In 1993, Michael Novacek, a member of an American Museum of Natural History expedition to the Gobi Desert, discovered the skeleton of a small theropod at Ukhaa Tolgod.

The species name as a whole honoured Byron Jaffe, "in recognition of his family's support for the Mongolian Academy of Sciences-American Museum of Natural History Paleontological Expeditions".

[5] Byronosaurus was a small dinosaur, measuring about 1.5–2 m (4.9–6.6 ft) long and 50 cm (20 in) tall; it weighed only about 4–20 kg (8.8–44.1 lb).

[10][8] Due to their large brains, possible stereoscopic vision, grasping hands, and enlarged sickle-claws, troodontids were generally assumed to have been predatory.

They suggested that this difference in coarseness may be related to the size and resistance of plant and meat fibres, and that troodontids may have been herbivorous or omnivorous.

They also pointed out that some features that had been interpreted as predatory adaptations in troodontids were also found in herbivorous and omnivorous animals, such as primates and raccoons.

They stated that troodontid anatomy was consistent with a carnivorous lifestyle, and pointed out that the structure of their serrations was not much different from those of other theropods.

The two specimens were found in a nest of oviraptorid eggs in the Late Cretaceous "Flaming Cliffs" of the Djadochta Formation of Mongolia.

[16] Not only is the claim regarding nest parasitism considered dubious, but other researchers have pointed out the differences in skull morphology, suggesting that these specimens do not belong to this genus.

[5] The eggs of Byronosaurus and other troodontids are not paired unlike oviraptorids like Citipati, but are "nearly vertically embedded with their round poles" up and are exposed barely above the sediment.