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I'm skeptical about the weight of amphicoelias
Topic Started: Jul 31 2012, 09:02 AM (13,568 Views)
Godzillasaurus
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Though amphicoelias was very large, the fact that it was a diplodocid is making me skeptical about its weight. Diplodocids were very slender and lightly built for sauropod standards, being longer, though lighter than brachiosaurs and titanosaurs. Most of the candidates for the "world's largest dinosaur" are dinosaurs like Argentinosaurus, puertasaurus, and bruhathkaysaurus, all of which were titanosaurs. Amphicoelias is another candidate. However, it was a diplodocid. When you look at size comparisons with other sauropods, it looks like a human with a bunch of mice surrounding it. IT LOOKS FRICKIN HUGE! Another large diplodocid, supersaurus, weighed in at only 35-40 tons. Amphicoelias was estimated to have weighed a whopping 122 tons! That is assuming the proportions were correct. Something isn't right here. It doesn't make sense that the diplodocids, which were slender and lightly-built for sauropod standards, would have the world's heaviest dinosaur (other than bruhathkaysaurus) on their side. Amphicoelias makes titanosaurs look like wimps. That is, if it wasn't much smaller, and/or if it even existed.
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theropod
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They are as robust and broad as they need to be. if Amphicoelias has to increase significantly in bulkyness, so needs every other animal.
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theropod
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actually how broad the ribcage is won´t change anyway, only the limbs would be thicker. I doubt that it would have a great effect. But from puertasaurus vertebrae you can easily see that it was much much bulkier than animals like Futalognkosaurus.
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Jinfengopteryx
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theropod
Aug 2 2012, 01:34 AM
Jinfengopteryx
Aug 2 2012, 01:30 AM
theropod
Aug 2 2012, 01:27 AM
[*]They might not have been warm blooded, and thus needed less food, even at an astronomic size
They were, at least for Plateosaurus we have evidence. I think they were very efficient in terms of energy.
For a 200t animal, endothermy is more of a disadvantage. The gigantoc body size is enough to keep the body warm, thus such an animal would hardly need as much food as a whale living in cold water. I think the largest sauropods probably didn´t show the type of endothermy as mammals have, rather some kind of gigantothermy.
It could be a kind of pseudo endotherm(endotherm, but with quite efficient metabolism).
However, being exotherm is a clear handycap here, because of the heat.
It is a big animal and because it has a lot of skin(not at party, in whole terms)the sun can shine at a lot of spots, if it can't regulate it's body temperature, it could die, also it needs a lot of energy for long migrations.
Being endotherm brings here more advantages than disadvantages.
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theropod
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If it was exotherm it would need far less food, and it wouldn´t constantly need to be vary from overheating. there is no "kind of pseudo endotherm". This animal has a lot of skin, but compared to it´s volume, the surface area is actually tiny, so it probably won´t overheat or become hypothermic very easily. In this case, gigantothermy is enough, like it can be seen in great whites for example.
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Jinfengopteryx
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With Pseudo Endotherm, I mean endotherm animals, who are very carefully with their energy, like Sauropods, who probably walked very slowly.
As an exotherm, it would need ways to keep it coll, but it is very big and has a lot of surface, where sun can shine on.
Also, it had airsacks, so it produces more heat while breathing(for example birds also use air sacks and their body temperature is very high).
It would need a way, to keep it's temperature constant.
Also they lived worldwide and even in this time, earth had habitats where it wasn't very warm(we found Sauropods in Antarctica and Australia).
Also exotherms need a place, to hide themselves, in the night, otherwise they get problems with the cold weather.
Sauropods can't do so, so they need to keep themselves warm in the night.
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theropod
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Actually I´m just talking about puertasaurus, which was huge and which didn´t live in a cold enviroment.
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Jinfengopteryx
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But if it was exotherm, other Titanosaurs also would have been so.
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theropod
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Maybe there were differences between the really large ones metabolism and the one of smaller forms. I think an animal that size could relatively easily regulate it´s temperature without being endoterm, simply due to it´s mass, and the advantages it brings are greater than the disadvantages.
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Godzillasaurus
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theropod
Aug 3 2012, 09:10 PM
Maybe there were differences between the really large ones metabolism and the one of smaller forms. I think an animal that size could relatively easily regulate it´s temperature without being endoterm, simply due to it´s mass, and the advantages it brings are greater than the disadvantages.
Is that even possible for a family to consist of both endo and ecto thermic species?
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theropod
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who knows? there are sharks that are gigantothermic, there are reptiles that are exothermic. imo gigantothermy would be enough for sauropods to regulate their body temperature, but naturally there´ll be differences between a 100t sauropod and a t sauropod in terms of metabolism, due to the enourmous disparity in body volume and surface. usually, for such an animal, the heat generated by the muscles is enough to keep it warm, and cooling down has nothing to do with endothermy.
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Godzillasaurus
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theropod
Aug 3 2012, 11:38 PM
who knows? there are sharks that are gigantothermic, there are reptiles that are exothermic. imo gigantothermy would be enough for sauropods to regulate their body temperature, but naturally there´ll be differences between a 100t sauropod and a t sauropod in terms of metabolism, due to the enourmous disparity in body volume and surface. usually, for such an animal, the heat generated by the muscles is enough to keep it warm, and cooling down has nothing to do with endothermy.
But modern reptiles are ALL ectothermic. Big or not, they require their surroundings to regulate their temperature. Although some dinosaurs may have been warm blooded, it doesn't seem likely that titanosaurs would be both warm and cold blooded.
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theropod
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Since when are all modern reptiles ectothermic? all modern dinosaurs are endothermic, and they represent the largest group of terrestrial vertebrates that exists!

I think gigantothermy is the most likely type of metabolism, because they won´t need that much food. In smaller types, a more active metabolism might be needed, but maybe a faster movement will be enough to keep them warm.
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Godzillasaurus
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theropod
Aug 4 2012, 01:48 AM
Since when are all modern reptiles ectothermic? all modern dinosaurs are endothermic, and they represent the largest group of terrestrial vertebrates that exists!

I think gigantothermy is the most likely type of metabolism, because they won´t need that much food. In smaller types, a more active metabolism might be needed, but maybe a faster movement will be enough to keep them warm.
I forgot to tell you that I left out birds. Yes, birds are endothermic, but should be considered more advanced reptiles. I was referring to the non-dinosaur reptiles like lizards and snakes.
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theropod
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of course, but I was referring to Reptiles by means of the valid clade sauropsida, which includes all dinosaurs, not by means of paraphyletic Reptilia.
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Godzillasaurus
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theropod
Aug 4 2012, 02:02 AM
of course, but I was referring to Reptiles by means of the valid clade sauropsida, which includes all dinosaurs, not by means of paraphyletic Reptilia.
I was referring to the latter, but that's cool.
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