Dinosaur With 'Hair' And 'Ribbons' Has Scientists Enthralled

Scientists have recently discovered a dinosaur species that had long, flat, stiff shoulder ribbons of keratin and a mane of hair-like structures.

Named Ubirajara jubatus, the ancient animal was chicken-sized and lived about 110 million years ago (Aptian stage of the Cretaceous period) in what is now Brazil. Its ribbons each with a small sharp ridge running along the middle. Its arms were covered in fur-like filaments down to the hands.

Luxquine/Wikimedia Commons

Ordinary inside, extraordinary outside

On the inside, it was ordinary, with a skeleton similar to many small dinosaurs from the preceding Jurassic Period, scientists said on Tuesday. On the outside, it was anything but.

¡°There are plenty of other strange dinosaurs, but this one is unlike any of them,¡± said David Martill, a paleobiology professor at the University of Portsmouth in England, who helped lead the study, published in the journal Cretaceous Research.

Ubirajara¡¯s hair-like structures appear to be a rudimentary form of feathers called protofeathers. This was not actual hair, an exclusively mammalian feature. Many dinosaurs had feathers. In fact, birds evolved from small feathered dinosaurs about 150m years ago.

Bob Nicholls, paleocreations.com.

Unique for a dinosaur

¡°Likely from a distance it looked hairy rather than feathery,¡± Martill said. ¡°Likely it had hair-like protofeathers over much of its body but they are only preserved along its neck, back and arms. The ones on its back are very long and give it a sort of mane that is unique for dinosaurs."

Ubirajara¡¯s ribbon-like structures may have been used for display, possibly to attract mates or intimidate adversaries or in inter-male rivalry, Martill added. Such displays often are made by male animals ¨C think of a peacock¡¯s elaborate tail feathers ¨C leading Martill to make an ¡°educated guess¡± that this Ubirajara individual was male.

¡°The ribbons that seem to come from the shoulders are like nothing I have seen in nature before,¡± Martill said.

While it is impossible to know from the fossil ¨C which arrived at a museum in Cear¨¢ state in the early 1990s, ScienceNews reported ¨C Martill said Ubirajara may have been colorful.

¡°I bet it was,¡± he added.

First of its kind

The fossilized partial skeleton of Ubirajara jubatus was collected from the Lower Cretaceous Crato Formation of Northeast Brazil.

Smyth et al., doi: 10.1016/j.cretres.2020.104686.

¡°Ubirajara jubatus is the first non-avian dinosaur to be described from Brazil¡¯s Crato Formation, a shallow inland sea laid down about 110 million years ago,¡± the paleontologists said.