It consists of four cartilaginous bones completely fused together and encircling a large passage, the foramen magnum, through which spinal cord comes out. It is the hindermost part of the cranium. The various bones constituting the cranium can be grouped into three segments, a posterior occipital segment, middle parietal segment and anterior frontal segment. Visceral skeleton includes the upper and lower jaws and hyoid apparatus. Sense capsules (olfactory, auditory and orbital) closely attached with the cranium, andģ. The skull of the rabbit can be divided into:Ģ. Canines are absent leaving a space, called diastema. Teeth are diphyodont (milk and permanent) and heterodont (different types). Premaxillae, maxillae and dentaries bear the thecondont teeth (teeth embedded in sockets). Prefrontal, postfrontal, parasphenoid and quadratojugal are lacking. Jaws suspensorium is craniostylic, i.e., dentary, articulates with the cranium (skull) by squamosal.ġ3.
Only a single bone, the dentary, forms one half of the lower jaw.ġ2.
Turbinal bones are much folded and, thus, increases the olfactory surface of nasal chambers.ġ1. Otic bones, prootic, epiotic and opisthotic, are fused to form a single periotic.ġ0. The articular and quadrate of the jaws become separated and free, and form malleus and incus respectively (two ear-ossicles of the three). The auditory capsules are formed by the union of periotic and tympanic forming a swollen tympanic bulla.Ĩ.
0 kommentar(er)
