Frog : Skull

• Skull is the skeleton of the head region. The skull of frog has six regions, namely cranium, auditory capsules, olfactory capsules, upper jaw, lower jaw and hyoid apparatus.

• Cranium or brain – case, is a bony casket that encloses the brain. At its posterior end is an opening called foramen magnum. Through this the spinal cord leads out from the brain.

• Auditory capsules enclose the internal ears. Olfactory capsules (nasal capsules) encloses the organ of smell.

• Upper jaw forms an arch around the cranium, known as maxillary arch. Each half of it is united with cranium in front and behind. In middle it is separated from the cranium by a wide space called orbit, where eye ball is lodged in this space.

• Lower jaw also forms an arch, known as mandibular arch. Teeth are absent on the lower jaw.

• Hyoid apparatus is a vestigial structure. It represents the remnant of the branchial (pharyngeal) skeleton of the larva. It is seen on the buccal floor. It provides the surface for the attachment of tongue.