Paleozoic Era Life and Events

The lecture by Tor Lacey covers the Early Paleozoic eon, focusing on the Cambrian and Ordovician periods. It discusses paleogeography, including continental shifts and climate changes, and the evolution and diversification of sea life. The lecture also addresses the Ordovician climate changes and mass extinctions, highlighting the impact of global cooling and warming on marine life. The conclusion summarizes the key events and transformations during this era.

What major geological event occurred during the early Cambrian that affected the paleogeography of Laurentia?

• Rifting of Laurentia from Gondwanaland

• Formation of the supercontinent Pangaea

• Subduction of the Pacific Plate under Laurentia

• Collision of Laurentia with an island arc

What was a significant consequence of the end of the Varangian glaciation?

• Formation of large ice sheets

• Rise in sea levels

• Expansion of desert regions

• Decrease in sea levels

Which of the following best describes the life forms that evolved during the early Paleozoic?

• They were large, complex sea animals.

• They were mostly small and simple organisms.

• They were predominantly flying insects.

• They were primarily terrestrial plants.

Which group of organisms dominated later Cambrian life?

• Trilobites

• Birds

• Dinosaurs

• Mammals

What geological feature formed at the eastern margin of Laurentia during the Ordovician?

• A deep ocean trench

• A mountain range

• A volcanic plateau

• A large desert

Which of the following animal groups evolved during the Ordovician and are still present today?

• Reptiles

• Corals

• Mammals

• Dinosaurs

What was one of the main causes of the first pulse of marine extinction at the end of the Ordovician?

• Global warming

• Global cooling and glacier growth

• Volcanic eruptions

• Meteorite impact

Which of the following groups suffered significant losses during the Ordovician mass extinctions?

• Mammals

• Birds

• Trilobites

• Amphibians

What was a major consequence of the climate warming at the end of the Ordovician?

• Formation of large ice sheets

• Rise in sea levels

• Decrease in sea levels

• Expansion of desert regions

What evidence do we have for the global cooling and warming events during the early Paleozoic?

• Volcanic rock layers

• Stratigraphic and fossil records

• Meteorite craters

• Ancient cave paintings