Researchers revealed that a fossilised femur bone left forgotten in a drawer at the Museum of Geology and Palaeontology in Palermo, Italy belonged to an abelisaur, a carnivorous dinosaur that lived 95 million years ago. The analysis published in the journal Peer J. on Feb. 29 showed that the dinosaur is one of the largest abelisaurs found, which grew nine metres in length  and weighed between one and two tonnes.

Researchers Alessandro Chiarenza, a Ph.D. student from Imperial College London, and Andrea Cau from the University of Bologna, add that the discovery helps scientists to figure out how big these dinosaurs grew. They explain that the Abelisauridae were a group of predatory dinosaurs from North Africa that were covered in feathers, had tiny forelimbs, a short deep face, small sharp teeth and powerful muscular hind limbs.

Imperial College London/Davide Bonadonna

Imperial College London/Davide Bonadonna

“Smaller abelisaur fossils have been previously found by palaeontologists, but this find shows how truly huge these flesh eating predators had become,” says Chiarenza. ”Their appearance may have looked a bit odd as they were probably covered in feathers with tiny, useless forelimbs, but make no mistake, they were fearsome killers in their time.”

The fossil was found in the Kem Kem Beds in Morocco where scientists found many giant predatory dinosaur fossils in 1912. The researchers explain that these dinosaurs did not live so closely with each other. The geological changes over time give the illusion that abelisaurs and other predatory dinosaurs shared the same land at the same time.

“While palaeontologists usually venture to remote and inaccessible locations like the deserts of Mongolia or the Badlands of Montana, our study shows how museums still play an important role in preserving specimens of primary scientific value, in which sometimes the most unexpected surprises can be discovered,” notes Cau.

The researchers say they will search for the dinosaur’s more complete remains so they could know more about its environment and evolutionary history.