Size and Weight:
Sinosauropteryx was the first of a series of spectacular fossil discoveries made at the Liaoning Quarry in China starting in 1996. This was the first dinosaur to bear the unmistakable (if somewhat faint) imprint of primitive feathers, proving (as many paleontologists had previously speculated) that at least some small theropods looked uncannily like birds. (In a new development, an analysis of preserved pigment cells has determined that Sinosauropteryx had rings of orange and white feathers alternating down its long tail, kind of a like a tabby cat.)
Sinosauropteryx might be even more famous today if it hadn't been quickly superseded by numerous other Liaoning dino-birds, such as Sinornithosaurus and Incisivosaurus. Clearly, during the early Cretaceous period, this region of China was a hotbed of small, birdlike theropods, all of which shared the same territory.