The discovery also suggests that scientists have only tapped a small proportion of the birds and dinosaurs that were living at that time.
The new bird, named “Longicrusavis houi,” belongs to a group of birds known as ornithuromorphs (Ornithuromorpha), which are rare in rocks of this age. Ornithuromorphs are more closely related to modern birds than are most of the other birds from the Jehol Biota.
“Longicrusavis adds to the magnificent diversity of ancient birds, many of them sporting teeth, wing claws, and long bony tails, that recently have been unearthed from northeastern China,” said Luis Chiappe, a co-author of the study in the Journal of Vertebrate Paleontology.
Photograph of part of the holotype specimen of Longicrusavis houi (slab B, PKUP V1069). Although the skeleton is mostly complete (the wings and legs are clearly visible), the head has been detached from the neck and is located between the legs. The beak is pointing toward the left.
(Photo credit: S. Abramowicz.)
“The new discovery adds information not only on the diversity these birds, but also on the possible lakeshore environment in which this bird lived," said co-author Gao Ke-Qin.
The legs of this new species are unusually long, suggesting that it spent much of its time wading in the shallows of ancient lakes. The name “Longicrusavis” means “long-shin bird,” highlighting this important aspect of the new specimen. The presence of ancient birds in this habitat suggests that modern birds might have originated from an ancestor that was adapted for life near rivers and lakes.
Previously undescribed feather impressions from a closely related species suggest that both it and Longicrusavis had a long, fan-shaped tail. These are the oldest species to have such a tail, which likely increased flying performance.
The rocks of the Yixian Formation of northeast China have produced a spectacular array of fossils in recent years including fishes, birds, mammals, invertebrates, and dinosaurs. These fossils are collectively are known as the Jehol Biota and they are remarkable because, in many instances, they preserve soft tissues such as feathers or hair in addition to teeth and bones.
O’Connor et al., 'A new ornithuromorph (Aves: Ornithothoraces) bird from the Jehol Group indicative of higher-level diversity', Journal of Vertebrate Paleontology, March 2010, 30(2)