Sometime before 1924, an amateur fossil hunter named Reginald Walter Hooley picked up a worn piece of bone at the foot of a cliff at Sudmoor Point, on the southwest coast of England’s Isle of Wight. After his death, London’s Natural History Museum bought it in May 1924. A study published on October 14, 2026, says that piece of bone is a new dinosaur species, and the first megaraptoran ever found in Europe.
The fossil then sat in the museum’s collections for decades. According to the museum, it “was acquired by the Natural History Museum in 1924 and had been overlooked for study until now.”
The team named the animal Invictibellatrix amberina. It lived about 120 million years ago, in the Early Cretaceous. “It is a real mystery that this fossil was overlooked for so long, sitting in a drawer for nearly 100 years,” lead author Dr. Cassius Morrison of UCL Earth Sciences said in the Natural History Museum’s announcement.
Small heads, long arms and huge claws
“Megaraptors are regarded as the most mysterious of the large, meat-eating dinosaurs, as few megaraptor fossils have been found,” the museum said. Megaraptorans belong to the theropods, the group that includes every meat-eating dinosaur, and the museum says they “were closely related to tyrannosaurs including Tyrannosaurus rex but had slender heads, attacking prey with their large arms and giant curved claws instead of their jaws.”
Later in the Cretaceous, according to the museum, megaraptors “became apex predators throughout Gondwana in the south, reaching gigantic sizes, with claws up to 35cm (14in) long.” Invictibellatrix means “unconquered female warrior,” a nod to that future role.
The size of a tiger, and a danger to people
“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,” Morrison said in the museum’s release. That is about 10 to 13 feet long and 5 feet tall.
“It would likely have had feathers and its claws might have been about 10cm to 20cm long,” he added, roughly 4 to 8 inches. “It would have eaten small dinosaurs, lizards and mammals,” filling “a similar role in the food chain to the hyena today.”
Morrison also took on the question everyone asks. “It was not the apex predator of its time, but for humans this dinosaur would have been more dangerous than a T. rex. We would have been perfectly sized prey, about a third of their body weight. They definitely would have chased us,” he said.
Scientists estimate that about 2.5 billion T. rex once lived in North America. In the museum’s release, Morrison put it simply. “A T. rex would not have bothered, as we would have been too small.”
What the drawer was hiding
The fossil, numbered NHMUK PV R6775, is a partial braincase, the box of bone at the back of the skull that held the brain. The authors call it “a beach-rolled, rather poorly preserved and incomplete braincase,” and they say it “has never been formally described.”
“For the study, researchers undertook a CT scan of the fossil, creating a 3D model of this part of the skull as well as a model of the interior of the skull, i.e. the brain,” the museum said. What settled it was “a unique combination of skull features, including an oval hole where the spinal cord entered the brain and an hour-glass-shaped crest.”
The bones of the braincase are fused so tightly that “the sutures between the individual bones are not visible, even in the µCT scans, indicating that the individual is at least a sub-adult,” the paper says. The braincase is also “similar in size to the corresponding region in Timurlengia euotica,” which points to an animal of roughly 440 to 660 pounds (200 to 300 kilograms).
Other megaraptorans reached 20 to more than 33 feet (6 to 10+ meters), so the authors write that this “would make Invictibellatrix among the smallest, if not the smallest, megaraptoran discovered so far.”
A missing stop on the route south
Megaraptorans “are thought to have originated in Asia, before migrating through Europe and becoming apex predators throughout the southern land mass of Gondwana,” according to the museum. “But until now, this theory was missing key fossil evidence, as no megaraptorans had been found in Europe.”
“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,” Scherer said in the UCL release.
The paper’s own summary is that the animal “likely evolved from an Asian megaraptoran population, before dispersing into European biotas,” and that “regional extinctions of megaraptorans in the Late Cretaceous of Laurasia led to the observed range contraction of the group, with only Gondwanan megaraptorids surviving.”
Why they died out in the north is still open. “The study did not explain why megaraptors likely died out in the north, but this may have been a result of shifts in climate or environment, or the presence of competing predators such as other tyrannosaurs,” the museum said.
Museum collections still hold surprises
The bone “was one of more than 1,000 specimens” from the same collector “that were acquired by the Natural History Museum after his death,” the museum said. The museum’s release spells his name Tooley, but the paper records the purchase from R. W. Hooley. Professor Paul Barrett of the Natural History Museum, the study’s senior author, thinks there is more where it came from.
“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,” Barrett said. “Work like this shows the exceptional value of working with historical museum collections where there are still many discoveries to be made.”
The paper makes the same point. “As Wealden Supergroup theropod remains have not always been studied in detail, it is possible that some of the unnamed specimens present in museum collections might represent additional taxa,” the authors write. It has happened with a fossil from Antarctica that sat in a museum drawer for 40 years and with a pangolin collected in 1836.
The name carries a dedication, too. It is meant “to give hope and strength to all those who are bullied, discriminated, victimized and oppressed that tomorrow will be theirs and not to give up in the face of such odds,” the authors write. The species name, amberina, refers to the amber in the rocks of the Wessex Formation.
One braincase leaves open questions
Length, claws and feathers all come from relatives, because the fossil has no limbs, teeth or claws. “The precise horizon from which NHMUK PV R6775 was collected is unknown,” the paper says, meaning nobody knows exactly which rock layer it came out of, although the authors think the lower plant debris beds at Sudmoor Point are the most likely source.
The family tree is not settled either. The authors refrain from calling the group “megaraptoran tyrannosauroids” because it “fails to highlight the phylogenetic uncertainty regarding the taxonomic affinities of Megaraptora among tetanurans.” On the lineage’s origin, they write that “overall, our analyses are ambiguous as to the biogeographic origins of Invictibellatrix.”
The full study was published in Royal Society Open Science.
For Morrison, the island is not done yet. “Lots of bones are found on the Isle of Wight,” he said, and “who knows what else is waiting to be discovered.”
Image: Sergey Krasovskiy and Pedro Salas
