New analysis of bone growth rings shows the'tyrant lizard king' grew very slowly. Breakthroughs, discoveries, and DIY tips sent six days a week. Based on the annual growth rings (like those on trees) within fossilized leg bones, scientists estimate that usually reach adulthood at around 25 years old. However, new research argues that their growth phase lasted significantly longer. They may have become fully grown--approximately eight tons--after 40 years.

If a Tyrannosaurus Rex living 66 million years ago featured a similar leg structure as an ostrich running in the savanna today, then we can assume bird legs stood the test of time – a good example of evolutionary selection. Graceful, elegant, powerful – flightless birds like the ostrich are a mechanical wonder. Ostriches, some of which weigh over 100kg, run through the savanna at up to 55km/h. The ostrich's outstanding locomotor performance is thought to be enabled by the animal's leg structure. Unlike humans, birds fold their feet back when pulling their legs up towards their bodies.

The inside of a tyrannosaur skull has clues about how the most famous dinosaur and its powerful teeth evolved, according to researchers who used 3D imaging to scan the fossil. They took a high-energy CT scan of a 74-million-year-old skull that came from a dinosaur dubbed the Bisti Beast, which was found in northwestern New Mexico about 20 years ago and is related to the Tyrannosaurus rex, the Los Alamos National Laboratory reported, calling the work the highest resolution scan scientists have ever taken of a tyrannosaur. The skull needed high-energy imaging because it is so thick and the work gave them a closer look at the skull structure, including in the sinus and the brain cavities. The scan revealed impacted teeth hidden in the jaw and the pathways that some nerves and blood vessels took in the 3.5-foot-long cranium. "The results add a new piece to the puzzle of how these bone-crushing top predators evolved over millions of years," the New Mexico laboratory said.