Deer antlers also grow very quickly. A deer's main antler beams are known to grown as much as 15 mm per day. Both horns and antlers are actually extended growths of the frontal skull plate. The core of the horn is a part of this frontal bone. Antlers grow from a part of this frontal bone at a point called the pedicel.
Antlers are true bones and are composed of calcium and phosphorous.
Unlike most mammal bones, they are solid and without marrow. Newborn male deer have two swirls of hair on their foreheads showing where the antlers will form as they get older. When he is only two or three months old, bony knobs, the pedicels, start to form on the young buck's forehead. It is from these bases that the antlers grow. At five or six months, the pedicels are about 19 to 25 mm long and are easily visible.