Chicken-size dinosaur discovered with fur and shoulder ‘spears’
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| The Ubirajara jubatus has fur-like feathers and ribbon-shaped spears emerging from its shoulders.© Bob Nicholls / Paleocreations.com 2020 |
The Ubirajara jubatus is a far cry from what we imagine when we think of dinosaurs.
The two-legged, chicken-size reptile was replete with long, fur-like feathers and two pairs of ribbon-like spears jutting from its shoulders — features unlike any other in the fossil record.
“What is especially unusual about the beast is the presence of two very long, probably stiff ribbons on either side of its shoulders that were probably used for display, for mate attraction, inter-male rivalry or to frighten off foe[s],” said University of Portsmouth researcher David Martill, whose international team of scientists dug up the prehistoric specimen near Brazil’s Crato Formation.
“Given its flamboyance, we can imagine that the dinosaur may have indulged in elaborate dancing to show off its display structures,” Martill added in a statement on the university’s website. Their discovery now appears in the journal Cretaceous Research.
The “enigmatic” creature was named after Brazil’s indigenous Tupi tribe; Ubirajara translates as “lord of the spear.” The diminutive dino existed about 110 million years ago and is considered the first primitive creature with “display structures … the effects of which we can still see today in living birds,” said Portsmouth’s Robert Smyth. Its long, flat shoulder spikes would have been made of stiff keratin, like fingernails, although they were not positioned to be used as weapons or shield them from predators — leading paleontologists to believe they might be a clue as to why birds flaunt feathery plumage to attract mates or scare away threats.
“We know lots of dinosaurs had bony crests, spines and frills that were probably used for display but we don’t see these very often in living birds. In birds, crests are made of feathers,” said Smyth. “Bone requires a lot of energy for a body to grow and maintain, it’s also heavy and can cause serious injury if broken.”
On the other hand, keratin — of which feathers, hair and nails are made — is “lightweight, flexible and can be regularly replaced if damaged,” he added.
Similar to a dog or porcupine, the Ubirajara jubatus’ long “mane” was controlled by its muscles, allowing the fur-like filaments to stand on end when threatened, or lay down flat in order to scurry through vegetation without becoming tangled.
“Any creature with movable hair or feathers as a body coverage has a great advantage in streamlining the body contour for faster hunts or escapes but also to capture or release heat,” said Martill.
“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,” said Smyth. “Ubirajara shows us that this tendency to show off is not a uniquely avian characteristic, but something that birds inherited from their dinosaur
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