Scientists uncover a 'bizarre' leggy dinosaur unlike anything seen before, and it could rewrite the history of bird evolution

• The Fujianvenator had elongated lower legs that were twice as long as its thighs.
• The 150-million-year-old dinosaur is likely a very early bird ancestor, as old as the Archaeopterix.

Scientists have uncovered a 150-million-year-old dinosaur that could rewrite the history of bird evolution.

The dinosaur, named Fujianvenator prodigiosus, is thought to be as old the Archaeopteryx, which many consider to be the first bird. But it looks like no other animal found before.

The "bizarre" new species had characteristic long legs, which suggest it may have been a runner, and likely not a very good flyer, paleontologist Min Wang of the Chinese Academy of Sciences, lead author on the study, told Reuters.

"Fujianvenator is far from similar to any modern birds," Wang said.

The findings, published in peer-reviewed journal Nature, add evidence to a growing body of research suggesting dinosaurs branched out into bird-like characteristics earlier than previously thought.

Fujianvenator was either a runner or a wader

Birds are largely thought to have evolved out of the therapods, a group of dinosaurs that contained Tyrannosaurus Rex and velociraptors.

But our understanding of bird evolution is seriously limited by a dearth of fossils showing the transition between therapods and birds — referred to collectively as avialans. These fossils, which appear around the end of the Jurassic period, tend to be rare because the animal's hollow bones make them particularly fragile, per Nature News.

The oldest known example of avialan is usually thought to be the Archaeopteryx, a 150-million-year-old feathered animal that was likely capable of flight.

But this new fossil, found near Nanping in Fujian province last October, provides a snapshot into a whole different type of evolution that was happening at around the same time.

It's difficult to know exactly what Fujianvenator looked like, because the chicken-sized skeleton is missing a head and tail, and its digits are poorly preserved.

Still, the animal's long lanky legs set it completely apart from other fossils on record.

Its lower leg is about twice as long as its thigh. That suggests the animal was either a speedy runner, like a road runner, or used its legs to wade in marshes in the area, like a crane or heron.

"I would put my money on runner," Wang told Reuters.

As to whether the animal would have been capable of flight, Wang is divided. It's shortened shoulder blade and fingers suggest its forearms may have been more adapted to grabbing, though it is thought that this animal would have had feathers, per the study.

"Based on the skeletal features, Fujianvenator probably is at least not good at flying," Wang said.

This suggests that Fujianvenator occupied a completely different ecological niche to Archaeopteryx, study author Hailu You, a paleontologist at the Chinese Academy of Sciences in Beijing, told Nature News.

The finding adds evidence to the idea that by 150 million years ago, dinosaurs had already evolved different types of bird characteristics, rather than these evolving out of a single type of dinosaur, Mark Loewen, a paleontologist at the University of Utah in Salt Lake City who was not involved in the discovery, told Nature News.

Much still needs to be uncovered to understand bird evolution, though.

There is still a 30 million-year-long gap in the fossil record between Archeopteryx and Fujianvenator and the next bird fossil on record, which appears in the Cretaceous, the study authors said in a press release.