About 148 to 150 million years ago, a strange pheasant-sized and bird-like dinosaur with elongated legs and arms built much like wings inhabited southeastern China, with a puzzling anatomy suggesting it either was a fast runner or lived a lifestyle like a modern wading bird.
Scientists said on September 6 they unearthed in Fujian Province the fossil of a Jurassic Period dinosaur they named Fujianvenator prodigiosus - a creature that sheds light on a critical evolutionary stage in the origin of birds.
The question of whether the Fujianvenator, with its curious mixture of skeletal features, should be classified as a bird depends on how one defines a bird, according to study leader Min Wang, a palaeontologist at the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences.
A remarkable event in dinosaur evolution came when small feathered two-legged dinosaurs from a lineage known as theropods gave rise to birds late in the Jurassic, with the oldest-known bird - Archaeopteryx - dating to roughly 150 million years ago in Germany.
Fujianvenator is a member of a grouping called avialans that includes all birds and their closest non-avian dinosaur relatives, Mr. Wang said. Despite their modest beginnings, birds survived the asteroid strike 66 million years ago that doomed their non-avian dinosaur comrades.
The Fujianvenator fossil, discovered last October, is fairly complete but lacks the animal’s skull and parts of its feet, making it hard to interpret its diet and lifestyle.
Fujianvenator’s lower leg bone - the tibia - was twice as long as its thigh bone - the femur. Such dimensions are unique among theropods; it also had a long bony tail.
“The forelimb is generally built like a bird’s wing, but with three claws on the fingers, which are absent from modern birds. So you can call it wing. It cannot be determined whether it could fly or not,” Mr. Wang said.
“The fossil itself does not preserve feathers. However, its closest relatives and nearly all the known avialan theropods have feathers … Therefore, it would not be a surprise if Fujianvenator had feathers,” Mr. Wang added.
Scientists are seeking a better understanding of the origin of birds as well as non-avian dinosaurs with bird-like traits.
The earliest chapters in the history of birds remain murky due to a fossils shortage. After Archaeopteryx - a crow-sized bird with teeth, a long bony tail, and no beak - there is a canyon of about 20 million years before the next birds appear in the fossil record.