Podocnemididae is a family of pleurodire (side-necked) turtles, once widely distributed. Most of its 20 genera and 30 species are now extinct. Seven of its eight surviving species are native to South America: the genus Peltocephalus, with only one species ; and the genus Podocnemis, with six living species of South American side-necked river turtles. 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.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 2001.
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.
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.
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.
Eugene S. Gaffney is an American paleontologist and leading authority on the morphology and evolutionary history of turtles.
Foxemys is an extinct genus of bothremydid turtle that was discovered at Fox Amphoux, France and also Hungary and Spain. Its skull and shell structure is similar to Polysternon. Two species are in the genus: F. mechinorum and F. trabanti.
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.
Galianemys is an extinct genus of turtle in the family Bothremydidae, discovered in the Kem Kem Beds.
The Kallamedu Formation is a Late Cretaceous (Maastrichtian) geologic formation located in India that forms part of the Ariyalur Group. Dinosaur remains and petrified wood samples are among the known fossils recovered from this formation.
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.
Rhothonemys is an extinct genus of bothremydid pleurodiran turtle that was discovered in the Paleogene of Morocco. The genus consists solely of type species R. brinkmani.
Ummulisani is an extinct genus of bothremydid pleurodiran turtle that was discovered in the Eocene of Morocco. The genus consists solely of type species U. rutgersensis.
Carteremys is an extinct genus of pelomedusid pleurodiran turtle from the Maastrichtian -Eocene, of India based on the type species C. leithi, which was named in 1953 by E. Williams and was originally placed in the genera Hydraspis by H. J. Carter in 1852 and Testudo, also by H. J. Carter, in 1871. A second species, C. pisdurensis, was named in 1977 by Sohan Lal Jain, but it was transferred to the separate genus Jainemys in 2020 by Joyce and Bandyopadhyay.
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.
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.
