? Ground Sloths Conservation status: Prehistoric
Fossil Eremotherium ground sloth skeleton at the National Museum of Natural History, Washington, DC
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Xenarthra
Families
Rathymotheriidae Scelidotheriidae Mylodontidae Orophodontidae Megalonychidae Megatheriidae

Ground sloths are extinct edentate (Order Xenarthra) mammals that are believed to be relatives of tree sloths and three-toed sloths. They may have died out as recently as 1550 in Hispaniola and Cuba (Nowak, 1999), but had long since been extinct on the mainland. Image File history File links Download high resolution version (600x800, 276 KB)Fossil ground sloth skeleton at the National Museum of Natural History; digital photo taken by User:Postdlf, 1-8-05 File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this... Categories: Museum stubs | Museums in Washington, DC | Smithsonian Institution | National Mall | Natural history museums ... Aerial photo (looking NW) of the Washington Monument and the White House in Washington, DC. Washington, D.C., officially the District of Columbia (also known as D.C.; Washington; the Nations Capital; the District; and, historically, the Federal City) is the capital city and administrative district of the United... Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Phyla Porifera (sponges) Ctenophora (comb jellies) Cnidaria (coral, jellyfish, anenomes) Placozoa (trichoplax) Subregnum Bilateria (bilateral symmetry) Acoelomorpha (basal) Orthonectida (flatworms, echinoderms, etc. ... Typical Classes Subphylum Urochordata - Tunicates Ascidiacea Thaliacea Larvacea Subphylum Cephalochordata - Lancelets Subphylum Myxini - Hagfishes Subphylum Vertebrata - Vertebrates Petromyzontida - Lampreys Placodermi (extinct) Chondrichthyes - Cartilaginous fishes Acanthodii (extinct) Actinopterygii - Ray-finned fishes Actinistia - Coelacanths Dipnoi - Lungfishes Amphibia - Amphibians Reptilia - Reptiles Aves - Birds Mammalia - Mammals Chordates (phylum Chordata) include the vertebrates, together with... Orders Subclass Multituberculata (extinct) Plagiaulacida Cimolodonta Subclass Palaeoryctoides (extinct) Subclass Triconodonta (extinct) Subclass Eutheria (includes extinct ancestors)/Placentalia (excludes extinct ancestors) Afrosoricida Artiodactyla Carnivora Cetacea Chiroptera Cimolesta (extinct) Creodonta (extinct) Condylarthra (extinct) Dermoptera Desmostylia (extinct) Embrithopoda (extinct) Hyracoidea Insectivora Lagomorpha Litopterna (extinct) Macroscelidea Mesonychia (extinct) Notoungulata (extinct) Perissodactyla Pholidota Plesiadapiformes... Families Myrmecophagidae Megalonychidae Bradypodidae Dasypodidae The order Xenarthra is a group of placental mammals, extant today only in the Americas. ... Families Myrmecophagidae Megalonychidae Bradypodidae Dasypodidae The order Xenarthra is a group of placental mammals, extant today only in the Americas. ... Families Megalonychidae P.Gervais, 1855 Bradypodidae Gray, 1821 Sloths are medium-sized South American mammals belonging to the families Megalonychidae and Bradypodidae, part of the order Xenarthra. ... Families Megalonychidae Bradypodidae Sloths are medium-sized South American mammals belonging to the families Megalonychidae and Bradypodidae, part of the order Xenarthra. ... Events February 7 - Julius III becomes Pope. ... Early map of Hispaniola The Hispaniola (from Spanish, La Española) is the second-largest island of the Antilles, lying east of Cuba. ...

The four identified species found in the United States consist of Harlan's Ground Sloth (Paramylodon harlani), Jefferson's Ground Sloth (Megalonyx jeffersonii), Laurillard's Ground Sloth (Eremotherium laurillardi), and the Shasta Ground Sloth (Nothrotheriops shastensis). All four were massive animals with large claws, and all are believed to have been herbivores. Jefferson's and Harlan's Ground Sloths can be found as fossil remnants in the midwestern U.S. In biology, a species is the basic unit of biodiversity. ... A deer and two fawns feeding on some foliage In zoology, an herbivore is an animal that is adapted to eat primarily plant matter (rather than meat). ... A fossil Ammonite Fossils are the mineralized remains of animals or plants or other traces such as footprints. ...

Families

Paleontologists divide the ground sloths in multiple families. Megalonychidae and Megatheriidae are among the most important. A paleontologist carefully chips rock from a column of dinosaur vertebrae. ...

Megalonychidae

The Megalonychid ('giant claw') ground sloths first appeared in the early Oligocene, about 35 million years ago, in southern Argentina (Patagonia). With the rise of the land bridge at Panama, these ground sloths began to migrate north. Eventually the Shasta giant ground sloth (Nothrotheriops shastensis) reached the Yukon. Megalonychids increased in size as time progressed. The first species were small and may have been partly tree dwelling, whereas the Pliocene (about 5 to 2 million years ago) species were already approximately half the size of the late Pleistocene Megalonyx jeffersonii. Some West Indian island species were as small as a large cat; their dwarf condition typified both tropical adaptation and their restricted island environment. The Oligocene epoch is a geologic period of time that extends from about 34 million to 23 million years before the present. ... A bit of history Before the arrival of the Spaniards, several indigenous groups populated the region. ... Motto: none Other Canadian provinces and territories Capital Whitehorse Largest city Whitehorse Commissioner Jack Cable Premier Dennis Fentie (Yukon Party) Area 482,443 km² (9th) • Land 474,391 km² • Water 8,052 km² (1. ... The Pliocene epoch (formerly Pleiocene) is the period in the geologic timescale that extends from 5. ... The Pleistocene Epoch is part of the geologic timescale. ...

The earliest known North American megalonychid, Pliometanastes protistus, lived in Florida about 8 million years ago. 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 the late Pliocene and Pleistocene of North America. World map showing North America A satellite composite image of North America North America is a continent in the northern hemisphere bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the south by the Caribbean Sea, and on the west by the... State nickname: Sunshine State Official languages English Capital Tallahassee Largest city Jacksonville Governor Jeb Bush (R) Senators Bill Nelson (D) Mel Martinez (R) Area  - Total  - % water Ranked 22nd 170,451 km² 17. ...

Closeup of skull

Jefferson's ground sloth has a special place in modern paleontology, for Thomas Jefferson's letter on Megalonyx ("great claw"), 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 was hoping they would find some living in the Western range. Megalonyx jeffersonii was appropriately named after Thomas Jefferson. Image File history File links Skull of fossil ground sloth skeleton at the National Museum of Natural History; digital photo taken by User:Postdlf, 1-8-05 File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links Skull of fossil ground sloth skeleton at the National Museum of Natural History; digital photo taken by User:Postdlf, 1-8-05 File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... A paleontologist carefully chips rock from a column of dinosaur vertebrae. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... The American Philosophical Society, founded in 1743 by founding father Benjamin Franklin, continues to operate to this day. ... Philadelphia is a village located in Jefferson County, New York. ... Groups Conodonta Hyperoartia Petromyzontidae (lampreys) Pteraspidomorphi (early jawless fish) Thelodonti Anaspida Cephalaspidomorphi (early jawless fish) Galeaspida Pituriaspida Osteostraci Gnathostomata (jawed vertebrates) Placodermi Chondrichthyes (cartilaginous fish) Acanthodii Osteichthyes (bony fish) Actinopterygii (ray-finned fish) Sarcopterygii (lobe-finned fish) Actinistia (coelacanths) Dipnoi (lungfish) Tetrapoda Amphibia Amniota Sauropsida/(Reptiles) Aves (Birds) Synapsida Mammalia... The Lewis and Clark expedition (1804-1806) was the first American overland expedition to the Pacific coast and back. ...

Megalonyx, a widespread North American genus, lived past the close of the last (Wisconsinan) glaciation, when so many large mammals died out. The last ground sloths died so recently that their dung ('coprolites') remains in caves. One of the skeletons, found in a lava tube (cave) at Aden Crater, adjacent to Kilbourne Hole, New Mexico, is now at the American Museum of Natural History. The American Museum of Natural History in New York City, has a sample of dung with a note attached to it that reads "deposited by Theodore Roosevelt". There were rumours during the 19th Century from Patagonia that some Ground Sloths had survived with one explorer noting that a very large hairy beast that looked like a giant armadillo trotted past them and disappeared into the undergrowth during an expedition. The local Guaraní Indians of the area said that the Ground Sloth buried itself in burrows it dug with its claws during the day and usually only came out at night. Coprolites are fossilized feces, or animal dung. ... Lava tubes are natural conduits through which lava travels beneath the surface of a lava flow. ... Kilbourne Hole is a Maar volcanic crater, located 30 miles west of the Franklin mountains of El Paso, Texas, in Doña Ana County, New Mexico. ... State nickname: Land of Enchantment Official languages English Capital Santa Fe Largest city Albuquerque Governor Bill Richardson (D) Senators Pete Domenici (R) Jeff Bingaman (D) Area  - Total  - % water Ranked 5th 315,194 km² 0. ... The American Museum of Natural History is a landmark of Manhattans Upper West Side in New York, USA, at 79th Street and Central Park West. ... Theodore Roosevelt (October 27, 1858 – January 6, 1919) was the 26th (1901–09) President of the United States. ... Alternative meaning: Nineteenth Century (periodical) (18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801-1900 in the sense of the Gregorian calendar. ... A bit of history Before the arrival of the Spaniards, several indigenous groups populated the region. ... Binomial name Priodontes maximus (Kerr, 1792) The Giant armadillo, known by the binomial name Priodontes maximus, and its synonym Priodontes giganteus, is the largest species of armadillo. ... Guarani was one of the most important tribal groups of South America, having the former home territory chiefly between the Uruguay and lower Paraguay Rivers, in what is now Paraguay and the Provinces of Corrientes and Entre Rios of Argentina. ...

Closeup of hand, showing claws

Image File history File links Hand of fossil ground sloth skeleton at the National Museum of Natural History; digital photo taken by User:Postdlf, 1-8-05 File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links Hand of fossil ground sloth skeleton at the National Museum of Natural History; digital photo taken by User:Postdlf, 1-8-05 File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...

Megatheriidae

The Megatheriid ground sloths appeared later in the Oligocene, some 30 million years ago, also in South America. The group includes the heavily-built Megatherium ( given its name 'great beast' by Richard Owen) and Eremotherium. Eremotherium eomigrans, which has been found in 2.2 million year-old sediments in Florida, reached a length of 6 meters and had the bulk of a bull elephant. Bones of a newly discovered ground sloth that is the oldest of its kind ever found in North America have been uncovered by a University of Florida research team. Weighing more than five tons and able to reach as high as 17 feet, the 2.2 million-year-old prehistoric creature was larger than today's African bull elephants, said UF paleontologist David Webb. Unlike other large-bodied ground sloths, the new species had an extra claw, representing a surprisingly primitive stage of evolution, Webb said. While all other giant sloths had four fingers with only two or three claws, this one had five fingers, four of them with large claws, the biggest being nearly a foot long, he said. Other ground sloths, such Nothrotheres as the slighter built Hapalops and Nothrotheriops line, reached a length of about 1.2 meters, still larger than the living three-toed sloths that are their descendents. Concerning ground sloths' skeletal structure it may be concluded that ground sloths were very massive animals, plus, very thick bones that end in even thicker joints, especially those on hind legs) would give his appendages tremendous power, their size and fearsome claws, combined with this power, provided a formidable good defence against any predator. Megatheria were a group of elephant-sized giant sloths that lived from 2 million to 8,000 years ago. ... Sir Richard Owen and Dinornis bird skeleton Sir Richard Owen (July 20, 1804 - December 18, 1892) was an English biologist, comparative anatomist and palaeontologist. ... Genera and Species Loxodonta Loxodonta cyclotis Loxodonta africana Elephas Elephas maximus Elephas recki † Stegodon † Mammuthus † Elephantidae (the elephants) is a family of animals, and the only remaining family in the order Proboscidea. ...

Cryptozoologists believe that a forest creature of the upper Amazon basin called the Mapinguari may be a surviving tropical ground sloth. Cryptozoology is the study of rumored animals that are presumed (at least by the researcher) to exist, but for which conclusive proof does not yet exist, or for animals which are generally considered extinct, but are occasionally reported. ... The Amazon Basin is the part of South America drained by the Amazon River and its tributaries. ... Rumored to exist by locals in the Amazon jungle of Brazil, the Mapinguari is said to be a giant sloth-like creature. ...

La Brea Tar Pits

Two ground sloths are among the animals that were trapped in the La Brea Tar Pits. Harlan's ground sloth (Paramylodon harlani) was six feet tall when it reared up to browse high twigs and leaves. One of the most interesting features of the Harlan's ground sloth were its skin bones, or dermal ossicles. These small bones were deep under the skin around the neck, shoulders and back and may have served as armor against attacking predators. The smaller ground sloth, less common in the La Brea Lagerstätte is the Shasta ground sloth (Nothrotheriops shastensis) La Brea Tar Pits in Los Angeles Countys Miracle Mile District. ... Lagerstätten (German, singular: Lagerstätte, literally: place(s) of storage or resting place(s)) are sedimentary deposits that exhibit extraordinary fossil richness or completeness. ...

Taxonomy of Ground Sloths

Harlan's ground sloth (Paramylodon harlani), National Museum of Natural History

Modified from McKenna and Bell (1997). "+" indicates an extinct group. Ground sloths consist of 6 families and 88 genera. Note that ground sloths do not form a monophyletic group. Some extinct ground sloths are more related to today's tree sloths than they are to other ground sloths. Image File history File links Paramylodon harlani ground sloth fossil at the National Museum of Natural History, Washington, DC; digital photo taken by User:Postdlf, 2/20/05 File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links Paramylodon harlani ground sloth fossil at the National Museum of Natural History, Washington, DC; digital photo taken by User:Postdlf, 2/20/05 File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... In phylogenetics, a group is monophyletic (Greek: of one stem) if all organisms in that group are known to have developed from a common ancestral form, and all descendants of that form are included in the group. ...

• Infraorder Phyllophaga - sloths
  • †Diellipsodon incertae sedis
  • †Amphiocnus incertae sedis
  • †Pseudoglyptodon incertae sedis
  • Family †Rathymotheriidae incertae sedis
    • †Rathymotherium
  • Parvorder †Mylodonta - mylodont ground sloths
    • Superfamily †Mylodontoidea
      • †Pseudoprepotherium incertae sedis
      • Family †Scelidotheriidae
        • Subfamily †Chubutheriinae
          • †Chubutherium
        • Subfamily †Scelidotheriinae
          • †Scelidotheriops
          • †Analcitherium
          • †Nematherium
          • †Neonematherium
          • †Elassotherium
          • †Scelidotherium
      • Family †Mylodontidae
        • †Urumacotherium incertae sedis
        • Subfamily †Mylodontinae
          • †Glossotheriopsis
          • †Promylodon
          • †Strabsodon
          • †Megabradys
          • †Pleurolestodon
          • †Mylodon
        • Subfamily †Lestodontinae
          • Tribe †Thinobadistini
            • †Thinobadistes
            • †Sphenotherus
          • Tribe †Glossotheriini
            • †Acremylodon
            • †Ranculcus
            • †Glossotherium
            • †Paramylodon
            • †Mylodonopsis
          • Tribe †Lestodontini
            • †Lestodon
            • †Lestodontidion
    • Superfamily †Orophodontoidea
      • Family †Orophodontidae
        • †Proplatyarthrus
        • †Orophodon
        • †Octodontotherium
        • †Octomylodon
        • †Octodontobradys
  • Parvorder Megatheria - ground sloths and modern tree sloths
    • Superfamily Megatherioidea
      • Family †Megatheriidae
        • Subfamily †Megatheriinae
          • Tribe †Megatheriini
            • Subtribe †Prepotheriina
              • †Proprepotherium
              • †Planops
              • †Prepotherium
            • Subtribe †Megatheriina
              • †Megathericulus
              • †Promegatherium
              • †Plesiomegatherium
              • †Megatheridium
              • †Pyramiodontherium
              • †Megatherium
              • †Eremotherium
              • †Ocnopus
              • †Perezfontanatherium
          • Tribe †Nothrotheriini
            • †Pronothrotherium
            • †Xyophorus
            • †Chasicobradys
            • †Gilsolaresia
            • †Diheterocnus
            • †Synhapalops
            • †Nothropus
            • †Thalassocnus
            • †Nothrotherium
            • †Nothrotheriops
        • Subfamily †Schismotheriinae
          • †Hapaloides
          • †Schismotherium
          • †Hapalops
          • †Pelecyodon
          • †Parapelecyodon
          • †Analcimorphus
          • †Hyperleptus
          • †Neohapalops
      • Family Megalonychidae - ground sloths and two-toed tree sloths
        • †Imagocnus incertae sedis
        • Subfamily †Ortotheriinae
          • †Proschisomotherium
          • †Eucholoeops
          • †Pseudortotherium
          • †Megalonychotherium
          • †Paranabradys
          • †Pliomorphus
          • †Torcellia
          • †Ortotherium
          • †Menilaus
          • †Diodomus
          • †Habanocnus
          • †Paulocnus
        • Subfamily Megalonychinae
          • †Pliometanastes incertae sedis
          • †Sinclairia incertae sedis
          • †Megalonychops incertae sedis
          • †Valgipes incertae sedis
          • †Meizonyx incertae sedis
          • Tribe †Megalonychini
            • Subtribe †Megalonychina
              • Infratribe †Megalonychi
                • †Protomegalonyx
                • †Megalonyx
              • Infratribe †Megalocni
                • †Megalocnus
                • †Neomesocnus
            • Subtribe †Mesocnina
              • †Neocnus
              • †Parocnus - greater Haitian ground sloth
          • Tribe Choloepodini
            • Subtribe †Acratocnina
              • †Miocnus
              • †Acratocnus
              • †Synocnus - lesser Haitian ground sloth
            • (Subtribe Choloepodina - modern two-toed sloths)
    • (Superfamily Bradypodoidea - modern three-toed sloths)

Families Megalonychidae P.Gervais, 1855 Bradypodidae Gray, 1821 Sloths are medium-sized South American mammals belonging to the families Megalonychidae and Bradypodidae, part of the order Xenarthra. ... Incertae sedis—of uncertain position (seat)—is a term used to define a taxonomic group where its broader relationships are unknown or undefined. ... Incertae sedis—of uncertain position (seat)—is a term used to define a taxonomic group where its broader relationships are unknown or undefined. ... Incertae sedis—of uncertain position (seat)—is a term used to define a taxonomic group where its broader relationships are unknown or undefined. ... Incertae sedis—of uncertain position (seat)—is a term used to define a taxonomic group where its broader relationships are unknown or undefined. ... Incertae sedis—of uncertain position (seat)—is a term used to define a taxonomic group where its broader relationships are unknown or undefined. ... Incertae sedis—of uncertain position (seat)—is a term used to define a taxonomic group where its broader relationships are unknown or undefined. ... The Mylodon was a smaller breed of ground sloth, approximately ox-sized, related to the Megatherium and modern three-toed sloths and two-toed sloths. ... Megatheria were a group of elephant-sized giant sloths that lived from 2 million to 8,000 years ago. ... This article refers to the South American mammal. ... Incertae sedis—of uncertain position (seat)—is a term used to define a taxonomic group where its broader relationships are unknown or undefined. ... Incertae sedis—of uncertain position (seat)—is a term used to define a taxonomic group where its broader relationships are unknown or undefined. ... Incertae sedis—of uncertain position (seat)—is a term used to define a taxonomic group where its broader relationships are unknown or undefined. ... Incertae sedis—of uncertain position (seat)—is a term used to define a taxonomic group where its broader relationships are unknown or undefined. ... Incertae sedis—of uncertain position (seat)—is a term used to define a taxonomic group where its broader relationships are unknown or undefined. ... Incertae sedis—of uncertain position (seat)—is a term used to define a taxonomic group where its broader relationships are unknown or undefined. ... This article refers to the South American mammal. ... Families Megalonychidae Bradypodidae Sloths are medium-sized South American mammals belonging to the families Megalonychidae and Bradypodidae, part of the order Xenarthra. ...

References

• McKenna, M. C, and S. K. Bell. 1997. Classification of Mammals Above the Species Level. Columbia University Press, New York, 631 pp.
• Nowak, R. M. 1999. Walker's Mammals of the World, Vol. 2. Johns Hopkins University Press, London.
• White, J.L. & MacPhee, R.D.E. 2001. The sloths of the West Indies: a systematic and phylogenetic review. pp 201-235 in Woods, C.A. & Sergile, F.E. (eds.). Biogeography of the West Indies: Patterns and Perspectives

External links

• Academy of Natural Sciences ground sloth page.
• Illinois State Museum ground sloth page.
• Ground sloths at La Brea.
• Eremotherium in Florida.
• Have some ground sloths survived in Argentina?
• Ground sloths in general.