Schizaster armiger
This species typifies the colloquial name for the spatangoid echinoids - 'heart urchins'. It is an easy species to recognize because of its deeply impressed ambulacra. The anterior one is indented across the front margin, giving the shell a heart-shaped outline. There is another, similar species of Schizaster known from the Oligocene of the southeast, but it has been found only once in Georgia, near Hawkinsville.
Schizaster armiger is known only from the middle and upper part of the Ocala Limestone in Georgia.
The form of the shell unequivocally indicates a preference for muddy sediments, and the species is typically found in rocks of this type.
AGE: LATE EOCENE
FORMATION: OCALA LIMESTONE