Legal Insurrection readers will recall I have covered the five great mass extinction events throughout geologic history, including the “Great Dying” at the end of the Permian era and the asteroid-induced wipeout of the dinosaurs.
Scientists have uncovered evidence of a 6th mass extinction event. Shockingly, it has nothing to do with mankind or Paul Erlich.
The Ediacaran Period’s odd animals never got their chance to shine, thanks to a precarious drop in oxygen levels about 550 million years ago that triggered the first-ever extinction event. At least, that’s the latest theory. A recent study has announced the discovery of an extinction event preceding all five of Earth’s other known mass extinction events.The study, published in November 2022 in the Proceedings of the National Academy of Sciences, merged research from Virginia Tech and the University of California Riverside to reach the conclusion that the Ediacaran Period—which stretched from 635 million to 540 million years ago—saw the extinction of about 80 percent of all animals.“This included the loss of many different types of animals, however those whose body plans and behaviors indicate that they relied on significant amounts of oxygen seem to have been hit particularly hard,” Scott Evans, lead researcher on the study, says in a news release. “This suggests that the extinction event was environmentally controlled, as are all other mass extinctions in the geologic record.”
Scientists point to the staggering 80% loss of species diversity between the White Sea stage of the Ediacaran Period and the last stage of that period, known as the Nama (550 to 539 million years ago), indicating a significant global environmental shift.
Past research has suggested that this decline may have been the result of mobile animals that burrowed or left trace fossils, which profoundly altered the environment and slowly replaced sessile filter feeders. This more recent evidence suggests that was not the case.All types of feeding modes and life habits experienced similar losses, with only 14 genera still seen in the Nama out of 70 known groups from the earlier White Sea stage. If more newly evolved species had taken over, there also would have been temporal overlap between the new and the old species. This wasn’t observed, the team argued, ruling out biotic replacement.”The decline in diversity between these assemblages is indicative of an extinction event, with the percentage of genera lost comparable to that experienced by marine invertebrates during the ‘Big 5’ mass extinctions,” Evans and colleagues wrote.Many of the White Sea animals that survived the extinction event and remained in the Nama period were large, frond-like organisms with a high surface area to volume ratio. This could be a sign these animals were adapting to deal with a reduction in oceanic oxygen.
In other research, scientists have unearthed fossils of an apex predator in South Africa that provides a peek into the conditions of the Permian Era’s “Great Dying.” The tiger-sized, saber-toothed proto-mammal forerunner as known as Inostrancevia, and wandered through Pangea attempting to survive the harsh conditions that followed the eruptions that created the Siberian Traps 252 million years ago.
The mass extinction, occurring over a span of a million years or so, set the stage for the rise of the dinosaurs in the subsequent Triassic Period. Massive volcanism unleashed lava flows across large portions of Eurasia and pumped carbon dioxide into the atmosphere for thousands of years. This caused a spike in worldwide temperatures, depletion of oxygen in the seas and atmosphere, ocean acidification and global desertification.Top predators were especially vulnerable to extinction because they required the most food and space.”They tend to take a relatively long time to mature and have few offspring. When ecosystems are disrupted and prey supplies are reduced or available habitat is limited, top predators are disproportionately affected,” Kammerer said.
As we consider volcanism in conjunction with mass extinctions, I would also like to note that research indicates that eruptions of the Yellowstone supervolcano occur in a series or through multiple vents spewing volcanic material in rapid succession.
Yellowstone volcano is not expected to erupt anytime soon. However, the finding that the Lava Creek eruption may have followed a similar pattern to that of the Huckleberry Ridge Tuff eruption could give an idea of what to expect if and when Yellowstone does blow. “These major caldera-forming eruptions might not be single events at Yellowstone, but instead have multiple phases,” Poland said.Researchers at the volcano now plan to carry out detailed examinations of the newly discovered units and the boundaries between them. This will allow them to paint a more detailed picture of what the Lava Creek eruption looked like — and maybe even what triggered it.
All this death and destruction, yet not one homo sapiens anywhere near when it happened.
CLICK HERE FOR FULL VERSION OF THIS STORY