Cenozoic Era

Definition

The Cenozoic Era is the most recent geological era, spanning from about 66 million years ago to the present. It is known as the 'Age of Mammals' due to the significant evolution and diversification of mammals and birds after the extinction of the dinosaurs. This era also saw major changes in Earth's climate, tectonic activity, and the development of modern ecosystems.

5 Must Know Facts For Your Next Test

1. The Cenozoic Era is divided into three main periods: Paleogene, Neogene, and Quaternary, each marked by distinct geological and biological developments.
2. During the Cenozoic, continents moved to their current positions, influencing climate patterns and ocean currents, which affected biodiversity.
3. The Cenozoic saw the rise of many mammalian groups, including primates, cetaceans (whales and dolphins), and large herbivores like elephants.
4. Major climatic changes occurred during this era, including periods of warming and cooling that impacted species survival and evolution.
5. The extinction events at the end of the Cretaceous paved the way for mammals to dominate terrestrial ecosystems during the Cenozoic Era.

Review Questions

• How did tectonic movements during the Cenozoic Era influence global climate and biodiversity?
  • Tectonic movements during the Cenozoic Era significantly influenced global climate by altering ocean currents and land configurations. As continents shifted towards their current positions, they created barriers that changed wind patterns and precipitation distribution. This resulted in varied habitats that promoted biodiversity, enabling different species to evolve based on their specific environmental conditions.
• Discuss how Earth's magnetic field has changed throughout the Cenozoic Era and its relevance to paleomagnetism.
  • Throughout the Cenozoic Era, Earth's magnetic field has undergone numerous reversals known as geomagnetic reversals. These changes are essential for paleomagnetism studies as they provide a timeline for dating geological events and understanding plate tectonics. By examining magnetic signatures in rocks formed during this era, scientists can reconstruct past continental movements and gain insights into historical climate patterns.
• Evaluate how the evolutionary trends observed in mammals during the Cenozoic Era reflect broader environmental changes in Earth’s history.
  • The evolutionary trends observed in mammals during the Cenozoic Era reflect significant environmental changes that occurred on Earth. As climates shifted from warm to cool conditions, mammals adapted through diverse evolutionary paths such as size variation, dietary changes, and new reproductive strategies. This adaptation was driven by changing ecosystems resulting from tectonic activities that influenced habitat availability and resource competition, showcasing how organisms can rapidly evolve in response to their environment over geologic time.

Related terms

Paleogene Period: The Paleogene Period is the first period of the Cenozoic Era, marked by the rapid evolution of mammals and birds, and significant changes in flora.

Neogene Period: The Neogene Period follows the Paleogene and is characterized by the further evolution of mammals and birds, as well as the formation of the modern continents.

Quaternary Period:

The Quaternary Period is the most recent period of the Cenozoic Era, encompassing the last 2.6 million years and featuring significant glacial cycles and human evolution.