Archelon is an extinct marine turtle from the Late Cretaceous, and is the largest turtle ever to have been documented, with the biggest specimen measuring 4.6 m (15 ft) from head to tail and 2.2–3.2 t in body mass. It is known only from the Pierre Shale and has one species, A. ischyros. In the past, the genus also contained A. marshii and A. copei, though these have been reassigned to Protostega and Kansastega, respectively. The genus was named in 1895 by American paleontologist George Reber Wieland based on a skeleton from South Dakota, who placed it into the extinct family Protostegidae. The leatherback sea turtle was once thought to be its closest living relative, but now, Protostegidae is thought to be a completely separate lineage from any living sea turtle.
The Romualdo Formation is a geologic Konservat-Lagerstätte in northeastern Brazil's Araripe Basin where the states of Pernambuco, Piauí and Ceará come together. The geological formation, previously designated as the Romualdo Member of the Santana Formation, named after the village of Santana do Cariri, lies at the base of the Araripe Plateau. It was discovered by Johann Baptist von Spix in 1819. The strata were deposited during the Aptian stage of the Early Cretaceous in a lacustrine rift basin with shallow marine incursions of the proto-Atlantic. At that time, the South Atlantic was opening up in a long narrow shallow sea.
Protostega is an extinct genus of sea turtle containing a single species, Protostega gigas. Its fossil remains have been found in the Smoky Hill Chalk formation of western Kansas, time-equivalent beds of the Mooreville Chalk Formation of Alabama and Campanian beds of the Rybushka Formation. Fossil specimens of this species were first collected in 1871, and named by Edward Drinker Cope in 1872. With a total length of 3.9 metres (13 ft), it is the second-largest sea turtle that ever lived, second only to the giant Archelon, and one of the three largest turtle of all time along Archelon and Gigantatypus.
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.
Corsochelys is an extinct genus of sea turtle that lived in the Late Cretaceous (Campanian). Zangerl (1960) named the type species, based upon remains found in Alabama within the Mooreville Chalk Formation.
Ctenochelys is an extinct genus of marine turtle, which existed during the Cretaceous period, and lived in the shallow waters of the Western Interior Seaway. Its fossils have been found in the Ripley Formation and Mooreville Chalk of central Alabama, United States. It was first named by C. H. Sternberg in 1904, and contains two species, C. stenoporus and C. acris.
Bouliachelys is an extinct genus of sea turtle from Cretaceous Australia. It was originally described as a member of Protostegidae. In 2013 study it was considered to be a member of Dermochelyoidae, although later studies consider it as a protostegid again.
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.
Mesodermochelys is an extinct genus of sea turtle known from the Campanian to the Maastrichtian of what today is Japan. One species is known, the type species M. undulatus; it was given its binomial name by Ren Hirayama and Tsutomu Chitoku in 1996. Studies of its skull indicate that it was a primitive member of the Dermochelyidae that was closely related to the Protostegidae. It has been described as the best representative of Mesozoic dermochelyids.
Cratochelone is an extinct genus of sea turtle in the family Protostegidae and containing a single species Cratochelone berneyi. The species is known only from the mid to late Albian Toolebuc Formation, part of the Rolling Downs Group, in the Hughenden of Central northern Queensland, Australia.
Terlinguachelys fischbecki is an extinct sea turtle that existed during the Late Cretaceous period some 80 million years ago. It is the sole species in the genus Terlinguachelys and is classified in the family Protostegidae along with other extinct marine turtles.
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 fossil trade is the purchase and sale of fossils. This is at times done illegally with stolen fossils, and important scientific specimens are lost each year. The trade is lucrative, and many celebrities collect fossils.
Eugene S. Gaffney is an American paleontologist and leading authority on the morphology and evolutionary history of turtles.
Ocepechelon is an extinct genus of giant protostegid sea turtle known from Late Cretaceous phosphatic deposits of the Oulad Abdoun Basin, Khouribga Province of Morocco. It is known from the holotype OCP DEK/GE 516, a complete but isolated 70-cm-long skull, making it one of the largest marine turtles ever described. It was first named by Nathalie Bardet, Nour-Eddine Jalil, France de Lapparent de Broin, Damien Germain, Olivier Lambert and Mbarek Amaghzaz in 2013, and the type species is Ocepechelon bouyai. The feeding apparatus of Ocepechelon, a bony pipette-like snout, is unique among tetrapods and shares unique convergences with both syngnathid fishes and beaked whales.
Rhinochelys is an extinct genus of sea turtles belonging to the family Protostegidae.
Sachicasaurus is an extinct genus of brachauchenine pliosaurid known from the Barremian of the Paja Formation, Altiplano Cundiboyacense in the Colombian Eastern Ranges of the Andes. The type species is S. vitae.
Thalassochelydia is a clade of extinct marine turtles from the Late Jurassic and earliest Cretaceous of Europe and South America. The group is defined as including Eurysternum, Plesiochelys and Thalassemys to the exclusion of Pelomedusa, Testudo and Protostega. While a clade uniting the families Eurysternidae, Plesiochelyidae and Thalassemydidae had been supported by phylogenetic evidence, a name was not given for the clade until 2017, when Jérémy Anquetin and colleagues coined Thalassochelydia.
Calcarichelys is an extinct genus of protostegid turtle from the Late Cretaceous of the Selma Formation in Alabama, and possibly from Angola. It contains only one species, C. gemma.
This list of fossil reptiles described in 2023 is a list of new taxa of fossil reptiles that were described during the year 2023, as well as other significant discoveries and events related to reptile paleontology that occurred in 2023.
