Late Devonian Extinction

Definition

The Late Devonian Extinction refers to a series of extinction events that occurred approximately 375 to 360 million years ago during the late Devonian period, leading to the loss of about 70-80% of marine species. This extinction event is notable for its prolonged duration, which likely involved several pulse events over millions of years, affecting primarily shallow marine life and disrupting ecosystems significantly.

5 Must Know Facts For Your Next Test

1. The Late Devonian Extinction is believed to have occurred in multiple phases rather than a single catastrophic event, impacting marine life over several million years.
2. Coral reefs suffered greatly during this extinction, leading to the decline of many reef-building organisms and altering marine ecosystems.
3. Several hypotheses have been proposed for the causes of this extinction, including anoxia (lack of oxygen) in oceans, climate change, and asteroid impacts.
4. This extinction event paved the way for major evolutionary advancements in the Carboniferous period, especially among terrestrial plants and animals.
5. The Late Devonian Extinction stands out as one of the five major mass extinctions in Earth's history, highlighting significant changes in biodiversity patterns.

Review Questions

• What were some potential causes of the Late Devonian Extinction, and how did they impact marine ecosystems?
  • Potential causes of the Late Devonian Extinction include oceanic anoxia, which reduced oxygen levels in shallow waters and led to widespread marine life die-offs. Climate change during this period may have also disrupted habitats and food chains. These factors combined to cause significant changes in marine ecosystems, with coral reefs suffering great losses and many species unable to adapt or survive the rapidly changing environments.
• Discuss how the Late Devonian Extinction influenced subsequent evolutionary trends during the Carboniferous period.
  • The Late Devonian Extinction created ecological niches that allowed for new species and groups to emerge during the Carboniferous period. With many dominant marine species gone, there was less competition, enabling different fish lineages and early amphibians to flourish. Additionally, the decline of certain plants during this time led to diverse adaptations in terrestrial flora that would shape future ecosystems.
• Evaluate the significance of understanding mass extinctions like the Late Devonian Extinction for modern biodiversity conservation efforts.
  • Understanding mass extinctions like the Late Devonian Extinction is crucial for modern biodiversity conservation because it provides insights into how ecosystems react to rapid environmental changes. By studying past extinctions, scientists can identify patterns in species vulnerability and resilience, informing current conservation strategies aimed at protecting endangered species from human-induced threats such as climate change and habitat destruction. This historical perspective underscores the importance of maintaining healthy ecosystems to prevent future mass extinctions.

Related terms

Devonian Period: The Devonian Period, often called the 'Age of Fishes,' lasted from about 419 to 359 million years ago and is characterized by significant advancements in fish diversity and the first appearances of amphibians.

Marine Biodiversity: Marine biodiversity refers to the variety of life forms in ocean ecosystems, which experienced drastic changes during the Late Devonian Extinction due to the loss of numerous species.

Mass Extinction: A mass extinction is a relatively rapid and widespread decrease in the biodiversity on Earth, with significant losses of species across various taxonomic groups, often triggered by catastrophic events or environmental changes.