End-Triassic extinction

Definition

The End-Triassic extinction was a major biodiversity crisis that occurred approximately 201 million years ago at the boundary between the Triassic and Jurassic periods. This event led to the extinction of about 76% of all species on Earth, including many marine reptiles, large amphibians, and various plant groups, significantly shaping the evolution of life in the Jurassic period and beyond.

5 Must Know Facts For Your Next Test

1. The End-Triassic extinction is one of the five major mass extinctions in Earth's history, and it played a key role in paving the way for the dominance of dinosaurs in the Jurassic period.
2. Research suggests that volcanic activity associated with the Central Atlantic Magmatic Province contributed significantly to climate change during this period, leading to ocean acidification and other environmental stresses.
3. Many groups were affected by this extinction event, including marine life such as ammonites and conodonts, as well as terrestrial species like archosaurs.
4. The recovery from the End-Triassic extinction allowed for new ecosystems to develop, resulting in the rapid evolution of dinosaurs and other groups that would dominate during the Jurassic.
5. The exact causes and mechanisms of this extinction event are still debated among scientists, highlighting its complexity and importance in understanding Earth's biological history.

Review Questions

• How did the End-Triassic extinction impact the evolutionary trajectory of life on Earth?
  • The End-Triassic extinction had a profound effect on Earth's evolutionary path by eliminating around 76% of species, which allowed surviving organisms to diversify and fill ecological niches. After this event, dinosaurs emerged as dominant terrestrial vertebrates, leading to their eventual reign during the Jurassic period. The extinction also opened up opportunities for other groups such as mammals and birds to evolve and adapt in ways they couldn't before.
• Discuss the potential causes of the End-Triassic extinction and their implications for Earth's climate.
  • The potential causes of the End-Triassic extinction are thought to include significant volcanic activity that led to global warming, ocean acidification, and changes in sea levels. The Central Atlantic Magmatic Province is often cited as a major contributor due to its massive volcanic eruptions. These changes not only caused widespread habitat loss but also disrupted food chains and ecosystems, illustrating how interconnected life is with environmental conditions.
• Evaluate the significance of understanding the End-Triassic extinction in relation to current biodiversity crises.
  • Understanding the End-Triassic extinction is crucial as it provides insight into how rapid environmental changes can lead to significant biodiversity loss. By studying this historical event, we can draw parallels with today's ongoing biodiversity crises due to climate change, habitat destruction, and pollution. Recognizing these patterns may help inform conservation strategies and policies aimed at mitigating similar impacts on modern ecosystems.

Related terms

Mass extinction: A rapid and widespread decrease in the biodiversity on Earth, typically defined by the loss of at least 75% of species in a relatively short geological time frame.

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 dominance of reptiles.

Jurassic Period: The second period of the Mesozoic Era, following the Triassic, known for the diversification of dinosaurs and the first appearance of birds.