Some of the features of an animal are scales,teeth, nares, and backbone. The ani...

•  cold-blooded ness;
• The teeth of reptiles are also less specialized in function than are mammalian teeth.
• a dry skin with scales but not feathers (a characteristic of birds) or hair (a characteristic of mammals);

NB: Birds do not have teeth, although they may have ridges on their bills that help them grip food.

       Birds swallow their food whole, and their gizzard (a muscular part of their stomach) grinds up the food so they can digest it.