Dinaosaurs extinction question

Feb 2016
1
France
#1
Hello everyone,

I'm here to discuss a little about the dinosaurs, i'm not an expert, and i just want to know if, actually, we are shure about the event that killed all those big guys ?

It is definitely a meteorite ?

I've seen that the earth's magnetic poles can be reversed, and eventually when this happen the magnetic protective field of our planet could be turned off during an unknown period... could this type of event be at the origin of a massive extinction ?
 
Jun 2015
1,252
Scotland
#2
There is a thin layer of rock worldwide which is 65 million years old. It contains elements that could only have come from a asteroid or comet. The crater of the impact can still be seen in geological surveys of the the Yukatan Peninsula and Mexican Gulf.
Below this layer, lots of Dinosaurs. Above the layer non. Not completely conclusive evidence but if I were a betting man.........
 
Jan 2015
2,903
MD, USA
#3
I actually saw a show on the Chixilub asteroid and the K-T boundary, long ago (pre-dating the History Channel, when TV documentaries were still respectable and not "EXXXXTREEEEEEM!!!"), and the scientist said that the number of dinosaur fossils and species was apparently dropping steadily long before the asteroid hit. And that the same species *are* found above the layer, for a depth implying a couple thousand years at least. *Then* they go away.

Maybe he was the only one saying such a thing, while smoking crack? Maybe everyone else is just parroting a neato cool theory? And it IS neato cool, don't get me wrong! And I certainly don't doubt that the asteroid hit, that's the coolest part, really.

So I don't know, and I don't know who does know. It's a good *theory*...

Matthew
 

kazeuma

Ad Honorem
Jun 2012
2,366
#4
There is another option that could also gone along with the meteor that hit Mexico.

After meteor showers there is an increase of flu outbreaks, the first recorded instance of the Black Death (in Asia) was after a meteor shower, and new bacteria is often discovered. There is a discredited theory is that meteors have bacteria and / or viruses.

So... take a massive meteor the size of Mount Everest hitting the earth - it must have massive amounts of bacteria inside of it. So not only do you have the sun blocked out killing the plants, you could also have a massive plague killing off the surviving Post KT dinosaurs.
 

VHS

Ad Honorem
Dec 2015
4,433
Florania
#5
There is another option that could also gone along with the meteor that hit Mexico.

After meteor showers there is an increase of flu outbreaks, the first recorded instance of the Black Death (in Asia) was after a meteor shower, and new bacteria is often discovered. There is a discredited theory is that meteors have bacteria and / or viruses.

So... take a massive meteor the size of Mount Everest hitting the earth - it must have massive amounts of bacteria inside of it. So not only do you have the sun blocked out killing the plants, you could also have a massive plague killing off the surviving Post KT dinosaurs.
Why birds were the lone survivors amongst the dinosauria?
Some have suggested that birds are scavengers and carnivores so they can eat what had died.
 

starman

Ad Honorem
Jan 2014
4,032
Connecticut
#6
I actually saw a show on the Chixilub asteroid
Chicxulub.

and the K-T boundary, long ago (pre-dating the History Channel, when TV documentaries were still respectable and not "EXXXXTREEEEEEM!!!"), and the scientist said that the number of dinosaur fossils and species was apparently dropping steadily long before the asteroid hit.
There was an apparent drop in diversity of large dinosaurs by (and perhaps also during) Hell Creek time. But this seems to have occurred only in one area--Laramidia. Lambeosaurs for example were still abundant in Europe--and possibly eastern Asia--around the time they declined and perhaps disappeared, in western North America.


And that the same species *are* found above the layer, for a depth implying a couple thousand years at least. *Then* they go away.
Their bones are thought to have been reworked by streams.
 

starman

Ad Honorem
Jan 2014
4,032
Connecticut
#7
Hello everyone,

I'm here to discuss a little about the dinosaurs, i'm not an expert, and i just want to know if, actually, we are shure about the event that killed all those big guys ?

It is definitely a meteorite ?
For quite some time, there's been a virtual scientific consensus on that--the impact c 66 Ma wiped out nonavian dinosaurs.

I've seen that the earth's magnetic poles can be reversed, and eventually when this happen the magnetic protective field of our planet could be turned off during an unknown period... could this type of event be at the origin of a massive extinction ?
Doubtful. In fact there were many polarity reversals throughout mesozoic time none associated AFAIK with extinction.
 

starman

Ad Honorem
Jan 2014
4,032
Connecticut
#8
Why birds were the lone survivors amongst the dinosauria?
Some have suggested that birds are scavengers and carnivores so they can eat what had died.
Relatively small size (=minimal requirements) the ability to fly to access what food there was, and scavenging explain it. Not surprising that gulls survived--look at seagulls at a garbage dump; they'll eat anything.:)
 
Dec 2015
518
Newburg, Missouri
#9
There have been many reversals of the earth's magnetic field, right through post-Cretaceous time and up to recent geological times. These are manifested in the sequence of "magnetic stripes" in the basaltic oceanic crust, mirrored on both sides of mid-ocean ridges where the lavas are erupted. They correlate with no mass-extinctions.

Bacteria from meteors? I think not.

It's "Chicxulub", by the way.