Utaetus | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Cingulata |
Family: | Dasypodidae |
Genus: | † Utaetus Ameghino 1902 |
Type species | |
†Utaetus buccatus Ameghino 1902 | |
Species | |
Dubious species
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Synonyms | |
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Utaetus is an extinct genus of mammal in the order Cingulata, related to the modern armadillos. The genus contains two species, Utaetus buccatus and U. magnum. It lived in the Late Paleocene to Late Eocene (about 60 to 36 million years ago) and its fossil remains were found in Argentina and Brazil in South America. [1]
This animal, about 1 metre (3.3 ft) long, was very similar to a modern armadillo. In particular, the appearance likely recalled that of the modern Euphractus , and it already had the typical well-developed xenarthral joints on the vertebrae. Among the other characteristics in common with the modern armadillos, Utaetus possessed a bony connection between the ischium and the sacrum (this structure was constituted by caudal vertebrae known as pseudosacral) and continuous-growth cylindrical teeth similar to chisels, with wear in the occlusal part. There were ten lower teeth on each side of the jaw; the first two were much smaller and are interpreted as incisors. Unlike later armadillos, however, Utaetus still had a varying amount of enamel on the lingual and buccal surfaces of the teeth, and the cervical vertebrae were separated (and not co-ossified). The skeleton shows that this animal was adapted for digging, as evidenced by the presence of a large acromion on the scapula and a prominent olecranon on the ulna. The posterior margin of the scapula was thickened, and formed a secondary incipient spine.
The genus Utaetus was first described in 1902 by Florentino Ameghino, based on fossil remains initially thought to date back to the Cretaceous. The type species is Utaetus buccatus, also known for cranial material, but Ameghino described further species based on fragmentary remains (U. deustus, U. lenis, U. laevus, U. laxus), now considered nomina dubia . Utaetus is considered a primitive member of the Dasypodidae, the family that includes the modern armadillos and their extinct relatives. In particular, Utaetus and its close relatives (such as Parutaetus) could be closely related to the modern genus Euphractus . The name Utaetus is an anagram of Eutatus , another extinct armadillo. In 2021, Claudia Herrera and colleagues named a new species of Utaetus based on several osteoderms that had been unearthed from the Middle Eocene strata of the Upper Lumbrera Formation in Salta Province, Argentina. [2]
Fossils of Utaetus have been found in: [3]
Cingulata, part of the superorder Xenarthra, is an order of armored New World placental mammals. Dasypodids and chlamyphorids, the armadillos, are the only surviving families in the order. Two groups of cingulates much larger than extant armadillos existed until recently: pampatheriids, which reached weights of up to 200 kg (440 lb) and chlamyphorid glyptodonts, which attained masses of 2,000 kg (4,400 lb) or more.
Peltephilus, the horned armadillo, is an extinct genus of armadillo xenarthran mammals that first inhabited Argentina during the Oligocene epoch, and became extinct in the Miocene epoch. Notably, the scutes on its head were so developed that they formed horns. Aside from the horned gophers of North America, it is the only known fossorial horned mammal. P. ferox had skull about 11.7 centimetres (4.6 in), and estimated body mass is around 11.07 kilograms (24.4 lb).
Hoplophorus is an extinct genus of glyptodont, a subfamily of armadillos. The only confidently known species was H. euphractus, found in Pleistocene deposits in Brazil, though fossils possibly from another species are known from Bolivia.
Glyptodon is a genus of glyptodont, an extinct group of large, herbivorous armadillos, that lived from the Pliocene, around 3.2 million years ago, to the early Holocene, around 11,000 years ago, in South America. It is one of, if not the, best known genus of glyptodont. Glyptodon has a long and storied past, being the first named extinct cingulate and the type genus of the subfamily Glyptodontinae. Fossils of Glyptodon have been recorded as early as 1814 from Pleistocene aged deposits from Uruguay, though many were incorrectly referred to the ground sloth Megatherium by early paleontologists.
Propalaehoplophorus, also written as Propalaeohoplophorus, is an extinct genus of glyptodont, which lived in South America during the Early Miocene epoch.
Stegotherium is an extinct genus of long-nosed armadillo, belonging to the Dasypodidae family alongside the nine-banded armadillo. It is currently the only genus recognized as a member of the tribe Stegotheriini. It lived during the Early Miocene of Patagonia and was found in Colhuehuapian rocks from the Sarmiento Formation, Santacrucian rocks from the Santa Cruz Formation, and potentially also in Colloncuran rocks from the Middle Miocene Collón Curá Formation. Its strange, almost toothless and elongated skull indicates a specialization for myrmecophagy, the eating of ants, unique among the order Cingulata, which includes pampatheres, glyptodonts and all the extant species of armadillos.
Neosclerocalyptus was an extinct genus of glyptodont that lived during the Pliocene, Pleistocene, and Holocene of Southern South America, mostly Argentina. It was small compared to many glyptodonts at only around 2 meters long and 360 kilograms.
The Guabirotuba Formation is a late Middle Eocene geologic formation of the Curitiba Basin in Paraná, Brazil. The formation crops out in and around the city of Curitiba and comprises mudstones and sandstones deposited in a fluvial floodplain environment.
The Geste Formation is a fossiliferous geologic formation of the Puna Plateau in the western Salta Province and northern Catamarca Province of the Argentine Northwest, northwestern Argentina.
Kraglievichia is an extinct genus of cingulate belonging to the family Pampatheriidae. It lived from the Late Miocene to the Early Pliocene, and its fossilized remains were discovered in South America.
Punatherium is an extinct genus of xenarthran, belonging to the family Dasypodidae. It lived during the Late Eocene, and its fossilized remains were discovered in South America.
Stenotatus is an extinct genus of cingulate, belonging to the family Dasypodidae. It lived from the Early to the Late Miocene in South America.
Astegotherium is an extinct genus of xenarthran, belonging to the family Dasypodidae. It lived from the Early to the Middle Eocene, and its fossilized remains are found in Argentina.
Proeutatus is an extinct genus of xenarthran, belonging to the order Cingulata. It lived during the Early Miocene, and its fossilized remains were discovered in South America.
Proeuphractus is an extinct genus of xenarthran, related to the modern armadillos. It lived from the Early to the Late Miocene, and its fossilized remains were discovered in South America.
Prozaedyus is an extinct genus of chlamyphorid armadillo that lived during the Middle Oligocene and Middle Miocene in what is now South America.
Eucinepeltus is an extinct genus of glyptodont. It lived during the Early Miocene, and its fossilized remains were discovered in South America.
Cochlops is an extinct genus of glyptodont. It lived from the Early to Middle Miocene, and its fossilized remains have been found in South America.
Dasypus neogaeus is an extinct species of armadillo, belonging to the genus Dasypus, alongside the modern nine-banded armadillo. The only known fossil is a single osteoderm, though it has been lost, that was found in the Late Miocene strata of Argentina.
Peltephilidae is a family of South American cingulates (armadillos) that lived for over 40 million years, but peaked in diversity towards the end of the Oligocene and beginning of the Miocene in what is now Argentina. They were exclusive to South America due to its geographic isolation at the time, one of many of the continent's strange endemic families. Peltephilids are one of the earliest known cingulates, diverging from the rest of Cingulata in the Early Eocene.