From wee rex to T. Rex: meet the horse-sized ancestor of prehistory’s most famous predator

Fossils unearthed in northern Uzbekistan’s remote Kyzylkum Desert of a smaller, older cousin of Tyrannosaurus rex are showing that the modest forerunners of that famous brute had already acquired the sophisticated brain and senses that helped make it such a horrifying predator.

Researchers said on Monday the horse-sized Cretaceous Period dinosaur, named Timurlengia euotica, that roamed Central Asia 90 million years ago sheds new light on the lineage called tyrannosaurs that culminated with T. rex, which stalked North America more than 20 million years later.

The researchers used CT scans to look inside Timurlengia’s braincase and digitally reconstruct its brain, sinuses, nerves, blood vessels and inner ear. The make-up of the inner ear indicated Timurlengia, like T. rex, excelled at hearing lower frequency sounds.

Timurlengia was relatively small but boasted the advanced brain and senses of the colossal apex predators like Tyrannosaurus rex that lived at the end of the dinosaur age, paleontologist Steve Brusatte of Scotland’s University of Edinburgh said. “This tells us that tyrannosaurs got smart before they got big.”

These traits came in handy when tyrannosaurs had the opportunity to rise to the top of the food chain and become very big after other large dinosaur predator groups disappeared.

Timurlengia, named for 14th century Central Asian conqueror Tamerlane, was only 3-4 metres long and about 270kg. T. rex reached about 13 metres long and weighed 7 tonnes.