Around 150 million years ago, a bird-like dinosaur with very long legs roamed around a swampy area in what is today southeast China. Exactly what the pheasant-sized creature was capable of doing—whether wading in the water, soaring through the air or running quickly on the ground—remains a mystery, but thanks to the discovery of its fossilized remains, researchers are deepening their understanding of bird evolution.
Scientists described the new species, Fujianvenator prodigiosus, in a paper published this week in Nature.
Paleontologists uncovered the fossil in China’s Fujian Provicing near the city of Nanping. F. prodigiosus, which dates to the Jurassic Period, had a bizarre mix of physiological features, including a long bony tail and elongated legs. Its lower legs were twice as long as its upper legs. In addition, it had forelimbs similar to a bird’s wing, but with the addition of three clawed fingers and claws.
The dinosaur may have had feathers, but researchers can’t tell for certain from the fossil. Because the fossil also lacked F. prodigiosus’ head and part of its feet, they can’t be sure what it ate or how it behaved. But based on its elongated legs alone, they suspect it was either skilled at running, like a roadrunner or an ostrich, or wading, like a heron or a crane.
Wading would make sense, given the other types of fossil researchers found nearby. In the same area as F. prodigiosus, they also discovered the remains of aquatic reptiles, fish and turtles, which they have collectived dubbed the “Zhenghe fauna.” And inhabiting a swampy area would explain why F. prodigiosus’ skeleton was so well preserved in the first place: The mud, sediment and water could’ve prevented oxygen from reaching its bones, which would have staved off decay.
Still, because of F. prodigiosus’ unusual leg anatomy, study co-author Min Wang, a paleontologist at Chinese Academy of Sciences, tells Reuters’ Will Dunham: "I would put my money on runner.”
Researchers also don’t know whether F. prodigiosus could fly but, based on its forelimbs, it was probably “not good” at it, as Wang tells Reuters.
Either way, F. prodigiosus is among the earliest bird-like dinosaurs. Many paleontologists consider Archaeopteryx to be the oldest-known bird—the crow-sized creature lacked a beak but had a bony tail and teeth. It was discovered in Germany in the 19th century and dates to around 150 million years ago.
F. prodigiosus “looks quite similar to Archaeopteryx … except the legs,” says Wang to ScienceNews’ Nikk Ogasa.
Both F. prodigiosus and Archaeopteryx are avialans, a group that split off from therapod dinosaurs like Velociraptor and Tyrannosaurus rex at some point and began the process of evolving into today’s modern birds.
But scientists still have many questions about bird evolution because they’ve discovered so few bird-like dinosaur fossils. That’s largely because birds’ ancestors had hollow skeletons, which don’t preserve as well as solid, denser bones. After the oldest-known bird, Archaeopteryx, scientists must contend with a 20-million-year gap in the fossil record. Because of that, F. prodigiosus may help them unravel even more of the bird origin saga.
“Early bird evolution is complicated,” says study co-author Hailu You, a palaeontologist at the Chinese Academy of Sciences, to Nature.