What is a Defining Characteristic of Members of the Class

Question

What is a defining characteristic of members of the Class Testudines?
A)They lack limbs.
B)They have a hard shell.
C)They have a kinetic skull.
D)They have a four-chambered heart.

Accepted Answer

The defining characteristic of members of the Class Testudines is that they have a hard shell. This shell is composed of two main parts: the upper carapace and the lower plastron.