The scaly, green Tyrannosaurus rex of monster movies is history. The real T. rex was probably covered in a fine feathery fuzz, as were most of the dinosaurs in its family, known as the theropods, which later gave rise to birds. Rich fossil beds in northeastern China have yielded specimens confirming that a wide variety of strictly earthbound dinosaurs sported feathers during the Cretaceous period, some 125 million years ago.