Early Miocene zapodids from Saudi Arabia are represented by two closely related species: Arabosminthus quadratus and Arabosminthus isabellae sp. nov. The new taxon differs from the other species of Asiatic zapodids in lacking the anteroconid on m1. A cladistic analysis involving species of Arabosminthus, Heterosminthus, Parasminthus, and Shamosminthus provides evidence that “Heterosminthus” gansus, and perhaps “Gobiosminthus” qiui, and “Parasminthus” huangshuiensis should be reallocated to Arabosminthus. This genus appears to represent an important clade of zapodid rodents basal to Parasminthus spp. Heterosminthus spp.