Interparietal Bone of Domestic Animals

The interparietal bone is a small cranial bone located in the upper back portion of the skull. Its structure, presence, and fusion vary among domestic animals, making it important in veterinary comparative anatomy and skull morphology studies.

Interparietal Bone of Ox

The interparietal bone of the ox is a single bone located in the posterosuperior part of the cranium. It is paired in the fetus, wedged between the parietal bones above and the supraoccipital below, and fuses with these bones before or shortly after birth.

The frontal sinus extends into it in the adult.

Comparative Anatomy of Interparietal

The interparietal shows notable variation among domestic animals in terms of its presence, structure, and degree of fusion.

Horse

• The interparietal of the horse is located on the dorsal aspect of the cranium.
• The external surface is quadrilateral, smooth, and presents the sagittal parietal crest.
• The internal surface presents a three-sided process—the internal occipital protuberance or the ossific tentorium.

Dog

• The location of the interparietal in the dog is similar to that of the horse.
• It fuses with the occipital bone before birth.
• It bears the high posterior part of the parietal crest.
• The ossific tentorium is of considerable size.

Fowl

• Interparietal is absent in fowl.