 The early 1990s saw the discovery of spectacularly preserved bird fossils in several Early Cretaceous geological formations in the northeastern Chinese province of Liaoning.In 1996, Chinese paleontologists described "Sinosauropteryx" as a new genus of bird from the Yixian Formation, but this animal was quickly recognized as a more basal theropod dinosaur closely related to "Compsognathus".Surprisingly, its body was covered by long filamentous structures.