End-triassic mass extinction

Definition

The end-Triassic mass extinction was a significant event that occurred around 201 million years ago, marking the boundary between the Triassic and Jurassic periods. It is characterized by the loss of approximately 76% of all species, including many marine reptiles and large amphibians, paving the way for the dominance of dinosaurs in the Jurassic period. This extinction event is often linked to several geological and climatic changes that disrupted ecosystems.

5 Must Know Facts For Your Next Test

1. The end-Triassic mass extinction is believed to have been triggered by intense volcanic activity, particularly from the Central Atlantic Magmatic Province (CAMP), which released large amounts of carbon dioxide and sulfur dioxide into the atmosphere.
2. As a result of the volcanic activity, there were significant climate changes, including global warming and acid rain, leading to habitat loss for many species.
3. This extinction event resulted in the decline of major groups such as Archosaurs and Ammonites, allowing dinosaurs to become the dominant terrestrial vertebrates in the subsequent Jurassic period.
4. The end-Triassic extinction is one of five major mass extinction events in Earth's history and has been crucial in shaping the evolution of life on our planet.
5. Research indicates that the recovery from the end-Triassic mass extinction took millions of years, significantly impacting marine and terrestrial biodiversity.

Review Questions

• What role did volcanic activity play in the end-Triassic mass extinction, and how did it affect the climate?
  • Volcanic activity was a key factor in triggering the end-Triassic mass extinction. The Central Atlantic Magmatic Province (CAMP) erupted extensively, releasing vast amounts of greenhouse gases like carbon dioxide, which led to global warming. This change in climate caused severe disruptions in ecosystems, resulting in habitat loss and making it difficult for many species to survive.
• Discuss how the end-Triassic mass extinction contributed to the rise of dinosaurs in the Jurassic period.
  • The end-Triassic mass extinction resulted in the disappearance of many dominant species, creating ecological opportunities for surviving groups. With large reptiles and amphibians declining or becoming extinct, dinosaurs were able to diversify and occupy various ecological niches. This shift allowed dinosaurs to become the primary terrestrial vertebrates during the Jurassic period, setting the stage for their dominance for millions of years.
• Evaluate the long-term ecological consequences of the end-Triassic mass extinction on both marine and terrestrial environments.
  • The long-term ecological consequences of the end-Triassic mass extinction were profound. The drastic reduction in biodiversity altered community structures in both marine and terrestrial environments. While it took millions of years for ecosystems to recover fully, new evolutionary pathways emerged as surviving species adapted to changed conditions. This event reshaped not only species composition but also influenced evolutionary trajectories that would lead to modern biodiversity.

Related terms

Mass Extinction: A widespread and rapid decrease in the biodiversity on Earth, typically characterized by the extinction of a large number of species in a relatively short geological timeframe.

Pangea: The supercontinent that existed during the late Paleozoic and early Mesozoic eras, which began to break apart during the Triassic period, affecting global climate and ecosystems.

Volcanism: The geological processes related to volcanic activity, which during the end-Triassic period contributed to environmental changes through massive volcanic eruptions releasing gases and ash into the atmosphere.