In a first, researchers have found details about how the Earth’s terrestrial ecosystems recovered following the Cretaceous-Paleogene extinction (K-T extinction) event - which put an end to the reign of the dinosaurs 66 million years ago - and suspect that volcanic eruptions in the Indian subcontinent may have contributed to the recovery.

The researchers, including those from the Denver Museum of Nature and Science in the US, found extremely rare fossils of terrestrial plants and animals who inherited the Earth after the K-T extinction in central Colorado’s Corral Bluffs.

The findings of the study, published in the journal Science, revealed a detailed snapshot of the first million years of recovery of species and their ecosystems following the extinction, showing the dynamic interrelationships of plants, animals and the climate.

What is K-T extinction?

Cretaceous-Tertiary extinction, also called K-Pg extinction or K-T extinction, was a global extinction event responsible for eliminating approximately 80 per cent of all species of animals at or very close to the boundary between the Cretaceous and Paleogene periods, about 66 million years ago. The K-T extinction was characterised by the elimination of many lines of animals that were important elements of the Mesozoic Era (252.2 million to 66 million years ago), including nearly all of the dinosaurs and many marine invertebrates.

How was the study conducted?

Most fossil sites from after the impact have gaps, but sediment accumulated nearly continuously for one million years on the flood plain that is now the Corral Bluffs site. So, the site preserves a full record of ancient life and the environment.

The discovery of an extraordinary treasure trove of fossils near Colorado Springs by Tyler Lyson and Ian Miller from the Denver Museum of Nature & Science reveals in striking detail how life recovered after the catastrophic asteroid impact that wiped out the dinosaurs.

Raccoon-size mammal species had swarmed the site before the catastrophe, but for 1,000 years afterwards just a few furry creatures no bigger than 600-gram rats roamed a ferny world where flowering plants, with their nutritious seeds and fruits, were scarce.

The study also revealed that the recovery was facilitated by a strong link between the planet’s geological cycles and the biosphere.

The team also classified 6,000 leaves, counting how many species at each time interval had smooth or toothed edges. Smooth-edged species are more common in hot climates. The team concluded that the site underwent three warming periods. They estimate that the first, just after the impact, saw temperatures rise about 5 degrees Celsius, agreeing with earlier work. This period coincides with the massive volcanic eruptions of India’s Deccan Traps, which could have warmed Earth by belching carbon dioxide.

“The Deccan Traps of the Indian subcontinent represent repeated and voluminous volcanic eruptions during the post-K-Pg Earth system succession. These eruptions might have induced warming pulses via the release of greenhouse gases,” the researchers said.

According to the study, the Deccan eruptions likely influenced the chemistry of the Earth’s atmosphere, in turn shaping the post-K-Pg ecosystem recovery across the planet.

What are the Deccan Traps?

The Deccan Traps are a large igneous province located on the Deccan Plateau of west-central India. It is one of the largest volcanic features on Earth. Its existence has interested scientists because of the huge amount of lava involved.

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