleurodiran turtle which existed some 110 million years ago. The genus is monotypic, with only type species Cearachelys placidoi known.
Sankuchemys is an extinct genus of side-necked turtle whose fossils had been found in the Intertrappean Formation of India during the late Cretaceous period. It was first named by Eugene S. Gaffney, Ashok Sahni, Herman Schleich, Swarn Deep Singh, and Rahul Srivastava in 2003, and contains the species Sankuchemys sethnai.
Kurmademys is an extinct genus of side-necked turtle which existed in India during the late Cretaceous period. It was first named in 2001, by Eugene S. Gaffney, Sankar Chatterjee, and Dhiraj K. Rudra, and contains the species Kurmademys kallamedensis. The species name is derived from the Kallamedu Formation of southern India, where the type specimen of the genus was discovered. It was assigned to the family Bothremydidae.
Araripemydidae is a family of freshwater aquatic turtles belonging to the order Pleurodira, known from the Early Cretaceous of South America and Africa. The family contains two recognised monotypic genera, Araripemys and Taquetochelys, from the Santana Group of Brazil and the Elrhaz Formation of Niger, respectively, which date to the Aptian-Albian stages of the Early Cretaceous. They are consider to be the most basal lineage within the Pelomedusoides. They are thought to have been specialised suction feeders. Laganemys was named in 2013 but was later determined to be synonymous with Taquetochelys.
Chedighaii is an extinct genus of marine bothremydid side-necked turtle that inhabited eastern and south-central North America during the Campanian stage of the Late Cretaceous. It is known from two species C. hutchisoni and C. barberi. The genus name is derived from ch’ééh digháhii, the Navajo word for turtle.
Galianemys is an extinct genus of turtle in the family Bothremydidae, discovered in the Kem Kem Beds.
Araiochelys is an extinct genus of bothremydid pleurodiran turtle that was discovered in the Ouled Abdoun Basin, Morocco. The genus consists solely of type species A. hirayamai.
Rosasia is an extinct genus of bothremydid pleurodiran turtle that was discovered in the Argilas de Aveiro Formation of Portugal. The genus consists of a single species, R. soutoi, named after Alberto Souto.
Inaechelys is a potentially dubious genus of bothremydid pleurodiran turtle that was discovered in the Maria Farinha Formation of Brazil. The genus consists solely of type species I. pernambucensis.
Elochelys is an extinct genus of bothremydid pleurodiran turtle that was discovered in the Campanian of Fuveau Basin, France. The genus consists solely of type species E. perfecta, though a second species was reassigned to the genus Iberoccitanemys.
Arenila is an extinct genus of bothremydid pleurodiran turtle that was discovered in the Western Desert of Egypt. The genus consists solely of type species A. krebsi.
Azabbaremys is an extinct genus of bothremydid pleurodiran turtle that was discovered in the Teberemt Formation of Mali. It was described in 2001, based on a skull that had been recovered in an expedition in 1981. The genus consists solely of the type species Azabbaremys moragjonesi. The genus name is derived from Azabbar, a monster in Tamasheq folk stories. The species is named for Morag Jones, a research student who participated in the discovery of the specimen and died in the expedition. Azabbaremys is most closely related to another Paleocene side-necked turtle, Acleistochelys.
Eotaphrosphys is an extinct genus of bothremydid pleurodiran turtle that was discovered in the Mont Aime Formation, France. Originally assigned to the genus "Tretosternum", it consists exclusively of type species E. ambiguum.
Phosphatochelys is an extinct genus of bothremydid pleurodiran turtle that was discovered near Oued Zem, Morocco. The genus consists solely of type species P. tedfordi.
Acleistochelys is an extinct genus of large, bothremydid pleurodiran turtle known from Paleocene deposits in the Teberemt Formation of Mali. The type species, A. maliensis, was named for the country in which it was found. The holotype specimen consists of a nearly complete skull, shell fragments, pelvic fragments, and a cervical vertebra. It is most closely related to another Paleocene Malian side-necked turtle, Azabbaremys.
Iberoccitanemys is an extinct genus of turtle from the Bothremydidae that is known from the Marnes d'Auzas Formation in France, and also the Sobrepena Formation and Villalba de la Sierra Formation in Spain.
