GEOL 1003 Lecture Notes - Actinopterygii, Dinosauromorpha, Dinos
Document Summary
Permian mass extinction allowed very few surviving organisms. Biota- mollusks, hexacorals (replace sponge & algae coral; modern framework builders; colonial. Ocean life- bivalves (most abundant), ammonoids (index fossil), brachiopods, urchins. Pelagic life- phytoplankton (dinoflagellates: protists, calcareous nanoplankton: chalk), conodonts (solely triassic), ray finned fish, sharks, marine reptiles (1st- nothosaurs, early crocs, lchthyosaur resembling dolphins, placodonts, plesiosaurs) Plant life- gymnosperms (conifers, ginkos), cycads & cycadeiods (resemble palm tree). Mass extinction causing most of the dinosaurs" competitors to disappear (therapsids). Caused by co2 increase b/c volcanism (pangea break up caused magma to surface), raise in temp. First carnivores appear 30 ka after end of extinction (dinos). Pterosaur: flying reptile, long wings, hallow bones, some had long tails, hook- like claws. Saurischia- lizard pelvis, herbivores/carnivores, largest dinos (sauropods, walked on 4 legs). Landforms- pangea begins to rift (euramerica & gondwanaland, opens atlantic and gulf of mexico, s. america & africa) causing volcanism to release co2 and raise temperature.
