Major events during periods

Question 1

Archaean

Answer 1

Origin of life, prokaryotes, photosynthesis generates O2, aerobic respiration

Question 2

Proterozoic

Answer 2

earliest eukaryotes, multicellular animals including Cnidaria, Annelida, Arthropoda

Question 3

Cambrian

Answer 3

marine animals diversify, earliest agnathan vertebrates

Question 4

Ordovician

Answer 4

echinoderms, mass extinction at end of period

Question 5

Silurian

Answer 5

diversification of agnathans, origin of jawed fishes, earliest terrestrial vascular plants, arthropods

Question 6

Devonian

Answer 6

bony fish diversification, triobites, ammonoids, amphibians, insects, ferns, seed plants, mass extinction at end

Question 7

Carboniferous

Answer 7

Gondwana forms, forests of vascular plants, winged insects, first reptiles

Question 8

Permian

Answer 8

continents in Pangaea, glaciations, low sea level, advanced fishes, amphibians decline, mammal-like reptiles diversify, major marine extinction

Question 9

Triassic

Answer 9

continents separate, marine diversity increases, gymnosperms dominant, first dinosaurs

Question 10

Jurassic

Answer 10

continents separating, diverse dinosaurs, first birds, first mammals, evolution of angiosperms, Mesozoic marine revolution

Question 11

Cretaceous

Answer 11

most continents separated, diversification of dinosaurs, diversity of angiosperms, mammals, birds, mass extinction of dinosaurs and ammonids at end of period

Question 12

Tertiary

Answer 12

continents near modern positions, cool, dry climate, radiation of mammals, birds, snakes, angiosperms, pollinating insects, teleost fishes

Question 13

Quaternary

Answer 13

Continents in modern positions, repeated glaciations, extinctions of large mammals and birds, evolution of Homo erectus to Homo sapiens