A new analysis of a dinosaur skull recovered from an English reservoir in 1910 has concluded it is the oldest-known relative of Tyrannosaurus Rex.

Initially named Megalosaurus bradleyi, the skull was later relabelled as Proceratosaurus.

“Although this specimen is still one of the most complete and best preserved theropod skulls from, and one of very few theropod skulls from the Middle Jurassic globally, it has received surprisingly little attention in recent literature,” write Oliver Rauthhut, Angela Milner and Scott Moore-Fay in the Zoological Journal of the Linnean Society.

To deal with this lack of attention, the researchers cleaned away rock from the fossil and subjected it to CT scans. Their conclusion: the 3-metre long beast was probably a 165-million-year old ancestor of the most iconic of dinosaurs.

“It was quite a surprise when our analysis showed we had the oldest known relative of T. rex,” says Milner, of London’s Natural History Museum (press release).

Image: NHM