Here we describe a fragmentary troodontid specimen from the sublocality of Grangers Flats at the Late Cretaceous locality of Ukhaa Tolgod, Omnogov, Mongolia. This specimen is provisionally referred to the coeval Saurornithoides mongoliensis. IGM 100/1083 displays a pattern of tooth replacement that is like that of basal avialans. The presence of this pattern in avialans has been used by some to refute a theropod origin for this group.