Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.
The most primitive tyrannosauroid yet discovered, described this week in Nature, has revealed the basic blueprint from which Tyrannosaurus rex and its kin evolved.