the dorsal part of a turtle's shell is called the
Turtle shell The carapace is the dorsal (back), convex part of the shell structure of a turtle, consisting of the animal's ossified ribs fused with the dermal bone. The spine and expanded ribs are fused through ossification to dermal plates beneath the skin to form a hard shell. Exterior to the skin the shell is covered by scutes, which are horny plates made of keratin that protect the shell from scrapes and bruises. A keel, a ridge that runs from front to the back of the animal is present in some species, these may be single, paired or even three rows of them. In most turtles the shell is relatively uniform in structure, species variation in general shape and color being the main differences. However the soft shell turtles, pig-nose turtles and the leatherback sea turtle have lost the scutes and reduced the ossification of the shell. This leaves the shell covered only by skin.[11] These are all highly aquatic forms.