[Phylogeny of the jaw].
Since primary life appeared in the sea about 3.8 billion years ago, the Agnatha improved a part of the respiratory organ, or brachial arch into the jaw during the evolutionary process. The resulting Gnathostomata could catch bigger fish by using the strong jaw. In addition, they developed specific sensory organs in the head, including nose, eyes and ears for detecting position of diets, brain for treating the sensory information, and muscles for masticating foods. Such development of jaw from the brachial arch had an important meaning in the evolutional history of organisms.
Takahashi
Kenichi
K
Osaka Prefecture College of Health Sciences.
D000818:Animals; D005075:Biological Evolution; D006801:Humans; D007448:Invertebrates; D007568:Jaw / Q000033:anatomy & histology* / Q000502:physiology; D010802:Phylogeny; D014714:Vertebrates