| Diet | Omnivore |
| Height | 1.5m |
| Length | 8m |
| Weight | 3 tonnes |
| Environment | Land |
| Era | Cretaceous |
| Period | Late Cretaceous |
| Type | Theropod |
| Location | China |
Beibeilong was a large theropod dinosaur that lived in what is now China during the Late Cretaceous period, approximately 96 to 88 million years ago. This remarkable dinosaur is known from a truly extraordinary fossil discovery - an embryonic skeleton found inside one of the largest dinosaur eggs ever discovered, along with a partial nest structure from the Gaogou Formation.
As a member of the caenagnathid group, Beibeilong would have been a toothless theropod with a distinctive beak-like mouth and long, powerful legs. Adult specimens likely reached lengths of around 8 metres, making Beibeilong one of the largest known oviraptorosaurs. Its body would have been covered in feathers, and it possessed long arms with clawed hands that were probably used for display, nest-building, and handling food.
Like other caenagnathids, Beibeilong was likely an omnivore, using its powerful beak to crack open tough plant materials, nuts, and possibly shellfish, whilst also opportunistically feeding on small animals. The discovery of embryonic remains with nest material suggests that Beibeilong, like other oviraptorosaurs, was a caring parent that built nests and may have brooded its eggs.
The fossil evidence indicates that Beibeilong laid enormous eggs - some of the largest ever found - measuring up to 45 centimetres long. This discovery has provided invaluable insights into the reproductive behaviour and development of large oviraptorosaurs during the Cretaceous period.
Beibeilong was distinguished by its enormous size for an oviraptorosaur, reaching 8 metres in length, and its massive eggs which are among the largest dinosaur eggs ever discovered. It possessed the characteristic toothless beak and feathered body typical of caenagnathids, but at a much larger scale than most of its relatives.
Beibeilong exhibited complex nesting behaviour, constructing large nests for its enormous eggs and likely brooding them like modern birds. The discovery of embryonic remains suggests that adults may have cared for their young, and like other oviraptorosaurs, they probably used elaborate feathered displays for communication and courtship.
Beibeilong was first described by Darla Zelenitsky and colleagues in 2017. The original fossils were discovered at Gaogou Formation, China.
