Paleocene Non-Avian Dinosaurs. Did They Actually survive?

Has Non-Avian Dinosaurs ever lived and survived the Paleocene.

  • Yes they have, but declined rapidly within the Paleocene.

    Votes: 1 12.5%
  • Maybe they had, but were already extinct in the Paleocene.

    Votes: 0 0.0%
  • They survived well into our time.

    Votes: 1 12.5%
  • No they did not survive into the Paleocene.

    Votes: 3 37.5%
  • I just dont know.

    Votes: 3 37.5%

  • Total voters
    8

starman

Ad Honorem
Jan 2014
4,115
Connecticut
Dinosaur and Pterosaur speciation was falling by the K-Pg anyway, pterosaurs lungs were taking their last breaths even before being filled with ash. Ornithischian species in North America had fallen sharply, maybe not the total number of individuals, but, in very general terms, not much more than herds of Triceratops and Edmontosaurs, some others of course. So I think that if any did survive, they were, for unknown reasons, already on their way out, no matter if conditions were improving, and while perhaps able to carry on for a few thousand years, or maybe only a few generations, were the dinosaur living dead.
Diversity did fall but as far as we know, only in Laramidia. (It is possible that extinctions--involving the last local lambeosaurs, nodosaurs and T. latus--occurred by mid Hell Creek time c 67 Ma or so instead of the start.) Things may have been different in Europe and Asia however. The Udurchukan may predate the Hell Creek but not by very much, and it had numerous lambeosaurs (wheareas in Laramidia only a single genus was still present in the early-late Maastrichtian.) Europe also had lambeosaurs such as Blasisaurus. They might've persisted to the end.
I don't think the dinosaurs were doomed to extinction just because diversity plunged before the end. This had happened before e.g. around the time of the Cenomanian-Turonian transgression. I note the last Laramidian ornithiscians, Triceratops, Ankylosaurus and Edmontosaurus, were quite sizeable, which to my mind argues against deterioration of the physical environment.
Btw as for pterosaurs, they were doing OK in the Javelina environment and elsewhere like Romania IIRC.

Off course huge numbers of other animals died out, the marine reptiles probably due to a lack of plankton causing a loss of sufficient fish for them.
Or ammonoids.

But it is interesting to play with the idea of just how much of the late Cretaceous fauna was dependent on a few species, but vast numbers of individuals, of hadrosaurs and ceratopsians. It seemed even without volcanoes and asteroids to have been a fragile world.
Dinosaurs in fact endured quite a lot including transgressions, cold spells, Morokweng, Manson etc before Chicxulub finally proved too much.
 
Last edited:

Corvidius

Ad Honorem
Jul 2017
3,047
Crows nest
Well, I can't really add to that, it's all correct to me, though I do think for pterosaurs the writing was on the wall, and it said "Move aside, birds coming through" Though certainly dinosaurs had many ups and downs, and I think they would have survived, except Chicxulub, as you say, being the final straw.

Three more days I think, and then Saurian, finally.
 

starman

Ad Honorem
Jan 2014
4,115
Connecticut
Well, I can't really add to that, it's all correct to me, though I do think for pterosaurs the writing was on the wall, and it said "Move aside, birds coming through"

In the past it was claimed birds had an advantage over pterosaurs, and so gradually displaced them. (Feathers were supposedly more advantageous than membrane, which could tear.) But I don't think the evidence for competitive replacement is good. By the time of Quetzalcoatlus, the two groups had coexisted for several tens of millions of years.
 

Corvidius

Ad Honorem
Jul 2017
3,047
Crows nest
I was probably being a little too general in my comments as I don't want to get into long convoluted discussion. Essentially you are right, but there is the matter of bird diversity seemingly increasing towards the end of the Cretaceous and pterosaur diversity seemingly decreasing. It may not be down to direct competition between the two groups, but that pterosaurs were almost coming down to one major group, the azhdarchids, was not a good sign. Animals that big and in small numbers are not in a good position to survive in the long term. We cannot know of course, but I would be surprised that in an alternate world without the extinction, that any pterosaurs existed by about 55 million years ago. But that is just my view. Also, I think the evidence, either way, for diversity at the end of the cretaceous is not good enough to make a solid statement that may be overturned in the coming years.
 
Last edited:
Jan 2013
1,207
Anywhere
Well in truth all I can say that birds are dinosaurs that survived. I read, watched and studied birds and non-avian dinosaurs to finally understand that avian-dinosaurs are the only dinosaurs that still exist today.
Well time to close this thread not just because i wanted to know what happened to the non-avian dinosaurs.


But there is one thing I might add. To those scientists who wished to clone a T-Rex or a Raptor. It is best not to clone but to fascinate the past. As we can still see dinosaurs today living, breathing and thriving in our modern world. Thank you guys for this.

Time to close this thread as I find it now irrelevant.
 
Last edited:

Bart Dale

Ad Honorem
Dec 2009
7,095
I find it quite perplexing that the paravians...highly advanced, feathered theropod dinosaurs which were on the verge of evolving into birds...did not survive the K-Pg extinction, whereas the genuine birds did. How can this be explained scientifically? The physiological differences between the two groups cannot have been very great.
Well, birds can fly, and so can more likely find a small patch here or there to seek out and find food. Dinosaurs, lacking that mobility, were at a disadvantage, and more likely to starve.

There were some nonflying aquatic birds that also seem to survive, but perhaps their aquatic environments were less effected by the KT event. I don't know of any aquatic dinosaur, the marine reptiles like the pleisosaur were not dinosaurs but a kind of reptile. And none were very small.

Crocodiles might have survived because they can go dormant for a while, and many mammals can hibernate. Birds rarely go dormant for long periods of time, most lack the ability, and the dinosaurs, if they were similar to birds, might not have also been unable to hibernate or go dormant for long periods. If you can hibernate for a few months, perhaps you could wait out the destruction until the seeds not destroyed in the KT event start growing and restablishing plant life.
 
Apr 2017
732
Lemuria
It is strange not a single species of dinosaurs survived. They must have reached an evolutionary dead-end because of some specific characteristics that rendered them unfit for the new environment.
We should also note only one group of birds made it out of countless of groups that went extincted. The fact that birds still exist is nothing short of a miracle. Is there anything stranger than a bird? Think about it.
 

Corvidius

Ad Honorem
Jul 2017
3,047
Crows nest
To paraphrase Thomas R. Holtz, Jr.

A bird is a saurischian*, theropod, tetanurine, coelurosaurian, maniraptoran dinosaur.

Birds could not be more dinosaurian if they tried, and are the most successful of all dinosaurs, not least that they alone survived, probably because they were the highest form of life on the planet at the time of the extinction, and well equipped to survive, even if only a handful.

* Might get moved to Ornithischia...
 
Last edited:

Bart Dale

Ad Honorem
Dec 2009
7,095
To paraphrase Thomas R. Holtz, Jr.

A bird is a saurischian*, theropod, tetanurine, coelurosaurian, maniraptoran dinosaur.

Birds could not be more dinosaurian if they tried, and are the most successful of all dinosaurs, not least that they alone survived, probably because they were the highest form of life on the planet at the time of the extinction, and well equipped to survive, even if only a handful.

All of it true, but it still leaves the mystery as to why all the non avian dinosaurs died out, and just one branch of the many branches of dinosaurs survived. Mammals branches as widely separated as Montremes (egg laying platupus), Masupials (kangara), and Placentals (man, dogs, horses, mice, etc/) all survived. There were even some other branches of mammals (Multitubulars) that also survived the KT extinction, but became extinct millions of years later.

Birds represent just one hightly specialized branch of dinosaurs, and it wasn't even all birds, but one particular family of birds. It is as if of all the families of mammals, only primates had survived and all other types mammals (rodents, canivores like cats and dogs, etc.) became extinct. Saying that birds are dinosaurs and they survived the KT doesn't take away the mystery of why all the other types of dinosaurs died out.

The complete lack of fossil records for non avian dinosaurs after the KT event meant that if any did survive the event, the must of disappeared rather quickly. Whether the non avian dinosaurs became technically extinct, all the non avian dinosaurs became effectively extinct after the KT event.
 
Last edited:

Corvidius

Ad Honorem
Jul 2017
3,047
Crows nest
It is as if of all the families of mammals, only primates had survived and all other types mammals (rodents, canivores like cats and dogs, etc.) became extinct.
That about primates is a good analogy for birds being the only dinosaurs to survive, as they were the dinosaur equivalent of a primate.

But why the rest went is really difficult beyond the obvious causes such as a collapse in the food chain. I think I remember something about a dig site in New Jersey or somewhere near there, where they thought they had found some evidence of a mass dying directly due to effects of the impact, but I'm not sure what effects would be directly felt that far North, a heck of a hot wind I'm sure, but maybe not an instant killer. Somewhere hidden in the ground there must be vast bonebeds of all manner of dinosaurs and other animals killed by the blast, but not close enough to have been shredded to pieces, and with the predators also dead, their remains left reasonably intact. Still seems odd that with so many dying over a presumably very short period of time, their remains are still very elusive.