End-Triassic

Definition

The End-Triassic refers to a significant geological boundary occurring approximately 201 million years ago, marking the end of the Triassic period and the beginning of the Jurassic period. This event is characterized by a major extinction event that resulted in the loss of many species, profoundly impacting biodiversity and allowing for the rise of dinosaurs as dominant terrestrial vertebrates.

5 Must Know Facts For Your Next Test

1. The End-Triassic event is estimated to have caused the extinction of approximately 50% of all species on Earth, including many marine reptiles and large amphibians.
2. Volcanic activity associated with the Central Atlantic Magmatic Province (CAMP) is believed to be a major factor contributing to the environmental changes that led to this extinction.
3. Following the End-Triassic extinction, dinosaurs quickly rose to prominence in various ecosystems, filling niches left vacant by extinct species.
4. The event had a long-term impact on terrestrial ecosystems, leading to significant shifts in flora and fauna during the Jurassic period.
5. Research suggests that climate change during this time, driven by volcanic eruptions and greenhouse gas emissions, played a critical role in altering habitats and biomes.

Review Questions

• What were the primary causes of the End-Triassic extinction event and how did they affect biodiversity?
  • The End-Triassic extinction was primarily driven by volcanic eruptions linked to the Central Atlantic Magmatic Province, which released massive amounts of greenhouse gases, leading to climate change and ocean acidification. These environmental shifts drastically altered habitats and contributed to the extinction of around 50% of all species, including many marine reptiles and large amphibians. The loss of these species significantly impacted global biodiversity, creating opportunities for other groups, particularly dinosaurs, to evolve and thrive in the post-extinction landscape.
• Analyze how the End-Triassic extinction shaped the evolutionary trajectory of dinosaurs during the Jurassic period.
  • The End-Triassic extinction set the stage for dinosaurs to become the dominant terrestrial vertebrates during the Jurassic period. With numerous ecological niches becoming available after the extinction of competing species, dinosaurs rapidly diversified and adapted to fill these roles. The decline of other reptiles and large amphibians created an environment where dinosaurs could evolve into various forms, leading to innovations in size, behavior, and habitat use that defined their success throughout the Jurassic and beyond.
• Evaluate the long-term ecological consequences of the End-Triassic event on modern biodiversity.
  • The End-Triassic extinction had profound long-term ecological consequences that can still be observed in today's biodiversity. By reshaping ecosystems and allowing new groups like dinosaurs to flourish, it created a foundation for subsequent evolutionary developments. Understanding this event helps illuminate patterns of resilience and recovery in ecosystems following mass extinctions. It also highlights how current biodiversity crises might unfold under similar environmental stresses caused by human activity, thereby stressing the importance of conservation efforts in preserving existing ecosystems.

Related terms

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

Triassic Period: A geologic period that lasted from about 252 to 201 million years ago, known for the emergence of early dinosaurs and mammals, as well as diverse plant life.

Jurassic Period: The geological period following the Triassic, lasting from about 201 to 145 million years ago, during which dinosaurs became the dominant land animals.