Temperature Drop Helped Kill Dinosaurs

[HeritageFossils]

Because we need some dissent from the "Only a comet killed the dinosaurs!" theory:

http://www.telegraph.co.uk/science/dinosaurs/7624014/Dinosaurs-died-from-sudden-temperature-drop-not-comet-strike-scientists-claim.html

-YvW

[32fordboy]

I thought the general consensus was that dino would have been warm-blooded? Maybe I'm misinformed...

[Auspex]

I thought the general consensus was that dino would have been warm-blooded?

IMHO, theropods yes, sauropods no.

[Nicholas]

IMHO, theropods yes, sauropods no.

This tends to be the general idea about dinosaurs or at least how I perceive them.

[32fordboy]

Huh, that's interesting. Ya learn something new every day. Thanks!

Nick

[Wakaritai]

1. General consensus among all scientists in the field agree that a large body colliding with earth was the root cause of the end of the dinos.

Apparently some here haven't heard...

but anyway, you should have been tipped off instantly that the claims in the article had very little weight. Consider the following:

"While studying fossils and minerals from the Arctic Svalbard, Norway [...]"

The study only took into account material from a very small area, neither random or representative of the population. 2. The study had nothing to do with extinction. That was not even part of the study whatsoever. The study was about temperature. They said that, from what they gathered, in that area, there was a drop in temperature of X degrees X million years ago. That is all.

The idea of this having caused extinctions is purely that- an idea. It is not even to the point of a hypothesis.

Calm down people. Beware of the wolves

[John]

1. General consensus among all scientists in the field agree that a large body colliding with earth was the root cause of the end of the dinos.

Apparently some here haven't heard...

Actually, that's the consensus of most geoscientists other than vertebrate paleontologists. While the evidence for a bolide impact is excellent, there is a lot of uncertainty about exactly when it happened and what effect it had on the biosphere. Vertebrate paleontologists have been quick to point out that a wide variety of species that, in the modern world, are considered highly sensitive to ecologic change, made it through the K/T boundary. This unusual selectivity has never had a good explanation whether bolide, volcano or anything else. In other words, why did frogs, salamanders and small mammals survive, but most things above 70 kilograms didn't? Complicating the picture further, a number of croc species bigger than 70kg made it through to the Paleocene, but the dinos didn't. Recent work in New Mexico is even challenging the dogma that dinos didn't make it into the Paleocene, but no one knows yet where that will lead.

The other problem with arguing for causation between the bolide impact and the dinosaur extinction is pretty simple. What if the bolide hit 5 minutes after the last dinosaur kicked the bucket? Our ability to resolve geologic time is somewhat limited and the vertebrate record is sufficiently spotty that we can't be sure dinosaurs weren't already in serious decline at the end of the Cretaceous. A bolide may have been the coup de gras, or the dinosaurs may have already been gone.

The real monkeywrench in all of this, though, is the simple fact that we don't understand extinction all that well in the first place. The fossil record has a variety of extinction events that have no bolide or even drastic climate change to act as an easy explanation. The extinction of the Pleistocene megafauna is a good example of an extinction that is hotly debated and has no good explanation at all.

Even in the modern world where we can collect all kinds of data that is impossible to get from the fossil record there are still no easy answers to a lot of extinction patterns we see right now.

Did an asteroid whack the planet about 65 million years ago? Yes.

Does it explain the pattern of extinctions we see at the end of the Cretaceous? Sort of, with unexplained exceptions.

John

[Wakaritai]

There was an impact (among other extreme events) during the time period.

Large animals died.

There is much evidence for the impact being the primary root cause of the extinctions.

There is no evidence that it wasn't.

There is some supporting evidence that shows other events may have caused the extinction, but, most importantly, significant evidence against those hypotheses.

To be possible, an idea can have any amount of data supporting it, but it cannot have any evidence against it.

The impact simply explains everything the most completely, and there is no evidence against it. Therefore, it is the best known explanation.

This is how the scientific process with these things works. Any or none evidence supporting it: possible. Even a tiny shred of evidence against: impossible.

That being said, all that doesn't mean the impact was certainly the primary root cause. Such a claim is a belief, and has nothing to do with science. It is also a belief that such an impact certainly was not the primary root cause of the extinctions.

Aliens could have abducted them or killed them off with high-tech weaponry-- an intergalactic safari, if you will. God may have willed them away. Though those are unfalsifiable, they are possible. But they are unscientific due to the lack of falsifiability. Of course those are extreme examples, but it puts thongs in perspective. I think it all comes from misunderstandings of the scientific process. There are very few knowns, just best explanations. Because research is being done on alternative theories does not mean that the scientists involved believe their hypothesis is true. They are simply ruling things out, to improve the best explanation.

Science is NOT religion. Religion works by different principles.

For religious beliefs: Any or no evidence supporting it: it is absolutely certainly true. Any amount of evidence against (including one): this evidence is ignored, and the belief is still held with absolute certainty.

That doesn't mean that the beliefs held are not true absolutely-- they are just unscientific. God may will there to be evidence against something that actually happened. But testing such ideas is pointless (and, well impossible) as they are not falsifiable.

But, believing something for the sake of believing it (or for spite or coolness factor) is unscientific. Doubt is scientific, belief (either for or against something) is not.

[Auspex]

I'm attracted to the "Multiple Impact" theory, but not wedded to the idea that impact is the only factor in the K-T extinctions.

>Click here for Multi-Impact details<

[Wakaritai]

I'm attracted to the "Multiple Impact" theory, but not wedded to the idea that impact is the only factor in the K-T extinctions.

>Click here for Multi-Impact details<

Thanks for the info.

That also made me think of another thing that catches people. Every extinction has multiple factors. What most scientists in the field are researching is what the most probable primary root cause is. When people see evidence that there were other factors they mistakenly think that it is mutually exclusive to any hypotheses about the primary root cause.

Kind of like a rube goldberg machine. The first action does not directly cause most of the events, but many of those later events would not have occured if the first event didn't occur. The impactor itself didn't smush all the dinosaurs directly, but it caused a chain of events that devastated them. Other factors could have played in by chance (other impacts, volcanos, etc.), but whether all that devastation caused the extinctions is uncertain (though probable). It could have been a completely different scenario that we haven't even come up with yet.