GEOL 1003 Chapter : GEOLOGY EXAM 4 Ch 16
Document Summary
16 the early mesozoic era: triassic and jurassic periods. 100(successful recovery!: brachiopods, diversified in early mesozoic. Swimming predators: evolved rapidly: 1million yr species range= good early mesozoic guide fossils, belemnoids, an extinct group of marine mollusks that were related to ammonoids, belemnoid=greek for dart or arrow. Swimming predators that resembled squid-- jet propulsion used for movement: the dark was an internal hard part that controlled bouyancy, most abundant during triassic and jurassic, conodonts. Small fish-like vertebrates: teeth of conodont fish are called conodonts, common in triassic rock and mark as guide for sections, by jurassic time, conodonts disappeared, ray-fish in the early mesozoic seas. Scales barely overlapped and were diamond shaped: more modern evolved appearance, tail had an asymmetrical support with a distinctive upturned spinal column, many ray-fin had peg-like teeth adapted to crush shell fish. Jaw was relatively simple: early mesozoic sharks. Sharks were well represented in early mesozoic seas.
