Dinosaur fossil ‘sitting in a drawer’ for 100 years identified as new T-rex relative

A long-overlooked fossil kept at a museum has been identified as a new T-rex relative – the first of its group discovered in Europe.

The long-clawed, meat-eating dinosaur species, about the size of a large tiger, was identified based on a skull fossil found on the Isle of Wight in 1924.

It belongs to a group of agile, two-legged carnivores called megaraptorans, closely related to tyrannosaurs, including the mighty Tyrannosaurus rex.

This group was the most mysterious of the large meat-eating dinosaurs, as few megaraptor fossils have been found till date.

“It is a real mystery that this fossil was overlooked for so long, sitting in a drawer for nearly 100 years. Lots of bones are found on the Isle of Wight – who knows what else is waiting to be discovered,” palaeontologist Cassius Morrison from University College London said. The fossil was kept at the Natural History Museum.

The new species, named Invictibellatrix amberina, had slender heads, attacking prey with its large arms and giant curved claws instead of its jaws.

Invictibellatrix means “unconquered female warrior” and researchers say the name was chosen with the intention to “give hope and strength to all those who are bullied, discriminated, victimised, and oppressed that tomorrow will be theirs and not to give up in face of such odds”.

The species name, amberina, meanwhile, refers to the amber found in the rocks where the fossil was discovered.

“Based on what we know about its closest relatives, Invictibellatrix would have been three to four metres long and just over a metre and a half in height – about as tall as a human,” Dr Morrison said.

“It would likely have had feathers, and its claws might have been about 10cm to 20cm long. It would have eaten small dinosaurs, lizards and mammals – occupying a similar role in the food chain to the hyena today,” he said.

While it was not the apex predator of its time, I. amberina would have been more dangerous for humans than a T-rex, researchers say.

“We would have been perfectly sized prey, about a third of their body weight. They definitely would have chased us. A T-rex would not have bothered, as we would have been too small,” Dr Morrison said.

Megaraptors are thought to have originated in Asia, before migrating through Europe and becoming apex predators throughout the southern landmass of Gondwana, which includes present-day Africa, South America and Antarctica.

“This new species is the first proof we have that megaraptorans were also present in Europe and that they reached Gondwana this way rather than island-hopping further south,” said Charlie Scherer, another author of the study published in the journal Royal Society Open Science.

In the study, scientists took CT X-ray scans of the back of the fossil skull, creating its 3D model as well as a model of the interior of the skull.

They then compared the model with the brain cases of tyrannosaurs, spinosaurs, raptors and other two-legged meat-eating dinosaurs.

Researchers found a unique combination of skull features in the fossil specimen, including an oval hole where the spinal cord entered the brain, and an hourglass-shaped crest, helping conclude that it indeed belonged to a yet-undiscovered species.

Further analysis of the skull revealed that the dinosaur belonged to the megaraptoran family.

The findings help better understand the spread of megaraptors around the world over time.

Scientists concluded that megaraptors were globally widespread in the Early Cretaceous – at the time of Invictibellatrix.

But by the Late Cretaceous, tens of millions of years later, they had likely become extinct in the giant northern landmass of Laurasia, which includes modern-day Europe.

During this later period, megaraptors became apex predators throughout Gondwana in the south, reaching gigantic sizes, with claws up to 35 cm (14 in) long, scientists say.

Megaraptors likely died out in the north due to shifts in climate or environment, or the presence of competing predators such as other tyrannosaurs, they say.

“Despite over 200 years of collecting, the Isle of Wight continues to surprise us with new dinosaur species, and finds of carnivorous dinosaurs, such as Invictibellatrix, have been particularly elusive,” said study senior author Paul Barrett.

“Work like this shows the exceptional value of working with historical museum collections where there are still many discoveries to be made,” Dr Barrett said.