The Day That Dinos' Died......

[us.2u]

IMHO I truly believe going back to the KT boundary; that the meteorite that crashed in Mexico at that time can be the one & only true castrophic event that wiped the poor Dinos' out I really can't see any other plausible explanation. I think something like that would've caused global flooding, global volcanos not to mention evidence of Iridium; are most of you with me on this one? or does anyone have different plausible explanations?....I've heard other stories but I feel most of these would've wiped out life completely being unable to give our planet any rebirth of life it will be so interesting for all your views on this one.....us.2u

[coquina]

There was an article in Discover Magazine called "The Day North America Burned". It was several years back, but it discussed the angle of impact based on the seismic plots of the crater and the fact that there is a "barren zone" throughout North America just above the boundary. In this immediate area, the KT boundary is disrupted by the Chesapeake Bay Impactor, but I have seen description of cores outside the immediate area that describes the area as "barren, with a few pieces of carbon".

 

edited to add -

 

In addition to the debris thrown into the atmosphere by the impact, the clouds of smoke added to the sunblocking effect.

 

Some geologists think the Deccan Traps, located in India and of about the same age, also had an effect on the extinction, and some think the impactor caused the eruptions on the other side of the globe that formed the traps.

 

http://volcano.und.nodak.edu/vwdocs/volc_images/europe_west_asia/india/deccan.html

[us.2u]

Thank-you Coquina for your quick response & the info; at least to us it seems the Mexican meteorite was responsible...I think that just about sums it up...us.2u

[Hellbender]

one & only true castrophic event that wiped the poor Dinos' out

 

not to nitpick, but it wiped out most if not all the large animals living at the time, including the plesiosaurs, thalattosuchians, mosasaurs, pterosaurs, etc.

[Aardvark]

I'm sorry. If the previous message was meant for me, i never meant to belittle or offend. I just saw the oppurtunity to correct a small miscomprehension, thats all.

 

I'm guessing it was Newtonian who caused the offence, not your quite sensible, informative post.

 

As it happens some scientists are now challenging the theory that a metorite strike caused the mass extinctions. They point out that the Earth was suffering major environmental stresses for some time before the KT boundary, the atmosphere was becoming toxic from dramactically increased vulcanism and the oceans were, ineffect stagnant, much more shallow and without the strong currents that now exist. Also the plate tectonics of the time were not conducive to healthy ecology, with the continents being more closely together than they are now, resulting in reduced average coastline, leading to greater continental climatic patterns which are always more extreme.

 

Personally i don't think this is sufficent to explain the mass KT extinction. Ecological stresses would have been a significant factor in weakening the ability of species to withstand mass bolid collision, but the coincidence of there being a mass bolid collision and the mass extinction seems to close to be merely coincidence.

[us.2u]

Some scientists may indeed challange the Mexican meteorite being the reason for wiping out our Dinos at the KT boundary; & any other "ANIMALS" that may have been living at that time? but if their only explanation was Earths enviromental stresses sometime before the KT boundary & that the atmosphere was becoming toxic & the oceans were stagnant then I don't buy any of that... where's the geological proof? & also Mammals being terriffic survivors that still live today would surely have been extinct forever? IMHO I find your post with no geological backup a sheer nonsense....us.2u

[coquina]

There was a one word "really" in a previous post - it has been removed and an apology made. I wasn't angry - just pointing out that we don't have the same backgrounds.

 

Yes - some scientists still believe that the dinosaurs died out because of environmental stresses. All geologists were once taught "uniformitarianism" the idea that the processes that shaped the earth over the past were the same as those that are occurring today:

http://reference.allrefer.com/encyclopedia/U/uniformi.html

 

The alternate hypothesis is "catastrophism", that major, sudden events transformed the surface of the earth.

 

http://reference.allrefer.com/encyclopedia/C/catastro.html

 

The real physical damage an impact can do to a planet was shown when the "string of pearls" comet, Shoemaker-Levy, hit Jupiter in 1994. We sat here on earth and watched in safety, but measurements were taken and observations made. The clouds of debris over the surface of Jupiter after each of the twenty-one impacts were greater than the size of the earth. We have large impact craters that we can see and measure - we can correlate the amount of damage based on Shoemaker Levy, so we know it is immense.

 

The other hypothesis that fits in with catastrophism is "punctuated equilibrium" but forth by Stephen Jay Gould, author of "Wonderful Life" and other books. He noticed that through out geologic time there were abrupt ends to one kind of life, followed by a rapid evolution of other kinds. He surmised that before a catastrophic event, most ecological niches were filled, so a significant positive adaptation had to occur for one organism to unseat another, so to speak. However, after a catastrophic event, so much of life was erased that many niches were wide open. After the planet healed a little, the organisms that managed to survive, found another niche to fill as they evolved.

 

I think that both theories are right to some extent. When continents are all piled together in a heap, there is less surface area for contact with the ocean, and the ocean's circulation patterns change too, so the weather patterns are totally different. I suspect that the dino's were on there way out, but the asteroid did them in.

 

Over too hundred impact craters of significant size have been found to date. When we think of what anthropocentric climate forcing (the proper term for "global warming" caused by man) will do to the planet in a couple of thousand years, we have to remember that major impacts occur every 100,000 years or so and we are overdue.

 

That's not to say we shouldn't mind our p's and q's, but I figure we'll get hit just about the time I am ready to retire.

[us.2u]

Thank-you for your post Sandi the web-links are informative but I have this feeling that the Mexican meteorite was the main cause of extinction in the Jurassic period; I stand to be corrected if proved wrong but for now, to me at least I seem to find that the most likely cause. Like you, I was not indeed angry at a previous sarcastic post but I felt I had titled my thread "THE DAY THE DINOS' DIED" So whether dogs or cats or whatever was around at the Jurassic time; to me bore no relavance, as I was referring to what had wiped out the Dinosaurs. Oh well no bad feelings, I just stick to my own script...us.2u

[Aardvark]

IMHO I find your post with no geological backup a sheer nonsense....us.2u

 

Which post are you refering to?

 

If it is mine then i don't think you have understood it. I pointed out an alternate explanation for the mass extinction event at the KT boundary but then concluded that i think the meotorite strike (bolid collision) is still the most likely scenario.

 

If you have any factual critic of that i'd welcome it but i don't think it appropriate or fair to dismiss the entire post as 'sheer nonsense'.

[jdurg]

I really don't believe in any "one" event causing the mass extinction, and I think that anybody who does believe it was just one event is doing themselves a disservice. Science is about being open-minded and looking at the evidence; all of it. To say that it was ONLY the meteor that did it, or it was ONLY pre-existing conditions is just ignorant in my opinion. I fully feel that it was a combination of numerous things, some of which we may never be able to fully provde. (Like perhaps some type of bacterial or viral outbreak that severely weakened the population, and then the meteor(s) comes along and wipes out the rest. If the earth was in a bad shape after the onslaught, evidence of that bacteria may be very difficult, if not impossible, to find).

 

In science, people become strongly attached to their beliefs. That is why new 'theories' and 'ideas' are shot down like crazy and those who believe in them and come up with them are thought of as 'idiots'. This has happened all throughout history. Look at Priestly and the 'Phlogiston' debates. The better scientists out there are the ones who feel strongly about what they believe in, but are willing and able to toss aside their beliefs when conclusive proof arises which disproves their theories.

 

I feel that it was more than just a meteor that wiped out the dinosaurs. I think it was a combination of many things. This is simply because the violence of a meteor impact would surely do more than just wipe out the dinosaurs. I have trouble seeing how it couldn't wipe out life entirely. I think that 'higher life' was moving along with some 'issues' and then the meteor(s) came down and just sped things along. If I'm right, I'm right. If I'm wrong, I'm wrong. My life will still go on. What happened millions upon millions of years ago is not going to affect how I live my day to day life.

[Aardvark]

This is simply because the violence of a meteor impact would surely do more than just wipe out the dinosaurs. I have trouble seeing how it couldn't wipe out life entirely. I think that 'higher life' was moving along with some 'issues' and then the meteor(s) came down and just sped things along.

 

 

You contradict yourself. First you state that you think a meteor strike would be too violent, potentialy wiping out all life. Then you state that a meteor strike could have happened in conjuncture with 'other issues' to 'sped things along'.

 

Those are distinct and contradicitory positions.

[jdurg]

Yeah, I worded that wrong. I'm trying to say that if it was only a meteor that did it, it would have to be a pretty violent one and would take out nearly all the life on earth when it hit. Plus, it would have left a lot more evidence than what we have seemed to find thus far. I believe that smaller meteor impacted which helped push along the demise of the dinos.

[us.2u]

AS I said in my previous post "I STAND TO BE CORRECTED IF PROVED WRONG" as I said my feeling is.... "The Mexican meteorite"... but I have never said this is definately the case...us.2u

[coquina]

Evidence:

 

http://miac.uqac.ca/MIAC/chicxulub.htm

[jdurg]

There's no doubt that there's evidence. It's just that so many scientists refute the evidence saying that it's not "100% conclusive". (Then again, it could just be that they don't want to be proven wrong. )

[us.2u]

Dear Aardvark I do apologise for dismissing your post I believe I was too engrossed with my own beliefs, so I am sorry to be too quick off the mark; indeed you may have valid contributions to Dinos' extinction; but IMHO I honestly believe the Mexican Meteorite was the major cause,I've heard so many explanations throughout my life & I find this one seems to hold the most logic....us.2u

[coquina]

Dear Aardvark I do apologise for dismissing your post I believe I was too engrossed with my own beliefs, so I am sorry to be too quick off the mark; indeed you may have valid contributions to Dinos' extinction; but IMHO I honestly believe the Mexican Meteorite was the major cause,I've heard so many explanations throughout my life & I find this one seems to hold the most logic....us.2u

 

The "Mexican Meteorite" is commonly called the Chicxulub Bolide. If you Google that term, as well as "Chicxulub Inpact Crater", you will find a ton of sites about it. A bolide is an object that explodes in the air - it could be either a comet or an asteroid. The speed of these objects can be as high as 70km/second, so they usually vaporize above the ground.

 

I think most geologists now believe that the bolide was the culprit that x'd the dinos and other large animals. They are looking for other craters that are the same age as other geologic time boundaries. One has recently been found off Australia that coincides with the biggest extinction event of all - the Permian.

 

The Chesapeake Bolide hit at the end of the Eocene, and some other craters of the same age have been found in Siberia. It has been hypothesized that it broke apart into 2 or more pieces, as did Shoemaker-Levy.

 

So, I think for the most part, when you state that you believe the Chicxulub Bolide caused the K/T extinction, you are "Preaching to the choir."

[Hellbender]

not indeed angry at a previous sarcastic post but I felt I had titled my thread "THE DAY THE DINOS' DIED" So whether dogs or cats or whatever was around at the Jurassic time; to me bore no relavance, as I was referring to what had wiped out the Dinosaurs. Oh well no bad feelings, I just stick to my own script...us.2u

 

It was never meant to be sarcastic, if you are referring to my post. To my knowledge, "dogs and cats" evolved long after the Cretaceous, which was ended by the mass extinction of all large animals, including your beloved dinosaurs. Since whatever casue their extinction simply didn't single dinosaurs out to kill, so the mention of other animals is hardly irrelevant.

 

PS. Whatever was around at the Jurassic time period is irrelevant. Some species of dinosaurs and other animals were already extinct by other causes by the end of the Cretaceous, when your "death of the dinos" occured.

[Aardvark]

Dear Aardvark I do apologise for dismissing your post I believe I was too engrossed with my own beliefs, so I am sorry to be too quick off the mark; indeed you may have valid contributions to Dinos' extinction; but IMHO I honestly believe the Mexican Meteorite was the major cause,I've heard so many explanations throughout my life & I find this one seems to hold the most logic....us.2u

 

No problems, like coquina states, you're preaching to the choir here.

 

The evidence certainly looks powerful to me that a meteorite strike was the main cause for the KT mass extinction event. As far as i was aware that is on its way to becoming the generally accepted hypothesis. You seem to be expecting to be attacked for holding that opinion. Have you encountered any serious resistance to this hypothesis?

[Aardvark]

Yeah, I worded that wrong. I'm trying to say that if it was only a meteor that did it, it would have to be a pretty violent one and would take out nearly all the life on earth when it hit. Plus, it would have left a lot more evidence than what we have seemed to find thus far. I believe that smaller meteor impacted which helped push along the demise of the dinos.

 

Understood.

 

Well the evidence does seem to indicate a meteorite strike at the same time as other ecological stresses so some combination of factors may be possible. But i think the meteorite would still have to be the prime candidate as the biggest factor.

[AzurePhoenix]

Cave man interpretation; years o' stress, storms are at their best, things get real rough, cranky volcanos go puff, asteroid go smack and break the camel's back, mega-tsunamis go splash, pissed-off volcanos go "ROOOOAARR," dinos get dead, and now birdies go "tweet" and we shoot them for meat

[us.2u]

Thanks for your insight Sandie it's true that I don't understand intense English as I'm hardly articulate in my vocabulary most of my curriculum is self taught so my words of meaning, are not so vast & prolific as I would like them to be, but I do try I will say my beliefs are certainly strong; so if I'm preaching to the choir... let's all sing "The day the Dinos died just joking.....us.2u

[AzurePhoenix]

Gosh, I'm so sorry, I wasn't implying poor english or anything, i swear to everything, its just a cute thing i've been doing lately to sum up long complicated explanations when a short when might be somewhat sufficient. God I'm crying, did I offend you? cuz if their is some small gramatical error in your posts somewhere, i swear i didn't notice. oh gosh, I feel so bad now. My "Cave-man interpretation" had nothing to do with you whatsoever, oh man, I am SOOOOOO sorry!!!!

[Phi for All]

Let me step in here a moment us.2u, if you don't mind. No one here is implying anything is wrong with anyone's intelligence, education or articulation. There are all levels on these boards and the ones who make fun of others get smacked down, hard. Or banned.

 

I fear that I might have started a bad tone in an earlier post of mine (which I deleted later) when I asked you if you wanted me to close the thread after Coquina agreed with you. You had said, "Well, I guess that sums it up!" and I made an un-witty comment about preserving your theory. For that I apologize. It was meant to be tongue-in-cheek, not foot-in-mouth.

 

AzurePhoenix is a good member here and doesn't belittle anyone. Keep your thread topic clear, you're doing fine, backing yourself up with solid evidence and you are definitely holding your own here. Let's stay on topic.

[coquina]

I thought your poem was neat - wish I could sum things up so compactly. Keep 'em coming.

 

I think U2 was referring to my "preaching to the choir" comment, which is a saying common to my area which means, "you don't need to convince me, I'm on your side."

 

One of the very neat things about this forum is that people of all nationalities may participate. One of the unfortunate things is that when we speak idiomatically, people of a different language than ours may not understand the humor.

 

I try to put stuff like that in quotes so that the other reader will know that I'm speaking tongue in cheek. The important thing here is that we all learn from each other, so if you don't "get" what I write, ask for clarification.