End-triassic extinction

Definition

The end-Triassic extinction was a significant event that occurred around 201 million years ago, leading to the extinction of approximately 50% of all species on Earth, including many marine and terrestrial organisms. This extinction marks one of the five major mass extinction events in Earth's history and set the stage for the rise of dinosaurs during the Jurassic period.

5 Must Know Facts For Your Next Test

1. The end-Triassic extinction is believed to have been caused by massive volcanic activity associated with the Central Atlantic Magmatic Province, leading to climate change and ocean acidification.
2. Many species that went extinct during this event included large amphibians, early reptiles, and various marine organisms such as ammonites and certain types of corals.
3. This extinction event opened ecological niches that allowed dinosaurs to become the dominant terrestrial vertebrates during the Jurassic period.
4. The end-Triassic extinction is notable for its relatively quick occurrence, happening over a time span estimated to be less than 1 million years.
5. The aftermath of this extinction resulted in significant evolutionary changes and laid down the foundation for the ecosystems we recognize today.

Review Questions

• How did volcanic activity contribute to the end-Triassic extinction, and what were its broader environmental impacts?
  • Volcanic activity during the end-Triassic period released vast amounts of carbon dioxide and sulfur dioxide into the atmosphere, leading to climate change characterized by global warming and acid rain. These changes disrupted habitats both on land and in the oceans, causing widespread extinctions among many groups of organisms. The resulting environmental stress was a key factor that contributed to the dramatic loss of biodiversity seen during this mass extinction event.
• Evaluate the ecological consequences of the end-Triassic extinction on subsequent evolutionary trends in terrestrial ecosystems.
  • The end-Triassic extinction had profound ecological consequences, particularly by eliminating many dominant species and creating opportunities for other groups to thrive. The disappearance of large amphibians and early reptiles allowed dinosaurs to fill ecological roles left vacant. This shift not only facilitated their rise to dominance but also set the stage for evolutionary developments in mammals and birds that would follow in later periods, illustrating a direct link between this extinction event and subsequent biodiversity.
• Assess the significance of understanding mass extinctions like the end-Triassic extinction in relation to current biodiversity crises.
  • Studying mass extinctions such as the end-Triassic helps us comprehend patterns in biodiversity loss and recovery over geological timescales. Insights gained from past events reveal how ecosystems respond to dramatic environmental changes, which can inform our understanding of current biodiversity crises driven by human activities. By analyzing how life rebounded after previous mass extinctions, we can better strategize conservation efforts and mitigate potential future losses in biodiversity due to ongoing climate change and habitat destruction.

Related terms

Mass Extinction: A rapid and widespread decrease in biodiversity on Earth, typically defined by the loss of a significant percentage of species in a relatively short geological timeframe.

Triassic Period: The first period of the Mesozoic Era, lasting from about 252 to 201 million years ago, characterized by the emergence of dinosaurs and the diversification of reptiles.

Paleoecology: The study of ancient ecosystems and environments through the examination of fossil records, helping to understand how past life forms interacted with their surroundings.