Did proboscideans help drive Paraceratherium to extinction?

[Infinity Blade]

Although it seems that Paraceratherium's cause of extinction was unknown, one of the proposed explanations for its extinction was that its food sources were eaten up by gomphotheres. I can no longer find the full paper (I have seen it before), but Wikipedia sums up the theory well.

"Theorised reasons include climate change, low reproduction rate, and invasion by gomphothere proboscideans from Africa in the late Oligocene (between 28 and 23 million years ago). Gomphotheres may have been able to considerably change the habitats they entered, in the same way that African elephants do today, by destroying trees and turning woodland into grassland. Once their food source became scarce and their numbers dwindled, Paraceratherium populations would have become more vulnerable to other threats."

I remember one of the things that the paper tried to address as a bit of a defense of this theory: that is, why did giant ground sloths, which were also giant herbivores that would have fed off of trees (at least some taxa) not get displaced by proboscideans? If I recall correctly (someone please correct me if I'm wrong), they argued that like proboscideans, ground sloths too would have been tree-destroying habitat changers too, or something like that.

Except one thing: why couldn't Paraceratherium have been one as well? I'm sure it could have destroyed trees and had a significant effect on habitats with its great size as well, and I'm willing to bet these giant hyracodonts were probably bigger than the gomphotheres that invaded (only some select proboscidean taxa rivaled or exceeded Paraceratherium in mass, and I don't think any of them were gomphotheres).

Any thoughts on this?

[creature386]

It might have helped that ground sloths tended to be smaller than Paraceratherium and were perhaps less vulnerable to resource scarcity (I'm assuming grasslands generally have less primary production that woodlands; so even if Paraceratherium destroyed trees, it did not help it)? This is not based on any research, just a quick thought.

[dinosauria101]

Infinity Blade as was discussed in the Paraceratherium vs Apatosaurus thread on Carnivora, it's been downsized to 11 tons.
Would some gomphotheres have gotten bigger or comparable in size to that? If so, they could very well have played a role in it.

[Infinity Blade]

Infinity Blade as was discussed in the Paraceratherium vs Apatosaurus thread on Carnivora, it's been downsized to 11 tons.

I already knew that. I'm still unaware of any gomphotheres getting that large. Mastodons, mammoths, and other elephantids, but not gomphotheres. Anyway, the point of bringing up size was just to show how I think the giant hyracodonts could likely have been tree destroying megaherbivores too.

It might have helped that ground sloths tended to be smaller than Paraceratherium and were perhaps less vulnerable to resource scarcity (I'm assuming grasslands generally have less primary production that woodlands; so even if Paraceratherium destroyed trees, it did not help it)? This is not based on any research, just a quick thought.

I guess a better point for me to have made was this: how much more of an effect would proboscideans have honestly had on a landscape already inhabited by an 11t hyracodont?

But maybe I'm looking at this wrong.

[dinosauria101]

^You could be.
Thinking about it some more, wasn't there a small extinction event around 25-30 million years ago that had to do with climate change? That could've been the cause as well.

[Infinity Blade]

Well, the Wikipedia excerpt I mentioned above does mention climate change as one potential cause of extinction. It wouldn't hurt me to look up any scientific literature on that, though.

[spartan]

Apr 21, 2019 6:37:35 GMT 5 Infinity Blade said:

Infinity Blade as was discussed in the Paraceratherium vs Apatosaurus thread on Carnivora, it's been downsized to 11 tons.

I already knew that. 

Really? When?

[creature386]

Apr 21, 2019 6:37:35 GMT 5 Infinity Blade said:

It might have helped that ground sloths tended to be smaller than Paraceratherium and were perhaps less vulnerable to resource scarcity (I'm assuming grasslands generally have less primary production that woodlands; so even if Paraceratherium destroyed trees, it did not help it)? This is not based on any research, just a quick thought.

I guess a better point for me to have made was this: how much more of an effect would proboscideans have honestly had on a landscape already inhabited by an 11t hyracodont?

But maybe I'm looking at this wrong.

There could have been factors like low reproduction that kept Paraceratherium from destroying their own habitat. Under this view, adding the proboscideans just disrupted the natural balance.

Think of how humans annually emit much less CO2 than nature does, but due to overburdening the carbon sinks, we increase net influx and cause problems.

[theropod]

From what I know about mammals, it might have something to do with teeth.

[Infinity Blade]

Apr 21, 2019 22:09:45 GMT 5 spartan said:

Apr 21, 2019 6:37:35 GMT 5 Infinity Blade said:

I already knew that. 

Really? When?

blaze actually seems to have elaborated well on this here, not on Carnivora. According to him, one specimen found was indeed larger than what previous workers thought was the largest specimen, but this one was still no more than 90% the size of a 4.8 meter tall Paraceratherium. Evidence for an indricothere that tall may or may not be well supported.

theworldofanimals.proboards.com/thread/1127/new-largest-terrestrial-mammal

Although, scaling down, it looks to be more around 12 tonnes as opposed to 11.

There could have been factors like low reproduction that kept Paraceratherium from destroying their own habitat. Under this view, adding the proboscideans just disrupted the natural balance.

Think of how humans annually emit much less CO2 than nature does, but due to overburdening the carbon sinks, we increase net influx and cause problems.

It may not have affected them as much for (possibly) being smaller, but the gomphotheres themselves should be under the same low reproduction constraints, if they too were also colossal. After all, modern elephants are pregnant for nearly two years with one calf. Though, it could be that they just proved to be too much for the ecosystem to handle.