The basic shapes are always present in the anatomy of an animal. You must study your subject carefully and identify these basic shapes before you begin to draw. This will make your drawing more accurate.
This diagram shows how important the basic shapes are. You can clearly see the cylinder and the egg repeated in the anatomy of the deer. Understanding these shapes will make your drawing appear much more dimensional and realistic.
The close-up study of an antler shows how the rendering can turn a basic cylinder into a believable object. The antler closely resembles the trunk of a tree. They are both made up of cylinders. The process for drawing them is identical. Draw this in your segment drawing notebook.
The egg shape is obvious in the jaw of the deer. The shadows and reflected light created with the five elements of shading make it look curved. The proper placement of the reflected light and shadows gives a subject dimension and realistic form.