Fossilized Braincase Identified on the Isle of Wight as Europe’s First Megaraptoran Dinosaur
A fossilized braincase sitting in the Natural History Museum in London collection for a century has been identified as Europe’s first megaraptoran dinosaur, a lineage previously believed to have flourished primarily in the southern hemisphere. University College London paleontologist Cassius Morrison and colleagues described the specimen in a study published in Royal Society Open Science, revealing that the animal roamed Earth approximately 120 million years ago during the Early Cretaceous period.
Discovered at the base of a cliff located at Sudmoor Point close to Brook along the southwestern shoreline of the Isle of Wight, the specimen was acquired from Rev. R. W. Hooley in May 1924, and it is from the Barremian-aged strata of the Wessex Formation and has never been formally described.
Size Comparisons and Physical Characteristics of Invictibellatrix amberina
Named Invictibellatrix amberina, the newly identified species belongs to a group of agile, two-legged carnivores known as megaraptorans. The braincase of Invictibellatrix amberina matches the size of Timurlengia, a small tyrannosauroid estimated to weigh between 200 and 300 kg and measure no more than 4 meters long, leading researchers to conclude the new species possessed a comparable size. While other megaraptorans reached lengths of 6 to 10 meters or more and weighed upwards of 2,000 kg, this specimen stands as one of the smallest known members of its group, reinforcing the theory that megaraptorans evolved their massive body sizes relatively late.
Based on what we know about its closest relatives, Invictibellatrix would have been 3-4 m long and just over a 1.5 m in height — about as tall as a human,
Dr. Morrison stated. The animal likely featured feathers alongside claws measuring roughly 10 to 20 cm in length. Its ecological niche mirrored that of the modern hyena, feeding on small dinosaurs, lizards, and mammals. It was not the apex predator of its time, but for humans this dinosaur would have been more dangerous than a Tyrannosaurus rex. We would have been perfectly sized prey, about a third of their body weight. They definitely would have chased us. A Tyrannosaurus rex would not have bothered, as we would have been too small,
Dr. Morrison explained.
Biogeographical Implications for Early Cretaceous Migration
The best-known members of the Megaraptora, such as Megaraptor and Australovenator, hail from South America and Australia, with the earliest southern hemisphere fossils dating younger than the Isle of Wight specimen. The global distribution of megaraptorans during the early stages of the Cretaceous period aligns seamlessly with the characteristics of Invictibellatrix amberina.
Researchers propose that the group originated in Asia, arrived in Europe by approximately 130 million years ago, and subsequently migrated through Africa into the southern continents. Charlie Scherer, a Ph.D. student at University College London, noted that the discovery provides evidence that megaraptorans were present in Europe and that they reached Gondwana this way rather than island-hopping further south.
Frequently Asked Questions About Invictibellatrix amberina
When and where was the Invictibellatrix amberina fossil discovered?
The fossilized braincase was recovered from the foot of a cliff at Sudmoor Point on the southwest coast of the Isle of Wight. It was purchased by the Natural History Museum in London from Rev. R. W. Hooley in May 1924.
What geological formation yielded the megaraptoran fossil?
The specimen is from the Barremian-aged strata of the Wessex Formation, dating back approximately 120 million years to the Early Cretaceous.
How does the size of Invictibellatrix amberina compare to other megaraptorans?
Measuring 3 to 4 meters long and standing just over 1.5 meters tall, Invictibellatrix amberina is one of the smallest known megaraptorans, contrasting with other megaraptorans thought to have reached 6 to 10 meters or more and to have weighed over 2,000 kg.
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