A New Mass Extinction Event Has Been Discovered - Carnian Pluvial Episode

Does anyone know how many mass extinctions this makes? The article doesn’t say and I haven’t studied it, but I’m curious. 8? If anyone has a good, very current resource that explains each in a timeline, I’d be grateful.

Abstract:

The Carnian Pluvial Episode (Late Triassic) was a time of global environmental changes and possibly substantial coeval volcanism. The extent of the biological turnover in marine and terrestrial ecosystems is not well understood. Here, we present a meta-analysis of fossil data that suggests a substantial reduction in generic and species richness and the disappearance of 33% of marine genera. This crisis triggered major radiations. In the sea, the rise of the first scleractinian reefs and rock-forming calcareous nannofossils points to substantial changes in
ocean chemistry. On land, there were major diversifications and originations of conifers, insects, dinosaurs, crocodiles, lizards, turtles, and mammals. Although there is uncertainty on the precise age of some of the recorded biological changes, these observations indicate that the Carnian Pluvial Episode was linked to a major extinction event and might have been the trigger of the spectacular radiation of many key groups that dominate modern ecosystems.

Paper:
https://advances.sciencemag.org/content/advances/6/38/eaba0099.full.pdf

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There have been five mass extinctions during which a large proportion of species and higher taxonomic groups rapidly (by geological standards) died out. Some people argue that we currently find ourselves in a human-caused sixth mass extinction event.

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There have of course been other extinction events; those are the major ones, and the actual number depends on what standard you set for “major”. The end-Permian stands apart from all the others. I wonder how the Carnian compares in magnitude to the Frasnian-Famennian (one extinction or two?), etc.

And it may be that there were such events before the Phanerozoic that we can’t easily see. One would think that both the snowball earth and the oxygenation of the atmosphere would lead to mass extinctions, but how would we know about them?

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Is that before or after the one described? Why does it stand out?

Before, and because it was much bigger than all the others. I’m suspecting that the article @davecarlson posted talks about all that.

Incidentally, according to YEC none of these extinctions actually happened, since the fossil record is just the result of some kind of sorting of species that all existed at the same time. That’s another reason to reconsider YEC.

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An estimated 90% of all life went extinct

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If a species gets wiped out, does its genetics as well or could a higher or different life form evolve those same characteristics that had disappeared?

I’m probably not asking a very clear question. Hopefully you can make some sense of it.

Afraid I can’t. Of course its genetics is wiped out; genomes are contained within organisms and have no separate life. Then again, convergence happens, and similar features may evolve in different species, though usually the similarities are not at the genetic level.

Basically what @John_Harshman said. Once a lineage is gone it’s gone for good, barring any human shenanigans like cloning Wooly Mammoths or something similar. Almost certainly, the specific combination of features unique to that species is lost and cannot be recovered. Of course, some relatively similar features may arise in other lineages, as in the the flying squirrels and sugar gliders, which are not closely related at all but look (and behave?) somewhat similar.

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Ok, thanks. I still have a question. So if the lineages were lost early and species began to evolve more complexity after that why couldn’t they recover any complexity they already had?

Does evolution basically give it a particular direction it’s stuck in then?

This isn’t about complexity. Evolution isn’t a ladder of increasing complexity, and mass extinctions do not preferentially remove complex species. So it isn’t clear what you’re getting at.

Give what a particular direction? And “huh?”

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Apparently I’m stuck thinking like a creationist and I need to study this topic more. Thanks. It helps to know my questions are the wrong ones.

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There is no reason to think that the species that went extinct were in any way more ‘complex’ (whatever that means) than those species that survived the event.

What is interesting is that right after such major extinction events we see evolution accelerating in the sense that the rate at which new species come into being is significantly faster compared to what was happening just before the extinction. The extinction left many niches empty and evolution rapidly moved in to fill them up again.

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Yes, I didn’t mean that the species that went extinct were more complex, I meant that if genetic diversity was lost, why didn’t subsequent life regain the lost diversity?

Your answer seems to be that they evolved particularly to the new climate?

Am I anywhere near the ball park?

Subsequent life, seen as a whole, did regain diversity, and it did so very quickly because so many niches became empty. Of course the new species adapted to whatever the conditions were after the extinction.
You can read a bit more about this here.

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It did regain diversity, just not the same species re-appearing. That would be weird. After an extinction, evolution has a different starting point than evolution before the extinction. If tyrannosaurus disappears, there’s no reason to expect a shrew (or its early Tertiary equivalent, not actually a shrew) to turn into a tyrannosaurus. But shrews (equivalent) did eventually turn into lions, wolves, and other predators. That’s how diversity is regained.

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Yes, but much more besides. The changing environment for an animal largely consists of other animals - predators, parasites, scavengers, symbiotic relationships, and competitors for the same resource. When that is disrupted, there is a world of difference in terms of selective pressures.

So if a grazer becomes extinct, that opens up that niche. But the previous occupant might have relied on a bony hide as a defense, the new creature has a very different history and, depending on the starting point of the organism, may rather adapt with agility and speed. Then the predators adapt counter measures of their own. You end up with organisms which probably appear very different, even if the ecological niches are quite similar and convergence can be identified.

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