The Modern Marine Fauna became dominant after the Permo-Triassic extinction, but Paleozoic style communities were still abundant through the early
, Planktonic Foraminifera
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.
crabs/lobsters: specialized can opener claw-peel snail shells.
spines, grab surrounding environment to hide. Bivalves-
moved lower down where less predators present. Epifaunal to infaunal. Crinoids-
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.
next of kin to lepidosaurs. mid Triassic-end cretaceous.
short necked. Pursuant predator
mid-end cretaceous. Serpents. Undulated entire body for movement-sea snakes/crocs. Ineffiecent. Ambush
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.
next of kin of archosaur. Late Triassic.
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
laid eggs in large/isolated rookeries. Crests on heads used for male attraction
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
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.
Mammary glands, hair, endothermy/high
Three ear bones, complex teeth-shapes, types, occlusion, reduced number of bones, big complex brains.
crawl to pouch and attach to nipple to develop. Slow growth rate, small brain, low metabolism.
fully developed young. Fast growth, large brain, high
flowering plants that are often insect pollinated. Cretaceous(ferns/Cycads decline).