What if an asteroid didn't kill off the dinosaurs?

What if an asteroid (or whatever) didn’t kill off the dinosaurs?

Would we still exist? Would we be dinosaurs?
If we did exist (as humans or whatever form), would we even be at the level of technology we are now? Or further along?
Would the ice age have killed the dinosaurs anyway?

Anyone have any ideas?

My deeply uninformed guess is that Humans would still exist as decendants from apes, but would be far more advanced due to the increased need to find ways to survive and to control the dinosoars. That is if they managed to survive for long enough to reach a point where they would be able to consistently survive.

My basis for this guess is the knowledge that medical and technological advances are far more rapid during wartime than during peacetime. And living with dinosoars might be a bit like being in a war.

From all accounts, it was the demise of the dinosaurs that allowed mammals to flourish. If dinos were still around, I suspect we would not be here to enjoy the spectacle.

Granted, if dinosaurs suddenly appeared today, or even 5000 years ago, we would have to get smarter (or knowledgeable) or die. But would humans or apes have even evolved in the first place?

Firstly, I’d like to state that as a mammal, my opinion could be viewed as biased. In that spirit, I’d like to hear the opinions of any surviving dinosaurs in order to keep this thread balanced.

The dinosaurs would have died regardless of the asteroid. For starters, climate change would disrupt the food chain. At their size and with their enormous caloric requirements, it would be very bad for them. I’ve also read a theory that stated that the dinosaurs populations were dropping anyways, possibly by disease (I remember reading it in Discover magazine, but not which one).

Small mammals would still be more adaptable and need less food, so they would still come out ahead in the long run. Worst case scenario, I’d be posting this a while later than I am now.

They wouldn’t have evolved. Mammals took over the niche that dinosaurs held.

This town just ain’t big enough for the both of us. Partner.

Although I think the corpus of scholarly work on this question is lacking, the 1993 motion picture Super Mario Bros. does explore the possibility. Dinosaurs would have evolved to look like humans, with Dennis Hopper as their draconian despot. Also, “Walk the Dinosaur” by Was (Not Was) would be the top dance club selection.

My guess is that the ice age would have got 'em.

Yeah, screw the dinosaurs! Up with people!!!

Since you asked… Birds are considered by most paleontologists, ornithologists, and other -ologists to be a surviving lineage of dinosaurs.


Keep in mind that not all dinosaurs were big. Also, there were, indeed, lineages of dinosaurs which appear to have already gone extinct, at least in certain areas of the world, by the end of the Cretaceous (sauropods are thought to have become extinct in North America by that time, for example). But there is no real evidence of a global decline, especially one attributable to disease.


There is no real evidence of mammals outcompeting dinosaurs at any time during the reign of the latter (nor is there any real evidence that mammals and dinosaurs occupied niches which would have brought them into competition with one another), so any increased adaptability (a questionable claim in itself, mind you) that the mammals had would have only been relative to who they were most likely competing with: each other.

The truth is, none of the questions asked in the OP have anything resembling factual answers. Would we still exist? Hard to say, but probably not. History is, by and large, non-repeatable. So, if things did not happen as they did, the outcome 65 million years later would likely have been very different. How different is impossible to say. Would dinosaurs have evolved sentience had they survived? Again, difficult to say, since we can’t really determine if sentience exists outside of ourselves right now. We may be unique, or there may be budding sentience evolving in our oceans or in birds or other apes or who knows where else.

As for the ice age killing dinosaurs: well, birds and crocodiles (the closest living relatives of the dinos) both survived quite nicely.

Of course, if you want speculation, there’s always this.

The Chicxulub impact didn’t wipe out all of the dinosaurs, just the big ones. Descendants of the little ones are everywhere. We just call them birds.

On preview, damn!

There is evidence that it was not just the asteroid that wiped out the dinasaurs.

There was an immense volacanic event in what is now India in an area called the Deccan traps.

This has a huge magma field and can only be appreciated by satellite, it took place over a long period and changed the environment.

Geologists carried out magnetometer readings at various depths around in the river canyons and discovered, to their amazement, that it was all laid down in one go.Some of these layers are 1.5 miles thick and that is after 65 million years of erosion!

As a comparson, look at the Laki eruptions in Iceland, an event hundreds if not thousands of times smaller.This event lasted eight months, spewed out 14Km[sup]3[/sup] of basalt and caused the original “year without a summer” which led to the river Thames being frozen over and snow , an event not repeated until Mount Tambora exploded in 1816.

The Laki eruptions threw up at around a thousand times more material than Mt St Helens.The Deccan eruptions put up around one million times more dust and gases than Mt St Helens.

There is another similar lava field in Siberia, which is larger still, and its eruption around 245 million years ago coincides with another mass etinction event.

Darwin’s Finch, I was not suggesting that mammals would outcompete the dinosaurs. We wouldn’t have to. Assuming that there was no giant impact (or whatever) to wipe out the dinosaurs but keeping everything else the same (climate changes, continental drift, etc.) the dinos would have bit it anyways. That leaves the mammals behind and in a pretty good position to take over, same as before.

There’s a very interesting sci-fi novel by Harry Harrison that delves this issue. It’s called “West of Eden.” The premise is that during an ice age, reptiles migrated to the southern hemisphere while mammals developed in the northern. Both, of course, developed an intelligent species, but the dinosaurs themselves still did not survive.

It has been suggested that the climate and atmospheric composition allowed both dinosaurs and insects to grow to these enormous sizes during the relevant periods. I don’t know the details, but chances are, if they didn’t die out, they wouldn’t be the size they were then. Dragonflies were once humungous creatures and are now about the length of your finger. Crocodiles are one of he closest relatives to the dinosaur and although they can be an impressive size, they probably do not nearly rival the size of their ancestors.

Also worth mentioning is that an asteroid didn’t wipe out “The” Dinosaurs.

An impact event at the end of the Cretaceous was coincident with a mass extinction event that did include the remaining dinosaurs (including T. rex). However, most dino species had been long extinct by this time–major dinosaur extinctions also occurred near the end of the Jurassic and early Cretaceous and in the middle Cretaceous.

Of course, the Traps are, on an adjusted-for-Continental-Drift globe, more or less opposite the Yucatan impact site, leading some (no ready cite, I got it from BBC’s Earth Story) to speculate that the KT boundary meteorite set off the vulcanism. There is also the Siberian flood vulcanism associated with the much more massive Permian extinction of 220 My ago.

On another note, there’s no need to assume an ice age would kill off more dinosaurs than mammals - last I heard, dinosaurs were considered warm-blooded just like mammals.

Nowhere near a thousand times more, I’d think. What figures are you basing that on?

If dino’s were around for millions of years before they died, they would have lived the several ice ages anyhow, correct?

From Igneous and Metamorphic Petrology, 2nd edition, by Myron Best. © 2003, Blacwell Publishing.

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Hardly hundreds, much less thousands. In terms of total eruptive products, Laki was 36x larger than St. Helens, and similar in terms of ash.

I’ve always suspected that it didn’t.

<whispers>I think they’re…hiding. </whispers> :eek: :eek: