T. rex was no lumbering brute, medical scans show

Although soft tissues cannot survive millions of years of fossilised preservation, scientists are beginning to piece together the muscles, nerves and sinews that enabled T. rex to become the top predator.

Medical scanners have enabled scientists to gain deeper insights into the soft body parts that are key to understanding the behaviour and movements of dinosaurs, Professor Lawrence Witner of the Ohio University College of Osteopathic Medicine said.

"We're now at a point where we're starting to put a lot of pieces together. We can begin to flesh these animals out in the literal sense and start to get an integrated picture of dinosaur sensory biology."

Scientists compared the braincases of T. rex and diplodocus, a large herbivorous dinosaur, and found the predator probably had well-developed senses of smell, sight and balance.

"What we see in T. rex is very different to diplod-ocus," Professor Witner said. "We see an inner ear - the organ of balance - that is associated with a much smaller, more highly agile animal. T. rex is a gigantic animal and we might have expected its inner ear to be more like that of diplodocus.

"This may show that T. rex had a heightened sense of equilibrium and balance and was able to employ relatively rapid turning movements of its eyes and its head," he told the American Association for the Advancement of Science.

T. rex had a tiny brain in proportion to its body. Scans of the inner lining also showed its brain was not extensively folded, like the brains of modern mammals.

But Professor Witner said T. rex's brain had a relatively large olfactory centre indicating it had a good sense of smell. It was also able to move its eyes quickly from side to side to follow rapidly moving prey.