Late Devonian Extinction

Definition

The Late Devonian Extinction refers to a series of events during the Late Devonian period, approximately 375 to 360 million years ago, that led to significant loss of biodiversity in marine and terrestrial ecosystems. This extinction is marked by multiple pulses of extinction, impacting various species, particularly marine life such as corals, trilobites, and jawless fish, which contributed to profound changes in the structure of aquatic environments.

5 Must Know Facts For Your Next Test

1. The Late Devonian Extinction is considered one of the five major mass extinctions in Earth's history, with significant losses in marine species.
2. It is believed that environmental changes such as global cooling, sea-level fluctuations, and possibly asteroid impacts played a role in triggering the extinction.
3. Some studies suggest that up to 75% of all species were lost during this extinction event, particularly affecting reef-building organisms.
4. This extinction event unfolded over a prolonged period with multiple phases rather than occurring in a single catastrophic moment.
5. Following the Late Devonian Extinction, ecosystems underwent significant restructuring, leading to the rise of new species and communities during the subsequent Carboniferous period.

Review Questions

• Compare the Late Devonian Extinction to other mass extinctions in terms of its timing and impact on marine biodiversity.
  • The Late Devonian Extinction occurred approximately 375 to 360 million years ago and is one of the five recognized mass extinctions. Unlike some other mass extinctions, which often happen rapidly, the Late Devonian Extinction unfolded over a longer time frame with multiple extinction pulses. It significantly impacted marine biodiversity by causing the loss of around 75% of species, especially those dependent on reef ecosystems, highlighting a shift in the structure and composition of marine life compared to previous extinction events.
• Analyze the potential causes of the Late Devonian Extinction and discuss their implications for understanding mass extinction events.
  • The potential causes of the Late Devonian Extinction include climatic changes such as global cooling and fluctuations in sea levels, along with possible impacts from celestial bodies like asteroids. These factors led to significant habitat disruptions in marine environments and are key to understanding how changes in Earth's systems can drive mass extinction events. Studying these causes provides insight into resilience and vulnerability in ecosystems, which can inform current conservation efforts amidst modern biodiversity crises.
• Evaluate the long-term ecological consequences of the Late Devonian Extinction on subsequent evolutionary trends in terrestrial and marine ecosystems.
  • The long-term ecological consequences of the Late Devonian Extinction were profound, leading to shifts in evolutionary trends for both marine and terrestrial ecosystems. The loss of dominant reef-building organisms allowed for new species to flourish in their absence, which contributed to increased diversity during the Carboniferous period. Additionally, changes in available niches prompted evolutionary innovations, including the rise of more complex terrestrial flora and fauna. This restructuring laid the groundwork for future biodiversity patterns and ecosystem dynamics seen throughout Earth's history.

Related terms

Devonian Period: A geological period that lasted from about 419 to 359 million years ago, known for the diversification of fish and the early appearance of amphibians.

Biodiversity: The variety and variability of life forms within a given ecosystem or on Earth as a whole, crucial for maintaining ecological balance.

Mass Extinction: A widespread and rapid decrease in the biodiversity on Earth, characterized by the extinction of a large number of species across various habitats.