Megalonyx leptostomus—Narrow-mouthed Sloth //Megalonyx jeffersonii—Jefferson's Ground Sloth //Megalonyx wheatleyi—Wheatley's Ground Sloth
?Irvingtonian/Rancholabrean: Emery Borrow Pit (Jefferson 1991b).
Irvingtonian/Rancholabrean: Manix Lake (Jefferson 1991b).
Rancholabrean: Campbell Hill (Jefferson 1991b); San Pedro Lumber Yard (Jefferson 1991b).
Sangamon: San Pedro Lumber Co. (Jefferson 1991b).
Mid Wisconsin: McKittrick (Schultz 1937: ?).
Late Wisconsin: La Mirada (Jefferson 1991b).
Literature. Jefferson 1991b; Schultz 1937.
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)
Sangamon: Newport Bay Mesa (Jefferson 1991b; cf.).
Mid/Late Wisconsin: Rancho La Brea (Stock and Harris.
Literature. Kurtén and Anderson 1980; McDonald et al. 2004; Mead et al. 2005; Stock and Harris 1992.
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: 2 Mar 2014