Some Dinosaurs may survived after the KT event.

[B5C]

Not All Dinos Died at Once

University of Alberta researchers determined that a fossilized dinosaur bone found in New Mexico confounds the long established paradigm that the age of dinosaurs ended between 65.5 and 66 million years ago.

The U of A team, led by Larry Heaman from the Department of Earth and Atmospheric Sciences, determined the femur bone of a hadrosaur as being only 64.8 million years old. That means this particular plant eater was alive about 700,000 years after the mass extinction event many paleontologists believe wiped all non-avian dinosaurs off the face of Earth, forever.

The research was published online, January 26, in the journal, Geology.

Heaman and colleagues used a new direct-dating method called U-Pb (uranium-lead) dating. A laser beam unseats minute particles of the fossil, which then undergo isotopic analysis. This new technique not only allows the age of fossil bone to be determined but potentially can distinguish the type of food a dinosaur eats. Living bone contains very low levels of uranium but during fossilization (typically less than 1000 years after death) bone is enriched in elements like uranium. The uranium atoms in bone decay spontaneously to lead over time and once fossilization is complete the uranium-lead clock starts ticking. The isotopic composition of lead determined in the hadrosaur's femur bone is therefore a measure of its absolute age.
http://www.astrobio.net/pressrelease...s-died-at-once

This maybe one of the biggest science news of the year.

[CtrlAltDe1337]

I don't see how this is anything new, its pretty common sense don't you think? There is really no reason they had to all die out at any given time; other species survived.

[cpdwane]

Yeah likewise, I don't think it's a paticularly suprising find and it doesn't really change alot either.

[Muizer]

It may indeed be sensible to think not all non-avian dinosaurs were wiped out in a single event. However, with me anyway it does raise the question why dinosaurs were so successful as an evolutionary concept before the event, but not after? If they survived, why didn't they make a full recovery? I'd guess that's where the relevance of the find might be.

[Helm]

Kind of interesting but carbon dating isn't always 100% accurate.

[Jack04]

Kind of interesting but carbon dating isn't always 100% accurate.

Good job they didn't use it then. Nor have they ever used it for such time-scales.

[MathiasOfAthens]

Kind of interesting but carbon dating isn't always 100% accurate.

Good thing they didnt use it then. Considering scientist know its not valid beyond 70,000 years or something, but anything before that is accurate to a pin drop.


On another note 700,000 years is a very long time. This is pretty huge.

[Tiwaz]

On another note 700,000 years is a very long time. This is pretty huge.

Well, some dinos survived. But look at big picture. Those dinos who survived were no longer in world where reptilians ruled.

What KT event did was open up lots of space for new evolution. Dinos lasted as long as the evolving competition did not drive them out of business, which took 700 000 years.

Why dinosaurs did not evolve? Who knows... Maybe they just found themselves in evolutionary dead end where it just did not happen anymore, or at least not in sufficient level.

[Helm]

In any case they say the dinosaurs were slowly on the decline before the KT impact so that wasn't the only factor responsible for their extinction. Otherwise they may well have survived the impact and still be here now. In a way they are still here now as birds are to dinosaurs what bats are to mammals.

[Sphere]

It may indeed be sensible to think not all non-avian dinosaurs were wiped out in a single event. However, with me anyway it does raise the question why dinosaurs were so successful as an evolutionary concept before the event, but not after?

That is big misconception most people have. The fossil record has always been at odds with the KT event theory. The fossil record shows a long decline of dinosaur species before the KT event. So any theory on dinosaur extinction cannot be as neat and tidy as a single cosmic impact. It has to include reasons for the long decline preceding the impact, which may, or as this bit of evidence suggests, may not have been the final blow.

[chamaeleo]

That is big misconception most people have. The fossil record has always been at odds with the KT event theory. The fossil record shows a long decline of dinosaur species before the KT event. So any theory on dinosaur extinction cannot be as neat and tidy as a single cosmic impact. It has to include reasons for the long decline preceding the impact, which may, or as this bit of evidence suggests, may not have been the final blow.

Glad somebody else mentioned this, Chicxulub was but one of the final nails in the coffin. 10 My before the KT boundary:

Pangea was increasingly fragmented. Ocean crust production ranged to within an order of magnitude higher than present, and flood basalts were flowing in great quantities (Deccan traps, most significant). India had separated from Africa, and would ride N for several million years before eventually colliding w Eurasia.

The Tethys seaway, a warm equatorial belt of water wrapping the Earth, had dominated the ocean's circumpolar circulation for millions of years...but it was breaking up. By 65Mya, N and S America will have fused together, as had Africa and Eurasia. The oceans' circumpolar belt was shunted south to occupy the cold belt surrounding Antarctica (which had also just separated from S America). Mean sea temps plummetted worldwide in response to the shift from warm, equatorial current, to cold, circumpolar current. Oceanic temperature gradients appeared, and the warm, sluggish deepwater was replaced by a more stratified regime.

....lots going on, geographically. The fossil record says plenty more.

True I would expect that too. No reason why only Avians would survive, not like they are immune to Asteroids and blockage of the sun. Obviously Turtles and crocs/aligators are not part of the avian family yet they have a shared lineage to the age of Dinosaurs.

Birds can fly....what do birds do today, when faced with seasonal changes in climate?

Turtles and crocs were THE winners, seeing hardly any extinctions at all. Low metabolism and resilience were key: as sit and wait predators, they need but sit in watering holes and allow their ever more desperate food items to pay their daily visit. THe only lineages to have gone extinct seem to be the more gigantic species, such as Protostega archelon. Skull morphology suggests that they specialized on giant ammonites, which themselves went bust around the KT boundary.

[Helm]

I'm just saying it's possible that they could have made some kind of mistake, it's not Earth shattering even if true anyway. Perhaps if they found a dinosaur fossil from 10 million years ago or something like.

[Tacitursa]

Be interesting to know how many dinosaur fossils they have used this new dating technique on.

fossils have been found below and above the K-T boundary and clearly move position so there could be several species of dinosaur that survived.

[Angrychris]

nah just one

[MathiasOfAthens]

Well avian dinosaurs all survived the end of the world event... most of the avian dinos. This dino is not part of the avian blood pack so thats why its interesting.

[Helm]

Perhaps 5 or 6 small species of dinosaurs survived on a few small islands a million years after the KT impact or something along those lines. I don't see why they should have all been killed in the impact when it didn't wipe out all of everything else.

[MathiasOfAthens]

Small species of dinos like cat size are still going to need a food source. Most small islands dont have too many animals on them to begin with.
The dino in question is also pretty tall I think about the same size as a raptor.
Where was this fossil found??

[Helm]

Small species of dinos like cat size are still going to need a food source. Most small islands dont have too many animals on them to begin with.
The dino in question is also pretty tall I think about the same size as a raptor.
Where was this fossil found??

Same goes for all other surviving reptiles, mammals, birds or whatever else. There's no good reason why 100% of all dinosaurs species had to have been wiped out in one event. More like the vast majority of them which were then eventally out competed by the other surviving animals.

[cpdwane]

Well avian dinosaurs all survived the end of the world event... most of the avian dinos.

In fact the vast majority of avain dinosaur families went extinct as well, they were alot more varied before the Cretacious then they have been since: many for example still had forelimb claws and teeth.

The dino in question is also pretty tall I think about the same size as a raptor.

It's a hadrosaur, so it won't have been that small. The average size for the Hadrosaurines that lived at that time was about 30-40ft. For example Edmontosaurus, which was the most common hadrosaur around at the time:

Spoiler Alert, click show to read: 

The scientists themselves probably don't know precisely what sort of Hadrosaur they found, especially if they only found a femur bone, but it would most likely have been around this size.

Where was this fossil found??

New Mexico, unless I'm mistaken, which is suprisingly close to the impact site of the asteroid and also was almost certainly part of the mainland at that time.

[MathiasOfAthens]

Wasn't the atmosphere also changing slowly over time? I've always been under the impression that atmospheric composition along with climate change over millions of years produced an enviroment less favourable to dinosaurs, and that the KT event was just sort of a massive kick in the nuts while they were already in decline.

I was under the impression that the climate and general vegetation was incredibly different then todays. Trees were larger and they were Pine trees for the most part. I also think the land was mostly swamp. There wasnt any grass but low ground cover like Mosses and Ferns.

So your right in that something changed but I dont know what caused that. Whatever the reason animals for the most part would of evolved to adapt with the changes which would of most likely occurred slowly. There would be no reason to suspect Without the KT event that the dinos would still die off due to climate change.
Turtles are still alive.

Same goes for all other surviving reptiles, mammals, birds or whatever else. There's no good reason why 100% of all dinosaurs species had to have been wiped out in one event. More like the vast majority of them which were then eventally out competed by the other surviving animals.

True, it wouldnt make much sense and the KT event happened in Mexico so you would think animals living in some far off continent would be unaffected but obviously the makeup of the earths continents was entirely different.

In fact the vast majority of avain dinosaur families went extinct as well, they were alot more varied before the Cretacious then they have been since: many for example still had forelimb claws and teeth.

True I would expect that too. No reason why only Avians would survive, not like they are immune to Asteroids and blockage of the sun. Obviously Turtles and crocs/aligators are not part of the avian family yet they have a shared lineage to the age of Dinosaurs.

It's a hadrosaur, so it won't have been that small. The average size for the Hadrosaurines that lived at that time was about 30-40ft. For example Edmontosaurus, which was the most common hadrosaur around at the time:

Spoiler Alert, click show to read: 

The scientists themselves probably don't know precisely what sort of Hadrosaur they found, especially if they only found a femur bone, but it would most likely have been around this size.

Makes sense... and its prob more likely it was the smaller one if the overall food source of the planet shrunk. After the KT event the plants would become fewer and that would create smaller herds and less food for Meat eaters. I could imagine the larger creatures died off over time if not for food then lack of breeding partners and smaller herds made the smaller meat eaters eat less.

New Mexico, unless I'm mistaken, which is suprisingly close to the impact site of the asteroid and also was almost certainly part of the mainland at that time.

Thats what I am thinking. Is it possible it migrated there maybe 300/600,000 years after the KT event. Cant imagine it living there since the KT event right?