The Megatheriinae (Xenarthra, Tardigrada) of the Ituzaingó Formation (Upper Miocene-Pliocene) of the Entre Ríos Province. The subfamily Megatheriinae is known from the Friasian (Middle Miocene) to the Lujanian (Late Pleistocene-Early Holocene). A summary of the present state of knowledge of the megatheriines of the Ituzaingó Formation of Entre Ríos Province is given. The diversity of Megatheriinae of the Ituzaingó Formation is higher than that of any other unit of the Late Miocene-Pliocene of Argentina. However, the nature of the deposits and the fragmentary and dissociated remains on which the species types were recognized, have led to an overestimation of the diversity in this formation. Thus, the Megatheriinae diversity of the Ituzaingó Formation should have been lower than previously considered.Fil: Brandoni, Diego. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentin