Examining the patterns of the appearance and disappearance of characters is the key to figuring out the relatedness of organisms. Related species share a common ancestor and thus will share some common features.
The illustrations of Deinonychus and Gallus (a chicken) show typical skeletons for an advanced non-avian theropod and a modern bird. Use these interactive illustrations to examine the skeletal characters of the two specimens and compare similar features.
Few fossil dinosaur bones are white. Minerals that precipitate out of the ground water affect the color of the bone. Any color is possible. Sometimes the coloration can even vary on a single specimen. The bones in the chicken skeleton are white, first, because they are not fossils, and secondly, because they have been bleached. The non-avian bones are all fossils or casts of fossils but from a variety of related specimens.
To look at this interactive illustration, move your cursor over any circle to reveal a close-up of this feature on both specimens. Click once on the featured circle to see photos of real bones and a brief description of the character and the similarity of the character between the two specimens.