Megalonychidae

Megalonychidae is an extinct family of ground sloths in the order Pilosa, suborder Folivora, superfamily Megatherioidea, whose name means giant claw for the animals large claws. Early megalonychids were small and possibly tree-dwelling, while later Pleistocene forms such as Megalonyx jeffersonii grew far larger. The family originated in southern Argentina during the Oligocene, later dispersed north by island-hopping across the Central American Seaway around nine million years ago, and spread through Central America, Mexico, and South America before dying out roughly twelve thousand years ago during the Quaternary extinction event that followed human arrival in the Americas.