A terrifying dinosaur armed with claws as long as kitchen knives once stalked the Isle of Wight, archaeologists have revealed.

The fearsome predator – the size of a large tiger – roamed southern England around 120million years ago during the Early Cretaceous period. 

Researchers have identified the new species from a fossil skull fragment that spent almost a century sitting unnoticed in a museum collection.

Named Invictibellatrix amberina, the dinosaur belonged to a mysterious group of predators known as megaraptorans.

The agile meat-eaters were close relatives of tyrannosaurs but hunted in a very different way. Instead of relying on bone-crushing jaws, they used enormous arms tipped with giant curved claws to seize and slash their prey.

‘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,’ lead author Dr Cassius Morrison, from University College London, said.

‘It would likely have had feathers and its claws might have been about 10cm to 20cm (four to eight inches) long.

‘It would have eaten small dinosaurs, lizards and mammals – occupying a similar role in the food chain to the hyena today.’

Dr Morrison said the predator would actually have been more threatening to humans than a Tyrannosaurus rex, in a hypothetical scenario where both co-existed.

While a T. rex may have ignored people because they were too small to bother with, humans would have fallen squarely within Invictibellatrix's preferred prey range.

‘It was not the apex predator of its time, but for humans this dinosaur would have been more dangerous than a T. rex,’ he said.

‘We would have been perfectly sized prey, about a third of their body weight.’

The fossil was originally discovered on the Isle of Wight by amateur palaeontologist Reginald Walter Tooley.

After being acquired by the Natural History Museum in 1924, however, it remained largely overlooked for decades.

It was only when scientists carried out CT scans and built detailed 3D models of the skull that its true identity emerged.

Megaraptors are regarded as the most mysterious of the large, meat-eating dinosaurs, as few fossils have been found.

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

But until now, this theory was missing key fossil evidence, as no megaraptorans had been found in Europe.

Professor Paul Barrett, the study’s senior author from the Natural History Museum, said: ‘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.

‘Work like this shows the exceptional value of working with historical museum collections where there are still many discoveries to be made.’

In the paper, published in the journal Royal Society Open Science, the researchers said the name Invictibellatrix was intended 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’.

Amberina, meanwhile, refers to the amber found in the rocks where the fossil was discovered, as well as to the female name.