A Fossil Left in a Museum Drawer for a Century Is a New Meat-Eating Dinosaur

A fragment of dinosaur skull that sat largely unnoticed in a drawer at London’s Natural History Museum for about 100 years has been identified as a previously unknown species of predator, researchers reported this week.

The animal, named Invictibellatrix amberina, lived about 120 million years ago on what is now the Isle of Wight, off England’s southern coast. The museum acquired the fossil, a partial braincase, in 1924. It was stored away until a couple of years ago, when researchers took a fresh look. The findings were published in the journal Royal Society Open Science.

Invictibellatrix belongs to the megaraptorans, a group of carnivorous dinosaurs from the Cretaceous period known for long, powerful arms and enormous hand claws, which they likely used to seize prey. That set them apart from Tyrannosaurus rex, which relied on its head and crushing bite. The new species walked on two legs and was described in news coverage as a relative of T. rex.

By megaraptoran standards it was small: about 10 to 13 feet long, according to the researchers, and roughly the weight of a large tiger, making it one of the smallest members of the group yet found. The researchers think its body may have been covered in filament-like feathers.

The lead author, Cassius Morrison of University College London’s earth sciences department, worked with co-author Charlie Scherer, a doctoral student at the same university. Beyond adding a new name to the dinosaur family tree, the fossil fills in details of what early megaraptoran skulls looked like, a part of their anatomy that has been poorly known.

Its location may matter most. Invictibellatrix is the first megaraptoran known from Europe. Its discovery supports the hypothesis that the group spread from Asia through Europe to Africa and then to South America, at a time when the continents were arranged very differently than they are today.

Some caution is warranted. The species is based on a single partial skull, so estimates of its size, appearance and exact place in the family tree are inferences that later discoveries could revise. Still, the find is a reminder of how much may be waiting in museum collections, where specimens gathered generations ago can yield new answers when examined with modern methods.

For the Natural History Museum, the identification turns a long-overlooked specimen into a named species, nearly a century after it first entered the collection.