Explore this animal in Size of Extinct Animals ↗
300 / Cenozoic
Jefferson's Ground Sloth
Megalonyx jeffersonii
Huge curved claws belonged to a forest browser whose name is tied to Thomas Jefferson.
View original image · 1536 × 1024- Time range
- About 5 million–11,000 years ago
- Final stage
- End of the Pleistocene
- Geographic range
- Forests, river valleys and woodland edges · North America
01 / DEFINITION & ECOLOGY
What was Jefferson's Ground Sloth?
Jefferson's Ground Sloth (Megalonyx jeffersonii) was an extinct organism known from About 5 million–11,000 years ago, with a range in Forests, river valleys and woodland edges · North America.
Life and ecology
Megalonyx jeffersonii stood on its hind limbs to pull branches, using powerful arms while living farther north than many ground sloths.
02 / DISAPPEARANCE
Why did Jefferson's Ground Sloth disappear?
Late-glacial climate change and human expansion both overlap with its disappearance; their relative roles are not established.
03 / EVIDENCE
How do scientists know about Jefferson's Ground Sloth?
Skeletons, teeth and footprints across North America document range, browsing and locomotion.
04 / SOURCES & FURTHER READING
Check the source record
Use the scientific name to compare taxonomy, occurrence records and the fossil record. Database coverage and classifications may differ.
05 / REVISION HISTORY
How has this record changed?
- Rewrote an extinction cause that presented environmental or faunal turnover as established; it is now given as context the record does not prove.
- Verified authoritative entity sources and added three responsive reconstruction sizes.
- Initial bilingual species record published.
06 / CORRECTIONS & ADDITIONS