when did the dinosaurs die out?

Answer 1

he K-T event is a mass extinction which killed the dinosaurs and many other species, the 2nd largest extinction ever (to the Permo-Triassic). It is famous for the large bolide (extraterrestrial object) impact that occured off the Yucatan, creating the Chixulub crater. Glass from the crater is dated to 64.98 +/- .01 million years ago.

This event caused global devistation, evidenced by:
1) Differing Sr ratios from global wildfires
2) Microdiamonds from fried Carbon
3) Tsunami deposits found all over the southeast US
4) Stishovite (a variety of quartz which forms in extreme pressures)
5) Worldwide Iridium anomaly. Ir is usually found abundantly in space, but it is very rare on earth. All over the world, at the K-T layer, the amount of Ir is much higher than normal.

It is theorized that the impact created magnitude 12 earthquakes and blocked the sun for as long as 9 weeks.

Answer 2

About 65 million years ago when a gigantic asteroid collided with the Earth. Not all species died directly from the heat and explosion. The fallout of the collision burned everything on the surface which would have covered the earth in darkness. This 'nuclear winter' blocked out the sun and caused all vegetation to die off. The dinosaurs would have lost their entire food sources and would have had a very hard time surviving more than a few months.

I just read a fiction book by Douglas Preston called Tyranosaurus Canyon which proposes a theory that perhaps on this asteroid there was an alien virus that also contributed to the deaths of the dinosaurs. If you enjoyed Jurassic Park, this is a great book to read.

Answer 3

There are dozens of theories to explain a probable cause or causes. Throughout the Mesozoic Era, individual dinosaur species were evolving and becoming extinct for various reasons. The unusually massive extinction at the end of the Cretaceous exterminated the last of the dinosaurs, the flying reptiles, and the large swimming reptiles, as well as many other marine animals. There is now widespread evidence that a meteorite impact was at least the partial cause for this extinction. Impact craters are visible on most planets in our solar system. A spectacular example of this was witnessed in 1994, when Jupiter was struck by a series of cometary fragments. Some of these impact blasts were larger than the Earth's diameter. Other factors such as extensive release of volcanic gases, climatic cooling (with related changes in ocean currents and weather patterns), sea-level change, low reproduction rates, poison gases from a comet, or changes in the Earth's orbit or magnetic field may have contributed to this extinction event.

Answer 4

By the end of the Cretaceous Period ,about 65 million years ago,all the dinosaurs were extinct.
The dinosaurs,the pterosaurs,all marine reptiles and a large number of other
species all died out at the end of the Cretaceous.
No one yet knows why this was so,but the evidence shows that the event was quite abrupt. It is thought by some scientists that a massive asteroid (a large rocky object in space) may have crashed into earth.The resulting explosion may have filled the atmosphere with dust,blotting out the sun and lowering tempretures for years on end.
By another theory,a massive volcanic eruption could have taken place on
Earth,blating millions of cubic kms of lave into atmosphere, producing the same effect on the climate as an asteroid collision.
Evidence for both theories comes from the discovery by geologists of a layer
of metal called iridium,in late cretaceous rocks.this metal is believed to be found int core of the earth and in asteroids,but nowhere else .Iridium dust is thrown up by an exploding asteroid or lava from inside the earth may have settled on the surface,then later compacted in the rocks of the time.

Answer 5

As already answered above, it was at the end of the Cretaceous period, at 65 million years ago.

A large meteorite hit a shallow sea near Mexico and the resulting debris caused widespread fires in North America. The dust also blocked out the sun for many years. Without any sun there was no photosynthesis and no plant food.

But there were also a huge number of volcanic eruptions at the time that also contributed dust.
In India the Decan Traps lava flow produced so much lava at this time that it would cover the whole USA to a depth of 1km.
The Atlantic was just starting to open up, and there are lots of lava flows associated with this. The Giants Causeway in Northern Ireland is one example.

Answer 6

Can the people who are suggesting that the dinosaurs didn't die out because we still have crocodiles and turtles please note that both of these REPTILES pre date the dinosaurs and are are not classed as such.

And just to concur with what has already been said - about 65million years ago.

Answer 7

At the end of the Cretaceous Period, 65 million years ago, dinosaurs suffered a catastrophic extinction, which ended their dominance on land

Answer 8

Oh have they died out… I wish someone would tell my husband that, he’s a bloody dinosaur!

Answer 9

65 million years ago (on January 23 at 10:00 am).

Answer 10

yesterday when some1 4 got 2 make another Jurassic Park