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.
Description
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-groupPodocnemidoidae, 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]
Name
The name Amabilis, according to Hermanson et al., is from the "Latin for 'lovable', for its tiny size."[2]
^"Amazonian turtles". Wildlife Conservation Society Brazil. Retrieved November 30, 2021. 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.
^Rafferty, John P (2008). "Side-necked turtle". Britannica. Retrieved November 25, 2021.
^Eugene S. Gaffney; Peter A. Meylan; Roger C. Wood; Elwyn Simons; Diogenes De Almeida Campos (2011). "Evolution of the Side-Necked Turtles: The Family Podocnemididae". Bulletin of the American Museum of Natural History. 350: 1–237. doi:10.1206/350.1. hdl:2246/6110. S2CID83775718. 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.
^Nardelli, Luciana (February 13, 2020). "Região de Rio Preto identifica tartaruga de 85 milhões de anos" [Rio Preto region identifies 85-million-year-old turtle]. Diário da Região (in Portuguese). Retrieved November 25, 2021. 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.)
