What Caused The Dinosaurs To Die?

Mosasaurs were large aquatic dinosaurs that lived during the Cretaceous period and became extinct along with the dinosaurs.
Mosasaurs were large aquatic dinosaurs that lived during the Cretaceous period and became extinct along with the dinosaurs. | Source

How Did Dinosaurs Become Extinct?

The extinction of the dinosaur is one of the world's mysteries that we will never truly know. Most of what scientists believe had caused the destruction of an entire species is just theories, at best. The theories are formed from the limited knowledge we have of our solar system and our planet's history. Even with this knowledge many of the hypotheses are just wild guesses. Some are ludicrous and involve the idea that the dinosaurs became extinct because their brains were too small, which caused them to be unable to adapt to a changing world. Since things with even smaller brains have survived, there had to be more than just small brains at work. There are also more plausible theories as well. One thing that most scientists agree upon is that there was one catastrophic event that caused many animals, not just dinosaurs to die at the same time. Here are some of the most popular theories about what led to the extinction of the dinosaurs.

A Meteor Hitting The Earth

Created by NASA to show what may have happened millions of years ago.
Created by NASA to show what may have happened millions of years ago. | Source

Did a Meteor Kill the Dinosaurs?

One of the most well respected theories is the Asteroid Collision Theory that was brought to attention by Walter Alvarez in 1980. He believed that an asteroid impacted the Earth 16.5 million years ago. There are many beliefs surrounding this idea, although there is still a discrepancy as to how the asteroid affected the Earth, and what truly caused the dinosaurs to become extinct.

Dust: Some scientists believe that when the meteor hit the earth, a huge dust cloud blocked the sun's rays for several years. Due to the lack of direct sunlight, many of the vegetation died off. Since dinosaurs were losing their primary food source, they were unable to survive. Although some scientists believe that the dust caused more than just the vegetation to die. It is unknown whether the dust would have settled after a few months or a few years. Since there are animals who did survive the Cretaceous Period, we know that not all the vegetation died off. What would account for some animals dying, but not others?

A Deep Chill: One theory is that the dust caused a deep chill. When the meteor hit the earth and caused dust to raise, the dust blocked the sun. Since the sun was blocked, not only did the vegetation die off, but the entire world began to cool down, leaving earth a very dark, cold place. Dinosaurs were not built to withstand long periods of cold, because most were cold-blooded. Consequently, they were not able to regulate their body heat, and essentially froze to death.

Greenhouse Effect: Ironically, although some scientists state that the earth cooled, others argue that the whole earth warmed up rapidly as a result of the meteors hitting the earth. The dust surrounding the earth along with a sudden volcanic eruption triggered a greenhouse effect, which ultimately led to the earth becoming overheated. Since cold-blooded creatures cannot regulate their own body temperatures, overheating is just as dangerous as freezing to death. This may have also killed off some of the warm-blooded creatures, since many warm-blooded creatures can only survive in certain climates.

Triceratop Bones

Triceratops were named because of their three horns.
Triceratops were named because of their three horns. | Source

Did Dinosaurs Die In a Flood?

The Great Flood: Not all scientists agree that the earth was hit by a meteor. They believe that there was a different catastrophic event such as a flood. Many people assume it was by the Great Flood, which Christians attribute to the story in the bible about Noah's Arc and other religions attribute to their own corresponding story. They believe that all animals except dinosaurs were protected. Although there is evidence that a Great Flood really did occur, many scientists believe that the flood that killed off the dinosaurs was more gradual.

A Gradual Flood: Over time the continents began to separate, slowly becoming the land masses we know today. As this occurred sea levels rose, this began to flood out the low-lying land, limiting vegetation and shelter for many of the dinosaurs. They believe when this occurred; flowering plants became more abundant, which made way for mammals to flourish. This is partly believed because the animals most related to the dinosaurs are birds and marine life; a gradual flood would not have hindered the existence of either of these creatures, but may have hindered land roaming dinosaurs, since birds would have been able to find homes even with a flooded floor, as well as marine life like lobsters, turtles, and sharks, which are still around today.

Many Questions Go Unanswered: Although not all sea creatures were as lucky during this event, and did become extinct, while there were also some land animals, who somehow survived this period. What we do know is that a gradual flooding truly did occur around the same time as the dinosaurs, which is believed to be before the Great Flood. This suggests a more gradual decline in dinosaur's extinction, while the evidence shows that dinosaurs were killed off abruptly, by some unknown event.

Tyrannosaurus Rex

One of the fiercest, most scary dinosaurs, now extinct.
One of the fiercest, most scary dinosaurs, now extinct. | Source

Did a Sudden Severe Weather Change Kill the Dinosaurs?

We do know the earth went through some major changes around the time the dinosaurs died that had nothing to do with a flood or meteors. They believe that the event that occurred was a natural solar cycle of our own world. It is interesting that many of these theories contain many similar attributes, despite the fact that these theories have little to do with floods or meteors.

The Parting of the Seas: It is known that that there has definitely been a change in land mass and that seas developed over time. It is believed that due to the rapid shift in land and water, a build up of Carbon Dioxide (CO2) abruptly occurred in the atmosphere. If the earth were to have increased levels of CO2, then the earth's temperature would rise, and the earth would become extremely hot. As stated in many of the theories, it was their cold-blooded nature that essentially killed off the dinosaurs. This would have affected many of the animals both in the sea and earth, who cannot survive in a carbon dioxide rich atmosphere.

Volcanic Activity: There is also a belief that a sudden surge of volcanic activity occurred around this time, unlike any we have seen. Some theorists believe that this was triggered by a meteor shower, while others believe it was a natural event that could happen again. If many volcanoes were to erupt at the same time, this would cause massive destruction to the earth's ozone layer. Once the ozone layer was destroyed, the atmosphere would allow an unhealthy level of ultraviolet radiation to reach the earth's surface. The ultraviolet radiation ultimately would kill the dinosaurs. Yet the question remains, then how come there are some remaining animals from that period?

No one will ever truly know how the dinosaurs became extinct. One fact remains clearer than the rest; many of these theories coincide with one another. The truth probably lies somewhere, where all of these theories collide.

What do you think caused the extinction of dinosaurs?

See results without voting

Sources

Gibbons, Gail. Dinosaur Discoveries: Holiday House; New York. 2005

National Wildlife Federation. Ranger Rick's: Nature Scope: Digging Into Dinosaurs: Chelsea House Publishers, Philadelphia. 1997.

Norman, David, Ph.D., and Angela Milner, Ph.D. Eyewitness Books: Dinosaur:Alfred A Knopf; New York. 1989.

© 2012 Angela Michelle

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Comments 39 comments

monkeyminds profile image

monkeyminds 4 years ago from My Tree House

There is a rational explanation for why the dinos went extinct.

All species die from either background extinction or mass extinction. The dinosaurs died from mass extinction due to the inversion of the ecological pyramid.

http://monkeyminds.hubpages.com/hub/What-AboutThe-...


angela_michelle profile image

angela_michelle 4 years ago from United States Author

Thank you so much!


Dubuquedogtrainer profile image

Dubuquedogtrainer 4 years ago from Dubuque, Iowa

Well written and interesting. Voted up!


angela_michelle profile image

angela_michelle 4 years ago from United States Author

I appreciate it quite well, I like how everyone is adding to the research I did.


Patty Inglish, MS profile image

Patty Inglish, MS 4 years ago from North America

Very very interesting comments, are they not? This is a pretty good discussion thread.


angela_michelle profile image

angela_michelle 4 years ago from United States Author

You always give such insightful comments hirundine. Thank you for adding to my article.


hirundine profile image

hirundine 4 years ago from Nelson, B.C. Canada

I'm generally in agreement with Patty Inglish, MS. You make a lot of sense. Though like angela_michelle, just being an interested party; I seldom see any other types of dating done that is not radiocarbon. Though that does not diminish the interest.

Uwe George, a scientist, in his book; "In the deserts of this world" ..... I think? Anyway, part of the thrust of his argument was that. Earth is an an aberration in nature. That true nature is desert. Once Earth becomes desert, it takes a very long time to change back? If ever? That homo sapiens, human beings. Are nature's way of achieving that goal, desert, on this planet? ....... Bit of a stretch? I agree!

Yet, over the 30 years since learning of his idea, it is becoming actually quite valid, when one looks at the people run amok with greed. Using what the planet has put here and then claiming it as "theirs". Doing all manner of despicable action; to hold on to that stuff, selling and doling it out for profit until they die. A lot of people are comfortable with that and there are more and more people; wanting some. So, I kinda' see where Uwe was coming from ....


angela_michelle profile image

angela_michelle 4 years ago from United States Author

Thanks for stopping by Gloshei. I appreciate your comment.


angela_michelle profile image

angela_michelle 4 years ago from United States Author

Patty, I actually often question the radiocarbon dating, but I have not found any evidence of any other timing.


angela_michelle profile image

angela_michelle 4 years ago from United States Author

rahul thank you for the great compliment.

It does appear that there is evidence of something causing volcanic activity and something caused the land to really split, but I don't know if we will ever really know.


Gloshei profile image

Gloshei 4 years ago from France

Thanks for that angela my excuse is it's an age thing! (with me)

Keep up the interesting hubs.


Patty Inglish, MS profile image

Patty Inglish, MS 4 years ago from North America

Since radiocarbon dating is reliable only to 40,000 - 60,000 years to the past, I discount the asteroid impact being 16.5 million yrs past as a statistical fallacy; and, our colleges and universities here are teaching other theories of extinction. The proliferation of the asteroid was pushed by money and politics. As Big 10 and other US and International schools begin to overturn the asteroid idea, I believe they have more accurate information. Their research scientists are some of the best in the world.

Our scientists here may not think the thunder lizards became smaller, but have an idea that dinos consumed all/most of their resources and this is esteemable, because when a planet loses its vegetation (consumed), it begins to lose its atmosphere and finally becomes an ice ball. That's happening right now to Earth. It gets warmer, resources get used up, it gets warmer, atmosphere escapes, then its gets very cold.


rahul0324 profile image

rahul0324 4 years ago from Gurgaon, India

A great Write Angela! (love your name :))

I have always stood by the Meteor theory 'cause that sounds the most practical to me! We see a certain change in evolutionary mechanism after the Jurassic Age which tends towards the theory of a major catastrophe rendering a change in the mechanism of evolution. When questions like these arise, The Meteor and its dust causing immediate cooling or sudden eradication of the Dinosaurs seem explainable!

A wonderful article.. loved it!


angela_michelle profile image

angela_michelle 4 years ago from United States Author

I actually didn't even run across the algae theory. Interesting. I did run across suggestions of Dino farting, but ignored that as just humorous. LOL. Thank you for your insights.


Patty Inglish, MS profile image

Patty Inglish, MS 4 years ago from North America

I enjoyed reading this Hub, because of the number of theories reviewed. Another taught in some College classes is one of accumulating algae in the oceans and seas, even more than we currently have. At the same time, two sides of argument look at the algae causing and preventing an ice age by absorbing either warmth or Co2.

A blurb on the Internet recently supported the greenhouse gases theory with a mention "Dino farting", like the cows and pigs producing too much methane today...and we have so many people doing the same.

I think the theory I like best is a newer one, in which some dinosaurs did not go extinct, but became progressively smaller because of lack of resources to keep them big. Hence, our giant variety of crocs and many other lizards of today.

The asteroid theory was quite popular for awhile, but is waning in my area.

Cloning may remotely have a chance to work short-term -- Dolly the Sheep that was cloned didn't live the usual lifespan; and probably the 1st or 2nd progeny might be extinct if I recall from genetics classes not sure. More prone to cancer, though.Anyway, all interesting.

Thanks for he Hub and I rated it Up and several more.


angela_michelle profile image

angela_michelle 4 years ago from United States Author

hirundine, I can understand both perspectives, but honestly, I am not completely for cloning. I have a lot of reservations when it comes to cloning as well.


angela_michelle profile image

angela_michelle 4 years ago from United States Author

Deancash, So far they have not been able to clone anything and have it survive into adulthood, so I'm not so sure how long that will be from now.


angela_michelle profile image

angela_michelle 4 years ago from United States Author

Gloshei, actually the ice age is when the mammoth and the saber tooth cat became extinct. The dinosaurs became extinct prior to this. I am a geek and know these things. :)


hirundine profile image

hirundine 4 years ago from Nelson, B.C. Canada

Dear DeanCash,

I find it quite interesting that you voice your support for "cloning". That some human beings think that everything and everyone; is here for our use in some bizarre fashion? Including other life forms. This, I find baffling?

Do you think you have an environment even suitable, to support this? Not everything has to be reduced to test-tube values. Respect for the other life-forms; that share our environment, needs to be valued. When dead monsters, from earth's past require more funding than those hungry now. Just because "you can" it should not be prelude to "do".

What's there to understand? It is the "now" we need to understand. .... Cheers!


DeanCash profile image

DeanCash 4 years ago

This is very interesting. But looking to the future I think it might be possible too, to clone what it was from past so we could better understand them.


Gloshei profile image

Gloshei 4 years ago from France

This is a great hub and interesting, we all have heard different theories and still not sure.

I always thought it was the ice age but now I am not so sure.

One thing I am glad they are not still around. Thanks again for a good hub.


angela_michelle profile image

angela_michelle 4 years ago from United States Author

I wish we had hard core facts, so we knew exactly what is gone and the true impact of all decisions made.


hirundine profile image

hirundine 4 years ago from Nelson, B.C. Canada

While in general, I agree with the meteor impact theory? Likely there was not, one event?

Given the nature of today's globe it was a creeping change over a few thousand years. As the planet became colder and more like today's weather patterns. That's just my personal gut feeling? After all it took a few million years to change?

What I find surprising is the amount of time expended on the past and we leave our future up to those industrialists; that would turn this planet into another desert. The crude oil of today, is a legacy of those days; of dinosaurs and of the planet's development.

Apparently it all belongs to corporations! All owned by one family. Now how does that work? ...... Cheers!


angela_michelle profile image

angela_michelle 4 years ago from United States Author

Vegas Elias,

That was one of the many theories, but I didn't feel there was enough scientific evidence to include it on my list. there were a lot of other ones as well, I didn't include for much the same reason.


angela_michelle profile image

angela_michelle 4 years ago from United States Author

I'm glad you enjoyed it, wewillmake!


Vegas Elias profile image

Vegas Elias 4 years ago from Mumbai

Predators including prehistoric ancestors of man also might have contributed to the extinction of the dinosaurs by killing them for food after trapping them in trenches. Of course I also agree with the other reasons given in this article.


wewillmake profile image

wewillmake 4 years ago from kerala-INDIA

Nice article... I love the research articles very much.. Very informative..


angela_michelle profile image

angela_michelle 4 years ago from United States Author

Thank you so much!


sgbrown profile image

sgbrown 4 years ago from Southern Oklahoma

Very interesting hub. I have always wondered what could have occurred to cause so many animals to die at the same time. There are some very good, well explained theories here. Voted up and interesting! Have a great day! :)


angela_michelle profile image

angela_michelle 4 years ago from United States Author

Thank you so much!


angela_michelle profile image

angela_michelle 4 years ago from United States Author

Thank you very much for the nice comment.


chrissieklinger profile image

chrissieklinger 4 years ago from Pennsylvania

Interesting hub and a good read for someone just interested in the topic, or someone doing a project for school....great job!


BethDW 4 years ago

Such an interesting hub...you managed to summarize all the different theories really nicely. I also like that you provided citations (so many authors of more 'scientific' hubs often don't, and it lends your writing a lot more credibility). Voted up and shared!


angela_michelle profile image

angela_michelle 4 years ago from United States Author

teaches12345, thank you very much. I find dinosaurs so fascinating.


angela_michelle profile image

angela_michelle 4 years ago from United States Author

thelyricwriter, It is actually quite amazing if you think about it. Not all dinosaurs fossilized, so there are actually dinosaurs that we will never know about, because none of them managed to fossilize.


angela_michelle profile image

angela_michelle 4 years ago from United States Author

JKenny, Thank you very much. There are actually even more theories than I listed, but these were the ones I felt made the most sense.


teaches12345 profile image

teaches12345 4 years ago

This question is one that may never be answered in our lifetime, but your research and coverage holds some valid concepts. Great science lesson on these creatures.


thelyricwriter profile image

thelyricwriter 4 years ago from West Virginia

Voted up, useful, and interesting. I have always liked dinosaurs. It is interesting that we can learn so much from their 65 million year old bones. Scientist have did a great job putting the puzzle together. Cool article.


JKenny profile image

JKenny 4 years ago from Birmingham, England

I've always subscribed to the meteor impact theory, but your hub makes it clear in a very good and balanced way, that there are still many unanswered questions. Great work. Voted up and shared.

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