Megalonyx leptostomus—Narrow-mouthed Sloth //Megalonyx jeffersonii—Jefferson's Ground Sloth //Megalonyx wheatleyi—Wheatley's Ground Sloth
Kurtén and Anderson (1980) noted that this taxon was widespread by the middle Pliocene and probably was ancestral to the larger and geologically later Megalonyx wheatleyi.
Late Blancan: 111 Ranch (Morgan and White 2005); La Union Fauna (La Union Local Fauna) (McDonald and Morgan 2011); La Union Fauna (Santa Teresa Local Fauna) (McDonald and Morgan 2011).
Literature. Kurtén and Anderson 1980; McDonald and Morgan 2011.
Jefferson's Ground Sloth was the largest of the North American megalonychid ground sloths (Kurtén and Anderson 1980).
Rancholabrean: Coconino Cavern (Mead et al. 2005); Springerville (McDonald et al. 2004)
Literature. Kurtén and Anderson 1980; McDonald et al. 2004; Mead et al. 2005.
Vanderhill (1986) examined a nearly complete left femur that represents Megalonyx wheatleyi. It is intermediate in size between the Blancan/Early Irvingtonian M. leptostomus and smaller than M. jeffersonii. The specimen lacks stratigraphic data, but likely comes from the upper 45 m of Rio Grande Valley fill (Vanderhill 1986). This is the specimen referenced by Morgan and Lucas (2003, 2005).
Irvingtonian: El Golfo (Croxen et al. 2007).
Early Irvingtonian: Adobe Ranch (McDonald and Morgan 2011; Morgan and Lucas 2003, 2005; Vanderhill 1986).
Medial Irvingtonian: Gutierrez Gravel Pit (McDonald and Morgan 2011: cf.).
Literature. Croxen et al. 2007; McDonald and Morgan 2011; Morgan and Lucas 2003, 2005; Vanderhill 1986.
Last Update: 18 Oct 2013