Fossilized Fish Inhaled Meteorite Ejecta

[sevenperforce]

In the flat disc Earth theory thread, we were talking about standards of proof and evidence in the past. Saw this and it reminded me of that conversation. 

https://gizmodo.com/scientists-find-fossilized-fish-that-may-have-been-blas-1833671176

The hypothesis is an asteroid impact that wiped out the dinosaurs.

The evidence is a layer of glass spherules with an iridium-enriched layer of debris and dust above it.

The smoking gun: freshwater and saltwater fish buried together who inhaled glass spherules as they died.

So fascinating!!!

[Shpaget]

Fascinating and, for some reason, very sad. Grim Reaper had a very busy few hours.

Very interesting find. I'm curious how it will impact the future of giant impact hypothesis.

[MinimumSky5]

I'm not sure that it actually will change all that much in the debate between Chixulub and the Deccan Traps being the major stressor event. They've confirmed that fish were killed fairly close to the impact site, and while those fossils are fascinating and awesome to consider, no one was seriously suggesting that nothing was wiped out by Chixulub, its always been accepted as the major causitive event of the extinction in the western hemisphere. The debate was over the extinction events in Eurasia, Africa, India, and Austro-Antarctica, and the Hell Creek Formation doesn't have much to say about those localities. 

Beautiful fossils though! 

[Green Baron]

Beautiful fossils !

My 5 cents: Chixchulub was a continental disaster and possibly the "last drop for the cask to spill over", for the environmental collapse to happen. Flood basalt had a much larger global impact on an already stressed environment, and for a longer time. The monstrous plant eating dinosaurs had already disappeared at the time of the impact, their realm being more and more constrained presumably by the continental breakup that disrupted large connected living spaces into smaller ones. Hadrosaur traces were found in Europe above the iridium layer of the impact, but this is debated.

Many of today's dinosaur finds are from America, and there is a clear distinction between below and above the boundary. But i would not be too surprised if for example Chinese palaeontology one day presents us dinosaurs from the lower paleogene ...

Edited March 30, 2019 by Green Baron

[Scotius]

There is some evidence that remnants of dinosaurs indeed survived for at least 200 000 years after the extinction event happened. But it is very little and debatable evidence. Still, it is surprising this very successful and widespread group of organisms could die out so quickly and completely. True - birds lineage survived. But same goes for crocodilians, turtles and other reptiles. Why mammals survived relatively unscathed, while dinosaurs of comparable size, metabolic rates, geographical distribution and overall similiar development level did not? Or if they did survive for even several thousands of years after the worst of disaster had happened, why didn't they rebound along with other animal taxa?

Those are million dollar questions of paleonthology.

[Green Baron]

1 hour ago, Scotius said:

There is some evidence that remnants of dinosaurs indeed survived for at least 200 000 years after the extinction event happened. But it is very little and debatable evidence. Still, it is surprising this very successful and widespread group of organisms could die out so quickly and completely. True - birds lineage survived. But same goes for crocodilians, turtles and other reptiles. Why mammals survived relatively unscathed, while dinosaurs of comparable size, metabolic rates, geographical distribution and overall similiar development level did not? Or if they did survive for even several thousands of years after the worst of disaster had happened, why didn't they rebound along with other animal taxa?

Those are million dollar questions of paleonthology.

Writing out of the wrist, where is the salt shaker ... :-)

Many taxa, especially the individually huge ones, where already gone long before the K/P event, eventually with the continental breakup.

- Living spaces became restricted, biomes smaller and more diversified

- Global cooling through increased weathering rates (an underestimated effect because it is soooo slow, but effective !)

- Deep sea trenches, less shallow, warm sub continental waters

- Flood basalt (another very effective cooling "method").

- Impact (was that necessary at that time :-) ?)

- Beginning glaciation, albedo rising

- Mammals may be more effective to regulate body temperature. Fur is a better insulator than scales. Not everybody had feathers ...

- Food chains disrupted in changin' times

- others ?

Edited March 30, 2019 by Green Baron

[kerbiloid]

Probably the Chixchulub meteorite was just the last drop in the dinos' bleak and lousy life.

[Scotius]

Alright, so big herbivores were already on their way out ( which i would debate, because Laurasian hadrosaurids and ankylosaurids and Gondwanan sauropods were still diverse and widespread at the end of Cretaceous). But what about small\medium sized generalists? Troodontids for example - small, fast, feathered. With comparatively huge brains and dentition indicating at least a degree of omnivory. Basically equivalent of modern foxes or racoons. How did they fail at survival, while seemingly being prime candidates for continuous existence? Birds, their very close relatives managed to avoid extinction without advantages mammals enjoyed - but why only birds? What crucial factor was missing in non-avian dinosaurs that led to their death?

[Green Baron]

I doubt we can isolate single factors. For that the whole extinction scenario is too complex, too widespread, too encompassing, even contradictory. Especially the mentioned biome thing i love so much :-), i doubt it is quantifiable in terms of of causality without much simplification.

A lot of simulation work has been published in the last years, dealing with he flood basalt and impact. It partly contradicts itself, (is cooling by sulphuric acid or sulphur dioxide stronger than warming through carbon dioxide ?), how fast where gases released ? Where organisms able to adapt fast enough ? Do we have a worldwide continuous record of fossils to judge the global effects or is it limited to regions ? Even a supernova in the vicinity has been checked as a contributing factor, but afaik the idea was discarded.

How do the effects add up ? Or cancel themselves out ? Are there positive feedbacks ? Thresholds to activate sinks and wells for stuff ? Circulation pattern changes ? Gradually or abruptly ? Continentally or globally ?

Evolution is not uniform in all organisms, some evolve faster, others are more stable, the rate can change over time. Species come and go naturally. Faster evolving organisms may occupy new niches more quickly.

It is quite to easy to lump everything together and say global cooling + flood basalt + impact = bad, but for a detailed answer i doubt we know enough.

Valid until correction :-)

Edited March 30, 2019 by Green Baron

[Scotius]

Yes, it's quite baffling. Global cooling? But there were polar species of dinosaurs, adapted well to low temperatures. Basalt flows + meteor impact? Yes - it would be global and brutal. But why birds survived, while other maniraptorans and pterosaurs died out? Early birds weren't that much different from their dromaeosaurid cousins and smaller species of pterosaurs. Oh, paleonthology - you are such fascinating and frustrating discipline

[kerbiloid]

Afair, things were that simple.

Big dinos had small chickens.
Very small, like a hen.
Because of very small eggs.
Because if the egg were big, its shell would be thick, and a chicken could not break it.
So, the eggs were small. And chickens.

Small prehistorical rikkitikkitavians were eating the small and tasty brontochickens, tyrannochickens, tricerachickens, etc. And the chickens' huge parents even didn't know about that.
Poor, poor dinochickens. Cutie, cutie rikki-tikkis.

Small dinos were protecting theire eggs, they could bite a rikki-tikki.
But they were poikilothermic, because they were reptilians (with no heat regulator), and they were too small to stay warm all night long.
So, at the morning they were slow and couldn't protect their eggs and chickens as well.
While warm and hungry fuzzy cuties were active and were eating their chickens on breakfast.

Turtles and crocos were living on the coastline, so their eggs were protected by mammalian hydrophobia. Do you love digging wet sand with your nose? They too.
So, crocochickens  and teenage ninja turtles happily survived.

Birds were not exactly birds. They were small warm-blooded dinos which could protect their nests at any time.
The best of them survived and became birds, because the birds were the best of them.

So, finally there stayed mammals and birds (two champions), crocos, turtles, usually poisonous snakes, and scattered lizard trash (just too much of them to eat them all).

***

But why did the mammals not have eaten the dinochicken before?
Because there was a few of them.

But why it got a lot of them?
Because their food had spreaded around.

But what was that food spreading around?
It was crops. Because of grass.

***

Originally there were palms, fur-trees, ferns and other gymnosperms.
They give a lot of leaves, but no grain.

A small and poor mouse would be unhappy with that green dietic food.
While a bigger mammal immediately became a dino food itself.
Because the reptiles are more primitive, so they quickly occupied all available seats and were trolling and bullying the small and harmless mammals, keeping them small and shy.

So the mammals were mostly insectivorous, and there was a few of them, though they have appeared almost simultaneously with the reptiles.

They were eating various invertebrata junk like flies, dragonflies, roaches, worms, etc.
And they were a prey for even a medium-sized dino.

***

But some plants had evolved their ovary(?) into flowers, bright and fool of edible pollen wet of sweet nectar.
Some kind of wasps became bees, while some kind of caddisflies became butterflies.
And they started flying and eating the nectar and pollen, carrying some uneaten pollen from plant to plant.

This allowed to the flower plants spread around occupying every place free of ferns and furtrees after, say, a wood fire. (Which were often in that oxygen-rich atmosphere)

And unlike the ferns, palms, and furtrees, the flower plants did not require being full-grown to make an ovary.
Some of them were reducing (see neoteny) and became a small single stem with a pair of long narrow leaves and a big ovary on top.
We call it grass.

Those gymnosperm losers were not able to do that well. And they required a lot of water even to pollinate each other.
So they lost and now occupy just the places too uncomfortable for the flower plants.

The grass (pollinated by insects or by wind) occupied every free place on the Earth.
And every such place was full of good nutritious food - the grass seeds. The biggest of them we call crops.

Small and hungry insectivorous mammals were eating the seeds. Somebody of them was keeping surviving and spreading around,
So, the mammal rodents got numerous.

Other small insectivorous mammals were eating the kids of the herbivorous mammals, and became mini-predators like rikki-tikki-tavi.
And they spreaded around.

***

As the rikki-tikki were too stupid, brave, and hungry to distinguish a dinochicken from a rodent, they were eating the dinochickens as well.

Sometimes dinos were eating them.
But on the morning mammal mini-predators were competing only with proto-birds, who were eating the dinochickens as well.

***

So, both big dinos and cold-blooded dinos were losing their chickens, while hot-blooded mammals and proto-birds were fine, while crocos were hiding in Louisiana. gators were hiding in Louisiana, and crocos were hiding in Africa.

Dino population was shrinking.
This was causing inbreeding and other bad things, so the dinos became sicker and sicker, while the birds and mammals were getting bolder and bolder.

***

Then the Chick-sulub hit.
Mammals and birds turned their heads to look what the freak, saw nothing interesting, and continued eating the next fallen dino.

***

Later the giant birds began dominating and eating the mammals. So the mammals kept partisaning.

But later the horrible ultimate nocturnal mammal predator evolved from the creodonts, and the bird chickens followed the dino ones.

Spoiler

***

Upd.

So, once the plants created flowers, the dino countdown started, and the dinocyde became inevitable.

But why did the plants created flowers?
Probably because they were too far from water (they were still ferns or so), and had no other way to reproduce except the aerial pollination.

And why did the insects start flying?
Because original proto-spiders were not making nets, but were making sticky rows on the substrate.
So, jumping over the sticky traps and from branch to branch became the flight.

But why did all of that happen?
Because the green coastline became too wide to let the farthest plants touch the water.

But why did the green coastline got wide?
Because many generations of coastal plants created a thick layer of humus turning the sand into soil.

So, that was just a question of time.

Edited March 30, 2019 by kerbiloid

[Barzon]

woah. that's  a lot. you been taking lessons from @Snark ? 

[kerbiloid]

No, I have been reading books.

Edited March 30, 2019 by kerbiloid

[Green Baron]

1 hour ago, Scotius said:

But there were polar species of dinosaurs, adapted well to low temperatures.

That is relative. The late Cretaceous arctic probably was not colder than -2° at the lower range, and >15° in the warmer months. Before the late Cretaceous, temps were higher, a nice warm worldwide greenhouse, apart from isolated events with lower temperatures. They could have occupied niches up there when conditions were favourable.

https://www.sciencedaily.com/releases/2015/05/150528083818.htm

Quote

But why birds survived, while other maniraptorans and pterosaurs died out?

I have no reasonable idea ...

Edited March 30, 2019 by Green Baron

[MinimumSky5]

@kerbiloidit's kind of been proven that at least theropods were homeothermic, based on bone studies. 

[kerbiloid]

5 minutes ago, MinimumSky5 said:

at least theropods were homeothermic, based on bone studies. 

Some of them.

And for the big ones this doesn't matter. Eggs are anyway small.

Edited March 30, 2019 by kerbiloid

[Shpaget]

4 hours ago, kerbiloid said:

The best of them survived and became birds, because the birds were the best of them.

This is one of the best explanations of evolution I've ever seen.

[magnemoe]

2 hours ago, Green Baron said:

That is relative. The late Cretaceous arctic probably was not colder than -2° at the lower range, and >15° in the warmer months. Before the late Cretaceous, temps were higher, a nice warm worldwide greenhouse, apart from isolated events with lower temperatures. They could have occupied niches up there when conditions were favourable.

https://www.sciencedaily.com/releases/2015/05/150528083818.htm

I have no reasonable idea ...

Yes, not an good setup for an nuclear winter on steroids. 
Some theory that birds who survived had beaks for eating seeds who kept during the dying years, same with burrowing mammals living of roots and tubers 

Deccan Traps might well being buffed by the impact as it was on the other side of the world and the shock wave has an impact. 
Dinosaurs probably had other issues like an disease going on.
Perfect storm. 

[kerbiloid]

4 minutes ago, Shpaget said:

This is one of the best explanations of evolution I've ever seen.

It's from a professional paleontologist's book.  (An expert in dead arachnides)

[Green Baron]

9 minutes ago, kerbiloid said:

... expert in dead arachnides ...

Spoiler

Alice Cooper ?

 

[kerbiloid]

1 minute ago, Green Baron said:

Alice Cooper ?

No, Kirill Eskov.

[Gargamel]

50 minutes ago, kerbiloid said:

No, Kirill Eskov.

For one of the bigger jokesters on the Forums, you sure missed that one.... He even used your own "joke in spoiler" method. 

https://en.wikipedia.org/wiki/Alice_Cooper

 

 

 

[kerbiloid]

3 minutes ago, Gargamel said:

For one of the bigger jokesters on the Forums, you sure missed that one.... He even used your own "joke in spoiler" method. 

I didn't miss. I wrote that with a serious face. 

(Though I don't know what's common between the musician I 've heard about and the arachnides.)

Edited March 30, 2019 by kerbiloid

[Green Baron]

 

@kerbiloid, 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

University level introductory knowledge about creatures with a spine and how they are connected. You also get to learn methods like cladograms for example. Definitely a buy if these things interest you !

Edited March 30, 2019 by Green Baron

[StrandedonEarth]

On 3/30/2019 at 12:16 PM, kerbiloid said:

(Though I don't know what's common between the musician I 've heard about and the arachnides.)

Probably a bit of crossover between his songs “Dead Babies” and “Black Widow” along with his other creepy-crawly songs. (on mobile or I’d post links)

One could also posit that it’s a member of The Who looking for “Boris the Spider”

Interesting to find an extinction-level-event fossil bed

Edited March 31, 2019 by StrandedonEarth
added links