Cenozoic

Definition

The Cenozoic is the most recent geological era, spanning from about 66 million years ago to the present. It is marked by significant changes in climate, geography, and biodiversity, including the rise of mammals and birds after the mass extinction event that wiped out the dinosaurs. This era is further divided into three periods: the Paleogene, Neogene, and Quaternary, which reflect major developments in the evolution of life on Earth.

5 Must Know Facts For Your Next Test

1. The Cenozoic Era is often referred to as the 'Age of Mammals' because it witnessed their dominance after the extinction of dinosaurs.
2. During the Cenozoic, continents shifted to their current positions due to tectonic activity, influencing global climate and ecosystems.
3. Major climate changes occurred in this era, leading to periods of warming and cooling that affected species distribution and evolution.
4. The Cenozoic saw significant developments in flowering plants, which diversified and became dominant in many ecosystems.
5. The evolution of humans occurred during the latter part of the Cenozoic, particularly in the Quaternary period, shaping ecological interactions and landscapes.

Review Questions

• Compare and contrast the major evolutionary changes that occurred during the Paleogene and Neogene periods of the Cenozoic Era.
  • During the Paleogene period, mammals began to diversify significantly following the extinction of dinosaurs, leading to the emergence of various groups such as primates and cetaceans. In contrast, the Neogene period saw further diversification and adaptation of mammals, including the evolution of modern families like horses and elephants. The climate during these periods also played a crucial role; while Paleogene was warmer and tropical, Neogene experienced cooler temperatures that contributed to changing habitats.
• Evaluate how tectonic activity during the Cenozoic Era influenced global climate patterns and biological diversity.
  • Tectonic activity during the Cenozoic resulted in significant continental drift, which altered ocean currents and atmospheric circulation patterns. This led to shifts in climate from tropical to more temperate conditions across various regions. Such changes impacted biological diversity by creating new habitats while also contributing to extinctions. The formation of mountain ranges like the Himalayas further affected weather patterns, promoting both adaptation and speciation among flora and fauna.
• Synthesize information about human evolution within the context of Cenozoic environmental changes and their impact on ecosystems.
  • Human evolution unfolded against a backdrop of dramatic environmental changes during the Cenozoic, particularly in the Quaternary period marked by repeated glacial cycles. These fluctuations created diverse ecosystems that influenced human ancestors' adaptations, such as bipedalism and tool use. As habitats changed due to climate shifts, early humans developed strategies for survival that included migration, which not only affected their own species but also had profound impacts on other flora and fauna as they altered landscapes through hunting and gathering.

Related terms

Paleogene:

The first period of the Cenozoic Era, lasting from about 66 to 23 million years ago, characterized by the diversification of mammals and the appearance of modern plants.

Neogene:

The second period of the Cenozoic Era, lasting from about 23 to 2.6 million years ago, during which significant climatic changes occurred and many modern mammal families evolved.

Quaternary:

The most recent period of the Cenozoic Era, beginning around 2.6 million years ago, known for its glacial cycles and the development of human civilization.