Non-marine animals (amphibians, reptiles, birds and mammals) have experienced at least 10 extinct parts in the last 300 million years. Eight of these extinction events coincide with the known marine mass extinction, which was previously evidenced for the final period between 26.4 and 27.3 million years ago. In the new research, a team of scientists from New York University and the Carnegie Institution of Science analyzed ten valid non-marine mass extinctions and found a statistically significant underlying period of 27.5 million years; They also found that this mass extinction coincided with asteroid effects and destructive volcanic eruptions of lava that erupted into flood-basalt eruptions.
Ankylosaurus magnigantris, A large armed dinosaur species, has witnessed the impact of asteroids falling on the Yucatan Peninsula 66 million years ago. Image Credit: Fabio Manuchi.
“It looks like the pulses of large-body effects and the inner-Earth activity that created the flood-basalt volcano could move toward the same extinct 27-million-year-old drumbeat, perhaps running from our orbit in the galaxy.” Professor Michael Rampino, lead author and researcher in the Department of Biology, New York University.
About 60 million years ago, as a result of the catastrophic collision of a giant asteroid or comet with the Earth, 70% of all species on land and in the ocean, including non-avian dinosaurs, suddenly became extinct.
Subsequently, paleontologists discovered that such a large extinction of marine life, in which 90% of the species disappeared, was not a random event, but appears to have occurred in a cycle of 26.4-27.3 million years.
In their new study, Professor Rampino and colleagues examined records of large-scale extinction of land-colonial animals and concluded that they were linked to the extinction of marine life.
They also performed a new statistical analysis of the extinction of land species and showed that these events follow a similar cycle of about 27.5 million years.
What could be the reason for the periodic large-scale extinction of land and sea?
Mass extinction is not just an event that occurs in cycles: the age of impact craters – created by asteroids and comets collapsing on the Earth’s surface – but also follows a cycle aligned with the extinction cycle.
Astrophysicists estimate that periodic comet precipitation occurs in the solar system every 26 to 30 million years, producing cyclonic effects and periodic mass extinctions.
The Sun and the planets cycle through the Milky Way galaxy’s crowded mid-plane in about 30 million years.
During that time, comet rain is possible, causing a major impact on Earth.
Influences can create conditions that will stress and potentially cut off land and marine life, including widespread black and cold, wildfires, acid rain, and ozone depletion.
“These new findings of accidental, sudden mass extinctions on land and in the oceans, and the cycles of normal 26 to 27 million-year cycles, support the idea of periodic global catastrophic events for reasons of extinction,” the professor said. Rampino said.
“In fact, the three mass extinctions of species on land and at sea are known to have occurred at the same time as the three greatest influences of the previous 250 million years, each capable of causing global extinction and resulting in mass extinction. ”
Scientists were surprised to find possible explanations for mass extinction other than asteroids: flood-basalt eruptions, or massive volcanic eruptions covering large areas with lava.
Eight mass-extinction of land-colonies and marine animals matched at the time of the flood-basalt eruption.
These eruptions would also have created severe conditions for life, including severe cold, acid rain and ozone depletion and increased radiation; Long-term, outbreaks can lead to deadly greenhouse heat and more acid and less oxygen in the ocean.
Professor Rampino said the disappearances of the global mass were apparently caused by the biggest catastrophic effects and large-scale volcanoes, perhaps sometimes working in concerts.
The research is published in Hist Historical Biology, International Journal of Palebiology.
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Michael R. Rampino Et al. The extinction episode of Non-Marine Tetrapods found a periodic under 27.5-M. .Historical Biology, December 10, 2020 published online online; doi: 10.1080 / 08912963.2020.1849178
