like other member of the compsognathid family of theropods, Sinosauropteryx was a slender predator, with a long and pointed snout, that probably hunted for small vertebrate and invertebrate prey. what makes sinosauropteryx fossils so significant is the discovery of a covering of fuzzy proto-feathers-an extremely important discovery because of the evolutionary position of compsognathids in relation to birds. Subsequent findings proved that some of the later theropods that shared a common ancestor with compsognathids inherited the same feathery, meaning that even Tyrannosaurus and Velociraptor had feather of some kind.