The species was named and described in 2017 through analysis of an embryonic skeleton (nicknamed Baby Louie) and partial nest with large eggs that were discovered in the Gaogou Formation of China (Henan Province) between 1992 and 1993.

The paleoenvironments in which Beibeilong lived consisted of relatively mesic (humid, well-watered) floodplains crossed by rivers with semi-arid to tropical climates.

During the late 1980s and early 1990s, Chinese farmers excavated and collected a large amount of fossilized dinosaur eggs from Cretaceous strata of the Gaogou Formation in Henan Province, China, many of which were directly embbeded in sediments (in situ).

Although Chinese authorities tried to regulate the export and illegal sales of newly discovered dinosaur eggs during the early 1990s, many ended up outside the country where they were displayed at rock and gem shows, markets, and stores, instead of being used for paleontological research.

Among these, a partial specimen block containing a 38 cm (15 in) long embryonic oviraptorosaur skeleton with several large eggs—discovered between December 1992 and early 1993 by farmer Zhang Fengchen—became well-known to the public and scientific communities.

In 1996, the specimen was featured on the cover of National Geographic Magazine, which nicknamed the embryonic skeleton Baby Louie in honor of its photographer, Louis Psihoyos.

[1] In 2015, paleontologists Hanyong Pu, Philip J. Currie, Junchang Lü, Eva B. Koppelhus, and Songhai Jia traveled to the site where Zhang Fengchen purportedly discovered the specimen and found eggshell fragments identical to those observed on the eggs associated with Baby Louie, confirming that Baby Louie was excavated in the Heimaogou locality (Xixia County) in outcrops assigned to the Late Cretaceous Gaogou Formation (Xixia Basin).

The generic name, Beibeilong, is derived from the pinyin transliteration for the Chinese 贝贝 (bèibei) and the word 龙 (lóng), meaning "baby dragon".

[1] A small depression on the top border of the posterior process (bony projection pointing backwards) of the lacrimal allowed the frontal bone to overlap, which was unique to Beibeilong.

[1] The dentary (front bone of the lower jaw) of Beibeilong was relatively short and deep with proportions similar to that of other caenagnathids (such as Gigantoraptor or Microvenator), and had an overall plate/shovel-like tip with a downturned sharp edge.

The articular (bone located just below the surangular) developed a convex crest-like articulation for the quadrate, which is mostly common in the distantly related oviraptorids.

Unlike most oviraptorosaurs, Beibeilong femora lacked a ridge-like feature extending along the shaft between the lesser trochanter and the lower mid-condyle (rounded region for articulation).

[1] The eggshell of Beibeilong eggs was ornamented on its external surface, characterized by a rugose texture composed of nodes that were both scattered and that formed ridge-like and irregular chain-like structures.

[9][12] For instance, members of Oviraptoridae have deep and robust jaws, highly positioned nasal cavities, as well as different hand morphologies (such as the Heyuanninae subfamily).

[8] Caenagnathids, on the other hand, have more elongated, pointy, and flat skulls with low nasal cavities, and in turn their manual ungual anatomy is rather generic/simple.

[12] Below is the obtained cladogram by Pu and team in 2017:[1] Microvenator celer Beibeilong sinensis Gigantoraptor erlianensis Epichirostenotes aurrier Anzu wyliei Hagryphus giganteus Chirostenotes pergracilis Apatoraptor pennatus Elmisaurus rarus Leptorhynchos elegans Caenagnathus collinsi Caenagnathasia martinsoni In their 2017 description of Beibeilong, Pu and team compared embryonic Baby Louie to Gigantoraptor, which together represent informative stages in the ontogeny (growth) of giant caenagnathids.

They have argued that the phylogeny of Caenagnathidae, along with other primitive oviraptorosaurs such as Avimimus, implies that simple dentaries lacking complex structures (such as vestigial alveoli) are the ancestral condition of caenagnathids.

Most notably, the team has suggested that the entire Beibeilong nest receoved with Baby Louie was likely in an advanced stage of incubation when it was buried given that perinate skeletal remains were found in association with 2–3 eggs in the block specimen.

These traits indicate that both caenagnathids and oviraptorids probably had fairly comparable nesting behaviours, but also that these features are ancestral for at least the whole Caenagnathoidea (superfamily containing both Caenagnathidae and Oviraptoridae).

[16] The overall sedimentology across the Gaogou Formation, made up bofy floodplain and lacustrine conglomerates, sandstones, and mudstones, indicates a dry subtropical or tropical climate during deposition.

[18] In addition, numerous scattered amber remains of conifer origin from Gaogou indicate that Araucariaceae were largely present in the Northern Hemisphere of Asia during the Late Cretaceous, including the paleoenvironments in which Beibeilong lived.

Changes in the humidity and precipitation levels negatively altered the paleoflora as well as both river and floodplain paleoenvironments, forcing herbivorous organisms to migrate between the foot of the mountain and flood plains.

In addition, carbonate carbon/oxygen isotope analyses indicate that extended periods of climatic changes ultimately deteriorated the Gaogou Formation paleoecosystem as a whole, triggering the loss of foliage cover and the extinction of the local herbivorous dinosaurs.

For instance, the entire skull has collapsed into a horizontal layer, where bones from the right side are best visible, and the premaxillae and dentary tips were partially destroyed after the individual died.

There are indications of postmortem scavenging damage left by either osteophagous or boring insects in bones, including the lower portion of the right leg, the ilium, and the upper end of the femur.

While not visible, it is suggested that the tail could lie underneath the rest of the body or matrix, or alternatively, that it was ripped off by scavenging predators.