''Chasicobradys'' is an extinct genus of ground sloths of the family

Nothrotheriidae Nothrotheriidae is a family of extinct ground sloths that lived from approximately 17.5 mya—10,000 years ago, existing for approximately . Previously placed within the tribe Nothrotheriini or subfamily Nothrotheriinae within Megatheriidae, they ...

that lived in what is now

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

. ''Chasicobradys'' was discovered in the

Arroyo Chasicó Formation Arroyo often refers to: * Arroyo (watercourse), an intermittently dry creek Arroyo may also refer to: Places United States * Arroyo, Pennsylvania * Arroyo, Puerto Rico, a municipality * Arroyo, West Virginia Spain * Arroyo (Santillana del Mar), ...

, in

Buenos Aires Province Buenos Aires, officially the Buenos Aires Province, is the largest and most populous Provinces of Argentina, Argentine province. It takes its name from the city of Buenos Aires, the capital of the country, which used to be part of the province an ...

. It is only known from jaw fragments and teeth, which allowed the identification of this species, and was classified as a member of the nothrotheriid subfamily Nothrotheriinae, which comprises small to medium-sized species of ground sloths.

Etymology

The genus name, ''Chasicobradys'', is derived from the

in Argentina and ''bradys'' meaning "slow". was found. The specific name means "intermediate".

Description

''Chasicobradys'' is a medium-sized species, similar in size to the

Argentine Argentines, Argentinians or Argentineans are people from Argentina. This connection may be residential, legal, historical, or cultural. For most Argentines, several (or all) of these connections exist and are collectively the source of their ...

species '' Neohapalops rothi'', characterized by a very high mandibular ramus and characteristics of its molariform teeth, such as the lack of a diastema between the first and second molars and the oblique location of the fourth molars. ''Chasicobradys'' is one of the few sloths present in the Arroyo Chasicó Formation. Additional remains found in the area suggest the presence of other nothrotheriines along with a genus of

megatheriid Megatheriidae is a family of extinct ground sloths that lived from approximately 23 mya—11,000 years ago. Megatheriids appeared during the Late Oligocene (Deseadan in the SALMA classification), some 29 million years ago, in South America. ...

sloth, '' Anisodontherium''. The remains of these sloths show that at this time the nothrotheriids were already differentiated from the megatheriids and possessed the characteristics that would identify them in later times.

Palaeoecology

The Arroyo Chasicó formation was, in the Miocene, on the tip of a peninsula bordered by the

Paranaense Sea Paranaense may refer to: *Campeonato Paranaense, Brazilian association football league *Clube Atlético Paranaense, Brazilian association football club * Paranaense F.C., a Paraguayan association football club *Sport Club Corinthians Paranaense ...

. ''Chasicobradys'' would have lived alongside various genera of

Cingulata Cingulata, part of the superorder Xenarthra, is an order of armored New World placental mammals. The armadillos, whose species are split between the families Dasypodidae and Chlamyphoridae, are the only surviving members of the order. Two grou ...

, including the last horned armadillo '' Epipeltephilus'', the

Dasypodidae Dasypodidae, from Ancient Greek δασύς (''dasús''), meaning "hair", and πούς (''poús''), meaning "foot", is a family of mostly extinct genera of armadillos. One genus, ''Dasypus'', is extant, with at least seven living species. __TO ...

'' Vetelia'' and '' Chasicotatus'', the

Euphractinae Euphractinae is an armadillo subfamily in the family Chlamyphoridae. Euphractinae are known for having a well developed osteoderm that has large cavities filled with adipose tissue, and more hair follicles with well developed sebaceous glands ...

Proeuphractus ''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. Description This animal was quite similar to the m ...

'', the

Glyptodont Glyptodonts are an extinct clade of large, heavily armoured armadillos, reaching up to in height, and maximum body masses of around 2 tonnes. They had short, deep skulls, a fused vertebral column, and a large bony carapace made up of hundreds o ...

inae ''

Kelenkura ''Kelenkura'' is an extinct genus of heavily armored mammals belonging to the subfamily Glyptodontinae, from the family Chlamyphoridae that contain most of the modern armadillos. It was a medium-sized South American animal, distantly related to ''D ...

'' and the

pampathere Pampatheriidae ("Pampas beasts") is an extinct family of large cingulates related to armadillos. They first appeared in South America during the mid-Miocene, and '' Holmesina'' and '' Pampatherium'' spread to North America during the Pleistocen ...

Kraglievichia ''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. Description ''Kraglievichia'' looked li ...

''. Other

xenarthra Xenarthra (; from Ancient Greek ξένος, xénos, "foreign, alien" + ἄρθρον, árthron, "joint") is a superorder and major clade of placental mammals native to the Americas. There are 31 living species: the anteaters, tree sloths, and ...

ns includes several genera of

ground sloths Ground sloths are a diverse group of extinct sloths in the mammalian superorder Xenarthra. They varied widely in size with the largest, belonging to genera '' Lestodon'', ''Eremotherium'' and ''Megatherium'', being around the size of elephants. G ...

, such as the

Mylodontidae Mylodontidae is a family of extinct South American and North American ground sloths within the suborder Folivora of order Pilosa, living from around 23 million years ago (Mya) to 11,000 years ago. This family is most closely related to another fa ...

'' Octomylodon'', the

Megalonychidae Megalonychidae is an extinct family of sloths including the extinct ''Megalonyx''. Megalonychids first appeared in the early Oligocene, about 35 million years (Ma) ago, in southern Argentina (Patagonia). There is, however, one possible find datin ...

'' Protomegalonyx'', the fellow

'' Xyophorus'', and the

Megatheriidae Megatheriidae is a family of Extinction, extinct ground sloths that lived from approximately 23 Annum, mya—11,000 years ago. Megatheriids appeared during the Oligocene, Late Oligocene (Deseadan in the South American land mammal age, SALMA cl ...

'' Anisodontherium''. Several genera of

rodents Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...

were recovered from the formation, such as the earliest genus of

tuco-tucos A tuco-tuco is a neotropical rodent in the family Ctenomyidae. Tuco-tucos belong to the only living genus of the family Ctenomyidae, ''Ctenomys'', but they include approximately 60 different species. The common name, "tuco-tuco", comes from the " ...

, maras and

capybaras The capybara or greater capybara (''Hydrochoerus hydrochaeris'') is the largest living rodent, native to South America. It is a member of the genus ''Hydrochoerus''. The only other extant member is the lesser capybara (''Hydrochoerus isthmiu ...

such as '' Cardiomys'', '' Procardiomys'' and '' Cardiatherium'',

Octodontidae Octodontidae is a family of rodents, restricted to southwestern South America. Fourteen species of octodontid are recognised, arranged in seven genera. The best known species is the common degu, ''Octodon degus''. Octodontids are medium-sized ...

such as '' Chasicomys'' and '' Chasichimys'', the

Echimyidae Echimyidae is the family of neotropical spiny rats and their fossil relatives. This is the most species-rich family of hystricognath rodents. It is probably also the most ecologically diverse, with members ranging from fully arboreal to terr ...

'' Pattersomys'', the plain viscacha ''Lagostomus telenkechanum'' and its relative '' Prolagostomus'', and large-sized

Dinomyidae The Dinomyidae are a family (biology), family of South American hystricognath rodents: the dinomyids were once a very speciose group, but now contains only a single living species, the pacarana. Several of the extinct dinomyids were among the la ...

like '' Carlesia''. Meridiungulates were also present in the formation, with

Litopterna Litopterna (from "smooth heel") is an extinction, extinct order of South American native ungulates that lived from the Paleocene to the Pleistocene-Holocene around 62.5 million to 12,000 years ago (or possibly as late as 3,500 years ago), and we ...

genera such as the

Macraucheniidae Macraucheniidae is a family in the extinct South American ungulate order Litopterna, that resembled camelids. They had three functional digits on the fore and hind feet, as well as elongate necks. The family is generally divided up into two sub ...

Cullinia ''Cullinia'' is an extinct genus of litoptern, an order of South American native ungulates that included horse-like and camel-like animals such as ''Macrauchenia''. It is only known from fragmentary remains. ''Cullinia levis'' is known from Chasi ...

'' and ''

Paranauchenia ''Paranauchenia'' is an extinct genus of South American litopterns belonging to the family Macraucheniidae. It is known only from fossil finds in Argentina. It possessed three toes and long limbs. The species ''Paranauchenia denticulata'' lived i ...

'' and the

Proterotheriidae Proterotheriidae is an extinction, extinct family of Litopterna, litoptern ungulates known from the Eocene-Late Pleistocene of South America. Members of the group were small-medium sized cursorial Herbivore, herbivores with brachydont Tooth, teet ...

Neobrachytherium ''Neobrachytherium'' is an extinct genus of proterotheriid mammal from the Late Miocene of Argentina and Uruguay. It is represented by multiple species, including the type ''N. intermedium'', originally named in 1891 by Moreno and Mercerat as a ...

'', while

notoungulates Notoungulata is an extinct order of ungulates that inhabited South America from the early Paleocene to the end of the Pleistocene, living from approximately 61 million to 11,000 years ago. Notoungulates were morphologically diverse, with forms re ...

were represented by genera such as the large-sized late surviving

Homalodotheriidae Homalodotheriidae is an extinct family comprising four genera of notoungulate mammals known from the Late Eocene (Tinguirirican) through Late Miocene ( Chasicoan) of Argentina and Chile in South America South America is a continent ent ...

Chasicotherium ''Chasicotherium'' is an extinct genus of a large notoungulate mammal known originally from a partial skull and mandible discovered in the Arroyo Chasicó Formation, in the stream of Party of Villarino, Buenos Aires, Argentina. The sediments in ...

'', the

Toxodontidae Toxodontidae is an extinct family of notoungulate mammals, known from the Oligocene to the Holocene (11,000 BP) of South America, with one genus, '' Mixotoxodon'', also known from the Pleistocene of Central America and southern North America (a ...

'' Paratrigodon'', the Interatheriidae ''

Protypotherium ''Protypotherium'' is an extinct genus of Notoungulata, notoungulate mammals native to South America during the Oligocene and Miocene epoch (geology), epochs. A number of closely related animals date back further, to the Eocene. Fossils of ''Prot ...

'', the

Mesotheriidae Mesotheriidae ("Middle Beasts") is an extinct family of notoungulate mammals known from the Oligocene through the Pleistocene of South America. Mesotheriids were small to medium-sized herbivorous mammals adapted for digging. Characteristics Mes ...

'' Typotheriopsis'', and the

Hegetotheriidae Hegetotheriidae is an extinct family of notoungulate mammals known from the Oligocene through the Pliocene of South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a c ...

'' Paedotherium'', '' Pseudohegetotherium'' and '' Hemihegetotherium''. The largest

predators Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill ...

were the

Sparassodonta Sparassodonta (from Ancient Greek, Greek to tear, rend; and , gen.

, ' The comma is a punctuation mark that appears in several variants in different languages. Some typefaces render it as a small line, slightly curved or straight, but inclined from the vertical; others give it the appearance of a miniature fille ...

tooth) is an extinct order (biology), order of carnivore, carnivorous metatherian mammals native to South America, related to modern marsupials. They were once cons ...

'' Pseudolycopsis cabrerai'' and '' Lycopsis viverensis'', and the small

terror bird Phorusrhacids, colloquially known as terror birds, are an extinct family of large carnivorous, mostly flightless birds that were among the largest apex predators in South America during the Cenozoic era. Their definitive fossil records range from ...

Psilopterus ''Psilopterus'' (Greek for "bare wing") is an extinct genus of phorusrhacid ("terror bird") from the Middle Oligocene to possibly the Late Pleistocene of Argentina and Uruguay. Compared to other phorusrhacids, members of the genus are both relat ...

''.

References

{{Taxonbar, from=Q113876373 Prehistoric sloths Prehistoric placental genera Miocene mammals of South America Miocene xenarthrans Neogene Argentina Fossils of Argentina Fossil taxa described in 1987