Fossilized Fish Inhaled Meteorite Ejecta

[kerbiloid]

13 hours ago, Green Baron said:

when you're into reading, let me recommend

https://www.amazon.com/Vertebrate-Palaeontology-Michael-Benton/dp/1118406842/ref=sr_1_1?crid=13SJ3JD2KG4BK&keywords=vertebrate+paleontology+benton&qid=1553977525&s=gateway&sprefix=benton+pal%2Caps%2C257&sr=8-1

Spoiler

I'm not reading, I'm writing.

Does it explain that dinos died, while others not?
If yes - it probably takes several lines to quote.
If no - maybe I'll read it a little later.

[Green Baron]

5 minutes ago, kerbiloid said:

  Hide contents

I'm not reading, I'm writing.

Read more, write less ;-)

 

[kerbiloid]

3 minutes ago, Green Baron said:

Read more, write less ;-)

So, just another "read this library" advice.

[Green Baron]

19 minutes ago, kerbiloid said:

Does it explain that dinos died, while others not?

It is not pop science.

[kerbiloid]

1 minute ago, Green Baron said:

It is not pop science.

So, "No".

[MinimumSky5]

No, it's saying 'here are several pages describing the hypotheses behind the K-Pg extinction mechanisms, and we will not be giving you a firm answer, because that would be dishonest, as no one has a firm answer' 

Not all questions in science can be answered with a simple sentence, many of them require whole books to explain. We're not passing you off here, we're directing to to the best answer that we can give i.e. it's complicated! 

Oh, and the idea that the dinosaurs were at a low species diversity during the Late Maastrictian is just bad science IMO. We do only have one good Lägerstatten from that age (the Morrison Formation, from which we get our aquatic friends mentioned in the OP), but that could simply be a sampling bias. Here in Britain we have no rocks of that age, and continental Europe is similarly impoverished, so drawing conclusions based on that, doesn't seem very scientifically valid. 

[Green Baron]

1 hour ago, MinimumSky5 said:

No, it's saying 'here are several pages describing the hypotheses behind the K-Pg extinction mechanisms, and we will not be giving you a firm answer, because that would be dishonest, as no one has a firm answer' 

Exactly.

Quote

Oh, and the idea that the dinosaurs were at a low species diversity during the Late Maastrictian is just bad science IMO. We do only have one good Lägerstatten from that age (the Morrison Formation, from which we get our aquatic friends mentioned in the OP), but that could simply be a sampling bias. Here in Britain we have no rocks of that age, and continental Europe is similarly impoverished, so drawing conclusions based on that, doesn't seem very scientifically valid. 

The focus on North America in the late Cretaceous is an artefact that narrows the global view on dinosaur diversity, that is correct, but actually clades had declined before the event, groups from their "high time" in the late Jurassic and early Cretaceous were already gone. But you are right, there still was enough diversity among them, Ceratops and Hadrosaurus roamed about.

https://www.researchgate.net/publication/278018238_Diversity_of_late_cretaceous_dinosaurs_from_Mexico

https://www.nature.com/articles/ncomms1815

-----------

Ah, look at that. A surprisingly fresh work supporting your argument (again North America) even suggests little diversity decline, from climate and niche modelling (open access):

https://www.nature.com/articles/s41467-019-08997-2

Interesting, interesting (starts reading)

:-)

Ok. Less spectacular than i thought.

The main thing that's missing now are find sites, deposits, to document a similar diversity in the upper Cretaceous like in the Jurassic and lower C.

Edited March 31, 2019 by Green Baron

[Green Baron]

@kerbiloid: I just read it up. Though the book is about vertebrate evolution in general Benton dedicates ~8 pages to the extinction event, discussing gradual as well as catastrophic models because it is much under research. Most has been said already here, as @MinimumSky5 said, it is not easy and the record is not equally well everywhere. It is especially difficult if not impossible to identify survival rates and reasons of certain groups among others, as nearly all groups marine and on land where affected, but reptiles in general and plesio-, ptero- and dinosaurs in special got an obliterating blow (100%), but birds and marsupials where cut by 75% as well, if that pleases you :-)

Ichtyosaurs were already gone by the mid of the Cretaceous, pterosaurs and plesiosaurs and other groups like mussels, ammonites, had already contracted before the event. Some situations like the in the OP show a catastrophic event, lasting hours to months, others a more gradual, spanning up to 5-10 million years. If this is a view on reality or an artefact because of the find- and dating situation is an open question.

I won't go in detail about dating methods and other uncertainties because derail and so :-)

There are ~200 K/Pg profiles worldwide, marine or terrestrial, though by for not all with fossils, and all show the same sequence.

:-)

Edited March 31, 2019 by Green Baron

[kerbiloid]

7 hours ago, MinimumSky5 said:

No, it's saying 'here are several pages describing the hypotheses behind the K-Pg extinction mechanisms, and we will not be giving you a firm answer, because that would be dishonest, as no one has a firm answer' 

Not all questions in science can be answered with a simple sentence, many of them require whole books to explain. We're not passing you off here, we're directing to to the best answer that we can give i.e. it's complicated! 

Oh, and the idea that the dinosaurs were at a low species diversity during the Late Maastrictian is just bad science IMO. We do only have one good Lägerstatten from that age (the Morrison Formation, from which we get our aquatic friends mentioned in the OP), but that could simply be a sampling bias. Here in Britain we have no rocks of that age, and continental Europe is similarly impoverished, so drawing conclusions based on that, doesn't seem very scientifically valid. 

Probably I should explain something, regardless of dinos and other meat. (At last they are dead, and that's fine, whoever killed them.)

There is always a difference between the "claim" (i.e. "cross my heart, that's so") and the "working hypothesis" ("at the moment I find this hypothesis the most reasonable and consider it as the main one").
Before making a final claim you have to check various hypotheses and to reject all but one (a deduction).
You may have as many intermediate hypotheses as you need. 

At the beginning of any investigation, scientific or not, you have just scattered random facts, and no clue about what's happened.

While you keep gathering facts, a pattern appears, and you make the initial working hypothesis.
Just to have a thread to keep your pearls together.

You do not claim that it's right, no. You understand that very possibly it's incorrect. If that's so, this will reveal later.
But it's the first approximation which you should follow it, perhaps without fanatism.

You are following your current working hypothesis and trying to use the new facts for its explanation.
You keep in mind that the explanation may appear wrong, but this doesn't matter. 

Because following a wrong working hypothesis you will just reach some place where you obviously see that the working hypothesis contradicts the collected facts, and should be replaced.
And as a bonus you have proven by contradiction an alternative hypothesis, and disproven by reductio ad absurdum the working one.

Because a clear draft line is better than chaotic "we dunno!", "things are way more complicated!" and so on.
If the alchemists were awaiting for periodic table, the humans would still be prehistorical savages.
It's much, much better to "mate the blue dragon with the red queen" than just to mix substances without a system.

So, you are making working hypotheses one by one, and trying to keep following the most reasonable of them.

You keep collecting facts. Some of them contradict your working hypothesis. 
It's normal. It doesn't disprove it. 
It just means that there are facts requiring an additional explanation, which at the moment don't match with your hypothesis. Nothing more.
Later you will either reveal the facts were incorrectly prepared or described, or that there is already a critical mass of such facts making you to extend or replace your working hypothesis.

But this doesn't mean that any scientific or another local result which contradicts the current working hypothesis immediately disproves it. No.
Things may be complex, but their explanation is always logical.  

So any "But a year ago John Doe has published an article which contradicts this hypothesis! Read this article in arxiv and feel wrong!" is just a noise.
Because if you ask John's colleague Jane Doe from the same academic serpentarium, she will explain that John never had a clue what he's saying, and the things are absolutely different, as you can see in Jim Doe's article published two years ago.
This doesn't depend on their academic or another status.

Only once the facts contradicting your hypothesis get enough numerous to create an alternative explanation of facts, they mean something and make you to change your working hypothesis.
Until that they are a set of raw facts requiring an explanation. Which may be true but may be false. 
(The continental drift hypothesis was rejected by every true scientist until the collected facts became so numerous that made to treat it as the main hypothesis and start laughing at those who was believing them before.
Try to seriously claim now that the continents don't move.)

At last your current working hypothesis faces less and less contradicting facts.
Then you can make a claim that the the things have happened this way [and send the prepared papers to the court, lol]

At once I can see only one reasonable explanation of the described problem which I'd described in that long post.
It's not a claim, it's the only reasonable working hypothesis which I've found and shared.

If you know another working hypothesis clearly explaining these events, feel free to share it.

Probably you know the facts which contradict it, I don't argue with that, you know better.
But until they form an alternative clear working hypothesis explaining the same, they are a set of raw facts mismatching the posted hypothesis and requiring further investigation and explanation. 
Nothing more even if all academicians of the world are promising that this doesn't work this way.

Of course, emotional manipulative "arguments" like "nonsense", "this doesn't work so", "read the library first" are a white noise and by definition → /dev/nul.

P.S.
Of course, maybe they taught you another way.

Edited March 31, 2019 by kerbiloid

[Scotius]

In other words - nothing conclusive. Some taxa declined, some were stable, some have been on the rise. And every continent had its own set of trends. I'd say it looks pretty normal for a healthy biosphere. Nothing really alarming or indicating looming disaster. The mere fact that sauropods managed to remain a significant part of the biosphere, despite the increasing competition from more advanced herbivores (hadrosaurids and ceratopsians) says to me dinosaurs still had a firm grip on their respective niches. Same with pterosaurs. Dying taxon seems unlikely to produce environmentally demanding genera like gigantic azdarchids (Hatzegopteryx for example).

[Green Baron]

 

http://www.sciencemag.org/news/2019/04/astonishment-skepticism-greet-fossils-claimed-record-dinosaur-killing-asteroid-impact

There's no original text on the PNAS site yet. where the original paper should be published ...

[wumpus]

20 hours ago, kerbiloid said:

Because a clear draft line is better than chaotic "we dunno!", "things are way more complicated!" and so on.

If the alchemists were awaiting for periodic table, the humans would still be prehistorical savages.
It's much, much better to "mate the blue dragon with the red queen" than just to mix substances without a system.

I have no reason to believe that any alchemical system caused *any* advancement.  Presumably specific reactions were remembered, and the overall goal of transmuting metals kept them in the lab, but the overall system was fundamentally useless.

Phlogiston chemists, on the other hand had a quite useful system.  They had a pretty good grasp of plenty of reactions, only had them completely backwards (their "phlogiston" was actually the absence of oxygen).

[Green Baron]

2 hours ago, wumpus said:

I have no reason to believe that any alchemical system caused *any* advancement.

There are rumours that the European version of the gunpowder was "accidentally" invented when someone (some guy named Berthold Schwarz) tried to transform coal into cold (and paid for it). This, of course, is no defence for alchemy.  And it is just an unclear tell-tale, its not clear if he even existed. And one can debate whether the invention of gunpowder was an advancement.

Edited April 1, 2019 by Green Baron

[Listy]

5 hours ago, Green Baron said:

 

http://www.sciencemag.org/news/2019/04/astonishment-skepticism-greet-fossils-claimed-record-dinosaur-killing-asteroid-impact

There's no original text on the PNAS site yet. where the original paper should be published ...

It's in the early access / pre-print section for now, which may require a subscription to access, but the link is below. I imagine it will be published with the next issue of PNAS in a few days.

"A seismically induced onshore surge deposit at the KPg boundary, North Dakota"; Robert A. DePalma et al.

https://www.pnas.org/content/early/2019/03/27/1817407116

I had a quick read - it sounds like a remarkably well preserved site & likely captures the immediate aftermath of the Chicxulub impact (eg there are a couple of impressive looking CT scans of a fish gill fossil full of tiny glassy spherules, that might be impact ejecta) but I'm no paleontologist so I'll leave any further interpretation to the experts.