Dinosaur extinction: Scientists estimate 'most accurate' date

[Steve Williams]

Scientists believe they have determined the most precise date yet for the extinction of dinosaurs.

Researchers from Glasgow University were part of an international team that has been investigating the demise of the dinosaur.

By using dating techniques on rock and ash samples, they established the creatures died out about 66,038,000 years ago - give or take 11,000 years.

That date appears to coincide with the impact of a comet or asteroid.

http://www.bbc.co.uk/news/uk-scotland-glasgow-west-21379024

 

[Orb]

Question I love asking is why did crocodiles survive the K/T event, the case put forward then is that nothing larger than them survived (although the largest species and family of crocodiles at the time was up to 9m to survive).
But then what about semi-prehistoric shark; Otodus (60mil to 45mil years ago) that was roughly just over 9metres and this evolved to an even larger shark the Megalodon (roughly just over 13meters and makes the Great White Shark a junior in the killer heirachy).
http://www.prionace.it/otodusobliquusENG.htm
Also another one to consider at the 60mil years ago period is the known Titanoboa that grew to 40ft and weighed more than 1 ton.
http://scitechdaily.com/titanoboa-a-paleogene-period-40-foot-long-snake/

And if size is a consideration, then what about the dinosaurs that had feathers and were small, or dinosaurs with physiology comparable(ish) to smaller crocs-snakes-largest mammals (or a bit larger)
OK I accept K/T in reality is only 1 partial aspect of a much larger jigsaw and just adding to the banter (this subject was always lively on SP in the past, ah fun days).
But what really killed off all dinos is rather intriguing IMO, because the shark (especially this one),the largest snakes, and croc break the model of K/T event and the following years killing off everything greater than a small size and ignores smallest dinos.

Worth remembering mammals were pretty insignificant to the above, earliest sea-based mammal would roughly be the Ambulocetus 3meters in length and similar to a crocodile in appearance and was around 50mil years ago, and earlier mammals were rat size around 65mil years ago (so roughly 15mil years to achieve being comparable in some ways to a crocodile) .
Interesting subject to be sure.

For size context; largest example of modern Great White shark is just over 6meters (so the largest crocs at the time were 50% larger albeit with a strong tail, but those crocs were still massive considering modern croc grow to around 5meters), says something about those other sharks I mention (which finally went extinct between 2m to some say 10ks of years ago for the Megalodon) and the Titanoboa snake.

Interesting how nearly every species apart from mammal came down in size over time starting from around 50-45mil years ago to more modern times.
Apologies if a few mistakes in post did check it a bit, however it is Friday and late-ish
Thanks for the link Steve.
Orb

 

[GaryProtein]

Scientists believe they have determined the most precise date yet for the extinction of dinosaurs.

Researchers from Glasgow University were part of an international team that has been investigating the demise of the dinosaur.

By using dating techniques on rock and ash samples, they established the creatures died out about 66,038,000 years ago - give or take 11,000 years.

That date appears to coincide with the impact of a comet or asteroid.

http://www.bbc.co.uk/news/uk-scotland-glasgow-west-21379024

That's pretty frightening when you consider we could go just as easily.

 

[Steve Williams]

Armageddon. One of my wife's favorite movies

 

[JackD201]

Question I love asking is why did crocodiles survive the K/T event, the case put forward then is that nothing larger than them survived (although the largest species and family of crocodiles at the time was up to 9m to survive).
But then what about semi-prehistoric shark; Otodus (60mil to 45mil years ago) that was roughly just over 9metres and this evolved to an even larger shark the Megalodon (roughly just over 13meters and makes the Great White Shark a junior in the killer heirachy).
http://www.prionace.it/otodusobliquusENG.htm
Also another one to consider at the 60mil years ago period is the known Titanoboa that grew to 40ft and weighed more than 1 ton.
http://scitechdaily.com/titanoboa-a-paleogene-period-40-foot-long-snake/

And if size is a consideration, then what about the dinosaurs that had feathers and were small, or dinosaurs with physiology comparable(ish) to smaller crocs-snakes-largest mammals (or a bit larger)
OK I accept K/T in reality is only 1 partial aspect of a much larger jigsaw and just adding to the banter (this subject was always lively on SP in the past, ah fun days).
But what really killed off all dinos is rather intriguing IMO, because the shark (especially this one),the largest snakes, and croc break the model of K/T event and the following years killing off everything greater than a small size and ignores smallest dinos.

Worth remembering mammals were pretty insignificant to the above, earliest sea-based mammal would roughly be the Ambulocetus 3meters in length and similar to a crocodile in appearance and was around 50mil years ago, and earlier mammals were rat size around 65mil years ago (so roughly 15mil years to achieve being comparable in some ways to a crocodile) .
Interesting subject to be sure.

For size context; largest example of modern Great White shark is just over 6meters (so the largest crocs at the time were 50% larger albeit with a strong tail, but those crocs were still massive considering modern croc grow to around 5meters), says something about those other sharks I mention (which finally went extinct between 2m to some say 10ks of years ago for the Megalodon) and the Titanoboa snake.

Interesting how nearly every species apart from mammal came down in size over time starting from around 50-45mil years ago to more modern times.
Apologies if a few mistakes in post did check it a bit, however it is Friday and late-ish
Thanks for the link Steve.
Orb

On the topic of size, studies propose that the decrease in barometric pressure is what forced living creatures to become smaller. Sort of why insects, which don't have lungs, can only grow to be so big today whereas in prehistoric times there were dragon flies as large as large birds. In one experiment a Paco (fish from the Amazon related to the Piranha) was placed in a tank that was pressurized to 2 bar. It grew to almost twice the size.

 

[Orb]

Yeah heard about that model, along with mixture of oxygen-nitrogen-carbon dioxide-etc.
Still that is a head scratcher because the shark grew in size from its Cretaceous relative the Otodus and that was big itself, so why did (technically not dinos) but similar marine reptiles die (well apart from Loch Ness monster hehe).
Then also the Titanoboa snake that grew to 50ft and weighed over 1 ton at a time crocs with 2 species surviving well into Eocene period coming in at 9meters and 6meters
Some of these break those models because the snake was only found a few years ago, and previously it was thought the largest snake species grew to around 30ft I think 35mil to 20mil years ago and idea of the Titanoboa was unthinkable apart from in Sci Fi B movies (ah the B moves - wonder if the giant 2headed shark really exists!!!).

If it was barometric pressure, then why did one species (mammals) continue to grow and nearly all others diminish, consider the largest whales evolved from; small hunting mammal 65mill years ago branched-evolved into a 3meter amphibeon by 50mil years ago, and eventually became what we know as some of the most beautiful species on earth (Blue Whale-dolphins-etc).
So couple of things I think break the model; mammals did grow from shrew-small cat size to 3meter examples over 15mill years after K/T event, also a few species maintained their massive size and even grew but nearly everything else (non-mammals) shrank in terms of evolution size.
The switch between mammals growing much quicker and other species diminishing was from 50mill years ago to more modern times.

Hey great comment about insects, forgot about those in the Cretaceous-to-Cenozoic era and there were some beauties.
Cheers
Orb

 

[jadis]

It's really mind boggling to read about years in the hundreds of millions of years. Like human life is about only 80-100 years and how do I try to imagine what was it like 1 millions years ago, let alone hundreds of million years ago? Just the other day I was reading about 'Lucy', a Australopithecus afarensis hominin that lived 3.2 millions years ago. Telling that to my wife, she couldn't believe it is an evolutionary ancestor to humans.

 

[Orb]

Yeah when you look at all evolution from plants to various species and even single-cell/viruses/etc it is quite amazing.
I am one of those in the camp that feel nothing is random, and that evolution of life and its cycle is an example of how chance/randomness has nothing to do with it.
This then comes onto the future is already set and our decisions already made (free will is an illusion), ooh brain ache

This is not saying there is/is not a God, just that the path of evolution is not a set of random scenarios/biological paths that those following Darwin propose (specifically evolution boiling down to chance and randomness filtered against survival of the fittest).
Cheers
Orb

 

[jadis]

And when we try to bridge the gap, and try to explain rationally how, for example, the creation story of Adam and Eve, ties up to the evolution of man from millions of years ago, frankly sometimes I run into a brick wall.

 

[JackD201]

Eve made from Adam's rib? We'd end up watching Ancient Aliens on H2. LOL.

 

[jadis]

Eve made from Adam's rib? We'd end up watching Ancient Aliens on H2. LOL.

 

[Orb]

And when we try to bridge the gap, and try to explain rationally how, for example, the creation story of Adam and Eve, ties up to the evolution of man from millions of years ago, frankly sometimes I run into a brick wall.

The only way a creationist can get out of that trap is to say the story is a parable, or humans back thousands of years ago just could not get to grips with what they dream/told beyond their current perception and translate this to something they understand; many creationists make it easy to debate with because they are very rigid and cannot question-look at it from another perspective the structure and framework of their belief.

Modern case in point about rigid concepts-perception; if (big if and not proven anyway due to our current understanding of quantum maths-mechanics) eventually they mostly prove (cannot be a definite) randomness does not exist and the universe is is pre-determined so no free will; society will never accept the concept because those who cause crimes were always going to from the moment they were born.
It is an aspect I keep well away from as part of free will/deterministic universe debates because it upsets a lot of people (understandbly so), but shows how even modern society would have problems understanding or accepting some ideas even if eventually they become more solid.
Interesting how many scientists also cannot accept or consider the concept that free will is an illusion and may not exist.

That said about creationists, there are some highly regarded theologian philosophers.
Anyway some of the most interesting debates from various experts and some societies are paleontology,astrophysics, theology, and of course evolution that appears on its own or with the others.
Life is definitely far from boring in the academic world
Cheers
Orb

 

[jadis]

The only way a creationist can get out of that trap is to say the story is a parable, or humans back thousands of years ago just could not get to grips with what they dream/told beyond their current perception and translate this to something they understand; many creationists make it easy to debate with because they are very rigid and cannot question-look at it from another perspective the structure and framework of their belief.

Modern case in point about rigid concepts-perception; if (big if and not proven anyway due to our current understanding of quantum maths-mechanics) eventually they mostly prove (cannot be a definite) randomness does not exist and the universe is is pre-dertimined so no free will; society will never accept the concept because those who cause crimes were always going to from the moment they were born.
It is an aspect I keep well away from as part of free will/deterministic universe debates because it upsets a lot of people (understandbly so), but shows how even modern society would have problems understanding or accepting some ideas even if eventually they become more solid.
Interesting how many scientists also cannot accept or consider the concept that free will is an illusion and may not exist.

That said about creationists, there are some highly regarded theologian philosophers.
Anyway some of the most interesting debates from various experts and some societies are paleontology,astrophysics, theology, and of course evolution that appears on its own or with the others.
Life is definitely far from boring in the academic world
Cheers
Orb

Very good points, Orb. Agreed.

 

[Steve Williams]

Orb

you make some very interesting points.

 

[Orb]

Orb

you make some very interesting points.

Thanks and don't worry Steve, I will be back to my normal self and posts soon
Cheers
Orb

 

[Orb]

Armageddon. One of my wife's favorite movies

Ah man surely everyone loves Armageddon, well apart from the Russian government who complained about the scene of the Russian astronaut hitting a component and saying "This is how we fix problem in the Russian space station!"
Cheers
Orb

 

[jadis]

Ah man surely everyone loves Armageddon, well apart from the Russian government who complained about the scene of the Russian astronaut hitting a component and saying "This is how we fix problem in the Russian space station!"
Cheers
Orb

The Russian's dialogues were my favorite parts in the movie.

"Ever heard of Evel Knievel?"
Russian: " I don't watch STAR WARS!"

"American components! Russian components!. ALL MADE IN TAIWAN!"

I guess if there is a remake today, he will say all made in CHINA!.

 

[Orb]

Yes indeed
Shockingly (ok we should not be) fake microchips from China found their way in U.S. military systems and possibly space technology.
Stupid moving away from controlled fabrication, ah well we are going the way of the dinosaurs now
I swear the film Idiocracy is showing a very possible future.

Cheers
Orb

 

[JackD201]

I guess if there is a remake today, he will say all made in CHINA!.

Actually the PRC would say there is no Taiwan

 

[jadis]

Actually the PRC would say there is no Taiwan

That is quite true, Jack. That in itself is a 'ticklish' situation.