Originally, only one or possibly two individuals of "Saurornithoides" were known, closely associated within the same layer of the Djadochta Formation of Mongolia. The fossils were found on 9 July 1923 by a Chinese employee of an American Museum of Natural History expedition, Chih. The material contained a single skull and jaw in association, and vertebrae, a partial pelvis, hindlimb and foot associated nearby. More bones were initially included but later shown to belong to "Protoceratops". Henry Fairfield Osborn at first intended to name the animal "Ornithoides", the "bird-like one", and in 1924 mentioned this name in a popular publication but without a description so that it remained an invalid "nomen nudum". He then formally described the remains in the same year, finding them to be a new genus and species, which he named "Saurornithoides mongoliensis". The generic name was chosen because of the bird-like bones of the taxon, which was thought to represent a megalosaurian, translating as "saurian with bird-like rostrum". "Saurornithoides" was noted to resemble "Velociraptor", although more sluggish according to Osborn. The holotype specimen is AMNH 6516. This specimen was the first troodontid skeleton found, though at the time the connection with "Troodon", then known only from its teeth, was not realised.