Amabilis uchoensis Temporal range: Santonian ~ | |
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Amabilis uchoensis skull CT scan in dorsal (top left), ventral (top right), right lateral (centre left), anterior (centre right), left lateral (bottom left) and posterior (bottom right) views | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Order: | Testudines |
Suborder: | Pleurodira |
Hyperfamily: | Pelomedusoides |
Clade: | Podocnemidoidae |
Genus: | † Amabilis Hermanson et al., 2020 |
Species: | †A. uchoensis |
Binomial name | |
†Amabilis uchoensis Hermanson et al., 2020 | |
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.
Hermanson et al. (2020) described the Late Cretaceous turtle Amabilis uchoensis based on a single partial skull from the São José do Rio Preto Formation, in the Brazilian state of São Paulo. The São José do Rio Preto Formation is thought to have been deposited during the Santonian age of the Late Cretaceous, between 86.3 and 83.6 million years ago. [1]
The type-specimen skull, which is 2.25 cm long and 2.06 cm wide, suggests that the animal was smaller than any other fossil turtles found in Brazil's Bauru Group. [2] Modern Brazilian river turtles are also considerably larger, ranging in length from 34 cm (Podocnemis erythrocephala) to 90 cm (Podocnemis expansa.) [3] This skull is deposited in Uchoa's Museum of Paleontology. [2]
The fossil is in the suborder Pleurodira, also known as "side-necked turtles" because their defensive posture hides the head under the shell by pulling the head to one side, rather than by withdrawing the head directly back under the shell. [4]
The Amabilis genus is part of the superfamily or pan-group Podocnemidoidae, which groups the family Podocnemididae together with some related extinct genera, as well as the extinct family Peiropemydidae. [5] Podocnemidoids, first seen in the Late Cretaceous, were once widely distributed across "North and South America, Europe, Asia, and Africa," according to Gaffney et al. (2011.) [6] No surviving turtle species descend directly from Amabilis, which is therefore considered to be a stem group within its family and super-family. Because it is a member of Podocnemidoidae but not a member of the Podocnemididae. Hermanson et al. describe it as "a non-podocnemidid member of Podocnemidoidae." [2]
According to the local newspaper Diário da Região, A. uchoensis was the first fossil turtle found in the São José do Rio Preto region (near the city of São Paulo). The turtle skull fragment was found by Brazilian paleontologist Fabiano Vidoi Iori, very near to the 2014 discovery site of carnivorous dinosaur Thanos simonattoi . [7]
The name Amabilis, according to Hermanson et al., is from the "Latin for 'lovable', for its tiny size." [2]
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.
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.
The Big-headed Amazon River turtle, also known as the big-headed sideneck, is a species of turtle in the family Podocnemididae.
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.
Amabilis is derived from the Latin verb "amare," to love, and may be translated as "lovable" or as "lovely."
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.
The Bauru Group is a geological group of the Bauru Sub-basin, Paraná Basin in Minas Gerais, São Paulo, General Salgado, Itapecuru-Mirim, Mato Grosso, Brazil whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.
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.
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.
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.
Araiochelys is an extinct genus of bothremydid pleurodiran turtle that was discovered in the Ouled Abdoun Basin, Morocco. The genus consists solely of type species A. hirayamai.
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.
Eotaphrosphys is an extinct genus of bothremydid pleurodiran turtle that was discovered in the Mont Aime Formation, France. Originally assigned to the genus "Tretosternum", it consists exclusively of type species E. ambiguum.
Motelomama is an extinct genus of bothremydid pleurodiran turtle that was discovered in the Ypresian Salina Group near Negritos, Peru. The genus consists solely of type species M. olssoni.
Labrostochelys is an extinct genus of bothremydid pleurodiran turtle that was discovered in the Ouled Abdoun Basin, Morocco. The genus consists solely of type species L. galkini.
Caninemys is an extinct genus of large freshwater side-necked turtle, belonging to the family Podocnemididae. Its fossils have been found in Brazil and Colombia, in rocks dating back from the middle to late Miocene.
Ibirania is a genus of dwarf saltasaurine titanosaur dinosaur from the Late Cretaceous São José do Rio Preto Formation of Southeast Brazil. The type species is Ibirania parva. It is one of the smallest sauropods known to date, comparable in size to the titanosaur Magyarosaurus.
The age of the São José do Rio Preto Formation is estimated as Santonian, considering its stratigraphic relationship, i.e., partially correlated with the Araçatuba and Adamantina formations and overlying the Santo Anastácio Formation as well as the association of 'P.' brasiliensis, Megaraptora, I. bauruensis, I. wichmanni and isolated teeth of crocodyliformes.
A particularly large number of fossil pleurodires, many belonging to the Podocnemidoidae, has been recovered from the Upper Cretaceous Bauru Group outcrops of south-central Brazil...Amabilis differs from all other Podocnemidoidae in possessing a medially open fenestra postotica and lacking a basioccipital–opisthotic contact (also absent only in Mogharemys blanckenhorni).
WCS-Brazil decided to focus on conservation of Amazonian river turtles, especially the five species of the Podocnemididae family (described below), because they are threatened species due to high demand for their eggs and meat.
The relationships of the family Podocnemididae to its sister taxa Hamadachelys and Brasilemys are recognized by placing them in the epifamily Podocnemidinura. The epifamily Podocnemidinura is the sister group to the family Bothremydidae, and together they form the superfamily Podocnemidoidea.
The family Podocnemididae consists of 20 genera and 30 species considered here as valid and diagnosable by cranial characters. Three of these genera and eight species persist into the Recent fauna, barely reflecting the evolutionary diversity and distribution of the group. The family extends from the late Cretaceous to the Recent and occurs in North and South America, Europe, Asia, and Africa.
Esse é o perfil da Amabilis uchoensis, a primeira espécie de tartaruga fóssil descrita na região de Rio Preto, descoberta por pesquisadores brasileiros e até da Suíça. O fragmento que permitiu a identificação da nova "tartaruguinha" é um pedaço de crânio que foi localizado em um sítio paleontológico de Ibirá, no ano de 2014. (This is the profile of Amabilis uchoensis, the first fossil turtle species described in the Rio Preto region, discovered by Brazilian and Swiss researchers. The fragment that allowed the identification of the new "little turtle" is a piece of skull that was located in a paleontological site in Ibirá, in 2014.)