Chelidae is one of three living families of the turtle/tortoise suborder Pleurodira, and are commonly called Austro-South American side-neck turtles. The family is distributed in Australia, New Guinea, parts of Indonesia, and throughout most of South America. It is a large family of turtles with a significant fossil history dating back to the Cretaceous. The family is entirely Gondwanan in origin, with no members found outside Gondwana, either in the present day or as a fossil.
Chelodina, collectively known as snake-necked turtles, is a large and diverse genus of long-necked chelid turtles with a complicated nomenclatural history. Although in the past, Macrochelodina and Macrodiremys have been considered separate genera and prior to that all the same, they are now considered subgenera of the Chelodina, further Macrochelodina and Macrodiremys are now known to apply to the same species, hence Chelydera is used for the northern Snakeneck Turtles.
Meiolaniidae is an extinct family of large, possibly herbivorous stem-turtles with heavily armored heads and tails known from South America and most of Oceania. Though once believed to be cryptodires, they are not closely related to any living species of turtle, and lie outside crown group Testudines, having diverged from them around the Middle Jurassic. They are best known from the last surviving genus, Meiolania, which lived in the rain forests of Australia from the Miocene until the Pleistocene, and insular species that lived on Lord Howe Island and New Caledonia during the Pleistocene and possibly the Holocene for the latter.
Elseya is a genus of large side-necked turtles, commonly known as Australian snapping turtles, in the family Chelidae. Species in the genus Elseya are found in river systems in northern and northeastern Australia and throughout the river systems of New Guinea. They are identified by the presence of alveolar ridges on the triturating surfaces of the mouth and the presence of a complex bridge strut.
The Fitzroy River turtle is a species of freshwater turtle in the family Chelidae. It is the only surviving member of the genus Rheodytes, the other member being the extinct form Rheodytes devisi. The species is endemic to south eastern Queensland, Australia and only found in tributaries of the Fitzroy River.
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.
Paracryptodira are an extinct clade of turtles in the order Testudines. Initially treated as a suborder sister to the Cryptodira, they were then thought to be a very primitive lineage inside the Cryptodira according to the most common use of the latter taxon. They are now considered to be a third fundamental division of the Testudines, alongside Cryptodira and Pleurodira. The paracryptodirian turtles are said to have phylogenic relationships, noted as primary subclades, within the Baenidae and Pleurosternidae. Within each subclade, lies many biodiverse turtles that are continuously being investigated and added to the fossil record.
Elseya uberrima is an Eocene species of extinct Australian snapping turtle.
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.
The Myuchelys is a genus of turtles, the Australian saw-shelled turtles, in the family Chelidae and subfamily Chelodininae. They inhabit the headwaters and tributaries of rivers within their range and this led to the name Myuchelys, which is formed from the Aboriginal word myuna meaning clear water and the Greek chelys meaning turtle. They have a short neck and the intergular scute completely separates the gular scutes. They have no alveolar ridge separating them from the snapping turtles of the genus Elseya.
The Gulf snapping turtle or Lavaracks' turtle is a large species of freshwater turtle in the sidenecked family Chelidae. The species is endemic to northern Australia in northwest Queensland and northeast Northern Territory. The species, similar to other members of the Australian snapping turtles in genus Elseya, only comes ashore to lay eggs and bask. The Gulf snapping turtle is a herbivore and primarily consumes Pandanus and figs.
Rheodytes devisi is a Pleistocene fossil turtle from the Darling Downs of Queensland, Australia. It was described from material originally included in the description of Elseya uberima.
Brontochelys is an extinct genus of podocnemidid from the Miocene of Pakistan. The only species known, B. gaffneyi was classified before in the genus Shweboemys, which is known from the Pliocene of Burma. Brontochelys is represented only by its type specimen BMNH R.8570, a nearly complete skull, which exact locality is unknown but probably comes from the Lower Miocene sediments in the Bugti Hills, in Baluchistan, Pakistan. This skull is different from its relatives like Shweboemys, Lemurchelys and Stereogenys by its large, forward-faced orbits, a large frontal bone that composes most of the dorsal orbit margin and a palatal curved. The name of Brontochelys is formed by the Greek words bronte, "thunder" and chelys, "turtle", in reference to the large size of the skull.
Cordichelys is an extinct genus of podocnemidid turtle. It was around during the Eocene. Fossils of this turtle have been discovered at Wadi El Hitan as of November 2020.
Chelodina alanrixi is a species of snake-necked fossil turtle which was described in 2001 using material gathered in Redbank Plains, Queensland, Australia. It is a member of the Chelidae Pleurodira. The fossil has been dated to the Eocene Epoch.
Araripemydidae is a family of turtles belonging to the order Testudines. There are no living representatives of the family but fossil records have been used to identify it as part of the Pleurodira suborder. There are five collections of single fossils, four that were found in Brazil and one that was found in Niger. The family contains two recognised genera, Araripemys and Laganemys, and two species, Araripemys barretoi and Laganemys tenerensis. Fossils indicate they lived from the Late Cretaceous period (100mya) to the Paleocene period (55mya).
Turtles have been classified in different ways by different authors. While they were previously considered anapsids, they are now considered more derived. Recent analyses of molecular evidence have strongly suggested that they belong in the clade Archosauromorpha. Below are many of the possible classifications of Testudines and Testudinata:
Elseya rhodini, the southern New Guinea stream turtle, is a recently described aquatic species of chelid turtle found south of the central ranges of New Guinea. It inhabits small streams that flow into the major river drainage's south of the ranges.
Bauruemys is an extinct genus of turtles in the family Podocnemididae.
Bairdemys is an extinct genus of side-necked turtles in the family Podocnemididae. The genus existed from the Late Oligocene to Late Miocene and its fossils have been found in South Carolina, Puerto Rico, Panama and Venezuela. The genus was described in 2002 by Gaffney & Wood and the type species is B. hartsteini.
