How did dinosaurs become extinct

No shit. Perhaps it was my fault as I didn't make it clear. What I was pointing out, was that he said the shockwave from the impact from a meteor was what killed many of the dinosaurs, which is completely false. There is little doubt that a climate change was what killed the dinosaurs. I have taken archeology courses in university, and you are indeed correct. There are several marks found that indicate a large meteors have crashed to the Earth. But the even though the size of the craters are quite large, it shockwave from it would simply have not killed "a ton of dinosaurs," which was the point I was trying to say.

Like I said I made a mistake and forgot to expound that the dust cloud that formed killed them and that the initial impact killed only like 20-30% and the rest were killed thereafter and I also admit that I made a mistake with the Ice Age thing..

i was watching Discovery channel other day and some old dude and his wife disect amber with insects and found that some of them if not most bugs in cased were disseace carriers he believes most Dino's died from something like a flu or something tougher to cure in Dino's.

i thought that it was the 1st time i heard about such a theory then i remember the black plague which killed like 80 percent of humans in its hay day so maybe there was a supper virus that killed Dino's i dunno but that my 2 cents.

You really think that one meteor killed 20-30% of the dinosaurs? Need I remind you that the crater was in Mexico, while dinosaurs roamed world wide. The crater is only 180,000km in diameter, while the surface area the landmass of the Earth is roughly 148 million square kilometers. Not to mention, the land damage is only roughly half, as half the impact was on water. Overall, the crater is only 90,000km in diameter. So do you really think that the initial impact would kill 20-30% of dinosaurs?

I don't think it was due to a single cause that resulted in the extinction of dinosaurs. Like what some of the other members have mentioned, it could be a combination of various events, from volcanic eruptions to climate change.

Personally, I believe it is the inability of dinosaurs to adapt(or perhaps evolve) to changes which led to their decline. Some creatures such as cockroaches and sharks still exist today, but unfortunately, the latter is endangered due to over-hunting by human beings.

The nuclear bomb dropped on Hiroshima had a yield of 5.2 megatons. That asteroid that struck in Mexico had the force of 100 MILLION MEGATONS! The crater was about 180 km in diameter and 10 km deep. More than 50% of the worlds different species were killed off because of the climate changes caused by the dust that was thrown into the air. Nearly all of the dinosaurs eventually died from all of the changes that this impact event had on the Earth’s environment. Acid rain and fires would have finished those that did not die from the initial impact.

1) they ate themselves due to overpopulation.
2) A large Asteroid crashed into the earth and the debris blocked the sun rays and started Ice Age.
3) Lack of food for the Herbivores and thus crumbling down the food chain.
4) Some kind of solar flare.
5) Volcanoes erupted and created fissure everywhere.

Indeed. While there is no doubt that initial blast was extremely powerful. It was the climate change that killed most of the dinosaurs. If you take a look at a map of the earth during the Cretaceous, you'll see that the landmass had already shifted. Many of the continents are separated.



As you can see, the impact was just off the coast of the Yucatan Peninsula. The impact would've affected the southern part of North America, the northern part of South America, and even the Western part of Africa. But the rest of the world would not have felt much of the impact. Therefore, it is highly unlikely that the initial impact would kill 20-30% of the dinosaurs.

Granted, the impact alone wouldn't kill 20-30% of the dinos. But just because the asteroid came down on a body of water doesn't mean that the damage would be lessened. On the contrary, the water would flash-boil and the impact would no doubt cause massive tsunamis and possibly some seismic/volcanic activity. And let's not forget the aforementioned dustclouds and acid rain. All that combined would leave behind a freakishly large body count, all of which are linked back to the single impact. All in all, it'd be one hell of a show.

That was all I was trying to point out. The initial impact would not have killed so many. However, the after-effects would.

I'm just hesitant to call them after-effects. A climate change I would classify as an after-effect, yes. But a giant wall of water caused by a fire-fuck-ball striking the ocean seems a little more direct. Know what I mean?

Understandable. But I believe after-effects seems more suitable. As the direct-effect would the massive impact, which created the crater. I called them after-effects simply due to the fact that the scalding water, acid rain, and dust clouds are by-products of the aforementioned impact.

It's a simple question people with no need for an explanation.

This really cracked me up today.

Perhaps we will never know what really killed them, but we have those theories based on the evidence lying about so I guess a really huge meteor/asteroid collided on Earth, produced an ice age, produced a shortage of food for all dinosaurs...

Forced production of "The Flintstones."

Say, are we being serious here?



Anyway, short story, in my opinion; Meteor hit earth, all plants dead(due to the smoke covering atmosphere), ice age came, dino can't survive, end of story.

Dinosaurs did evolve. Into birds. I shit you not.


T. Rex anaylsis supports bird-dino link

Its truly amazing how they can look at tissue from a 65 million year old bone (or even older) and get some info from it. If science can look at my bones 65 million years from now, how would they view humans from our era? Pretty crazy stuff.

the caveman invented time then the wheel to power time in order to go farther into the future so the Meteor could hit in time.

You are quite far off, though to be fair, you freely admit your ignorance.

I don't know how you can accuse humanity of being weaker than the great apes. Yes we are physiologically weaker, but we have adapted to, you know, nearly every biome on earth. That is a very successful adaptation.

In fact, when talking about evolution you need to be careful in just thinking it makes species stronger, or even more adept at surviving. Remember, any change that is beneficial to sexual selection will be passed down even if it is neutral in respect to ability to survive, or in some cases even harmful to individual survival. Many animals have gaudy colors that completely fail as forms of camouflage and have no other purpose than for mating rituals, which is precisely why they are passed on.

If you are actually interested in the evolution of humans, a new hypothesis that was suggested is pretty neat:

A researcher was trying to find a way to fix a certain genetic musculature disease in humans and was going through the genes known to be associated with the growth of muscles and he found something very interesting. When looking at his own gene he found that it had an odd mutation that disabled it completely.

He was sort of shocked since he was pretty sure he didn't have any unusual conditions with his muscles. He checked in the same spot in the DNA of the other people working at the lab and found they all had that same gene mutated in that same way. In fact, in every single human he looked at was the exact same way. The gene existed, but apparently in human DNA it was turned off for some reason.

He decided to take it further and look in other animals. When he looked at a variety of apes they all had this gene and had it in it's fully functioning form, without the mutation. This was definitely very curious. It was looking to be something linked with the evolution of humans, but there was a problem. It doesn't take a rocket scientist to realize that if you are born with a gene involving your muscles not working, you probably aren't going to survive. He needed to learn more.

He got some testing done to determine exactly what the hell this gene did specifically. It turns out that this gene controls a lot of the growth of the masseter and temporalis muscles on the skull, or the so called "muscles of mastication". They are what control your ability to move your mandible up and down and side to side to chew. Gorillas, Chips, Orangutans, etc all of these animals have very, very powerful chewing muscles because they need to be able to eat things like hard, woody stems as well as chew bones when they eat meat. I probably don't need to tell you that humans aren't very good at those same things. If you don't trust me, go try and eat a treebranch and tell me how it goes.

It was still a bit confusing though. Why would a trait that weakens the jaws of some apes be passed on? How is it beneficial at all? And the answer to that is the key to this entire story: Complete and absolute, utterly beautiful sheer fucking coincidence.

You see, because of their powerful jaw muscles, great apes also need a very powerful anchor so that the sheer force they can put into biting things doesn't literally break their face. Their skulls therefore are much thicker than ours, much denser, and they set much, MUCH soon after birth. As you are probably aware, our skulls are quite pliable when born and they take a lot of time to form up into your final skull. However, your skull also grows quite a bit during your life and it isn't until your early 20s that it finishes growing and sets completely for the rest of your life. With stronger jaw muscles though, gorilla and chimp skulls need to finish growing as soon as a possible and fuse together.

This limits the size the brain can grow two physically in great apes. Any further growth would do damage to the brain. Whereas us puny, weakjawed humans have our brains growing for a very, very long time in comparison. Our skulls were open to change.

And THAT, my friend, is one of the ways that humans can evolve "weaker" to evolve "stronger".