A UCL-led team used CT scans to identify a tiger-sized Early Cretaceous predator from the Isle of Wight, filling a gap in our understanding of how megaraptoran dinosaurs reached the southern continents.

A partial dinosaur skull that sat largely unstudied at London's Natural History Museum for about a century belongs to a previously unknown predator, Invictibellatrix amberina, researchers reported Oct. 14 in Royal Society Open Science. The animal lived on what is now the Isle of Wight about 120 million years ago and is the first megaraptoran ever identified in Europe, according to University College London.

Megaraptorans were two-legged meat-eaters related to tyrannosaurs, but they hunted differently. Instead of relying on massive jaws, they had narrow skulls, powerful arms, and huge curved hand claws for seizing prey.

The find matters beyond one new name. It supplies the missing European link in a proposed migration route, and it shows how much science can still emerge from specimens already sitting in museum drawers.

A Century in a Museum Drawer

The fossil was collected by amateur paleontologist Reginald Walter Tooley near the base of a cliff on the island's southwestern coast. Tooley gathered more than 1,000 specimens in his lifetime, and the museum acquired his collection after he died in 1924, the Natural History Museum said.

The specimen is a piece of the back of the skull, from rock of the Lower Cretaceous Wessex Formation. Its significance went unrecognized for generations until lead author Dr. Cassius Morrison of UCL Earth Sciences and colleagues examined it.

The name means "unconquered female warrior," a nod to the giant predators that later evolved in this lineage. The species name, amberina, honors both the amber found in the fossil's rock layers and the female name Amberina.

Natural History Museum senior author Professor Paul Barrett said the island "continues to surprise us with new dinosaur species," according to Euronews. He noted that carnivorous dinosaur finds there have been especially rare.

CT Scans and Claws Up to 8 Inches

The team CT-scanned the fragment to build a 3D model of the skull piece and its inner cavity, which once housed the brain. Two features stood out: an oval opening where the spinal cord met the brain and a distinctive hourglass-shaped crest. Comparisons with tyrannosaurs, spinosaurs, raptors and other predators, plus computer analyses of shared traits, consistently placed the animal among megaraptorans.

Based on its closest relatives, Morrison estimates Invictibellatrix was 3 to 4 meters (about 10 to 13 feet) long and just over 1.5 meters (about 5 feet) tall. It likely had feathers, and its claws may have measured about 10 to 20 centimeters (4 to 8 inches). It probably ate small dinosaurs, lizards and mammals, filling a role similar to a hyena's.

It was not the top predator of its ecosystem — the study's artwork depicts a spinosaurid as the likely apex predator of the time.

Morrison made a pointed comparison. For humans, he said, this dinosaur "would have been more dangerous than a T. rex," ITV News reported, because a person would have been well-sized prey for it and too small to interest a giant tyrannosaur. Humans and non-bird dinosaurs never lived at the same time; the comparison is a way to picture the animal's size and hunting role.

A Missing Link on the Road to Gondwana

Scientists have long suspected that megaraptorans arose in Asia, spread through Europe and then reached Gondwana, the southern supercontinent that included today's Africa, South America and Antarctica. The problem was that no European fossils existed to support that route.

Invictibellatrix fills that gap. Co-author Charlie Scherer, a UCL PhD student, said the species offers the first proof that megaraptorans were present in Europe and reached the south that way rather than by island-hopping farther south.

The team's models suggest megaraptorans were widespread during the Early Cretaceous but had likely vanished from the northern supercontinent of Laurasia by the Late Cretaceous. In the south they thrived and grew huge. Some had claws up to 35 centimeters (14 inches), and Maip macrothorax of Argentina reached an estimated 9 to 10 meters, or about 30 to 33 feet. Why they disappeared from the north remains unknown; climate shifts and competition from tyrannosaurs are among the possibilities.

Weighing the Evidence

This is a peer-reviewed study in an open-access journal, built on one partial braincase. Body length, height, feathers and claw size are estimates drawn from related species, not measurements from this skeleton. The classification rests on statistical comparisons that could shift as more megaraptoran fossils turn up.

The study's broader migration conclusions are model-based reconstructions of ancient geography and climate, so they describe the most likely path rather than a proven one. The work was funded by the Palaeontographical Society, the Royal Society and UK Research and Innovation, with no commercial ties disclosed in the university's release.

For readers, the takeaway is less about danger and more about discovery — museum collections around the world, including in the United States, hold specimens catalogued decades ago with tools far simpler than today's CT scanners. Reexamining them is one of the fastest ways to add species to the fossil record.

The full paper is available through Royal Society Open Science. Nature World News will follow any additional Isle of Wight finds or new megaraptoran material that tests the team's conclusions.

The bottom line: a skull fragment stored since 1924 now places megaraptorans in Europe for the first time. More fossils will be needed to confirm how these giant-clawed hunters spread across the ancient world.

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What Readers Want to Know

What is Invictibellatrix amberina?

It is a newly named megaraptoran dinosaur from the Isle of Wight that lived about 120 million years ago, identified from a partial skull.

Why was the fossil overlooked for so long?

It entered the Natural History Museum's collection in 1924 and was not studied in detail until researchers examined it with modern CT scanning.

How big was it?

Researchers estimate 10 to 13 feet long and about 5 feet tall, roughly the size of a large tiger.

What are megaraptorans?

They are tyrannosaur relatives with narrow skulls, strong arms and large curved hand claws used to seize prey.

Was it really more dangerous than T. rex?

Lead author Cassius Morrison said it would have been more dangerous to humans because people would have been suitable prey. Humans never lived alongside these dinosaurs.

Why does this discovery matter?

It is the first evidence of megaraptorans in Europe and supports the idea that they reached the southern continents through Europe.