Abstract: Previously, rhinocerotoid eggysodontines have been confined to Oligocene deposits from Europe and Asia. Here we report a new primitive Late Eocene eggysodontine, Proeggysodon qiui gen. et sp. nov., from Erden Obo, Siziwangqi, Nei Mongol, China. Proeggysodon differs from other eggysodontines in being smaller; in having two pairs of well-developed, spatulate lower incisors, non-molarized lower premolars, a more lingually aligned cristid obliqua of p4, and an angled junction between the cristid obliqua and the hypolophid of each lower molar; and in lacking buccal cingulids on the lower cheek teeth. Furthermore, we propose that eggysodontines and forstercooperes are closely related, mainly because they share the following features: large and erect canine, relatively short diastema between canine and cheek teeth, and dorsoventrally deep and anteroposteriorly abbreviated symphysis associated with nearly vertically implanted incisors. The new specimen narrows the time gap between the Early to Middle Eocene forstercooperes and the Oligocene eggysodontines. The discovery of Proeggysodon in Asia also suggests that eggysodontines dispersed from this continent into Europe after the “Grande Coupure”.