Mesozoic and Cenozoic Eras Quiz

Mesozoic Era (Age of Reptiles)

• Also known as the Age of Reptiles.
• Pangaea separated, causing mountain formation and a rise in global sea level due to rapid spreading ridge systems.
• Atlantic Ocean's opening can be reconstructed using ridge system data.
• Climate interpretations are based on plant and Cretaceous fossils.
• Angiosperms (flowering plants) have flowers to attract insects and birds; gymnosperms bear seeds.
• Dominant terrestrial vertebrates were mammal-like reptiles.
• Dinosaurs dominated the Mesozoic Era.

Cretaceous-Tertiary Mass Extinction

• Occurred 66 million years ago.
• Caused by a large asteroid impact (Yucatán Peninsula crater) and substantial volcanic eruptions (India and Pakistan).
• The impact drastically altered climate.
• Evidence includes a large impact crater and volcanic activity.

Important Changes in Life Forms during the Mesozoic

• Reef-building corals were replaced by reef-building mollusks.

Cenozoic Era (Age of Mammals)

• Also called the Age of Mammals.
• Mountains rose, and numerous glaciation periods occurred.
• Plate tectonics, collisions, and mountain building can affect global temperature. Higher elevations experience cooler temperatures.
• Increased snow and ice raise planetary albedo, reflecting more solar radiation, leading to cooling.

Changes in Life Forms and Climate during the Cenozoic Era

• Cooling led to the extinction of warm-climate mammals and destroyed tropical forests.

Scientific Methods for Studying Past Eras

• Modern organisms help infer characteristics of extinct ones.
• Understanding relationships among mountains, volcanoes, earthquakes, and water bodies is crucial.
• Fossil animal tracks (ichnology) are studied.
• Differences in how cooling environments affect mammals and reptiles (temperature regulation mechanisms) were analyzed.

Miocene Epoch

• Tectonic activity was significant.
• Climate fluctuated from warmer to cooler.
• Antarctic ice sheet formation influenced global sea levels.
• Significant plant and animal diversification occurred. Grasslands expanded, leading to grazing mammal evolution.

How Past Epochs Explain Current Features

• Tectonic activity and erosion shaped present-day landforms.
• Cooling trends and evolutionary changes/extinctions are studied.
• Past sea level fluctuations are considered.

Evidence from Prehistoric Humans

• Human activities (hunting and agriculture) influenced species survival and interactions between Earth systems (soil, water, air, organisms).
• Greenhouse gases, increased over the last 200 years, contributed to rising temperatures.

Anthropocene Epoch

• Significant human-caused changes suggest a new epoch (Anthropocene).