Abstract: Two species of perissodactyls from the upper part of the Nomogen Formation (Bumbanian, Early Eocene) are described: the lophialetid tapiroidMinchenoletes erlianensis gen. et sp. nov., and the hyracodontid rhinocerotoidPataecops parvus. M. erlianensis differs from the known lophialetids in having smaller size, lower crowned cheek teeth, less developed lophs, smaller length/width ratio in M1–2, and proportionally longer M3. Both taxa extend the fossil records of the Lophialetidae and the Rhinocerotoidea to the earliest Eocene. Recent stratigraphic data shows that Minchenoletes is only found from the upper part of the Nomogen Formation (Bumbanian), while Schlosseria and Lophialetes occurred respectively in the Arshanto and the Irdin Manha formations, enhancing their significance in biostratigraphic correlations and understanding of early evolution of perissodactyls. Based on the new stratigraphic data and review of the fieldnote of the CAE we consider that the Mongolian specimens of Pataecops parvus probably came from a lower stratigraphic level than most taxa of the Kholobolchi fauna, possibly correlative to the Bumbanian age.