The Emergence of Humankind - Vocabulary Flashcards

Twenty-five vocabulary flashcards covering key terms from the Emergence of Humankind lecture notes.

Phanerozoic Eon

Fourth and current geologic eon (about 541 million years ago to the present); divided into the Paleozoic, Mesozoic, and Cenozoic eras.

Paleozoic Era

Era spanning from the first emergence of life to the emergence of dinosaurs; comprises six periods: Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian.

Cambrian Period

541–485 million years ago; life mostly in the oceans; early lifeforms include worms and jawless fishes; chordates, arthropods, and trilobites.

Ordovician Period

485–443 million years ago; marine life diversifies; ends with a mass extinction; horseshoe crabs later reach the shores.

Silurian Period

443–419 million years ago; many plants and animals appear, especially along seashores; notable fossils include sea scorpions, centipedes, and arachnids.

Devonian Period

419–359 million years ago; great diversification of fishes; appearance of bony, jawed fishes; lobefins; some fishes move onto land and breathe through their skin.

Carboniferous Period

359–299 million years ago; inland ecosystems develop from shore; forests with ferns and seed plants; woody stems; oxygen increased; giant amphibians and early reptiles appear.

Permian Period

299–252 million years ago; formation of Pangaea; varied climate; reptiles dominate on land; therapsids (mammal ancestors) regulate warmth internally.

Triassic Period

252–201 million years ago; reptiles fill ecological niches after the mass extinction; early mammals small and nocturnal; marine reptiles like ichthyosaurs and plesiosaurs dominant.

Laurasia

Northern landmass that formed as Pangaea began to break apart.

Gondwana (Gondwanaland)

Southern landmass that formed as Pangaea broke apart.

Tethys Sea

Ancient sea between Laurasia and Gondwanaland during Pangaea's breakup.

Jurassic Period

201–145 million years ago; dinosaurs dominate and diversify; includes large herbivores such as sauropods.

Sauropods

Large, long-necked herbivorous dinosaurs.

Theropods

Bipedal carnivorous dinosaurs.

Pterosaurs

Winged reptiles; flight-enabled, not dinosaurs.

Cretaceous Period

145–66 million years ago; dinosaurs dominate on land, sea, and air; new species like Iguanodon, Triceratops, and Tyrannosaurus rex; birds diversify; flowering plants appear; mammals remain small.

Tyrannosaurus rex

Large theropod dinosaur from the Late Cretaceous; iconic apex predator.

Triceratops

Horned ceratopsian dinosaur from the Late Cretaceous.

Iguanodon

Early herbivorous dinosaur; one of the new dinosaur species described in the Cretaceous.

Cenozoic Era

Era after the Mesozoic; Age of Mammals; continents shift toward current positions; includes Paleogene, Neogene, and Quaternary periods.

Paleogene Period

66–23 million years ago; mammals begin to evolve; birds and small reptiles survive; early whales appear.

Neogene Period

23–2.5 million years ago; mammals become widespread; primates and hominids appear.

Quaternary

2.5 million years ago to present; Age of Humans; includes recent ice ages and human evolution.

Flowering Plants

Plants that produce flowers (angiosperms); emerged during the Cretaceous, contributing to major ecosystem changes.