TYPE SPECIES:
• B. jaffei Norell, Mackovicky & Clark, 2000 "Byron Jaffe's Byron Jaffe's lizard"

Animalia
Vertebrata
Tetrapoda
Sauropsida
Archosauromorpha
Ornithodira
Dinosauria
Theropoda
Tetanurae
Coelurosauria
Troodontidae

This is the first troodontid known to have unserrated teeth, like those of birds.

 I.    Avimimus portentosus
 II.   Kakuru kujani (based on Avimimus portentosus)
 III.  Sinornithoides youngi
 IV.   Borogovia gracilicrus (based on other Troodontidae)
 V.    Byronosaurus jaffei
 VI.   Troodon formosus
 VII.  Tochisaurus nemegtensis (based on other Troodontidae)
 VIII. Saurornithoides mongoliensis
 IX.   Saurornithoides asiamericanus (based on Saurornithoides mongoliensis)
 X.    Saurornithoides isfarensis (based on Saurornithoides mongoliensis)
 XI.   Saurornithoides junior (based on Saurornithoides mongoliensis)