A new species of tyrannosaur adds to the fearsome group of dinosaurs to which Tyrannosaurus rex belonged. Scientists found its 90-million-year-old bones in the harsh deserts of Uzbekistan.

The newly described species, Timurlengia euotica, is an oddball. The horse-sized dinosaur resembles earlier, smaller tyrannosaurs. Yet its large brain and advanced ears—their outlines preserved in a skull fragment—mirror those of later tyrannosaurs like T. rex.

“Timurlengia is truly a curveball,” says Thomas Carr of Carthage College, who wasn’t involved with the study. “I had to readjust the way I thought about tyrannosaurs. It’s a weirdo.”

The new species, described Monday in the Proceedings of the National Academy of Sciences,  could also help untangle one of the most frustrating questions in dinosaur