Ubirajara jubatus Had Impressive Mane and Shoulder Ribbons
A maned theropod dinosaur with elaborate filamentous structures has been identified by a research team led by University of Portsmouth paleontologists.
The newly-discovered dinosaur species lived about 110 million years ago (Aptian stage of the Cretaceous period) in what is now Brazil.
Named Ubirajara jubatus, the ancient animal was chicken-sized with a mane of long fur down its back.
It also had long, flat, stiff shoulder ribbons of keratin, each with a small sharp ridge running along the middle. Its arms were covered in fur-like filaments down to the hands.
“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,” said co-author Professor David Martill, a paleontologist in the School of the Environment, Geography and Geosciences at the University of Portsmouth.
“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.”
Ubirajara jubatus’ 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.
“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,” Professor Martill said.
“The elaborate plumage of Ubirajara jubatus might have improved its chances of survival,” added lead author Robert Smyth, also from the School of the Environment, Geography and Geosciences at the University of Portsmouth.
The fossilized partial skeleton of Ubirajara jubatus was collected from the Lower Cretaceous Crato Formation of Northeast Brazil.
“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.
“It is also the first non-avian dinosaur found on the ancient supercontinent of Gondwana with preserved skin.”
“Ubirajara jubatus is not only important because of the integumentary structures present for the first time in a non-avian dinosaur, completely changing the way of seeing the behavior of certain dinosaurs,” said co-author Dr. Hector Rivera Sylva, a paleontologist at the Museo del Desierto, Mexico.
“Rather, the scientific value transcends, forming a watershed, since it is the first evidence for this group in Latin America, as well as one of the few reported for the subcontinent of Gondwana, expanding the knowledge about non-avian feathered dinosaurs for America, whose evidence is very scarce.”
The discovery is reported in a paper in the journal Cretaceous Research.
Robert S.H. Smyth et al. A maned theropod dinosaur from Gondwana with elaborate integumentary structures. Cretaceous Research, published online December 13, 2002; doi: 10.1016/j.cretres.2020.104686