Key Developments

A previously unknown dinosaur species, named Invictibellatrix amberina, has been identified from a fossil that remained hidden in a British museum for nearly 100 years. Described as a "long-clawed predator the size of a tiger," this new species is a cousin of the Tyrannosaurus rex, belonging to a group of two-legged carnivores known as megaraptorans. Unlike its more famous relative, Invictibellatrix is believed to have attacked its prey not with its mouth, but with its powerful long arms and giant curved claws.

Researchers, led by Dr. Cassius Morrison of University College London, estimate the dinosaur would have measured between 10 and 13 feet long and stood almost 5 feet tall. Its body was likely covered in feathers, and its diet would have consisted of smaller dinosaurs, lizards, and mammals. The fossil, a chunk from the back of a skull, was originally discovered by Reginald Walter Tooley on the Isle of Wight, off the south coast of England, in 1924. It was then acquired by the Natural History Museum in London, where it remained in a drawer until its recent re-examination.

The identification process involved taking a CT scan of the fossil to create a 3D model of the skull fragment. This model was then compared with the skulls of other two-legged meat-eating dinosaurs, including tyrannosaurs, spinosaurs, and raptors, revealing unique features that confirmed it as a new species. Invictibellatrix lived during the Early Cretaceous period, approximately 120 million years ago, and is considered one of the smallest and earliest known members of the megaraptoran group.

Key Takeaways

  • A new dinosaur species, Invictibellatrix amberina, a tiger-sized megaraptoran related to T. rex, has been identified from a fossil overlooked for 100 years.
  • Unlike T. rex, Invictibellatrix hunted with long arms and giant curved claws, not its mouth, and was feathered.
  • Researchers suggest this 120-million-year-old predator would have been a more dangerous threat to humans than a T. rex due to humans being "perfectly sized prey."

Why It Matters

The discovery of Invictibellatrix amberina highlights the ongoing potential for new scientific breakthroughs hidden within existing museum collections. Dr. Morrison noted it was a "real mystery that the fossil was overlooked for so long," underscoring the importance of re-examining historical specimens with modern technology. This identification provides valuable insights into the diversity and evolution of megaraptorans, a group closely related to tyrannosaurs, and helps to paint a more complete picture of the Early Cretaceous ecosystem. Furthermore, the unique hunting strategy of Invictibellatrix, relying on claws rather than jaws, offers a fascinating contrast to other large predators of its time and challenges previous assumptions about dinosaur predatory behavior.