Bolong

Bolong is one of the most primitive hadrosauroids ever found in Asia, meaning it was an early cousin of the duck-billed dinosaurs.1

Its skeleton was found lying on its left side with its neck curled back over its body, like a sleeping bird.1

Bolong had a special depression between its upper jaw and tear bone, where other iguanodonts had an opening called the antorbital fenestra.1

Its arm bones (ulna and radius) were short and sturdy, with a ratio of height to length of 0.28 for the ulna and 0.33 for the radius.1

The third metatarsal (foot bone) was very short compared to its thigh bone, only 18% of the femur length.1

Bolong lived alongside many small dinosaurs like Jeholosaurus and the theropod Dilong, as well as the larger herbivore Jinzhousaurus.1

Its fossils come from the Yixian Formation, which is famous for preserving feathered dinosaurs and early birds.1