last min study Flashcards
describe the cambrian
cambrian explosion with huge radiation of animal phyla, trilobites being the most common (evident through trace fossils)
origination: trilobites, chordates, gastropods.
the lack of predation allowed high diveristy
describe the pre cambrian and ediacaran
lots of trace fossils, with evidence of bilaterian life. microbial mats dominaten (stramatolites)
describe the ordovician
1st extinction caused by global cooling from continental drift.
brachiopods dominate over trilobites and adaptive radiation continues
origination: insects and jawless fish.
Extinction: marine animals such as brachiopods, corals, trilobites.
what happened in the silurian
plants and arthropods invade the terrestial system.
origination: jawed fishes, small vascular plants
describe the devonian
2nd mass extinction caused by global cooling from absorption of CO2 by plants
origination: insects, tetrapods (from fish to tetrapod) invading terrestial system. forests with horsetails and lycopods appear. ferns evolve complex vascular systems.
lungfish evolve into amphibians then into amniotes.
what happened in the carboniferous
the age of coal where swampy forests dominated. gymnosperms dominate with conifers being most common
origination: winged insects, crinoids dominate oceans, reptiles (from amniotes), synapids (from amniotes then into reptiles)
what happened in the permian
252 Ma 3rd extinction caused by volcanism resulting in global warming.
pangea fully formed and primed for dinosaurs.
origination: mammals (from synapids to therapids to mammals), seed ferns dominate forests
extinction: almost all species affected with trilobites hit hardest
describe the triassic
201 Ma 4th extinction caused by volcanism causing global warming
origination: rise of dinosaurs, turtles and mammals (from advanced therapids)
describe the jurassic
origination: birds and modern mammals
describe the cretaceous
66 Ma 5th extinction caused by asteroid impact.
angiosperms (outcompete gymnospems), marsupials, snails and sharks radiate
ends with extinction of non avian dinosaurs
what happened in palaeogene
the age of mammals
origination: modern insects, plants, birds, mammals and gastropod radiation
PETM
