Tag Archives: Mass Extinction

In 1981, Luis (left) and Walter Alvarez collected samples of layered sedimentary rocks in Gubbio, Italy, at the 65-million-year-old boundary between the Cretaceous (lower) and Paleogene (upper, formerly called Tertiary) geologic time periods.
1980: The Alvarez Hypothesis – Linking Asteroid Impact to Mass Extinction

The Alvarez Hypothesis suggests an asteroid impact caused the mass extinction at the K-Pg boundary, highlighted by the high iridium levels in Italian clay and the Chicxulub crater discovery

An artist’s depiction of a large asteroid striking Earth, representing the end of the Cretaceous and the start of the Paleogene period in geologic history, about 65 million years ago
c. 65 Million BCE: The Asteroid Impact and the Demise of the Dinosaurs

The extinction of dinosaurs 65 million years ago, marking the Cretaceous-Paleogene boundary, is attributed to a large asteroid impact, evidenced by global iridium deposits. This event led to dramatic climatic changes and the demise of [...]

A scenic pastoral landscape in the Western Ghats Mountains of southern India, showcasing the layered volcanic hills of the Deccan Traps
c. 66 Million BCE: The Deccan Traps – A Volcanic Phenomenon

The Deccan Traps, an example of massive volcanic activity, dramatically altered Earth's landscape and climate, potentially contributing to the mass extinction at the end of the Cretaceous period, showcasing the interplay of gradual and catastrophic [...]

A close-up microscopic image of a small, fossilized tooth from a conodont, a jawless, eel-like vertebrate from the Triassic period.
c. 200 Million BCE: The End Triassic Extinction – A Turning Point in Earth’s History

Discusses the End Triassic mass extinction event over 200 million years ago, which led to the extinction of half the species on Earth, including many archosaurs and marine species, paving the way for the rise [...]

A fossil of tabulate coral from just before the end of the Permian period, when it, along with 96 percent of marine species, went extinct.
c. 252 Million BCE: The Great Dying – Earth’s Largest Mass Extinction

Discusses The Great Dying, the largest mass extinction event around 252 million years ago, which wiped out approximately 96% of ocean species and 70% of land vertebrates, with various hypotheses about its causes and its [...]

Volcanic eruptions, continental glaciations, asteroid impacts, and ocean chemistry shifts potentially caused the End Ordovician and late Devonian mass extinctions, each eliminating 70-85% of species 450 and 360 million years ago
c. 450 Million BCE: nderstanding Mass Extinctions in Earth’s History

Delves into the history of mass extinctions, highlighting the catastrophic End Ordovician event 450 million years ago that wiped out up to 85% of species, mainly shallow water and planktonic marine organisms, likely due to [...]