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Temporal range: Late Cretaceous
~80  Ma
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Testudines
Suborder: Pleurodira
Family: Euraxemydidae
Genus: Caririemys
Oliveira and Kellner, 2007
C. violetae
Binomial name
Caririemys violetae
Oliveira and Kellner, 2007

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. [1]

A genus is a taxonomic rank used in the biological classification of living and fossil organisms, as well as viruses, in biology. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus.

Pleurodira suborder of reptiles

The Pleurodira are one of the two living suborders of turtles, the other being the Cryptodira. In many cases in the nomenclature of animals, ranks such as suborder are considered of little importance apart from nomenclatural or taxonomic reasons. However, this is not the case with the suborders of the turtles. This division 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, two living families are represented: Chelidae, also known as the Austro-South American side-necked turtles, and the Pelomedusidae, also known as the Afro-South American side-necked turtles. However, they are a cosmopolitan clade across the Cretaceous and Cenozoic, and even occurred in marine environments across the world.

Type species term used in zoological nomenclature (also non-officially in botanical nomenclature)

In zoological nomenclature, a type species is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen(s). A similar concept is used for suprageneric groups called a type genus.



The genus was named for the city of Santana do Cariri where the fossil was unearthed. [1] The species' specific name, violetae, honors Violeta Arraes, a former dean at the nearby Universidade Regional do Cariri. Arraes was a prominent local political figure during the 20th century and became instrumental in the development of paleontological studies in the area when she was appointed dean of the Universidade Regional do Cariri in 1997. [2] [3] [4]

Santana do Cariri is a municipality in the state of Ceará in the Northeast region of Brazil.

In zoological nomenclature, the specific name is the second part within the scientific name of a species. The first part of the name of a species is the name of the genus or the generic name. The rules and regulations governing the giving of a new species name are explained in the article species description.


Because the few remains used to describe the species were incomplete, anatomical characteristics used to differentiate Caririemys from other extinct and extant pleurodirans are derived mostly from the arrangement of the bony plates that form its domed carapace. [1]

Carapace part of exoskeleton in some animals

A carapace is a dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.

The genus and species were first described in 2007, from the fragmentary remains of a single fossil specimen unearthed in north-eastern Brazil two years prior to the publication of the description. The Santana Formation of Brazil where the specimen was discovered is a treasure-trove of prehistoric turtle remains including the early sea turtle Santanachelys . Caririemys was the fifth unique testudine genus to have been described from fossils found in the Romualdo Member section of the geologic formation. The lone specimen, officially labeled as MN6919-v now resides in the Museu Nacional da Universidade Federal do Rio de Janeiro. [1]

Sea turtle superfamily of reptiles

Sea turtles, sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the green sea turtle, loggerhead sea turtle, Kemp's ridley sea turtle, olive ridley sea turtle, hawksbill sea turtle, flatback sea turtle, and leatherback sea turtle.

<i>Santanachelys</i> species of reptile

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. It was even recorded as the oldest sea turtle in Encyclopædia Britannica, but a new fossil named Desmatochelyspadillai in 2015 is estimated to be as old as 120 million years.

The turtle skeleton found consisted of parts of the turtle's carapace, a few vertebral elements and a matching femur and pelvis. Since most of the elements used to systematically classify a fossil turtle in the Pleurodira (such as the skull) were missing, the species’ affiliation was determined by the attachment of the specimen's pelvis to its carapace. [1] Closer approximation and analysis of its carapace elements have shown that Caririemys is closely related to the turtle Euraxemys essweini from the same geographic locality and strata. [5]

Related Research Articles

Crato Formation

The Crato Formation is a geologic formation of Early Cretaceous (Aptian) age in northeastern Brazil's Araripe Basin. It is an important Lagerstätte for palaeontologists. The strata were laid down mostly during the early Aptian age, about 113 million years ago, in a shallow inland sea. At that time, the South Atlantic was opening up in a long narrow shallow sea.

Romualdo Formation geologic fossil accumulation in northeastern Brazils Araripe Basin

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 Albian 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.

<i>Araripemys</i> genus of reptiles

Araripemys is an extinct marine turtle genus from 112 to 109 million years ago, in the Early Cretaceous Crato and Romualdo Formations of the Araripe Basin in northeastern Brazil. It is one of the oldest known pleurodires.

<i>Santanaraptor</i> genus of reptiles (fossil)

Santanaraptor is a genus of tyrannosauroid dinosaur that lived in South America during the Early Cretaceous, about 112 million years ago.

Anhanguera is a genus of pterodactyloid pterosaur known from the Early Cretaceous Romualdo Formation of Brazil. This pterosaur is closely related to Ornithocheirus, and belongs in the family Ornithocheiridae within its own subfamily, Anhanguerinae.

Brasileodactylus a genus of pterosaur from the Aptian, Lower Santana formation of Chapada do Araripe, Ceará, Brazil.

<i>Mesodermochelys</i> genus of reptiles

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.

<i>Cearachelys</i> species of reptile (fossil)

Cearachelys is an extinct genus of pleurodiran turtle which existed some 80 million years ago. The genus is monotypic, with only type species Cearachelys placidoi known.

Santanichthys diasii is a species of extinct fish that existed around 115 million years ago during the Albian age. S. diasii is regarded as the basal-most characiform, and is the earliest known member of Otophysi. It appears as a small fish, similar in appearance to a modern-day herring little more than 30 millimeters in length. Its most striking characteristic is the presence of a Weberian apparatus, which makes it the most primitive known member of the order Characiformes, the order in which modern-day tetras are classified. Santanichthys has been unearthed from numerous locations throughout Brazil, in rocks dating to the Cretaceous Period. Its presence in these strata is seen as an indicator for the biogeography and evolution of its order.

Eurycephalella is an extinct genus of frogs which existed in what is now Brazil during the Early Cretaceous (Aptian). It was named by Ana M. Báez, Geraldo J.B. Moura and Raúl O. Gómez in 2009, and the type species is Eurycephalella alcinae.

Unwindia is a genus of pterodactyloid pterosaur from the Early Cretaceous of Brazil.

<i>Pleurosternon</i> genus of reptiles

Pleurosternon is an extinct genus of cryptodire turtle from the late Jurassic period to the early Cretaceous period. Its type species, P. bullocki was described by the paleontologist Richard Owen in 1853. Since then, and throughout the late 19th century, many fossil turtles were incorrectly assigned to this genus.

Anhanguera araripensis is a pterosaur species from the Albian-age Romualdo Member of the Early Cretaceous Santana Formation, of Barra do Jardim, Araripe Plateau, Ceará Province, Brazil. A. araripensis was named after the Araripe Plateau.

<i>Maaradactylus</i> genus of reptiles (fossil)

Maaradactylus is a genus of anhanguerid pterosaur known from the Lower Cretaceous Romualdo Formation of northeastern Brazil.

Araripe Basin

The Araripe Basin is a rift basin covering about 8,000 square kilometres (3,100 sq mi), in Ceará, Piauí and Pernambuco states of northeastern Brazil. It is bounded by the Patos and Pernambuco lineaments, and is situated east of the Parnaíba Basin, southwest of the Rio do Peixe Basin and northwest of the Tucano and Jatobá Basins.

<i>Basilemys</i> genus of reptiles

Basilemys is an extinct genus of land turtles belonging to the family Nanhsiungchelyidae. Fossils have been found in various Campanian to Maastrichtian formations of North America.

Bauruemys is an extinct genus of turtles in the family Podocnemididae.

Presidente Prudente Formation

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.

Santana Group Geologic group

The Santana Group is a geologic group, formerly included as the middle part of the Araripe Group, in the Araripe Basin of northeastern Brazil. The group comprises the Crato, Ipubi and Romualdo Formations and is dated to the Aptian to Albian stages of the Early Cretaceous. The formations of the group were deposited in a lacustrine to subtidal shallow marine environment in the Araripe rift basin.

Ipubi Formation

The Ipubi Formation is the middle geological formation of the Santana Group, the middle part of the Araripe Group, in the Araripe Basin of northeastern Brazil. The formation is dated to the Aptian to Albian stages of the Early Cretaceous, unconformably overlying the Crato Formation and unconformably overlain by the Romualdo Formation, formerly known as the Romualdo Member of the Santana Formation. The averaging 15 metres (49 ft) thick Ipubi Formation comprises shales and sandstones in the lower section and evaporites in the upper part of the formation, deposited in a transgressive to highstand lacustrine environment in the Araripe rift basin.


  1. 1 2 3 4 5 de Oliveira, Gustavo Ribeiro; Alexander Wilhelm Armin Kellner (2007-03-15). "A new side-necked turtle (Pleurodira, Pelomedusoides) from the Santana Formation (Early Cretaceous), Araripe Basin, Northeastern Brazil". Zootaxa. 1425: 53–61. doi:10.11646/zootaxa.1425.1.7 . Retrieved 2008-12-16.
  2. Dutra, Giselle (2008-06-18). "Violetae". Vida e Obra. Jornal O Povo. Retrieved 2008-12-16.[ dead link ]
  3. "Paleocurtas: As últimas do mundo da paleontologia". SPEAKERS: THE FOSSIL HUNTERS. Instituto Ciência Hoje. 2007. Archived from the original on June 10, 2007. Retrieved 2008-12-16.
  4. Vicelmo, Antonio (2007-03-31). "Classificado novo fóssil achado na Bacia do Araripe". Regional Paleontology (in Portuguese). Diario do Nordeste. Retrieved 2008-12-16.
  5. de Oliveira, Gustavo Ribeiro (2007). "Taphonomical Aspects of Testudines from Santana Formation (Lower Cretaceous), Araripe Basin, Northeastern Brazil". Anuário do Instituto de Geociências. 30 (1): 83–93.