BIO 1130 Study Guide - Final Guide: Fish Scale, Dentin, Gie

• School: University of Ottawa
• Department: Biology
• Course: BIO 1130
• Professor: Jon Houseman

Document Summary

Armoured fishes fish make their appearance they don"t look like anything we see today instead of having scales they had bony plates (armour) for protection. Pharynx used to draw water with food particles into their mouths and gills used to filter the food from the water lacked a true vertebral column. Vertebrate characteristic- 3 regions in brain (fore, mid, hind) Appeared in silurian, diversified in devonian and carboniferous. Bodies covered with large, heavy plates of bone anteriorly and smaller scales posteriorly jaws had sharp cutting edges but no separate teeth. Jawless fishes feed on sides of large fish (lamprey did this) Hagfish, lamprey,ostracoderm fed by ramming food in their mouth. Evolution of the jaw jaws evolved from paired gill arches in the pharynx of a jawless ancestor. One pair of ancestral gill arches formed bones in the upper and lower jaws, whereas a second pair was transformed into the hyomandibular bones that braced the jaws against the cranium.