Paleontologists have discovered a new species of dinosaur that’s a real show-off. Ubirajara jubatus is a small creature found with strange spikes sticking out of its shoulders, which scientists speculate were used as ornaments like a peacock’s tail.
At a glance, Ubirajara’s body shape looks pretty familiar. It’s a chicken-sized dinosaur in the compsognathid family – you might remember some of its relatives as those little blighters running underfoot and occasionally swarming people in the Jurassic Park/World movies.
Rather than the green scaly skin of its Hollywood counterparts, Ubirajara had a long, thick mane running down its back, and furry filaments covering its arms. The researchers believe that the animal could make its mane stand on end at will, the way a dog can raise its hackles when it feels threatened. In calmer times, it could lay the mane flat against its skin, to keep it out of the way while darting around the underbrush.
But the mane isn’t its most fascinating feature – that honor belongs to the weird structures poking out of its sides. They were long, flat, stiff ribbons with a small ridge down the middle. They’re not quite feathers, but they were made of keratin, the substance that makes up bird’s feathers and beaks and our own hair. Their positioning on the shoulders means they could probably also be raised and lowered as needed.
And most importantly, the team says that nothing like them has ever been found in the fossil record before.
“These are such extravagant features for such a small animal and not at all what we would predict if we only had the skeleton preserved,” says Robert Smyth, co-lead author of the study. “Why adorn yourself in a way that makes you more obvious to both your prey and to potential predators?”
The most likely answer, according to the researchers, can be seen in their descendants today. The ribbons were probably used as displays to attract mates, to outperform rivals, to frighten off predators, or some combination of those.
“The truth is that for many animals, evolutionary success is about more than just surviving, you also have to look good if you want to pass your genes on to the next generation," says Smyth. "Modern birds are famed for their elaborate plumage and displays that are used to attract mates – the peacock’s tail and male birds-of-paradise are textbook examples of this. Ubirajara shows us that this tendency to show off is not a uniquely avian characteristic, but something that birds inherited from their dinosaur ancestors.”
Dating back about 110 million years, Ubirajara is one of the oldest examples of this kind of ornamentation in dinosaurs. The insight was gleaned thanks to the immaculate fossil, which managed to preserve not only bone, but soft tissue like skin and these keratin structures.
The research was published in the journal Cretaceous Research.
Source: University of Portsmouth
