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.
Pneumatoarthrus is an extinct genus of sea turtle known from the Late Cretaceous Mount Laurel Formation of Monmouth County, New Jersey. Only a single species, P. peloreus, is known.
Protostegidae is a family of extinct marine turtles that lived during the Cretaceous period. The family includes some of the largest sea turtles that ever existed. The largest, Archelon, had a head one metre (39 in) long. Like most sea turtles, they had flattened bodies and flippers for front appendages; protostegids had minimal shells like leatherback turtles of modern times.
Santanachelys gaffneyi is an extinct species of sea turtle. It is the only species in the genus Santanachelys, which itself is a member of the extinct family Protostegidae. The species was first described from a 20-centimeter long fossil specimen unearthed in 1998 from the Santana Formation of eastern Brazil. From the rock layer from which it was excavated, it was determined that the specimen was from the Early Cretaceous period. It is therefore one of the oldest known sea turtles. but a new fossil named Desmatochelyspadillai in 2015 is estimated to be as old as 120 million years.
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.
Sinemys is an extinct genus of turtle from the Late Jurassic to Early Cretaceous of China. Three species have been named: S. lens, the type species, from the Kimmeridgian-Tithonian of Shandong; S. gamera, from the Valanginian-Albian of Nei Mongol, and S. brevispinus from Early Cretaceous of Nei Mongol. S. wuerhoensis, from the Aptian-Albian of Xinjiang, is not referrable to this genus. Specimen that may be belong to this genus were also known from Japan, although later abstract considered it as indeterminate sinemydid. The species S. gamera is noted for the presence of a pair of elongate spines projecting outwards and backwards from seventh costal of the carapace. These may have served a hydrodynamic function.
Desmatochelys is an extinct genus of sea turtles belonging to the family Protostegidae. This genus contains two known species, D. lowii and D. padillai. D. lowii was first discovered in 1895, followed by D. padillai in 2015. Having been estimated at over 120 million years old, D. padillai is currently the oldest known species of sea turtle.
Emarginachelys cretacea is a turtle belonging to the group Cryptodira, known from well preserved fossils from the Maastrichtian stage of the Late Cretaceous of Montana. Its exact phylogenetic position within Cryptodira is uncertain; different authors considered it to be either the earliest described chelydrid or a fossil relative of kinosternoids.
Caririemys is an extinct genus of side-necked turtles, belonging to the Pelomedusoides of the family Euraxemydidae. The type species is C. violetae. A single fossil of an individual was found in the Santana Formation in Brazil, an 80-million-year-old Late Cretaceous deposit that has so far preserved other fossil reptiles such as dinosaurs and crocodilians.
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.
Dorsetochelys is an extinct genus of turtle from the Early Cretaceous of southern England and northwestern Germany.
Kinkonychelys is an extinct genus of side-necked turtle which existed in Madagascar during the Late Cretaceous period. It contains the single species Kinkonychelys rogersi, named in honor of its discoverer, Raymond R. Rogers. The genus and species are based on UA 9748, a nearly complete skull, which represents the first turtle skull described from the pre-Holocene era in Madagascar. A number of isolated skull and jaw bones have also been assigned to K. rogersi. These specimens were found in rocks of the Maastrichtian-age Maevarano Formation in the Mahajanga Basin of northwestern Madagascar. Another specimen, FMNH PR 2446, is speculated to represent another species, currently known as Kinkonychelys sp., but consensus on its distinction from K. rogersi remains unclear.
Trionyx is a genus of softshell turtles belonging to the family Trionychidae. In the past many species in the family were classified in this genus, but today T. triunguis, the African or Nile softshell turtle, is the only extant softshell still classified as Trionyx. The other species still assigned to this genus are only known from fossils. T. triunguis is a relatively large, aquatic piscivore.
Baenidae is an extinct family of paracryptodiran turtles known from the Early Cretaceous to Eocene of North America. While during the Early Cretaceous they are found across North America, during the Late Cretaceous they are only found in Laramidia, having disappeared from Appalachia. The majority of lineages survived the K-Pg Extinction, but the family was extinct by the latest Eocene. The name of the type genus, Baena, appears to be of Native American origin. They are primarily found in freshwater deposits, and are considered to be aquatic, with a largely generalist habit.
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.
Macrobaenidae is an extinct family of turtles, known from the Early Cretaceous to Paleogene of Laurasia. Their relationships to other turtles and whether they form a monophlyletic group are controversial. They are typically interpreted as stem or crown group cryptodires, but some more recent analyses have found them to lie outside crown group Testudines. Macrobaenids can be distinguished from other testudinatans by the presence of a carotid fenestra, cruciform plastron with strap-like epiplastra, and a lack of extragulars.
Bauruemys is an extinct genus of turtles in the family Podocnemididae.
The Presidente Prudente Formation is a geological formation of the Bauru Group in the Paraná Basin, located in Brazil whose strata date back to the Late Campanian to Early Maastrichtian.
Itapecuruemys is an extinct genus of bothremydid pleurodiran turtle that was discovered in the Itapecuru Formation of Brazil. It is a monotypic genus, with only type species Itapecuruemys amazoniensis known.
Amabilis uchoensis is a species of prehistoric pleurodiran turtle from the Late Cretaceous of South America. It is the only species in the genus Amabilis.
