WI: No K-T extinction

[Zuvarq]

The K-T event doesn't happen, regardless of what every single cause was.

How does life evolve without it?

What organisms would we have now? How do mosasaurs and plesiosaurs evolve--do they eventually replace ichthyosaurs? What would happen to the last pterosaurs? What does T. rex evolve into? Does a sentient bird or dinosaur evolve? What happens to the mammals?

 

[ArKhan]

These people did a great job at it:
http://www.unet.univie.ac.at/~a0000265/Spec/index.html

 

[Emperor Norton I]

These people did a great job at it:
http://www.unet.univie.ac.at/~a0000265/Spec/index.html

That is a good resource.

***

I would hope some form of alternate intelligent species (The Dinosauroid, Dinosapien, Humanosaur, whatever you wanna call it) rises. But I'm not sure of the likelihood, or if they'd ever get to a human definition of civilization.

 

[Errnge]

i didn't know you were a paleontology nerd too! points!

anyway, i think that link is pretty right on. feathers would be utilized more widely by dino-descendants. this way they could survive in cooler environments.

i always picture a t-rex descendant that is just a giant head on legs with a long tail. the arms becoming unnecessary and the head just getting bigger to produce more biting force with a longer tail to compensate for the weight.

 

[Clipper747]

I recall an article I read many years ago about a WI situation. The results showed a "humanoid" reptilian creature that may have evolved had the meteor not struck.
However, say that specific impact had not occurred, odds are there would've been some extinction event that would've doomed life after that. The poor "reptohumanoids" would've had the odds stacked against them.

 

[Beedok]

Based off of some theories mammals would be dominant, but there would likely still be dinosaurs in the T rex role, and probably the sauropod role too.

 

[tormsen]

I recall an article I read many years ago about a WI situation. The results showed a "humanoid" reptilian creature that may have evolved had the meteor not struck.
However, say that specific impact had not occurred, odds are there would've been some extinction event that would've doomed life after that. The poor "reptohumanoids" would've had the odds stacked against them.

I don't see why that would be the case at all.

 

[Seawitch]

Lets say the events causing the KT extinction didn't stop the ice age happening, it happened quite quickly too. The Dinosaurs would have succumbed where the ice age reached. The T Rex was certainly in that zone. Many Dinosaurs were not a threat to man unless they happened to step on him, and I bet many would have been vulnerable to him.
I'm not sure our oldest ancestors wouldn't have stood on their back legs and evolved to become us.

 

[The Red]

I think the idea of dinosaurs continuing to dominate the earth is rather optimistic in my opinion, omnivores still have a massive natural advantage. Of course humans almost certainly won't exist, not our version anyway, but warm blooded mammals would still be dominant by the present day.

 

[tormsen]

Lets say the events causing the KT extinction didn't stop the ice age happening, it happened quite quickly too. The Dinosaurs would have succumbed where the ice age reached. The T Rex was certainly in that zone. Many Dinosaurs were not a threat to man unless they happened to step on him, and I bet many would have been vulnerable to him.
I'm not sure our oldest ancestors wouldn't have stood on their back legs and evolved to become us.

I think the idea of dinosaurs continuing to dominate the earth is rather optimistic in my opinion, omnivores still have a massive natural advantage. Of course humans almost certainly won't exist, not our version anyway, but warm blooded mammals would still be dominant by the present day.

You guys seem to have a somewhat outdated idea of what dinosaurs were like. They were not just big lizards.

Ice Ages and such climatic changes were much slower and infinately easier to adapt to compared to the K-T event. T-rex would certainly not still be around, but Dinosauria almost certainly would, in forms very different from they were 65 million years ago.

And who said dinosaurs couldn't be omnivores? Mammalia has been pretty awesome, and would likely continue to prosper even without the K-T event, but without that great culling of competition the rise and dominance of mammals is by no means pre-destined.

As for humans being able to best dinosaurs with our smarts and tools, remember all the precursors before modern man arose. To be a Homo habilis co-existing with the distant descendants of velociraptor on the savanna? No thanks, buddy, I'm gonna stay in this goddamn tree.

 

[Claudius]

You guys seem to have a somewhat outdated idea of what dinosaurs were like. They were not just big lizards.

Ice Ages and such climatic changes were much slower and infinately easier to adapt to compared to the K-T event. T-rex would certainly not still be around, but Dinosauria almost certainly would, in forms very different from they were 65 million years ago.

And who said dinosaurs couldn't be omnivores? Mammalia has been pretty awesome, and would likely continue to prosper even without the K-T event, but without that great culling of competition the rise and dominance of mammals is by no means pre-destined.

As for humans being able to best dinosaurs with our smarts and tools, remember all the precursors before modern man arose. To be a Homo habilis co-existing with the distant descendants of velociraptor on the savanna? No thanks, buddy, I'm gonna stay in this goddamn tree.

I think it is getting to be generally accepted these days that at least some lines of dinosaurs and possibly all dinosaurs were somewhat warm-blooded. In recent years, fossils with feathers and hairy or downy skin have been found in various places in China and elsewhere. Personally, I like the idea that the quite warm-blooded birds are a surviving branch of Dinosauria. So yeah some dinosaurs would have survived the Ice Ages. Heck, large reptiles like crocs and monitor lizards did as well. As to whether intelligence in dinosaur decendants, who knows?

 

[MikeTurcotte]

To be a Homo habilis co-existing with the distant descendants of velociraptor on the savanna? No thanks, buddy, I'm gonna stay in this goddamn tree.

Damn right!

Unless the alt-ancestors develop controlled fire, they're toast to something like a velociraptor. Heck, they're toast to something a good deal less capable than a velociraptor.

Of course should intelligence evolve in an isolated/protected area with few nastys about...well then...

Intelligence is the greatest force-multiplier in the history of this planet. No other species is as overwhelmingly lethal as the one intelliegent species to arise here - humans. No other macro species can hope to compete with us. Given enough time, T-Rexs, Velociraptors, whatevers would all be sport for whatever intelligence arose.

Mike Turcotte

 

[whitecrow]

Based off of some theories mammals would be dominant, but there would likely still be dinosaurs in the T rex role, and probably the sauropod role too.

Do you happen to have any web-links to those theories?

I'd like to read them.

 

[Snake Featherston]

In some ways there'd be a real difference with ecosystems. From more modern paleontological studies dinosaurian fauna were more limited than mammalian, the same species of dinosaur at different ages filled niches distinct separate mammalian species fill. Given the appearance of the Tyrannosaurids and their rapid spread, it's safe to say that absent the K-T boundary there may at some point be a faunal exchange where Tyrannosaurs drive South American Abelisaurs extinct the same way they did the Allosauroids.

Sauropods won't make it to the alt-world 2011 because the spread of flowering plants will drive them extinct, they weren't exactly adapted for that type of flora, where ceratopsians and hadrosaurids definitely were. Pterosaurs will ultimately be replaced by Avians, leaving a planet that is really and truly dinosaur-dominated.

As far as the seas......my guess is that there'd be more sea-reptiles evolving to replace the mosasaurs the same way they replaced the pliosaurs but I couldn't be more specific than that. An interesting question is whether segnosaurian-style herbivorous theropods start filling some niches vacated by the sauropods (large saurischian herbivores).

By today I think a more interesting scenario would prevail like that in the Permian, though stabler: no one fauna prevailing over the others, with dinosaurs still representing megafauna, though due to the ice ages they'd be smaller and many more feathered theropods. The truly interesting question is what the spread of squamates would mean.....

 

[Snake Featherston]

You guys seem to have a somewhat outdated idea of what dinosaurs were like. They were not just big lizards.

Ice Ages and such climatic changes were much slower and infinately easier to adapt to compared to the K-T event. T-rex would certainly not still be around, but Dinosauria almost certainly would, in forms very different from they were 65 million years ago.

And who said dinosaurs couldn't be omnivores? Mammalia has been pretty awesome, and would likely continue to prosper even without the K-T event, but without that great culling of competition the rise and dominance of mammals is by no means pre-destined.

As for humans being able to best dinosaurs with our smarts and tools, remember all the precursors before modern man arose. To be a Homo habilis co-existing with the distant descendants of velociraptor on the savanna? No thanks, buddy, I'm gonna stay in this goddamn tree.

For that matter all the hominini except our species went extinct during the last Ice Age so it's debatable whether our type of lifeform is that much better at surviving them. I do think dinosaurs would become smaller if mainly due to the harsher, colder, less vegetation climate.

Damn right!

Unless the alt-ancestors develop controlled fire, they're toast to something like a velociraptor. Heck, they're toast to something a good deal less capable than a velociraptor.

Of course should intelligence evolve in an isolated/protected area with few nastys about...well then...

Intelligence is the greatest force-multiplier in the history of this planet. No other species is as overwhelmingly lethal as the one intelliegent species to arise here - humans. No other macro species can hope to compete with us. Given enough time, T-Rexs, Velociraptors, whatevers would all be sport for whatever intelligence arose.

Mike Turcotte

Not necessarily. Neanderthals arguably had quite a few of the same traits we did, but they didn't make it to the modern day where we did do that. Humans were continually eaten by crocs into the Ancient World and as Gustav shows today it's still very, very possible for the Crocs to do that. Given dinosaurs would share the same kind of bad tempers that mark crocs and birds, but the predatory ones would all be bipedal and clawed.....yeah.

Human advantages WRT bipedalism are rather less so when there's bipedal predators that even the really, really enormous ones like Tyrannosaurus rex were able to outrun humans. In that case the evolutionary trends that favor bipedalism in primates and apes would have been stillborn.

 

[MikeTurcotte]

For that matter all the hominini except our species went extinct during the last Ice Age so it's debatable whether our type of lifeform is that much better at surviving them. I do think dinosaurs would become smaller if mainly due to the harsher, colder, less vegetation climate.



Not necessarily. Neanderthals arguably had quite a few of the same traits we did, but they didn't make it to the modern day where we did do that. Humans were continually eaten by crocs into the Ancient World and as Gustav shows today it's still very, very possible for the Crocs to do that. Given dinosaurs would share the same kind of bad tempers that mark crocs and birds, but the predatory ones would all be bipedal and clawed.....yeah.

Human advantages WRT bipedalism are rather less so when there's bipedal predators that even the really, really enormous ones like Tyrannosaurus rex were able to outrun humans. In that case the evolutionary trends that favor bipedalism in primates and apes would have been stillborn.

Well argued. My statement had less to do with 'humans' and more to do with intelligence. In this alt-world, I have no idea what form that intelligence would take, even if it arose at all. I just say that if it had, the results would be the same; the intelligent race dominates the planet.

Yes, I know that animals still kill humans even today. But that is exceedingly rare, and is usually predicated on risky human behavior. The crocadile has to get lucky to kill a human; a human does not to kill a croc.

As for Neanderthals, I go back and forth in my own mind on this. Maybe it's just me, but I can't get away from the fact that they were so much better adapted to surviving a harsh environment - so much physically stronger than modern humans - so better adapted to using the weapons technology of the day (a spear, say) - and yet they're gone and we're not. I can't help but draw the conculsion that we're smarter - way smarter - than them - and that intelligence trumps pure strength. Yes, I've heard the arguments about disease and interbreeding and all that. But I haven't seen any conclusive evidence of these.

Mike Turcotte

 

[TapReflex]

In honesty, The PETM would push some animals off the edge, and the ice ages would do in all of the large dinosaurs children gawk over.

Droaeosaurs and some small hadrosaurs along side alt-Mammals would be a likely outcome.

 

[Mongo]

In honesty, The PETM would push some animals off the edge, and the ice ages would do in all of the large dinosaurs children gawk over.

Droaeosaurs and some small hadrosaurs along side alt-Mammals would be a likely outcome.

I doubt it. The equatorial regions would still be quite warm (if dry), even during a glacial period, and in any case, dinosaurs are known to have survived in fairly cold regions of the Mesozoic Earth, such as Antarctica, which while not covered in an ice sheet, still got plenty cold during the winter.

 

[Snake Featherston]

Well argued. My statement had less to do with 'humans' and more to do with intelligence. In this alt-world, I have no idea what form that intelligence would take, even if it arose at all. I just say that if it had, the results would be the same; the intelligent race dominates the planet.

Yes, I know that animals still kill humans even today. But that is exceedingly rare, and is usually predicated on risky human behavior. The crocadile has to get lucky to kill a human; a human does not to kill a croc.

That's more than somewhat overblown. In the Third World large predators still eat people with more than somewhat regularity. There are parts of Asia where tigers eating people is not the norm, but neither is it a "ZOMG WTF" moment.

As for Neanderthals, I go back and forth in my own mind on this. Maybe it's just me, but I can't get away from the fact that they were so much better adapted to surviving a harsh environment - so much physically stronger than modern humans - so better adapted to using the weapons technology of the day (a spear, say) - and yet they're gone and we're not. I can't help but draw the conculsion that we're smarter - way smarter - than them - and that intelligence trumps pure strength. Yes, I've heard the arguments about disease and interbreeding and all that. But I haven't seen any conclusive evidence of these.

Mike Turcotte

I believe early humans and Neanderthals were equally intelligent. The difference was early human groups were larger, with a thinner body that required less food paired with groups of seventy relative to Neanderthal groups of eight. Neanderthals were extremely carnivorous, humans were able to exist on both plants and meat. We were more efficient but it was not so much intelligence as being able to support more individuals due to both gracility and greater capacity to eat plants.

There were only so many hominins that could be supported on Paleolithic bases and with humans able to support more with greater access to resources Neanderthals were never physically able to make use of.....

 

[Zuvarq]

The dinosaurs, if they survive the K-T event, would definitely survive the Ice Age.

The common ancestor of all the dinosaurs was a featherless 'lizard'. If one (actually one and a few species of another) group of dinosaurs could evolve feathers independently, others could too. Or, they all inherited proto-feathers from a common ancestor, meaning they all could re-evolve the proto-feathers into full size and capability.

All theropods could definitely evolve thicker feathers. No sauropods with feathers have been found if I remember correctly, but being Saurischia and related to theropods, it is quite possible that sauropods could evolve feathers. And there were several Ornithischia with feathers, though I think all of them were from the Jurassic.

If even one species of dinosaur manages to evolve its feathers thick enough to tough out the cooling climate, dinosaurs will reproliferate and by '2011' there will be at least a few distinct groups of dinosaurs.
Though likely many more would. Many dinosaurs were warm-blooded, too. Mammals do not really have advantages over feathered dinosaurs.

Also, one word: penguins.