A Chinese-American team of paleontologists has unveiled the most primitive tyrannosauroid dinosaur known. The 3-meter-long predator hardly resembles its later descendent, Tyrannosaurus rex. For starters, it's much smaller and has full-size arms. The biggest surprise was a large, thin crest on its head, perhaps used as a display. The pair of roughly 160-million-year-old fossils were found in northwest China and described in the 9 February issue of Nature.

The first fossil of a gliding lizard has been found in northeastern China, and judging by its wing design, it was an ace. Rather than using modified forelimbs for powered flight (as contemporary pterodactyls did), 15-centimeter-long Xianglong zhaoi sailed with a pair of webby wings built on supersized ribs, leaving its limbs free for grabbing and climbing trees, researchers report online the week of 19 March in Proceedings of the National Academy of Sciences. Despite its fine features, the 100-million-year-old glider seems to have been an early experiment: birds, which would soon dominate the skies, grew wings from their forelimbs, and the only gliding reptile around today, the draco lizard, has wings that are less aerodynamic.