Permian-Triassic Extinction Event

Definition

The Permian-Triassic extinction event, also known as the Great Dying, occurred approximately 252 million years ago and marks the most severe mass extinction in Earth's history. This event led to the extinction of around 90% of marine species and 70% of terrestrial vertebrate species, significantly reshaping biodiversity and ecosystems at the start of the Triassic period.

5 Must Know Facts For Your Next Test

1. The Permian-Triassic extinction event is estimated to have lasted about 60,000 years, significantly impacting both marine and terrestrial life.
2. One possible cause of this extinction event is volcanic activity in the Siberian Traps, which released vast amounts of carbon dioxide and sulfur dioxide, leading to severe climate changes.
3. The event resulted in the loss of about 95% of marine species and approximately 70% of terrestrial vertebrates, dramatically altering ecological dynamics.
4. Following the extinction event, biodiversity took millions of years to recover, paving the way for the dominance of dinosaurs in the subsequent Mesozoic era.
5. The Permian-Triassic extinction event set the stage for evolutionary innovations, including the rise of new species that would eventually lead to modern ecosystems.

Review Questions

• What were some primary causes and effects associated with the Permian-Triassic extinction event?
  • Primary causes of the Permian-Triassic extinction event include extensive volcanic activity in the Siberian Traps and drastic climate changes due to greenhouse gas emissions. The effects were catastrophic, resulting in about 90% of marine species and 70% of terrestrial vertebrates becoming extinct. This mass extinction drastically altered ecosystems and biodiversity, leading to new evolutionary pathways in the aftermath.
• Discuss how the Permian-Triassic extinction event influenced evolutionary patterns during the Triassic period.
  • The Permian-Triassic extinction event set off significant evolutionary changes during the Triassic period by creating ecological niches previously occupied by extinct species. As life began to recover from this catastrophic event, new groups of organisms emerged, including early dinosaurs and mammals. The absence of dominant species allowed for adaptive radiation, which fueled diversification and innovation among surviving lineages.
• Evaluate the long-term implications of the Permian-Triassic extinction event on Earth's biological history and its relevance to contemporary discussions on biodiversity loss.
  • The long-term implications of the Permian-Triassic extinction event are profound, as it reshaped Earth's biological history by paving the way for new dominant groups like dinosaurs. This event serves as a historical example that highlights how catastrophic events can dramatically alter ecosystems and biodiversity. In contemporary discussions on biodiversity loss due to human activities, understanding this mass extinction emphasizes the importance of conservation efforts to prevent similar large-scale extinctions in our current ecosystems.

Related terms

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

Pangaea: Pangaea was a supercontinent that existed during the late Paleozoic and early Mesozoic eras, including the time of the Permian-Triassic extinction event, affecting climate and biological diversity.

Triassic Period: The Triassic period is the first period of the Mesozoic era, following the Permian-Triassic extinction event, characterized by the emergence of dinosaurs and significant evolutionary changes in life forms.