Isotemnidae is a paraphyletic extinct family of notoungulate mammals known from the Early Eocene (Itaboraian) to Middle Miocene (Honda Group, Laventan) of South America.McKenna, Malcolm C., and Bell, Susan K. 1997. Classification of Mammals Above the Species Level. Columbia University Press, New York, 631 pp.
References
Further reading
M. McKenna. 1956. Survival of primitive Notoungulates and Condylarths into the Miocene of Colombia. American Journal of Science 254:736-743