Cenozoic

Definition

The Cenozoic is the most recent geological era, spanning from about 66 million years ago to the present. It is known as the 'Age of Mammals' because it is characterized by the dominance of mammals and birds following the mass extinction event that wiped out the dinosaurs. The Cenozoic era is marked by significant climatic changes, the formation of modern continents, and the evolution of diverse life forms, all of which contribute to our understanding of fossils and the fossil record.

5 Must Know Facts For Your Next Test

1. The Cenozoic era is divided into three main periods: Paleogene, Neogene, and Quaternary.
2. Major geological events during the Cenozoic include the uplift of mountain ranges like the Himalayas and the formation of ocean basins.
3. This era saw significant climate fluctuations, including ice ages that shaped environments and influenced species evolution.
4. Fossil evidence from the Cenozoic provides crucial insights into the evolutionary history of mammals, birds, and flowering plants.
5. The Cenozoic also marks the development of grasslands, which played a key role in shaping ecosystems and influencing mammalian adaptations.

Review Questions

• How did the extinction of dinosaurs influence mammalian evolution during the Cenozoic?
  • The extinction of dinosaurs created ecological niches that were previously occupied by these reptiles. With their disappearance, mammals were able to diversify and adapt to a wide range of habitats, leading to significant evolutionary developments. This shift allowed for the rise of larger mammals and birds, which became dominant in many ecosystems during the Cenozoic era.
• Discuss how climatic changes during the Cenozoic era affected fossil preservation and what this means for our understanding of past ecosystems.
  • Climatic changes during the Cenozoic era led to various environmental shifts, such as glaciation events that influenced where fossils could be preserved. Regions that experienced stable climates often yielded more well-preserved fossils, providing clearer snapshots of ancient ecosystems. This variability allows scientists to piece together a more comprehensive view of how different species interacted with their environments throughout this dynamic period.
• Evaluate the role of tectonic activity in shaping biodiversity patterns observed in the fossil record throughout the Cenozoic.
  • Tectonic activity during the Cenozoic played a crucial role in shaping global biodiversity by altering landforms and ocean currents. The movement of tectonic plates resulted in the formation of mountains and ocean basins, creating barriers that influenced species distribution. This geological transformation led to speciation and extinction events documented in the fossil record, highlighting how Earth's physical changes directly impacted evolutionary processes.

Related terms

Paleogene: The Paleogene is the first period of the Cenozoic era, encompassing the rise and diversification of mammals and birds after the extinction of dinosaurs.

Neogene: The Neogene is the second period of the Cenozoic era, characterized by further mammal evolution, including the emergence of many modern families and species.

Quaternary: The Quaternary is the most recent period within the Cenozoic era, marked by repeated glaciations and the appearance of humans.