Dinosaur Extinction?

[altariaking]

Hear is my theory. The Earth used to be one big giant continent before it became however many we have now. While the plates under the earth started to move away from each other, they formed massive earthquakes, destroying most land creatures, and burying them under ground. Then, a lot of other animals had no food, and starved, causing them to die out also.
Or:
The meteor thing could have possibly blocked out the sun, causing plants to die, meaning plant eaters die out, and then eventually carnivores eat all of them and there are none left.
So yeah, just two of my possible theories.

 

[Hyperion09]

both were reptiles but bird-hipped dinos must've been able to survive after KT extinction to evolve into modern day birds

Modern evidence suggests that birds evovled from lizard-hipped dinosaurs, despite what was originally thought.

The ornithischian hip structure is superficially similar to that of birds, which led Seeley to name them "bird-hipped dinosaurs," though he did not propose any specific relationship with birds. He termed saurischians "lizard-hipped" dinosaurs because they retained the ancestral hip anatomy also found in modern lizards.

However, as later study revealed, the hip structure possessed by modern birds actually evolved independently from the "lizard-hipped" saurischians (specifically, a sub-group of saurischians called the Maniraptora) in the Jurassic Period. In this example of convergent evolution, birds developed hips oriented similar to the earlier ornithischian hip anatomy, in both cases possibly as an adaptation to a herbivorous or omnivorous diet.

However, I consider crocodiles and such insects to be still living dinosaurs, and some were discovered via ocean and water.

Uh. What? Crocodiles are in a different clade of reptiles, and I have no idea what is making you think insects are closely related. (emphasis on closely)

Studied by several archeologists, dinosaurs are different, very different from reptiles. It's basically what separates cats from monkeys, kids.

:\ Tell me you just fell asleep during biology.

 

[metronome]

The whole asteroid theory is pretty solid by now. To appreciate its scale, you have to consider the massive destruction that the initial impact caused; it's a gigantic, 10-km across space rock ramming into the earth at 20km/s, causing an immediate incineration of whatever lay below it in the supercompressed, superheated air even before impact, and throwing up a huge wall of dark dirt and debris and dust as well as a gigantic shockwave that would kill and carry all sorts of debris for hundreds of miles in a deadly radius.

(kinda scary to think that this could happen right now with little warning)

On top of that, there would probably be several tsunamis and widespread spontaneous combustion. An impact that big is definitely going to throw huge amounts of dust and particles into the atmosphere; heck, it would have thrown huge rocks almost into orbit. Most of that stuff would have remained suspended for a long, long time, destabilizing the climate for perhaps thousands of years. Whole food chains would have collapsed. The ones who could find shelter, or needed less food than others (some birds, mammals) survived.

Insect theory is kinda not scientifically valid at all. Drainage of blood? You would need unreasonably large swarms. Virus? Evolved resistance, not easily spread (dinosaurs and moths did not live in the age of modern rapid transportation), and, well, viruses just don't collapse entire ecosystems. How do you explain the extinction of other types of organisms at around the same time with a dinosaur-exclusive virus?

 

[Livewire]

The whole asteroid theory is pretty solid by now. To appreciate its scale, you have to consider the massive destruction that the initial impact caused; it's a gigantic, 10-km across space rock ramming into the earth at 20km/s, causing an immediate incineration of whatever lay below it in the supercompressed, superheated air even before impact, and throwing up a huge wall of dark dirt and debris and dust as well as a gigantic shockwave that would kill and carry all sorts of debris for hundreds of miles in a deadly radius.

(kinda scary to think that this could happen right now with little warning)

On top of that, there would probably be several tsunamis and widespread spontaneous combustion. An impact that big is definitely going to throw huge amounts of dust and particles into the atmosphere; heck, it would have thrown huge rocks almost into orbit. Most of that stuff would have remained suspended for a long, long time, destabilizing the climate for perhaps thousands of years. Whole food chains would have collapsed. The ones who could find shelter, or needed less food than others (some birds, mammals) survived.

Insect theory is kinda not scientifically valid at all. Drainage of blood? You would need unreasonably large swarms. Virus? Evolved resistance, not easily spread (dinosaurs and moths did not live in the age of modern rapid transportation), and, well, viruses just don't collapse entire ecosystems. How do you explain the extinction of other types of organisms at around the same time with a dinosaur-exclusive virus?

Exactly. Dinosaurs weren't the only species of animal to die/go extinct during the Cretaceous event. All the large sea-going and airborne reptile species died as well, not to mention other varieties of insects and plants. And a disease virulent enough to jump from species to species like that would have shown up and/or made a bigger impact, but there's absolutely no evidence for that.

 

[Kotowari]

So while ice age creatures are more likely I
still don't think we'll be seeing them anytime soon, if at all.

Fun fact: Yesterday I read in the paper that a Japanese scientist plans on making a Mammoth embryo by going to hunt for mammoth DNA in Siberia (as you said, for soft tissue frozen in the Russian permafrost). He says in 4 or 5 years, they should have a baby mammoth. :'3 But, seeing is believing I guess. x3

And of course the dinosaurs weren't the only ones to go extinct. It would be odd if they were the only ones suffering from whatever happened 65Ma ago. Lots of lesser species suffered as well, but their disappearance is far from "as spectacular" as that of the "magnificent" dinosaurs.

Did you know that the KT extinction is placed 5th in the order extinctions?
Based on the disappearance of families the order is:
Perm - Trias (Paleozoic-Mesozoic)
Ordovicium - Siluur
Frasnian -Famennian
Trias - Jura
Cretaceous- Paleogene (KT)
Lower Cambrium - Middle Cambrium

When calculating the extinctions per genus and not per family (in the Phanerozoic), the KT boundary gets the 12th place.

Causes for mass extinction:
Meteorite impact
large-scale sea level drop
Ice ages
intense activity of LIPs (Large Igneous provinces)
Anoxic events
Instability of gaseous hydrates


Talking about LIPs, I learned of another possible cause of the dinosaurs' extinction: at the end of the Cretaceous times, the Deccan Traps (India) were formed. In this magmatic province 1*10^6km³ of magma came to the surface. If you think that 150km³ of a large vulcano eruption is enough to change the worldwide climate for year... Go figure what 10000 times as much could do.

 

[Rich Boy Rob]

Fun fact: Yesterday I read in the paper that a Japanese scientist plans on making a Mammoth embryo by going to hunt for mammoth DNA in Siberia (as you said, for soft tissue frozen in the Russian permafrost). He says in 4 or 5 years, they should have a baby mammoth. :'3 But, seeing is believing I guess. x3

Heard that myself aswell. After Googling it, the article I read said that his team had already successfully cloned a mouse that died 19 years ago. Apparently if his Mammoth project goes successfully (I can't remember, but I think there was something about using some legs discovered in permafrost) he plans to also clone a Woolly Rhino and open a prehistoric safari park in Siberia (o_O (bear in mind this was on the Daily Mail website, so that part is most likely untrue)).

 

[Callandor]

Many scientists believe that a meteor knocked out part of the earth and destroyed dinosaurs, knocking the earth into an ice-age, however scientists begin to question this theory, thinking that moths and flys drained out all of their blood, due to their long lifespan. In fact, some flys and moths today have dinosaur blood left in their bodies, leading to a possible rebirth. What do you think of this?

Do you realize what kind of swarm that would have to be, how huge it have to have been to drain all the blood of just one dinosaur? Also I'm pretty sure that moths and most species of fly don't drink blood.

 

[TRIFORCE89]

I don't think the died because of vampire insects, no.

As for bringing them back? It'd be cool, yes. But there'd be a lot of logistics to overcome (and don't bring back raptors, they can open doors :p)