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Mylodontidae

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118-403: 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 family of extinct ground sloths, Scelidotheriidae , as well as to the extant arboreal two-toed sloths, family Choloepodidae ; together these make up

236-468: A de jure sovereignty over the area. In 1669, the district around Puerto Deseado was explored by John Davis and was claimed in 1670 by Sir John Narborough for King Charles II of England , but the English made no attempt to establish settlements or explore the interior. The first European explorers of Patagonia observed that the indigenous people in the region were taller than the average Europeans of

354-813: A dissected topography . The Antarctic Plate started to subduct beneath South America 14 million years ago in the Miocene, forming the Chile Triple Junction . At first, the Antarctic Plate subducted only in the southernmost tip of Patagonia, meaning that the Chile Triple Junction was located near the Strait of Magellan . As the southern part of the Nazca Plate and the Chile Rise became consumed by subduction,

472-502: A land bridge which connected Asia and North America during the last glacial maximum . Mosimann and Martin (1975) suggested the first of these nomads descended from hunting families who had acquired the skills to track down and kill large mammals. By this time, humans had developed proficient hunting weapons, including the Clovis points , which were narrow, carved stone projectiles used specifically for big game. A couple of hundred years later,

590-455: A plesiomorphic extra claw. While other species of Eremotherium had four fingers with only two or three claws, E. eomigrans had five fingers, four of them with claws up to nearly a foot long. Recently recognized, ground sloths of Nothrotheriidae are often associated with those of the Megatheriidae , and together the two form the superfamily Megatherioidea. The most prominent members of

708-513: A Patagonian landscape; the presence of austral parakeets ( Enicognathus ferrugineus ) as far south as the shores of the strait attracted the attention of the earlier navigators, and green-backed firecrowns ( Sephanoides sephaniodes ), a species of hummingbird , may be seen flying amid the snowfall. One of the largest birds in the world, the Andean condor ( Vultur gryphus ) can be seen in Patagonia. Of

826-513: A bipedal stance while stationary, allowing the forelimbs to be used to grasp vegetation as well as to use their claws for defence, though whether they were capable of moving in this posture is uncertain. Some ground sloths have been suggested to be able to climb. Some authors have suggested ground sloths were largely solitary animals, like living sloths, though other authors have argued that at least some ground sloths are likely to have engaged in gregarious behaviour. Whether or not ground sloths had

944-516: A broad pelvis. Like other xenarthrans, the adult teeth of ground sloths lacked enamel , with the tooth surface being composed of relatively soft orthodentine . The number of teeth in the jaws is considerably reduced in comparison to other mammals, with most ground sloths only having 5 and 4 teeth in each half of the upper and lower jaws respectively, with some ground sloths exhibiting further tooth number reduction. These teeth were rootless and were continuously growing (hypselodont), and typically have

1062-419: A derivation meaning "land of the big feet". However, this etymology is questionable. The term is most likely derived from an actual character name, "Patagón", a savage creature confronted by Primaleón of Greece, the hero in the homonymous Spanish chivalry novel (or knight-errantry tale ) by Francisco Vázquez. This book, published in 1512, was the sequel of the romance Palmerín de Oliva ;it was much in vogue at

1180-549: A difficult winter at what he named Puerto San Julián before resuming its voyage further south on 21 August 1520. During this time, it encountered the local inhabitants, likely to be Tehuelche people , described by his reporter, Antonio Pigafetta, as giants called Patagons . The territory became the Spanish colony of the Governorate of New Léon, granted in 1529 to Governor Simón de Alcazaba y Sotomayor  [ es ] , part of

1298-421: 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 . Ground sloths represent a paraphyletic group , as living tree sloths are thought to have evolved from ground sloth ancestors. The early evolution of ground sloths took place during

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1416-475: A formidable defense against predators. The earliest megatheriid in North America was Eremotherium eomigrans which arrived 2.2 million years ago, after crossing the recently formed Panamanian land bridge. With more than five tons in weight, 6 meters in length, and able to reach as high as 17 feet (5.2 m), it was larger than an African bush elephant bull. Unlike relatives, this species retained

1534-629: A hunter-gathered lifestyle. The indigenous peoples of the region included the Tehuelches , whose numbers and society were reduced to near extinction not long after the first contacts with Europeans. Tehuelches included the Gununa'kena to the north, Mecharnuekenk in south-central Patagonia, and the Aonikenk or Southern Tehuelche in the far south, north of the Magellan strait. On Isla Grande de Tierra del Fuego ,

1652-405: A note that reads "deposited by Theodore Roosevelt ". Mylodontids are the only ground sloths confirmed to have had osteoderms embedded within their skin, though osteoderms were only present in a handful of genera and absent in many others. The largest mylodontid is Lestodon , with an estimated mass of 3,400–4,100 kilograms (7,500–9,000 lb). The ground sloth family Scelidotheriidae

1770-586: A part of the Los Lagos Region , is also located within Patagonia. By some definitions, Chiloé Archipelago, the rest of the Los Lagos Region, and part of the Los Ríos Region are also part of Patagonia. Patagonia's climate is mostly cool and dry year round. The east coast is warmer than the west, especially in summer, as a branch of the southern equatorial current reaches its shores, whereas the west coast

1888-422: A region of steppe -like plains, rising in a succession of 13 abrupt terraces about 100 m (330 ft) at a time, and covered with an enormous bed of shingle almost bare of vegetation. In the hollows of the plains are ponds or lakes of fresh and brackish water. Towards Chilean territory, the shingle gives way to porphyry , granite , and basalt lavas, and animal life becomes more abundant. Vegetation

2006-545: A relatively simple morphology. Some ground sloths have canine-like teeth at the front of the jaws separated from the other teeth by a gap (diastema). The skull shapes of ground sloths are highly variable. Those with narrow muzzles are likely to have had prehensile lips, while those with wider muzzles are likely to have had mobile tongues. The hands of ground sloths have ungual phalanges that indicate that they had well developed claws. In many ground sloth families (Megatheriidae, Mylodontidae, Scelidotheriidae and Nothrotheriidae),

2124-754: A site for the conservation of marine mammals . The Patagonian freshwater fish fauna is relatively restricted compared to other similar Southern Hemisphere regions. The Argentine part is home to a total of 29 freshwater fish species, 18 of which are native. The introduced are several species of trout , common carp , and various species that originated in more northerly parts of South America. The natives are osmeriforms ( Aplochiton and Galaxias ), temperate perches ( Percichthys ), catfish ( Diplomystes , Hatcheria and Trichomycterus ), Neotropical silversides ( Odontesthes ) and characiforms ( Astyanax , Cheirodon , Gymnocharacinus , and Oligosarcus ). Other Patagonian freshwater fauna include

2242-489: A slow metabolism like living xenarthrans (including living sloths) is debated. Like living sloths, ground sloths likely only gave birth to a single offspring at a time, with likely several years between the birth of offspring. At least some ground sloths engaged in long-term parental care , with one adult (presumably female) Megalonyx found with two juveniles of different ages, with the oldest juvenile suggested to be 3–4 years old. Juvenile ground sloths may have clung to

2360-467: A temperature of −25   °C has been recorded in Bariloche, and most places can often have temperatures between −12 and −15   °C and highs staying around 0   °C for a few days. Directly east of these areas, the weather becomes much harsher; precipitation drops to between 150 and 300 mm, the mountains no longer protect the cities from the wind, and temperatures become more extreme. Maquinchao

2478-531: A wide variety of environments, extending from the far south of Patagonia ( Cueva del Milodón Natural Monument ) to Alaska . Sloths, and xenarthrans as a whole, represent one of the more successful South American groups during the Great American Interchange after the connection of North and South America during the late Pliocene with a number of ground sloth genera migrating northwards. One genus, Thalassocnus , even adapted for marine life along

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2596-533: A young ground sloth, to raise the animal to butchering size. However, radiocarbon dates do not support simultaneous occupation of the site by humans and sloths. Subfossil remains like coproliths, fur and skin have been discovered in some quantities. Mylodontids are the only ground sloths confirmed to have osteoderms embedded within their skin, though osteoderms were only present in a handful of genera ( Mylodon , Paramylodon and Glossotherium ) and absent in others. The following sloth family phylogenetic tree

2714-636: Is a unitary state , its first-level administrative divisions—the regions—enjoy far less autonomy than analogous Argentine provinces. Argentine provinces have elected governors and legislatures, while Chilean regions had government-appointed intendants prior to the adoption of elected governors from 2021. The Patagonian Provinces of Argentina are Neuquén , Río Negro , Chubut , Santa Cruz , and Tierra del Fuego . The southernmost part of Buenos Aires Province can also be considered part of Patagonia. The two Chilean regions undisputedly located entirely within Patagonia are Aysén and Magallanes . Palena Province ,

2832-478: Is a few hundred kilometers east of Bariloche, at the same altitude on a plateau, and summer daytime temperatures are usually about 5   °C warmer, rising up to 35   °C sometimes, but winter temperatures are much more extreme: the record is −35   °C, and some nights not uncommonly reach 10   °C colder than Bariloche. The plateaus in Santa Cruz province and parts of Chubut usually have snow cover through

2950-825: Is an ancestral and very plesiomorphic member of this subfamily and does not belong to the main group of closely related genera, which include Scelidotherium and Catonyx . The following sloth family phylogenetic tree is based on collagen and mitochondrial DNA sequence data (see Fig. 4 of Presslee et al ., 2019). † Neocnus dousman † Parocnus serus † Neocnus comes † Acratocnus ye † Nothrotheriops shastensis † Megatherium americanum † Megalonyx jeffersoni   5 living spp.   † Scelidotherium sp. † Scelidodon sp.   2 living spp. † Lestodon armatus † Paramylodon harlani † Mylodon darwinii † Glossotherium robustus Radiocarbon dating places

3068-550: Is based on collagen and mitochondrial DNA sequence data (see Fig. 4 of Presslee et al ., 2019). † Megalocnidae (Caribbean sloths) † Scelidodon sp. † Scelidotherium sp. † Lestodon armatus † Paramylodon harlani † Glossotherium robustus † Mylodon darwinii Choloepus didactylus Choloepus hoffmanni † Megalonychidae     Bradypodidae (three-toed sloths) † Nothrotheriidae † Megatheriidae Ground sloth Ground sloths are

3186-497: Is called "Camwy" in Patagonian Welsh. Chupat, Chubut and Camwy have the same meaning and are used to talk about the river and the province. Welsh settlers and placenames are associated with one of the projects of the country of Wales, Project Hiraeth. Due to the language, culture and location, many Patagonians do not consider themselves Latinos and proudly call themselves Patagonians instead. People from Y Wladfa, Laurie Island,

3304-492: Is caused principally by the sudden melting and retreat of ice aided by tectonic changes, has scooped out a deep longitudinal depression, best in evidence where in contact with folded Cretaceous rocks, which are lifted up by the Cenozoic granite. It generally separates the plateau from the first lofty hills, whose ridges are generally called the pre-Cordillera. To the west of these, a similar longitudinal depression extends all along

3422-423: Is closer to Mylodontidae than Scelidotheriidae is. The only other living sloth family, Bradypodidae (three-toed sloths), belongs to a different sloth radiation, Megatherioidea . The mylodontoids form one of three major radiations of sloths. The discovery of their fossils in caverns associated with human occupation lead some early researchers to theorize that the early humans built corrals when they could procure

3540-481: Is more luxuriant, consisting principally of southern beech and conifers . The high rainfall against the western Andes ( Wet Andes ) and the low sea-surface temperatures offshore give rise to cold and humid air masses, contributing to the ice fields and glaciers , the largest ice fields in the Southern Hemisphere outside of Antarctica. Among the depressions by which the plateau is intersected transversely,

3658-742: Is now at the Yale Peabody Museum . The largest samples of Nothrotheriops dung can be found in the collections of the Smithsonian Museum. Another Nothrotheriops was excavated at Shelter Cave , also in Doña Ana County , New Mexico . The mylodontid ground sloths together with their relatives the scelidotheriids form the Mylodontoidea , the second radiation of ground sloths. The discovery of their fossils in caverns associated with human occupation led some early researchers to theorize that

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3776-637: Is very scarce. The weather only gets a bit colder further south in Chubut, and the city of Comodoro Rivadavia has summer temperatures of 24 to 28   °C, nights of 12 to 16   °C, and winters with days around 10   °C and nights around 3   °C, and less than 250 mm of rain. However, a drastic drop occurs as one moves south to Santa Cruz; Rio Gallegos, in the south of the province, has summer temps of 17 to 21   °C, (nights between 6 and 10   °C) and winter temperatures of 2 to 6   °C, with nights between −5 and 0   °C, despite being right on

3894-454: Is washed by a cold current. However, winters are colder on the inland plateaus east of the slopes and further down the coast on the southeast end of the Patagonian region. For example, at Puerto Montt , on the inlet behind Chiloé Island, the mean annual temperature is 11 °C (52 °F) and the average extremes are 25.5 and −1.5 °C (77.9 and 29.3 °F), whereas at Bahía Blanca near

4012-578: The Caribbean than on the American mainland, which correlates with the later colonization of this area by humans. Ground sloths varied widely in size from under 100 kilograms (220 lb) in the Caribbean ground sloths, to 3,700–4,100 kilograms (8,200–9,000 lb) in the largest ground sloth genera Megatherium , Lestodon and Eremotherium . The bodies of ground sloths were generally barrel-shaped, with

4130-560: The Cuncos (also known as Veliches) settled in Chiloé Island in Pre-Hispanic times as a consequence of a push from more northern Huilliches who in turn were being displaced by Mapuches . While being outside traditional Huilliche territory the western Patagonian volcanoes Michimahuida , Hornopirén and Chaitén have Huilliche etymologies. In Chubut Province modern toponymy comes from

4248-769: The Early Holocene (c. 9000 years BP ) much in the same way that Riesco Island was back then. A Selk'nam tradition recorded by the Salesian missionary Giuseppe María Beauvoir relate that the Selk'nam arrived in Tierra del Fuego by land, and that the Selk'nam were later unable to return north as the sea had flooded their crossing. Agriculture was practised in Pre-Hispanic Argentina as far south as southern Mendoza Province . Agriculture

4366-642: The Governorates of the Spanish Empire of the Americas. The territory was redefined in 1534 and consisted of the southernmost part of the South American continent and the islands towards Antarctica. Rodrigo de Isla , sent inland in 1535 from San Matías by Simón de Alcazaba y Sotomayor (on whom western Patagonia had been conferred by Charles I of Spain , is presumed to have been the first European to have traversed

4484-511: The Patagonian mara ( Dolichotis patagonum ) are also characteristic of the steppe and the pampas to the north. The fauna of Patagonia was heavily decimated by the end-Pleistocene extinction event around 12-10,000 years ago that resulted in the extinction of most large ( megafaunal ) animal species native to the region (as well as across the Americas). Species formerly present in the region include

4602-496: The Pliocene (about 5 to 2 million years ago) species were already approximately half the size of the huge Late Pleistocene Megalonyx jeffersonii from the last ice age . Some West Indian island species were as small as a large cat; their dwarf condition typified both tropical adaptation and their restricted island environment. This small size also enabled them a degree of arboreality. Megalonyx , which means "giant claw",

4720-497: The Selk'nam (Ona) and Haush (Manek'enk) lived in the north and southeast, respectively. In the archipelagos to the south of Tierra del Fuego were Yámana, with the Kawéskar (Alakaluf) in the coastal areas and islands in western Tierra del Fuego and the southwest of the mainland. In the Patagonian archipelagoes north of Taitao Peninsula lived the Chonos . These groups were encountered in

4838-619: The Yagagtoo , Musters , and Colhue Huapi , and others situated to the south of Puerto Deseado in the center of the country. Across much of Patagonia east of the Andes, volcanic eruptions have created formation of basaltic lava plateaus during the Cenozoic . The plateaus are of different ages with the older –of Neogene and Paleogene age– being located at higher elevations than Pleistocene and Holocene lava plateaus and outcrops. Erosion, which

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4956-521: The atlatl became widely used, which allowed them to throw spears with greater velocity. These inventions would have allowed hunters to put distance between them and their prey, potentially making it less dangerous to approach ground sloths. Certain characteristics and behavioral traits of the ground sloths made them easy targets for human hunting and provided hunter-gatherers with strong incentives to hunt these large mammals. Ground sloths often fed in open fields. Recent studies have attempted to discover

5074-555: The patagon personage in the chivalric romances Primaleon printed in 1512, ten years before Magellan arrived in these southern lands. This hypothesis was published in a 2011 New Review of Spanish Philology report. There are various placenames in the Chiloé Archipelago with Chono etymologies despite the main indigenous language of the archipelago at the arrival of the Spanish being Mapudungun . A theory postulated by chronicler José Pérez García explains this holding that

5192-606: The 40th parallel, they found a "land" or a "point extending into the sea", and further south, a gulf. The expedition is said to have rounded the gulf for nearly 300 km (186 mi) and sighted the continent on the southern side of the gulf. The Atlantic coast of Patagonia was first fully explored in 1520 by the Spanish expedition led by Ferdinand Magellan , who on his passage along the coast named many of its more striking features – San Matías Gulf, Cape of 11,000 Virgins (now simply Cape Virgenes ), and others. Magellan's fleet spent

5310-686: The Americas during the Late Pleistocene . Paleontologists assign more than 80  genera of ground sloths to multiple families . The megalonychid ground sloths first appeared in the Late Eocene , about 35 million years ago, in Patagonia. Megalonychids first reached North America by island-hopping, prior to the formation of the Isthmus of Panama . Some lineages of megalonychids increased in size as time progressed. The first species of these were small and may have been partly tree-dwelling, whereas

5428-652: The Atlantic Islands, Antarctica (including the Chilean town in Antarctica, "The Stars Village", and the Argentine civilian settlement, "Hope Base"), other non-latin speaking areas use this term as a patriotic and inclusive demonym. A Patagonian is a person that is part of the Patagonia region, language and culture. That person could be a citizen from Chilean Patagonia, Argentine Patagonia, or of native communities that existed before

5546-482: The Atlantic coast and just outside the northern confines of Patagonia, the annual temperature is 15 °C (59 °F) and the range much greater, as temperatures above 35   °C and below −5   °C are recorded every year. At Punta Arenas, in the extreme south, the mean temperature is 6 °C (43 °F) and the average extremes are 24.5 and −2 °C (76.1 and 28.4 °F). The prevailing winds are westerly, and

5664-473: The Atlantic coast of Patagonia. The geological limit of Patagonia has been proposed to be Huincul Fault , which forms a major discontinuity. The fault truncates various structures including the Pampean orogen found further north. The ages of base rocks change abruptly across the fault. Discrepancies have been mentioned among geologists on the origin of the Patagonian landmass. Víctor Ramos has proposed that

5782-450: The Atlantic coast, through the Strait of Magellan and northward along the Pacific coast, was memorable, yet the descriptions of the geography of Patagonia owe much more to the Spanish explorer Pedro Sarmiento de Gamboa (1579–1580), who, devoting himself especially to the south-west region, made careful and accurate surveys. The settlements that he founded at Nombre de Jesús and San Felipe

5900-419: The Pacific coast of South America during the late Miocene and Pliocene epochs. Ground sloths, which were represented by over 30 living species during the Late Pleistocene , abruptly became extinct on the American mainland as part of the end-Pleistocene extinction event around 12,000 years ago, simultaneously along with the majority of other large animals in the Americas. Their extinction has been posited to be

6018-542: The Patagonian landmass originated as an allochthonous terrane that separated from Antarctica and docked in South America 250 to 270 Mya in the Permian period. A 2014 study by R.J. Pankhurst and coworkers rejects any idea of a far-traveled Patagonia, claiming it is likely of parautochtonous (nearby) origin. The Mesozoic and Cenozoic deposits have revealed a most interesting vertebrate fauna. This, together with

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6136-422: The Patagonian plains. The Patagonian steppe is one of the last strongholds of the guanaco and Darwin's rheas ( Rhea pennata ), which had been hunted for their skins by the Tehuelches , on foot using boleadoras , before the diffusion of firearms and horses ; they were formerly the chief means of subsistence for the natives, who hunted them on horseback with dogs and bolas . Vizcachas ( Lagidum spp.) and

6254-589: The Santa Elina rockshelter in Mato Grosso Brazil, a specimen of Glossotherium is associated with hearths and stone tools, dating to 11,833–11,804 years BP. At Fell's Cave in southern Chilean Patagonia, a specimen of Mylodon with fractured and burned bones associated with human activity has been dated to approximately 12,766–12,354 years BP. Humans are believed to have entered the New World via Beringia ,

6372-559: The body of their mother for some time following birth, as occurs in living tree sloths. The earliest unambiguous fossil evidence of ground sloths comes from the early Oligocene . Ground sloths had dispersed into the Caribbean already by 31 million years ago, as evidenced by a femur found in Puerto Rico. During the Miocene , sloths diversified, with the major families of sloths appearing during this period, with diversity waxing and waning over

6490-771: The border with Chile, receives up to 434 mm of rain and snow in May, 297 mm in June, and 273 in July, compared to 80 in February and 72 in March. The total for the city is 2074 mm, making it one of the rainiest in Argentina. Further west, some areas receive up to 4,000 mm and more, especially on the Chilean side. In the northeast, the seasons for rain are reversed; most rain falls from occasional summer thunderstorms but totals barely reach 500 mm in

6608-401: The climate changes that others claim wiped out the ground sloths. Additionally, after the continental ground sloths disappeared, insular sloths of the Caribbean survived for approximately 6,000 years longer, which correlates with the fact that these islands were not colonized by humans until about 5500 yr BP. It is difficult to find evidence that supports either claim on whether humans hunted

6726-592: The coast in the north but happens more often in the south, and frost is usually not very intense. Immediately east from the coast are the Andes, cut by deep fjords in the south and by deep lakes in the north, and with varying temperatures according to the altitude. The tree line ranges from close to 2,000 m on the northern side (except for the Andes in northern Neuquén in Argentina, where sunnier and dryer conditions allow trees to grow up to close to 3,000 m), and diminishes southward to only 600–800   m in Tierra del Fuego. Precipitation changes dramatically from one spot to

6844-420: The coast. Snowfall is common despite the dryness, and temperatures are known to fall to under −18   °C and to remain below freezing for several days in a row. Rio Gallegos is also among the windiest places on Earth, with winds reaching 100 km/h occasionally. Tierra del Fuego is extremely wet in the west, relatively damp in the south, and dry in the north and east. Summers are cool (13 to 18   °C in

6962-596: The coastline of Patagonia is possibly mentioned in a Portuguese voyage in 1511–1512, traditionally attributed to captain Diogo Ribeiro, who after his death was replaced by Estevão de Frois, and was guided by the pilot and cosmographer João de Lisboa ). The explorers, after reaching Rio de la Plata (which they would explore on the return voyage, contacting the Charrúa and other peoples) eventually reached San Matias Gulf , at 42°S. The expedition reported that after going south of

7080-679: The course of the Miocene. Megalonychid and mylodontid sloths had migrated into North America by the Late Miocene, around 10 million years ago. At the end of the Miocene, ground sloth diversity declined, though their diversity would remain largely stable throughout the Pliocene and Pleistocene periods, up until their extinction. During the Pliocene and Pleistocene, as part of the Great American Interchange , additional lineages of sloths migrated into Central and North America. Prior to their extinction, there were over 30 living species of ground sloths across

7198-468: The deposition suddenly stopped. Steadman et al. argue that it is no coincidence that studies have shown that ground sloths disappeared from an area a few years after the arrival of humans. Trackways preserved in New Mexico (probably dating from 10 to 15.6 thousand years ago) that appear to show a group of humans chasing or harassing three Nothrotheriops or Paramylodon ground sloths may record

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7316-591: The details of which are as yet poorly understood. Several sites have been excavated, notably caves such as Cueva del Milodon in Última Esperanza in southern Patagonia, and Tres Arroyos on Tierra del Fuego, that support this date. Hearths, stone scrapers, and animal remains dated to 9400–9200 BC have been found east of the Andes. At the close of the Pleistocene around 12-11,000 years ago (10,000-9,000 BC) Fishtail projectile points (a type of knapped stone spear point) were widespread across Patagonia (along with much of

7434-715: The diet of ground sloths through fossils of their dung. Analysis of these coproliths have found that ground sloths often ate the foliage of trees, hard grasses, shrubs, and yucca; these plants were located in areas that would have exposed them, making them susceptible to human predation. Ground sloths were not only easy to spot, but had never interacted with humans before, so would not have known how to react to them. Additionally, these large mammals waddled on their hind legs and front knuckles, keeping their claws turned in. Their movement and massive build (some weighed up to 3,000 kilograms (6,600 lb)) imply they were relatively slow mammals. These reasonable after-the-fact inferences from

7552-580: The disappearance of ground sloths in what is now the United States at around 11,000 years ago. The Shasta ground sloth ( Nothrotheriops shastensis ) visited Rampart Cave (located on the Arizona side of the Lake Mead National Recreation Area ) seasonally, leaving behind a massive stratified subfossilized dung deposit, and seemed to be flourishing from 13,000 until 11,000 BP, when

7670-625: The discovery of the perfect cranium of a turtle ( chelonian ) of the genus Niolamia , which is almost identical to Ninjemys oweni of the Pleistocene age in Queensland , forms an evident proof of the connection between the Australian and South American continents. The Patagonian Niolamia belongs to the Sarmienti Formation. Fossils of the mid-Cretaceous Argentinosaurus , which may be

7788-415: The early humans built corrals when they could procure a young ground sloth, to raise the animal to butchering size. However, radiocarbon dates do not support simultaneous occupation of the site by humans and sloths. Subfossil remains like coproliths, fur and skin have been discovered in some quantities. The American Museum of Natural History has exhibited a sample of Mylodon dung from Argentina with

7906-404: The evidence might explain why ground sloths would have been easy prey for hunters, but are not certain. While ground sloths would have been relatively easy to spot and approach, big game hunters' weapons would have been useless from farther than 9.1 metres (30 ft) away. It would have been difficult to take down a ground sloth with a spear-thrower and would have required extensive knowledge of

8024-399: The first periods of European contact with different lifestyles, body decoration, and language, although it is unclear when this configuration emerged. Towards the end of the 16th century, Mapuche -speaking agriculturalists penetrated the western Andes and from there across into the eastern plains and down to the far south. Through confrontation and technological ability, they came to dominate

8142-461: The foot of the snowy Andean Cordillera. This latter depression contains the richest, most fertile land of Patagonia. Lake basins along the Cordillera were also gradually excavated by ice streams, including Lake Argentino and Lake Fagnano , as well as coastal bays such as Bahía Inútil . The establishment of dams near the Andes in Argentina in the 20th century has led to a sediment shortage along

8260-496: The great Patagonian plain. If the men under his charge had not mutinied, he might have crossed the Andes to reach the Pacific coast. Pedro de Mendoza , on whom the country was next bestowed, founded Buenos Aires , but did not venture south. Alonso de Camargo  [ es ] (1539), Juan Ladrilleros (1557), and Hurtado de Mendoza (1558) helped to make known the Pacific coasts, and while Sir Francis Drake 's voyage in 1577 down

8378-451: The ground sloths to extinction. Removing large amounts of meat from large mammals such as the ground sloth requires no contact with the bones; tool-inflicted damage to bones is a key sign of human interaction with the animal. A number of kill sites are known for ground sloths in the Americas, these include Campo Laborde in the Pampas of Argentina, where an individual of Megatherium americanum

8496-434: The group are the South American genus Thalassocnus , known for being aquatic, and Nothrotheriops from North America. The last ground sloths in North America belonging to Nothrotheriops died so recently that their subfossil dung has remained undisturbed in some caves. One of the skeletons, found in a lava tube (cave) at Aden Crater , adjacent to Kilbourne Hole , New Mexico , still had skin and hair preserved, and

8614-463: The heavily built Megatherium (given its name 'great beast' by Georges Cuvier ) and Eremotherium , which are the largest known ground sloths, thought to have had body masses of 3.5-4 tons. The skeletal structure of these ground sloths indicates that the animals were massive. Their thick bones and even thicker joints (especially those on the hind legs) gave their appendages tremendous power that, combined with their size and fearsome claws, provided

8732-739: The highly unusual aeglid crustaceans. Human habitation of the region dates back thousands of years, with some early archaeological findings in the area dated to at least the 13th millennium BC , although later dates around the 10th millennium BC are more securely recognized. Evidence exists of human activity at Monte Verde in Llanquihue Province , Chile, dated to around 14,500 years Before Present (~12,500 BC). The glacial-period ice fields and subsequent large meltwater streams would have made settlement difficult at that time. The region seems to have been inhabited continuously since 10,000 BC by various cultures and alternating waves of migration,

8850-1082: The hindfoot is inwardly rotated, meaning sole faces inwards and that the body weight was primarily borne on the fifth metatarsus and the calcaneum . Ground sloths are generally regarded as herbivores, with some being browsers , others grazers , and some intermediate between the two as mixed feeders (both browsing and grazing), though a number of authors have argued that some ground sloths may have been omnivores. Sloths that had longer snouts are presumed to have had greater olfactory acuity, but appear to have also had less binocular vision and poorer ability to localize sounds. A number of extinct sloth species are thought to have had hearing abilities optimized for low frequencies, perhaps related to use of infrasound for communication. Some ground sloths are suggested to have dug burrows . Their skeletal anatomy suggests that they were incapable of running, and relied on other strategies to defend against predators, though they were likely significantly more active and agile than living tree sloths. Ground sloths were likely able to adopt

8968-460: The land was divided by The Boundary Treaty of 1881 . Patagonia is divided between Western Patagonia (Chile) and Eastern Patagonia (Argentina) and several territories are still under dispute and claiming their rights. Mapuche people came from the Chilean Andes and voted to remain in different sides of Patagonia. Welsh settlers came from Wales and North America and voted to remain in Patagonia; when

9086-488: The large cow-sized ground sloth Mylodon , the large camel-like ungulate Macrauchenia , indigenous equines belonging to the genus Hippidion , the giant short-faced bear Arctotherium , and the large sabertooth cat Smilodon . The extinct fox Dusicyon avus (a close relative of the Falkland Islands wolf ) also formerly inhabited the region, until apparently becoming extinct around 500-400 years ago. Patagonia

9204-513: The largest of all dinosaurs, have been found in Patagonia, and a model of the mid- Jurassic Piatnitzkysaurus graces the concourse of the Trelew airport (the skeleton is in the Trelew paleontological museum; the museum's staff has also announced the discovery of a species of dinosaur even bigger than Argentinosaurus ). Of more than paleontological interest, the middle Jurassic Los Molles Formation and

9322-591: The late Paleogene and Neogene of South America, while the continent was isolated. At their earliest appearance in the fossil record, they were already distinct at the family level. Sloths dispersed into the Greater Antilles during the Oligocene , and the presence of intervening islands between the American continents in the Miocene allowed a dispersal of some species into North America. They were hardy as evidenced by their high species diversity and their presence in

9440-611: The late Pliocene and Pleistocene of North America, although work by McDonald lists five species. Jefferson's ground sloth has a special place in modern paleontology , for Thomas Jefferson 's letter on Megalonyx , read before the American Philosophical Society of Philadelphia in August ;1796, marked the beginning of vertebrate paleontology in North America. When Lewis and Clark set out, Jefferson instructed Meriwether Lewis to keep an eye out for ground sloths. He

9558-542: The many kinds of waterfowl the Chilean flamingo ( Phoenicopterus chilensis ), the upland goose ( Chloephaga picta ), and in the strait, the remarkable steamer ducks are found. Signature marine fauna include the southern right whale , the Magellanic penguin ( Spheniscus magellanicus ), the killer whale , and elephant seals . The Valdés Peninsula is a UNESCO World Heritage Site , designated for its global significance as

9676-875: The more northerly regions of the Antarctic Plate began to subduct beneath Patagonia so that the Chile Triple Junction advanced to the north over time. The asthenospheric window associated to the triple junction disturbed previous patterns of mantle convection beneath Patagonia inducing an uplift of c. 1 km that reversed the Miocene transgression. At a state level, Patagonia visually occupies an area within two countries: approximately 10% in Chile and approximately 90% in Argentina . Both countries have organized their Patagonian territories into nonequivalent administrative subdivisions: provinces and departments in Argentina, as well as regions , provinces , and communes in Chile. As Chile

9794-448: The north, 12 to 16   °C in the south, with nights generally between 3 and 8   °C), cloudy in the south, and very windy. Winters are dark and cold, but without the extreme temperatures in the south and west ( Ushuaia rarely reaches −10   °C, but hovers around 0   °C for several months, and snow can be heavy). In the east and north, winters are much more severe, with cold snaps bringing temperatures down to −20   °C all

9912-411: The northeast corner, and rapidly decrease to less than 300 mm. The Patagonian west coast, which belongs exclusively to Chile, has a cool oceanic climate, with summer maximum temperatures ranging from 14   °C in the south to 19   °C in the north (and nights between 5 and 11   °C) and very high precipitation, from 2,000 to more than 7,000 mm in local microclimates. Snow is uncommon at

10030-503: The northern limit of Argentine Patagonia. The archipelago of Tierra del Fuego is sometimes included as part of Patagonia. Most geographers and historians locate the northern limit of Chilean Patagonia at Huincul Fault , in Araucanía Region . At the time of the Spanish arrival , Patagonia was inhabited by multiple indigenous tribes. In a small portion of northwestern Patagonia, indigenous peoples practiced agriculture, while in

10148-476: The other and diminishes very quickly eastward. An example of this is Laguna Frías, in Argentina, which receives 4,400 mm yearly. The city of Bariloche, about 40 km further east, receives about 1,000 mm, and the airport, another 15 km east, receives less than 600 mm. The easterly slopes of the Andes are home to several Argentine cities: San Martín de los Andes , Bariloche, El Bolsón , Esquel , and El Calafate . Temperatures there are milder in

10266-532: The other peoples of the region in a short period of time, and are the principal indigenous community today. Navigators such as Gonçalo Coelho and Amerigo Vespucci possibly had reached the area (his own account of 1502 has it that they reached the latitude 52°S), but Vespucci's failure to accurately describe the main geographical features of the region such as the Río de la Plata casts doubts on whether they really did so. The first or more detailed description of part of

10384-801: The principal ones are the Gualichu , south of the Río Negro , the Maquinchao and Valcheta (through which previously flowed the waters of Nahuel Huapi Lake , which now feed the Limay River), the Senguerr (spelled Senguer on most Argentine maps and within the corresponding region), and the Deseado River . Besides these transverse depressions (some of them marking lines of ancient interoceanic communication), others were occupied by either more or less extensive lakes, such as

10502-458: The region, apparently hunting of guanaco, and to a lesser extent rhea ( ñandú ), were the primary food sources of tribes living on the eastern plains. It is also not clear if domestic dogs were part of early human activity. Bolas are commonly found and were used to catch guanaco and rhea . A maritime tradition existed along the Pacific coast, whose latest exponents were the Yaghan (Yámana) to

10620-475: The remaining territory, peoples lived as hunter-gatherers, traveling by foot in eastern Patagonia or by dugout canoe and dalca in the fjords and channels . In colonial times indigenous peoples of northeastern Patagonia adopted a horseriding lifestyle. While the interest of the Spanish Empire had been chiefly to keep other European powers away from Patagonia, independent Chile and Argentina began to colonize

10738-451: The rest of South America). At several sites these points have been found associated with extinct megafauna, including the large ground sloth Mylodon and the native equine Hippidion . The Cueva de las Manos is a famous site in Santa Cruz, Argentina. This cave at the foot of a cliff is covered in wall paintings, particularly the negative images of hundreds of hands, believed to date from around 8000 BC. Based on artifacts found in

10856-535: The result of hunting by recently arrived humans and/or climate change. A number of kill sites are known where humans butchered ground sloths dating just prior to their extinction. The Caribbean ground sloths , the most recent survivors, lived on Cuba and Hispaniola , possibly until 1550 BCE. However, radiocarbon dating suggests an age of between 2819 and 2660 BCE for the last occurrence of Megalocnus in Cuba . They survived 5,000–6,000 years longer in

10974-560: The scene of a hunt. The tracks are interpreted as showing seven instances of a sloth turning and rearing up on its hind legs to confront its pursuers, while the humans approach from multiple directions, possibly in an attempt to distract it. Those who argue in favor of humans being the direct cause of the ground sloths' extinction point out that the few sloths that remain are small sloths that spend most of their time in trees, making it difficult for them to be spotted. Although these sloths were well hidden, they still would have been affected by

11092-628: The singular mammal Pyrotherium , also of very large dimensions. In the Cenozoic marine formation, considerable numbers of cetaceans have been discovered. During the Oligocene and early Miocene , large swathes of Patagonia were subject to a marine transgression , which might have temporarily linked the Pacific and Atlantic Oceans, as inferred from the findings of marine invertebrate fossils of both Atlantic and Pacific affinity in La Cascada Formation . Connection would have occurred through narrow epicontinental seaways that formed channels in

11210-490: The slow-moving giant sloths were likely easy prey for early humans possibly hurling spears. Patagonia Patagonia ( Spanish pronunciation: [pataˈɣonja] ) is a geographical region that encompasses the southern end of South America , governed by Argentina and Chile . The region comprises the southern section of the Andes Mountains with lakes, fjords , temperate rainforests , and glaciers in

11328-560: The south of Tierra del Fuego, the Kaweshqar between Taitao Peninsula and Tierra del Fuego, and the Chono people in the Chonos Archipelago . The Selk'nam , Haush , and Tehuelche are generally thought to be culturally and linguistically related peoples physically distinct from the sea-faring peoples. It is possible that Isla Grande de Tierra del Fuego was connected to the mainland in

11446-466: The southern U.S. about 9 million years ago and is believed to have been the predecessor of Megalonyx . Several species of Megalonyx have been named; in fact it has been stated that "nearly every good specimen has been described as a different species". A broader perspective on the group, accounting for age, sex, individual and geographic differences, indicates that only three species are valid ( M. leptostomus , M. wheatleyi , and M. jeffersonii ) in

11564-767: The species. Additionally, the ground sloths' already thick hide was fortified by osteoderms , making it difficult to penetrate. Since ground sloths thrived in an environment filled with large predators, they evidently would have been able to also defend themselves against human predation, so there is no reason to expect that they would have been "easy pickings". When feeding, they had enough strength to use their long, sharp claws to tear apart tree branches; presumably their strength and formidable claws would be dangerous for hunters that attempted to attack them at close quarters. But fossilized evidence of humans hunting on ground sloth in White Sands National Park suggests that

11682-674: The still richer late Jurassic ( Tithonian ) and early Cretaceous ( Berriasian ) Vaca Muerta formation above it in the Neuquén basin are reported to contain huge hydrocarbon reserves (mostly gas in Los Molles, both gas and oil in Vaca Muerta) partly accessible through hydraulic fracturing . Other specimens of the interesting fauna of Patagonia, belonging to the Middle Cenozoic, are the gigantic wingless birds, exceeding in size any hitherto known, and

11800-494: The summer (in the north, between 20 and 24   °C, with cold nights between 4 and 9   °C; in the south, summers are between 16 and 20   °C, at night temperatures are similar to the north) and much colder in the winter, with frequent snowfall (although snow cover rarely lasts very long). Daytime highs range from 3 to 9   °C in the north, and from 0 to 7   °C in the south, whereas nights range from −5 to 2   °C everywhere. Cold waves can bring much colder values;

11918-484: The superfamily Mylodontoidea . Phylogenetic analyses based on morphology uncovered the relationship between Mylodontidae and Scelidotheriidae; in fact, the latter was for a time considered a subfamily of mylodontids. However, molecular sequence comparisons were needed for the correct placement of Choloepodidae. These studies have been carried out using mitochondrial DNA sequences as well as with collagen amino acid sequences. The latter results indicate that Choloepodidae

12036-515: The territory slowly over the course of the 19th and early 20th centuries. This process brought a decline of the indigenous populations, whose lives and habitats were disrupted, while at the same time thousands of Europeans, Argentines, Chilotes and mainland Chileans settled in Patagonia. The contemporary economy of eastern Patagonia revolves around sheep farming and oil and gas extraction, while in western Patagonia fishing , salmon aquaculture , and tourism dominate. The name Patagonia comes from

12154-569: The time, and a favorite reading of Magellan. Magellan's perception of the natives, dressed in skins, and eating raw meat, clearly recalled the uncivilized Patagón in Vázquez's book. Novelist and travel writer Bruce Chatwin suggests etymological roots of both Patagon and Patagonia in his book, In Patagonia , noting the similarity between "Patagon" and the Greek word παταγος, which means "a roaring" or "gnashing of teeth" (in his chronicle, Pigafetta describes

12272-446: The time, prompting some of them to believe that Patagonians were giants. According to Antonio Pigafetta, one of the Magellan expedition's few survivors and its published chronicler, Magellan bestowed the name Patagão (or Patagón ) on the inhabitants they encountered there, and the name "Patagonia" for the region. Although Pigafetta's account does not describe how this name came about, subsequent popular interpretations gave credence to

12390-469: The treaty was signed, they voted for culture and administration to be apart from the country keeping the settlement, language, schools, traditions, regional dates, flag, anthems, and celebrations. Patagonians also live abroad in settlements like Saltcoats, Saskatchewan , Canada; New South Wales , Australia; South Africa; the Falkland Islands; and North America. Argentine Patagonia is for the most part

12508-463: The way to the Rio Grande on the Atlantic coast. Snow can fall even in the summer in most areas, as well. The guanaco ( Lama guanicoe ), South American cougar ( Puma concolor concolor ), the Patagonian fox ( Lycalopex griseus ), Patagonian hog-nosed skunk ( Conepatus humboldtii ), and Magellanic tuco-tuco ( Ctenomys magellanicus ; a subterranean rodent ) are the most characteristic mammals of

12626-622: The west and deserts , tablelands , and steppes to the east. Patagonia is bounded by the Pacific Ocean on the west, the Atlantic Ocean to the east, and many bodies of water that connect them, such as the Strait of Magellan , the Beagle Channel , and the Drake Passage to the south. The Colorado and Barrancas rivers, which run from the Andes to the Atlantic, are commonly considered

12744-440: The westward slope has a much heavier precipitation than the eastern in a rainshadow effect; the western islands close to Torres del Paine receive an annual precipitation of 4,000 to 7,000 mm, whilst the eastern hills are less than 800 mm and the plains may be as low as 200 mm annual precipitation. Precipitation is highly seasonal in northwestern Patagonia. For example, Villa La Angostura in Argentina, close to

12862-615: The winter, and often experience very cold temperatures. In Chile, the city of Balmaceda is known for being situated in this region (which is otherwise almost exclusively in Argentina), and for being the coldest place in Chile. In 2017, temperatures even dropped down to −20   °C in the region. The northern Atlantic coast has warm summers (28 to 32   °C, but with relatively cool nights at 15   °C) and mild winters, with highs around 12   °C and lows about 2–3   °C. Occasionally, temperatures reach −10 or 40   °C, and rainfall

12980-550: The word patagón . Magellan used this term in 1520 to describe the native tribes of the region, whom his expedition thought to be giants. The people he called the Patagons are now believed to have been the Tehuelche , who tended to be taller than Europeans of the time. Argentine researcher Miguel Doura observed that the name Patagonia possibly derives from the ancient Greek region of modern Turkey called Paphlagonia , possible home of

13098-466: The word "chupat" belonging to a transitional language between the southern and northern Tehuelche ethnic groups that were located in that region called Tewsün or Teushen. The word means transparency and is related to the clarity and purity of the river that bears that name and runs through the province. It is also related to the origin of the Welsh pronunciation of the word "chupat" which later became "Chubut". It

13216-606: Was a widespread North American genus that lived past the close of the last (Wisconsin) glaciation , when so many large mammals died out. Remains have been found as far north as Alaska and the Yukon . Ongoing excavations at Tarkio Valley in southwestern Iowa may reveal something of the familial life of Megalonyx . An adult was found in direct association with two juveniles of different ages, suggesting that adults cared for young of different generations. The earliest known North American megalonychid, Pliometanastes protistus , lived in

13334-411: Was at times practised beyond this limit in nearby areas of Patagonia but populations reverted at times to non-agricultural lifestyles. By the time of the Spanish arrival to the area (1550s) there is no record of agriculture being practised in northern Patagonia. The extensive Patagonian grasslands and an associated abundance of guanaco game may have contributed for the indigenous populations to favour

13452-404: Was butchered at the edge of a swamp, dating to approximately 12,600 years Before Present (BP), with another potential Megatherium kill site being Arroyo Seco 2 in the same region, dating to approximately 14,782–11,142 cal yr BP. In northern Ohio, a Megalonyx jeffersoni skeleton dubbed the "Firelands Ground Sloth" has cut marks indicative of butchery, dating to 13,738 to 13,435 years BP. At

13570-462: Was demoted in 1995 to the subfamily Scelidotheriinae within Mylodontidae. Based on collagen sequence data showing that its members are more distant from other mylodontids than Choloepodidae , it was elevated back to full family status in 2019. Together with Mylodontidae, the enigmatic Pseudoprepotherium and two-toed sloths , the scelidotheriids form the superfamily Mylodontoidea. Chubutherium

13688-408: Was formerly inhabited by the jaguar subspecies Panthera onca mesembrina (which is considerably larger than living jaguars) during the Pleistocene, with jaguars continuing to inhabit Patagonia into historic times (until the late 19th century), but are now extirpated from the region. Bird life is often abundant. The crested caracara ( Caracara plancus ) is one of the characteristic aspects of

13806-576: Was hoping they would find some living in the Western range. Megalonyx jeffersonii was appropriately named after Thomas Jefferson. The megatheriid ground sloths are relatives of the megalonychids; these two families, along with the family Nothrotheriidae, form the infraorder Megatheria . Megatheriids appeared later in the Oligocene, some 30 million years ago, also in South America. The group includes

13924-541: Was neglected by the Spanish government, the latter being abandoned before Thomas Cavendish visited it in 1587 during his circumnavigation , and so desolate that he called it Port Famine . After the discovery of the route around Cape Horn, the Spanish Crown lost interest in southern Patagonia until the 18th century, when the coastal settlements Carmen de Patagones, San José, Puerto Deseado, and Nueva Colonia Floridablanca were established, although it maintained its claim of

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