Chilomycterus (burrfish) mouth plate a.JPG
Chilomycterus (burrfish) mouth plate
SITE LOCATION: Pungo River or Yorktown Formation, Aurora, Beaufort Co., North Carolina, USA
TIME PERIOD: Miocene age (5.3-23 Million Years Ago)
Data: Chilomycterus is a genus of diodontid tetraodontiform fishes commonly called "burrfish." The burrfish resembles the puffer in the positions of its dorsal and anal fins, but its skin is armed with short, stout, triangular spines instead of being merely prickly. These spines are sparsely scattered all over the trunk, with about 9 or 10 from nose to tail along any given line. Furthermore, the burrfish is oval in outline, not fusiform like the puffer; the openings of its nostrils are prolonged in a single tubular tentacle; its bony jaw plates are not divided by a median suture as they are in the puffer, hence each jaw apparently is armed with a single very broad incisor tooth instead of with two; the pectoral fins are not only much larger than in the puffer but their upper edge is level with the upper corner of the gill openings in the burrfish (considerable below it in the puffers); its eye is round, not oval; and its anal fin is below the dorsal, not behind the latter. We need only add that the soft dorsal and anal fins (it has no spiny dorsal) are both rounded, each has 10 to 12 rays; the caudal fin is very narrow and round-tipped; the pectorals are much broader than long, and there are no ventral fins.