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final study guide - The Modern Marine Fauna became dominant...

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The Modern Marine Fauna became dominant after the Permo-Triassic extinction, but Paleozoic style communities were still abundant through the early Mesozoic. Diatoms (early-late Jur) , Coccolithophores (late Tri) , Planktonic Foraminifera (early-mid Jur) : main groups of unicellular planktonic organisms. Predation drilling: single hole in shell, sharp, beveled egde, stereotyped place. Predation crushing/peeling: shell repair scars, unsuccessful attempts by crushing or peeling predators. Common after late Meso. Arthropod predators: Decapods: crabs/lobsters: specialized can opener claw-peel snail shells. Prey: Urchins- spines, grab surrounding environment to hide. Bivalves- moved lower down where less predators present. Epifaunal to infaunal. Crinoids- move offshore. Diversification of crushing/peeling,development of anti-predator morphology, bivalves and echinoids shift to infaunal habitats, decline of brachiopods, decreased epifaunal tiering @ early-mid jur. Evolution of drilling gastropods, radiation of durophagous fish, crinoids driven offshore. @ late cretaceous. Mesozoic reptiles sea/sky: Plesiosaurs: next of kin to lepidosaurs. mid Triassic-end cretaceous. Pliosaur: short necked. Pursuant predator Plesiosaur: long necked. Opportunistic/ambush predator. Mosasaurs: mid-end cretaceous. Serpents. Undulated entire body for movement-sea snakes/crocs. Ineffiecent. Ambush predators. Ichthyosaurs: Permian-Triassic Boundary. Body evolves to be more streamlined. Lizard like-tuna like. Fins become more paddle like for maneuvering. Increase stiffness of spine for efficient long distance swimming. Evolve dorsal fin and tail fluke. Pterosaurs: next of kin of archosaur. Late Triassic. Skeletal changes: thin membrane across hand forms wings. Sturdy fused sternum w/ keel. Short humerus, elongate coracoid for attachment of flight muscles. Bones become reduced in size/slender/hollow. Small pterosaurs eat fish. Large ones can’t go over ocean-terrestrial scavengers. Some strained small organisms from water. Reproduction: laid eggs in large/isolated rookeries. Crests on heads used for male attraction Flight Requirements: large wing surface, modification of hand, firm strut between arm/sternum to brace wing, sternum enlarged for flight muscles, light hollow bones, large cerebellum in brain, high metabolism. Avian Theropod Evidence: Osteology(Bone Structure), Oology(Eggshell, nest) - lay two eggs at a time, Behavior, Integument(Skin Covering) Feathers and flapping evolved before flight. Flight first evolved in eumaniraptoran theropods. Mammals: Squishy: Mammary glands, hair, endothermy/high metabolism. Hard: Three ear bones, complex teeth-shapes, types, occlusion, reduced number of bones, big complex brains. Marsupials: live young(embryos) crawl to pouch and attach to nipple to develop. Slow growth rate, small brain, low metabolism. Placentals: fully developed young. Fast growth, large brain, high metabolism. Angiosperms: flowering plants that are often insect pollinated. Cretaceous(ferns/Cycads decline).
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final study guide - The Modern Marine Fauna became dominant...

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