Archaeopteryx

All described specimens of Sinosauropteryx preserve integumentary structures (filaments arising from the skin) which most palaeontologists interpret as very primitive type of feathers. These short, down-like filaments are preserved along the back half of the skull, the arms, neck, back, and top and bottom of the tail.

• Despite its feathers, most palaeontologists do not consider Sinosauropteryx to be a bird.
• There is only one named species of Sinosauropteryx, S. prima.