Dinosaurs’ Time Begins with Another Extinction
Massive volcanic eruptions 233 million years ago released carbon, methane, and water vapor into the earth’s atmosphere. These violent eruptions, which we know to be happening on the west coast of Canada today, caused global warming. According to a new study, this incident affected the course of the planet, causing a mass extinction that killed the dominant quadrupeds and led to the dawn of the dinosaurs.
The last known mass extinction occurred in the late Cretaceous period 66 million years ago. This was the period when dinosaurs, pterosaurs, marine reptiles, and ammonites disappeared. This event was caused by a dark and cold by shutting off sunlight outside the impact of a giant asteroid that first hit the earth. All this was followed by great turmoil in the oceans and atmosphere.
Geologists and paleontologists agree that five more events ended in the mass extinction that took place during the Cretaceous period. Although the discovery of previously unknown mass extinction is an unexpected development, this event is called the Carnian Pluvial Event (Carnian Precipitation Period), and it seems that the species that were killed by the giant asteroid also disappeared during this period. Ecosystems on land and sea were greatly affected by this event as the planet warmed and became a drier place.
This event triggered radical changes in terrestrial plants and herbivores. In contrast, with the decline of dominant plant-eating tetrapods such as rhinos, the dinosaurs were given the environment for emergence.
Dinosaurs appeared about 15 million years ago, and research shows that as a result of CPE, they expanded rapidly over the next 10 million to 15 million years and became the dominant species in terrestrial ecosystems. In short, the CPE, which lasted 165 million years, is the real event that triggered the “age of the dinosaurs”.
Of course, dinosaurs weren’t the only ones walking the planet in this new order. Many modern quadrupedal groups, such as turtles, lizards, crocodiles, and mammals, date back to this newly discovered era.
This incident was first noticed in the 1980s. However, the event was thought to be limited to Europe. First, geologists in Germany, Switzerland, and Italy noticed a large decline in marine fauna around 232 million years ago in what was called the Rheingraben event.
Later, in 1986, it was independently concluded that there was a global decline between tetrapods and ammonites. But at the time, the determination was much weaker than it is now, and it was impossible to be sure whether the two were the same event.
The puzzle pieces began to settle in the UK and parts of Europe when some of the humid climates of about 1 million years were discovered by geologists Mike Simms and Alastair Ruffell. Later, geologist Jacopo dal Corsospot determined a link between the timing of the CPE and the eruptions of the Wrangellia basalt.
Wrangellia is a narrow tectonic plate connected by geologists to the west coast of the North American continent, north of Vancouver and Seattle.
Finally, with a review of evidence from rocks dating back to the Triassic era, the trace of CPE has been found not only in Europe but also in South America, North America, Australia, and Asia. This was far from being a purely European event. This event was global.
Large eruptions of Wrangellia sprayed carbon dioxide, methane, and water vapor into the atmosphere, causing global warming and worldwide precipitation increases. There were five eruption pulses associated with warming peaks from 233 million years ago. The eruptions caused acid rains as volcanic gases mixed with rainwater, washing the Earth with dilute acid. Thus, the shallow oceans were acidified.
This powerful warming took plants and animals away from the tropics; ocean acidification attacked all marine organisms with carbonate skeletons, while acid rain killed plants on land. This peeled off the surfaces of the oceans and land. As life began to recover fully, when the eruptions ended, temperatures remained high as tropical rains ceased. This is what caused the soil on which the dinosaurs flourished to dry up later.
The most unusual thing was the regeneration of carbonate surfaces in the sea. This is a spherical mechanism in which calcium carbonate forms large limestone thicknesses and provides materials for organisms such as corals and mollusks to build their shells. In light of this information, it suggests that the CPE is leading to fundamental changes in ocean chemistry, marking the beginning of modern coral reefs and most modern plankton groups.
Before the CPE, the main source of carbonate in the oceans came from microbial ecosystems such as limestone-dominated mud mounds on continental shelves. But after the CPE, this was provided by coral reefs and plankton. This led to the emergence of new groups of micro-organisms such as dinoflagellates.
This drastic change in the basic chemical cycles of the oceans was the beginning of modern marine ecosystems. From all this, we can learn important lessons about how to help our planet survive climate change.
But first, geologists need to investigate the details of Wrangellia volcanic activity and understand how these repeated eruptions are driving the climate and changing the Earth’s ecosystems. A series of volcanic-induced mass extinctions have taken place in the history of the world, and the resulting physical disturbances such as global warming, acid rain, ocean acidification are also challenges we face today.
Paleontologists will need to work harder on data they gather from fossils from the sea and continents. This will help us understand how the crisis impacted terms of biodiversity loss, while also making it easier to understand how the planet has recovered and has recovered from then to this time.