Some scientists had suggested that the juvenile specimen of Archaeornithoides may belong to a previously known species of Mongolian troodontid, either Saurornithoides or Byronosaurus. However, studies of a juvenile Byronosaurus skull showed that theropod dinosaurs possess many distinctive adult characteristics even as hatchlings or embryos, and that the lack of characters solidly linking Archaeornithoides to known adult specimens shows that it is probably a distinct species. Bever and Norell (in 2009) found no evidence to support the placement of Archaeornithoides close to Avialae, and only weak support for the idea that it is a juvenile troodontid.
