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Posted (edited)

Surely dinosaurs would be beaten by mammals, because the most advanced mammals, ie human beings, have invented guns.

 

These mammalian guns would quickly shoot the dinosaurs dead.

Edited by Dekan
Posted

 

No such thing as a brontosaurus guys...

 

And this is why no animal in the history of the world has ever messed with a brontosaurus and lived.
Posted

 

Your impression is mistaken exotic animals are causing problems all over the world, from pythons in the Florida everglades to large mouth bass in Japan. Just in my area Flathead catfish and blue catfish from the Mississippi river system have caused considerable harm to the native species. Rabbits and mice in Australia, I can go on and on but it's a real problem and natives often do not fair well when exotic species are introduced. Pacu introduced on some pacific islands have actually started harming humans, hence their nickname "nut cutter"

 

Disease is yet another problem, exotics often carry disease and the native fauna suffer greatly.

 

This is even happening in the oceans, lion fish , native to pacific waters introduced in Florida have now taken over many deep reefs and wreaks all along the east coast of the USA.

Right... We are departing from the theme now, but when I read your post I start thinking that maybe evolution is not as efficient in filing niches as we usually think it is (at least, I was imagining an efficient evolution). Okay, maybe in some cases some 'exotic' species moved in because of environmental changes (like temperature change), but as you said there certainly are many examples where exotic species were just a better fit, or just exploited an unused niche... Still I think that if you choose a random dinosaur and place it here in some random environment (or vice versa) it is unlikely the 'exotic' animal will flourish. But when I consider that the evolution might be inefficient, then I must agree with you that it probably would be possible to find a suitable today's environment for many dinosaur species.

 

...

 

I also noticed that you said that you believe 'egg laying' is a disadvantage for dinosaurs. Why do you think so? I would be cautious while making such claim because egg laying might give them opportunity to generate much larger number of offspring and this can also be a very successful strategy.

Posted (edited)

 

They grew that big because of predation and there's no reason to think the predators stopped growing.

As I said before, mammals cannot simultaneously that grow large and be as mobile as dinosaurs, their metabolism would be too high, that's why the biggest they really get on land is elephants. Elephants still get eaten by lions and tigers occasionally, but they just can't evolve to be much bigger, so instead they travel in groups.

 

 

 

Throttle back a bit dude, this is the speculations section, no one expects a time rift to open and see an apatosaurus come running out...

And I don't expect someone to trust a TV show more than rationality. You had question, that's fine, just don't use the TV show as the answer, otherwise there's no point posting here.

Edited by SamBridge
Posted (edited)

Whales don't have many predators, the only predators the smaller ones do have are giant squid, and even those squid don't eat blue whales.

 

 

Giant squid live too deep to be a threat to any whale other than the ones hunting them; even humpbacks have to learn/acclimatise to dive deep enough to catch them. The only predators most whales have are other whales.

 

As I said before, mammals cannot simultaneously that grow large and be as mobile as dinosaurs, their metabolism would be too high, that's why the biggest they really get on land is elephants. Elephants still get eaten by lions and tigers occasionally, but they just can't evolve to be much bigger, so instead they travel in groups.

 

When have I suggested this would be the case?

 

Sauropods would have nothing to fear from the fauna in this era, but I wonder if the flora, of today, would be suitable for their digestive system; if not they would quickly starve.

Edited by dimreepr
Posted

 

 

When have I suggested this would be the case?

You didn't, I did.

 

 

 

Sauropods would have nothing to fear from the fauna in this era, but I wonder if the flora, of today, would be suitable for their digestive system; if not they would quickly starve.

The larger ones wouldn't.

Posted

As I said before, mammals cannot simultaneously that grow large and be as mobile as dinosaurs, their metabolism would be too high, that's why the biggest they really get on land is elephants. Elephants still get eaten by lions and tigers occasionally, but they just can't evolve to be much bigger, so instead they travel in groups.

This is simply not true Paraceratherium http://en.wikipedia.org/wiki/Paraceratherium was quite large, as large as many dinosaurs. Dinosaurs also had high metabolisms, and animals like elephants do not have high metabolisms being at least partly gigantotherms.

 

And I don't expect someone to trust a TV show more than rationality. You had question, that's fine, just don't use the TV show as the answer, otherwise there's no point posting here.

And since i did not suggest any such thing this is a strawman, please review the rules..

 

Sauropods would have nothing to fear from the fauna in this era, but I wonder if the flora, of today, would be suitable for their digestive system; if not they would quickly starve.

I see no reason why sauropods couldn't eat modern flora, they existed both before and after modern flora dominated the earth.

 

I also noticed that you said that you believe 'egg laying' is a disadvantage for dinosaurs. Why do you think so? I would be cautious while making such claim because egg laying might give them opportunity to generate much larger number of offspring and this can also be a very successful strategy.

If we are talking of sauropods it is not believed they protected their eggs, of course that could be wrong, but baby sauropods would be just as vulnerable as baby mammals but with out the adults to protect them. Other dinosaurs evidently did protect their eggs and young so they might not have been as vulnerable if you compare them to modern dinosaurs like ostriches.

 

Of course if we include marine fauna in this there were mosasaurs and other marine reptiles that could have given marine mammals a run for their money as well...

Posted

 

You didn't, I did.

 

Then why quote me?

 

The larger ones wouldn't.

 

 

Why not? I can’t think of any animal that without digestible food wouldn’t starve.

I see no reason why sauropods couldn't eat modern flora, they existed both before and after modern flora dominated the earth.

 

In which case those that existed before modern flora may have problems with todays; and those that existed after would only struggle if they materialised in an arid region.

Posted

Then why quote me?

 

 

Why not? I can’t think of any animal that without digestible food wouldn’t starve.

 

 

In which case those that existed before modern flora may have problems with todays; and those that existed after would only struggle if they materialised in an arid region.

How would you assume that vegetation from one era would be indigestible in another? Sauropods lived right up till the end, changing vegetation didn't seem to have an effect...

Posted

How would you assume that vegetation from one era would be indigestible in another? Sauropods lived right up till the end, changing vegetation didn't seem to have an effect...

 

They, presumably, evolved digestively with the changes; so a sudden change may not be so digestible. I have wonder, for instance, how cattle would manage without grass.

Posted

 

They, presumably, evolved digestively with the changes; so a sudden change may not be so digestible. I have wonder, for instance, how cattle would manage without grass.

 

 

Cattle will eat vegetation other than grass..

Posted

 

 

Cattle will eat vegetation other than grass..

 

Having researched this, I have to concede, there’s no reason to suspect sauropods would be so tied to one source of flora; the use of cattle as an example was not well thought out and just a result of hearsay.

Posted

Having researched this, I have to concede, there’s no reason to suspect sauropods would be so tied to one source of flora; the use of cattle as an example was not well thought out and just a result of hearsay.

There's no reason to assume they wouldn't though either. Maybe cattle/grass wasn't the best example, but what about koalas and eucalyptus or pandas and bamboo? We really have little to no basis to judge what sort of dietary preferences or restrictions dinosaurs may have had beyond clues in their dentition.

Posted

 

Having researched this, I have to concede, there’s no reason to suspect sauropods would be so tied to one source of flora; the use of cattle as an example was not well thought out and just a result of hearsay.

 

 

Quite the contrary, I grew up on a farm and have personally observed cows browsing on brush, drier regions cattle often have little to graze on but rough vegetation..

Posted

Quite the contrary, I grew up on a farm and have personally observed cows browsing on brush, drier regions cattle often have little to graze on but rough vegetation..

I think you misunderstood Dimreepr. He was conceding that cattle eat more/other than grass. Nonetheless, the two mammal examples I gave have very restrictive vegetative diets and my point about not knowing about the dinosaurs stands.

Posted (edited)

I think you misunderstood Dimreepr. He was conceding that cattle eat more/other than grass.

 

Indeed.

Nonetheless, the two mammal examples I gave have very restrictive vegetative diets and my point about not knowing about the dinosaurs stands.

 

Panda’s can consume meat amongst other things and it’s just the predominance of bamboo that determines their diet; koalas are very particular on the type of leaves they choose and depend on eucalyptus as much for water as for food. In either case there’s no reason to assume they couldn't survive on another source.

Edited by dimreepr
Posted

 

Indeed.

 

Panda’s can consume meat amongst other things and it’s just the predominance of bamboo that determines their diet; koalas are very particular on the type of leaves they choose and depend on eucalyptus as much for water as for food. In either case there’s no reason to assume they couldn't survive on another source.

 

 

You are correct, I misread your post, sorry...

Posted

...

 

Pandas can consume meat amongst other things and its just the predominance of bamboo that determines their diet; koalas are very particular on the type of leaves they choose and depend on eucalyptus as much for water as for food. In either case theres no reason to assume they couldn't survive on another source.

On the koalas, I find a different view.

Koalas

...The partially worn molars of middle-aged koalas are optimal for breaking the leaves into small particles, resulting in more efficient stomach digestion and nutrient absorption in the small intestine,[44] which digests the eucalyptus leaves to provide most of the animal's energy.[42] A koala sometimes regurgitates the food into the mouth to be chewed a second time.[45] ...

I don't accept the idea that any old herbage will do for any-and-all herbivores when we see so many examples of specialization/adaptation among not only mammals but birds, and reptiles. That animals vary their diets to some degree is no evidence they can survive for long without whatever source is their mainstay.

Posted

On the koalas, I find a different view.

Koalas

 

I don't accept the idea that any old herbage will do for any-and-all herbivores when we see so many examples of specialization/adaptation among not only mammals but birds, and reptiles. That animals vary their diets to some degree is no evidence they can survive for long without whatever source is their mainstay.

 

I’m happy to concede this point, as my studies have been brief, if sufficient evidence exists; but specialisation does not necessarily mean exclusivity and symbiosis seems to be on a much more basic level than a mammal.

Posted

I’m happy to concede this point, as my studies have been brief, if sufficient evidence exists; but specialisation does not necessarily mean exclusivity and symbiosis seems to be on a much more basic level than a mammal.

Roger concession. Symbiosis? Did I miss that conversation? I'll review.

 

Another point on herbivore's diets is that if animals were so adaptable then it seems to me zoos would not have to pay so much attention to providing specialized diets.

Posted

Roger concession. Symbiosis? Did I miss that conversation? I'll review.

 

Another point on herbivore's diets is that if animals were so adaptable then it seems to me zoos would not have to pay so much attention to providing specialized diets.

 

 

I'm not sure how this is relevant, we have no idea if sauropods were specialists or not. We can see that a great many large herbivourus mammals eat highly varied diets, I would think it justified to assume dinosaurs were just as adaptable.

Posted

Roger concession. Symbiosis? Did I miss that conversation? I'll review.

 

Another point on herbivore's diets is that if animals were so adaptable then it seems to me zoos would not have to pay so much attention to providing specialized diets.

 

No evidence: no concession.

Posted (edited)

I'm not sure how this is relevant, we have no idea if sauropods were specialists or not. We can see that a great many large herbivourus mammals eat highly varied diets, I would think it justified to assume dinosaurs were just as adaptable.

It's relevant because as I said you have no reason to assume they didn't have specialized diets. That is part-and-parcel of your 'no idea if...'. Yes we see varied diets now, but we also see specialized/restricted ones. The scenario you laid out of the portal and sudden introduction does not bode well for adaptation which requires considerable more time than a single generation. So if an introduced dino already had a varied diet, it might do well enough to battle it out with mammals, but if that dino had a specialized diet it might just serve the mammals as carrion.

 

On the egg laying, we have the example of turtles which produce many eggs that they bury and abandon. Dinos with a similar habit might do as well as turtles in that regard were they to come through the portal.

 

No evidence: no concession.

I was referring to your concession in regard to my koala evidence. Here...

I’m happy to concede this point, as my studies have been brief, if sufficient evidence exists; but specialisation does not necessarily mean exclusivity and symbiosis seems to be on a much more basic level than a mammal.

A further perspective on animal diet below.

 

While pondering that, I found myself wondering what dino meat tastes like? I can't believe I ate the whole thing!

 

Generalist and specialist species

 

A generalist species is able to thrive in a wide variety of environmental conditions and can make use of a variety of different resources (for example, a heterotroph with a varied diet). A specialist species can only thrive in a narrow range of environmental conditions or has a limited diet. Most organisms do not all fit neatly into either group, however. Some species are highly specialized (the most extreme case being monophagy), others less so, while some can tolerate many different environments. In other words, there is a continuum from highly specialized to broadly generalist species.

 

Omnivores are usually generalists. Herbivores are often specialists, but those that eat a variety of plants may be considered generalists. A well-known example of a specialist animal is the koala which subsists almost entirely on eucalyptus leaves. The raccoon is a generalist because it has a natural range that includes most of North and Central America, and it is omnivorous, eating berries, insects, eggs and small animals. Monophagous organisms feed exclusively or nearly so on a single other species.

...

Edited by Acme
Posted

What dino meat tastes like is obvious... chicken... ;)

 

Yes there are mammals with specific diets and many that eat what ever they can get, my point is that larger animals tend to be a bit more eclectic in their eating habits but since we have no idea if this is true for dinosaurs one way or another speculation is moot.

 

It's quite possible my OP was a bit vague but what I had in mind was more of a thought experiment in what would happen if a particular species of dinosaur was released into our world, minus humans, how would they fair in competition with modern mammals. I have read some assertions that dinosaurs were superior to mammals in their physiology, they are thought to have had a superior method of breathing much as birds do today, hollow bones like birds for less weight and a stronger weight to strength ratio, even sauropods are now thought by some to have had these adaptations and they contributed to the size they were able to obtain.

 

Dinosaurs never competed with modern mammals but they did compete with and dominate the mammal like reptiles which had achieved dinosaur like size and domination of the environment before dinosaurs evolved and went on to dominate.

 

Possibly a better example would be a continent of dinosaurs "suddenly" being connected to continent of modern mammals and the interactions of both types, This is not unprecedented with placental mammals displacing most of the marsupials when north and south america connected after a long separation.

 

This is also relevant because terror birds went into north america when this happened and they were quite successful for a while.

 

The life styles of modern mammals and dinosaurs were both similar and wildly different, as for the turtle comparison hiding eggs the size of golf balls is bit easier than eggs the size of footballs but it is a valid comparison but we would need to know a bit more about how things like sauropods hid or protected their eggs.

 

I think it's obvious that a large adult sauropod or large adult theropod would be invincible to modern mammal predators but i think it would not be that simple. If dinosaurs were physiologically superior to modern mammals then over long time periods they should dominate at least some ecological niches.

Posted

From the OP:


If the two ecosystems were truly mixed in some way would Mammals beat out the dinosaurs or would dinosaurs reclaim their dominance?

"truly mixed" is hard to define, but I think I understand what the question was about. Moontanman asks if one is genuinely better than the other one (mammals vs dinos), or is it that both actually use the same 'technology' just optimized in somewhat different way.... Or what is it that you wanted to ask by the 'truly mixed', Moon?

 

At least I would like to hear opinions about the above dilemma. Note that because modern mammals are of later design, it does not mean that they are necessarily more advanced. It might be that dinosaurs were very advanced and then... bang - the reset happened and the evolution is now starting from the middle again.

 

BTW, there is one more thing that I read throughout this thread - in what way would one non-coordinated group sustain its dominance over the other group? I don't think dinosaurs were racist pigs that were intentionally suppressing mammals. How could they prevent mammals to slowly take over? What is it that prevents today birds to step down from the trees and slowly take over the land?

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