Massive volcanic eruptions more than 230 million years ago triggered ‘mega monsoons’ that wiped out half of the Earth’s animals and fuelled the rise of the dinosaurs, new study reveals 

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  • Carnian pluvial episodes (CPE) let dinosaurs dominate Earth 230M years ago
  • Researchers believe the CPE involved a ‘mega monsoon’ with extreme rainfall
  • They have linked volcanic events to environmental changes caused by CPE.

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A new study claims that the rise of dinosaurs was driven by large volcanic eruptions and ‘mega monsoons’ 230 million years ago.

Researchers from the University of Birmingham analyzed sediment and fossil plant records from a lake in the Jiyuan Basin in northern China.

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Chemical signatures in records, suggestive of volcanic pulses, relate to environmental changes forming the Carnian Pluvial Episode (CPE).

The CPE was a global crisis that occurred 234 million to 232 million years ago, during the late Triassic period, before continental drift when the world’s continents collided together.

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These included ‘mega monsoons’ of intense rainfall, as well as increases in global temperature and humidity due to the release of greenhouse gases.

It was a time of major volcanic eruptions, sudden changes in global climate, and mass extinctions for plants and animals. life, but it paved the way for dinosaurs to become the dominant species, researchers say.

Ecological change paved the way for dinosaurs to become the dominant species after intense volcanic activity during the Carnian pluvial episode 230 million years ago

The CPE also coincides with the founding of modern conifers, the group of cone-bearing seed plants that dominated the landscape when the dinosaurs flourished.

The Carnian Pluvial Episode

The Carnian Pluvial Episode (CPE) was a global environmental change and biological crisis that occurred during the Late Triassic period of 234 million to 232 million years.

It was a time of major volcanic eruptions, sudden changes in global climate, and extinctions.

This was accompanied by an increase in global temperature and humidity, massive volcanism and the ascent of dinosaurs.

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The new study is led by Professor Jason Hilton of the University of Birmingham’s Geography, Earth and Environmental Sciences.

“During CPE, the atmosphere became wetter and the lakes became deeper and larger, with these conditions favoring wetlands and aquatic species,” he said.

‘After the CPE season and atmosphere returned to drier conditions, terrestrial species adapted to the drier environment.

‘We see widespread turnover in plant and animal species during and after the CPE. As the situation has changed, dinosaurs and modern conifer families are the groups that have benefited from the globally drier conditions that occurred after the CPE.’

As well as benefiting the dinosaurs, CPE also helped in the development of terrestrial ecosystems and animal and plant life – including ferns, crocodiles, turtles, insects, and the first mammals.

Although the existence of the CPE is already known, this new paper ‘strongly shows’ that the CPR was largely driven by volcanism, which was split into four distinct episodes and spanned over a period of two million years, Professor Hilton told MailOnline.

“Each pulse of a volcano was accompanied by large-scale disturbances in the carbon cycle and changes in global climate and atmosphere,” he said.

Examples pollen, spores, and algae from the Carnian pluvial episode in China that recorded climate and environmental change after massive volcanism

Example pollen, spores, and algae from Carnian pluvial episodes in China that record climate and environmental change after massive volcanism

For the study, the research team examined terrestrial sediments from the ZJ-1 borehole in the Jiyuan Basin in northern China.

They used uranium-lead zircon dating and high-resolution chemostratigraphy – a technique to determine chemical variations within sedimentary rock – as well as Paleontological data (study of particles such as pollen and spores).

They found a correlation between terrestrial conditions in the Jiyuan Basin with large-scale volcanic activity in North America at the same time.

The most likely source of this volcanic activity was large eruptions in the Wrangelia large igneous province in North America, which was then west of the ‘supercontinent’ Pangea.

The CPE was a global crisis that occurred 234 million to 232 million years ago, during the late Triassic period, before continental drift when the world's continents collided together.  The volcanic eruptions that caused the CPE probably began in Wrangelia (labelled as 1 on the map), west of the supercontinent Pangea.

The CPE was a global crisis that occurred 234 million to 232 million years ago, during the late Triassic period, before continental drift when the world’s continents collided together. The volcanic eruptions that caused the CPE likely began in Wrangelia (labelled as 1 on the map), west of the supercontinent Pangea.

When did dinosaurs appear?

The origin of dinosaurs has been debated for a long time. It is agreed that the Triassic began with dinosaurs everywhere.

Although dinosaurs have been around since the beginning of the Triassic period, about 245 million years ago, they were relatively rare at this point in history.

About 232 million years ago, dinosaurs were explosively diverse, so the CPE essentially marks the beginning of the ‘Age of the Dinosaurs’ and their 165 million-year rule of Earth.

Source: Geological Society

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The results showed that there were four distinct episodes of volcanism during this period – based on mercury concentration data used as a proxy for eruptions – each associated with massive releases of carbon dioxide (CO2) into the atmosphere. Is.

Professor Hilton explained, ‘In the borehole core we studied, we sampled the rock to examine its chemistry and microfossils as evidence of environmental change.

‘Each pulse of the volcano is marked by changes in the carbon cycle and each has a peak in concentration of the toxic metal mercury.

The mercury emanated from the volcano and was eventually deposited into the lake directly from the atmosphere or washed into the lake by the surrounding land.

‘Microorganisms include pollen and spores produced by plants living in and around the lake, as well as cysts of algae that live in it.’

Microfossils revealed that each pulse of the volcano was marked by changes in…

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