In 1964, another specimen was described from the Late Cretaceous of Mongolia. The first specimen ever collected by a professional Mongolian palaeontologist, it was given the specimen number IGM 100/1. In 1974, it was described by Rinchen Barsbold as a new species, "Saurornithoides junior". It was assigned to the genus based on cranial comparisons, as well as the similar provincialism. However, since the description, many more troodontids have been described with cranial material, and as such, a 2009 study on "Saurornithoides" reassigned this species to its own genus, "Zanabazar".