Fujianvenator prodigiosus’s long legs would have made it well adapted to either sprinting or wading, according to a paper describing the newly discovered species.
The creature lived 148–150 million years ago toward the end of the dinosaur heyday of the Jurassic period (201–145 million years ago). The fossilised remains of Fujianvenator were found in the Zhenghe locality of southeastern China.
In a paper published in Nature, the researchers describe an animal about the size of a pheasant, but its most striking feature was its legs.
Unlike any other known dinosaur, Fujianvenator had a lower leg twice as long as its thighs. The authors suggest that this morphology would have made the animal suited to either sprinting or wading through marsh or swamp.
Alongside Fujianvenator, the palaeontologists uncovered other ancient aquatic and semi-aquatic animals such as bony fish, turtles and amphibious lizard-like reptiles. This assemblage, that the authors refer to as the Zhenghe Fauna, is suggestive of a swamp-like environment, making it likely that Fujianvenator was a wading dinosaur, like many modern wetland birds.
This would make Fujianvenator unique in the dinosaur lineage within which it is believed to reside.
Fujianvenator is one of the most recent members of a group of dinosaurs known as Jurassic avialans. This clade, Avialae, is generally defined as all the living dinosaurs (birds) and extinct theropod (bipedal) dinosaurs more closely related to modern birds than to deinonychosaurs (think Jurassic Park’s wrongly named and scientifically inaccurate “velociraptors”).
Understanding the divergence of the non-avialan decendents of birds in the late Jurassic is key to grasping the evolution of the bird body plan.
Fujianvenator adds another piece to a complex puzzle. The fact that, unlike every other avialan, it appears to be adapted to wading, not life in the trees or skies, suggests early diversification of these Jurassic pioneers.
“The unusually elongated lower leg and other morphologies of Fujianvenator, combined with geological and palaeontological data from the Zhenghe locality, suggest that it lived in a swamp-like environment – a previously unknown ecological niche for early avialans,” the authors write.
The exquisitely preserved fossil is a partial skeleton of a subadult. It does not include the animal’s skull which would provide more information about its feeding behaviour and other clues as to how it lived.