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Extinct Ground Sloths (Paramylodon harlani, Nothrotheriops shastensis, and Megalonyx jeffersoni) Fact Sheet: Distribution & Habitat

Extinct Ground Sloths (Paramylodon harlani, Nothrotheriops shastensis, and Megalonyx jeffersoni)

How Do We Know This?

Paleontologists use knowledge of the earth's rocks, global plate tectonic movements, ancient ecosystems, and the chemical process of fossilization to make sense of fossil distribution patterns and ancient habitats.


  • Paramylodon: widely distributed across U.S., especially in western states (excluding the Colorado Plateau) (McDonald et al 2004)
  • Nothrotheriops shastensis: primarily western U.S. but also in Florida, Texas, Mexico. (McDonald 1985)
  • Megalonyx: wide distribution in over 150 sites in United States, including Alaska, northwestern Canada, Mexico
  • Fossils of three taxonomic families of sloths were found at Rancho La Brea asphalt deposits in California.


  • Paramylodon: Not found in dry habitats; preferred areas of open grass or parkland; perhaps associated with permanent water in rivers and lakes from sea level to 2,330 m (7,644 ft) (Spaulding et al 1983) (McDonald 2004)
  • Nothrotheriops: Found in habitats that are deserts today and were drier in the Pleistocene. (McDonald et al 2004); open savanna scrub land with trees; deciduous forests. (Hoganson & McDonald 2007)
  • Megalonyx: Occupied gallery forests along rivers or lakes (Hoganson & McDonald 2007)
    • One skeleton from Illinois found with fossil pollen representing a spruce forest transitional to a mixed hardwood forest. (Schubert et al 2004)

Page Citations

Hoganson & McDonald (2007)
McDonald (1985)
McDonald et al. (2004)
Schubert et al. (2004)
Spaulding et al. (1983)

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