NEXT

DEVONIAN PERIOD

416-359 million years ago

HOME
PREVIOUS
skeleton

Ichthyostega's skeleton was a mix of primitive and derived characteristics.

Ichthyostega is a more advanced amphibian from the Upper Devonian. It still retained some primitive features such as a prominent notochord and 2 opercular bones of the skull. The pelvis of Ichthyostega was attached to the vertebral column and was composed of the same three separate bones found in all later tetrapod pelvises: the ilium, ischium, and pubis. (Although in adult humans there is only one "hip bone" or os coxa, fetal humans a have completely separate ilium, ischium, and pubis which fuse later in life to form each hip bone. Many parts of the adult hip still carry these original names such as the iliac crest, ischial tuberosity, and pubic symphysis.)

leg

hip