Wednesday, December 16, 2020

A dinosaur with 'hair' and 'ribbons' has scientists enthralled


Will Dunham
Tue, December 15, 2020

WASHINGTON (Reuters) - About 110 million years ago along the shores of an ancient lagoon in what is now northeastern Brazil, a two-legged chicken-sized Cretaceous Period dinosaur made a living hunting insects and perhaps small vertebrates like frogs and lizards.

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.

This dinosaur, called Ubirajara jubatus, possessed a mane of hair-like structures while also boasting two utterly unique, stiff, ribbon-like features probably made of keratin - the same substance that makes up hair and fingernails - protruding from its shoulders.

"There are plenty of other strange dinosaurs, but this one is unlike any of them," said paleobiology professor David Martill of 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 150 million years ago.

"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 - think of a peacock's elaborate tail feathers - 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, Martill said Ubirajara may have been colorful.

"I bet it was," he added.

Dancing chicken-sized dinosaur had mane of long fur and ribbons for peacock-like displays

Rob Waugh
·Contributor
Tue, December 15, 2020
The dinosaur had a mane of fur and strange 'ribbons'. (University of Portsmouth)

Birds like peacocks may have inherited their ability to ‘show off’ from the dinosaurs, after the discovery of an eye-catching dinosaur which could dance to impress mates.

The new species, Ubirajara jubatus, was chicken-sized with a mane of long fur down its back and stiff ribbons projecting out and back from its shoulders.

It’s unlike any previous fossil, and scientists believe its flamboyant features may have helped it find mates - or intimate enemies.

Lead author Robert Smyth, of the University of Portsmouth, said: “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. Why adorn yourself in a way that makes you more obvious to both your prey and to potential predators?

“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.

“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,” Smyth said.

“Ubirajara shows us that this tendency to show off is not a uniquely avian characteristic, but something that birds inherited from their dinosaur ancestors.”

Ubirajara jubatus is named after a Tupi Indian name for ‘lord of the spear’, in reference to the creature’s stiff, elongated spikes, and jubatus from the Latin meaning ‘maned’ or ‘crested’.

Birds like peacocks may have inherited their flamboyant displays from the dinosaurs. (Getty)

Researchers at the University of Portsmouth and the State Museum of Natural History, Karlsruhe, Germany discovered the new species while examining fossils in Karlsruhe’s collection.

The study is published in the scientific journal Cretaceous Research.

Professor David Martill said: “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.

“We cannot prove that the specimen is a male, but given the disparity between male and female birds, it appears likely the specimen was a male, and young, too, which is surprising given most complex display abilities are reserved for mature adult males.

“Given its flamboyance, we can imagine that the dinosaur may have indulged in elaborate dancing to show off its display structures.”

The ribbons are not scales or fur, nor are they feathers in the modern sense. They appear to be structures unique to this animal.

Ubirajara jubatus lived about 110 million years ago, during the Aptian stage of the Cretaceous period, and is closely related to the European Jurassic dinosaur Compsognathus.

A section of the long, thick mane running down the animal’s back is preserved nearly intact.

The arms were also covered in fur-like filaments down to the hands.

The mane is thought to have been controlled by muscles allowing it to be raised, in a similar way a dog raises its hackles or a porcupine raises its spines when threatened.

Ubirajara could lower its mane close to the skin when not in a display mode allowing the creature to move fast without getting tangled in vegetation.

Professor Martill said: “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.”


No comments: