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Post by Supercommunist on Jun 28, 2013 5:18:36 GMT 5
That's why I said in times of drought.
It should be obvious that droughts are devastating on smaller modern day herbivore populations in continents such as Africa, much less herds of sauropods and other elephant sized herbivores.
Correct me if I am wrong but most large sauropods don't live in consistently wet environments do they?
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Post by coherentsheaf on Jun 28, 2013 6:16:26 GMT 5
That's why I said in times of drought. It should be obvious that droughts are devastating on smaller modern day herbivore populations in continents such as Africa, much less herds of sauropods and other elephant sized herbivores. Correct me if I am wrong but most large sauropods don't live in consistently wet environments do they? Most?I would have no idea... this would require extremely much quantifiation none of us could presumably provide. I know that you said drought. I said why I did not think t a convincing argument that water is somehow limiting. In any case a giant sauropod would presumably be able to live longer than just reaching maturity and it could be viable strategy to just keep grwoing. (In fact that is what we seem to see) So just because some very old and giant specimen die in a drought does not constittute a selective disadvantage. |
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Fragillimus335
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Post by Fragillimus335 on Jun 28, 2013 9:05:48 GMT 5
Probably just rounded up, but the paleontologist working on the prints said the sauropod that made them could have been 7-8 meters tall at the hip, which is scary big, considering Argentinosaurus was only about 5.5 meters at the hip... lmao who said that? Even scaling for length, the dinosaur is not more than 1.135 times larger than Scott Hartmann's recent giant Alamosaurus reconstruction. 8m at the hip seems an absurd overstatement. In the very best case it would be somethng like 6.5m. Hartman makes his sauropods have exceptionally long feet, and his Alamosaurus is the most extreme by far. Use any other sauropod skeletal of his and the values will go up. A paper on sauropod prints found average hip height for titanosaurs is 4.586 times foot length, and 1.7x4.586=7.8 meters. BTW the guy you are laughing at is Dr. Steve Salisbury |
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Fragillimus335
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Post by Fragillimus335 on Jun 28, 2013 9:23:31 GMT 5
The guys don't take one inch of safety with that kind of informations, any optimistic statement is necessary true. It is likely true, considering most work on sauropod prints suggest ranges that high or higher. Speeds and stance of titanosaur sauropods: analysis of Titanopodus tracks from the Late Cretaceous of Mendoza, Argentina Bernardo J. González Riga-Hip height=4.586x foot length Tony Thulborn-Hip height=5.9x foot length. So you've got 7.8-10 meters based on the most recent scientific literature. Do some research before you insult someone next time. |
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Fragillimus335
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Post by Fragillimus335 on Jun 28, 2013 9:54:31 GMT 5
That's why I said in times of drought. It should be obvious that droughts are devastating on smaller modern day herbivore populations in continents such as Africa, much less herds of sauropods and other elephant sized herbivores. Correct me if I am wrong but most large sauropods don't live in consistently wet environments do they? Most?I would have no idea... this would require extremely much quantifiation none of us could presumably provide. I know that you said drought. I said why I did not think t a convincing argument that water is somehow limiting. In any case a giant sauropod would presumably be able to live longer than just reaching maturity and it could be viable strategy to just keep grwoing. (In fact that is what we seem to see) So just because some very old and giant specimen die in a drought does not constittute a selective disadvantage. I've got some interesting info on the water debate! The only moisture available to an oryx in the absence of drinking-water is from the food it eats. All plants contain some free water and this can simply be extracted as the material is mashed in the mouth and stomach. The vegetation favoured by oryx often contains as little as 1% water by weight, not enough to fully rehydrate themselves. However, water is also one of the main bi-products of metabolic reactions - carbohydrate and oxygen react together to give carbon dioxide and water - so all animals have an indirect way of getting moisture from their food. However, while metabolic reactions produce water they also require oxygen, and water is lost from an animal's lungs every time it exhales. Under normal circumstances, the loss of water associated with respiration equals or exceeds the gain from metabolic processes in mammals. However, if sauropods had a bird like respiratory system, like they almost certainly did, the rate of production would exceed the rate of loss, so simply eating food would be a huge extra source of water. Coupled with an efficient urine system and sauropods might not have had to drink at all! (Although they probably did) Oryx info stolen from Chris Lavers. |
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Post by coherentsheaf on Jun 28, 2013 15:27:19 GMT 5
lmao who said that? Even scaling for length, the dinosaur is not more than 1.135 times larger than Scott Hartmann's recent giant Alamosaurus reconstruction. 8m at the hip seems an absurd overstatement. In the very best case it would be somethng like 6.5m. Hartman makes his sauropods have exceptionally long feet, and his Alamosaurus is the most extreme by far. Use any other sauropod skeletal of his and the values will go up. A paper on sauropod prints found average hip height for titanosaurs is 4.586 times foot length, and 1.7x4.586=7.8 meters. BTW the guy you are laughing at is Dr. Steve Salisbury If he thinks that 8m hip height somehow is a reliable inference, the laughter is deserving indeed. Hartman's sauropod feet are supported by evidence as far as I know. Can you give me a link to the paper? Edit: Hartmans Futalognkosaurus also gives me 6.6m at the hip. |
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Post by theropod on Jun 28, 2013 16:43:03 GMT 5
I doubt the largest gigapods would have been social, rather solitary like elephant bulls. Water doesn't seem to be that problematic, as already pointed out. Even huge herds constituting a tremendous amount of biomass can survive in dry environments. Also, due to their lower surface area relative to volume, larger animals should have an advantage in keeping the water where it is needed. With an efficient metabolism and respiratory system, they are entirely possible. That droughts are problematic for all animals is out of the question tough. coherentsheaf: the problem is, futalognkosaurus has no appendicular elements preserved. Maybe have a try with a creature that has, eg. Brachiosaurus. Grey: And you automatically assume the "worst case" scenario, that everything above the minimum estimate is too liberal. That's not viable either. You have to accept it, 200t is part of the proposed range (proposed by scientists which is what you were asking for), and bases on evidence. You have no argument for favouring the lower range here, yet you yell at people who don't. It makes perfect sense that the biggest dinosaurs may be ichnotaxa, it seems more likely for such an animal to leave trace fossils than to fossilise itself. |
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Post by coherentsheaf on Jun 28, 2013 16:51:07 GMT 5
I doubt the largest gigapods would have been social, rather solitary like elephant bulls. Water doesn't seem to be that problematic, as already pointed out. Even huge herds constituting a tremendous amount of biomass can survive in dry environments. Also, due to their lower surface area relative to volume, larger animals should have an advantage in keeping the water where it is needed. With an efficient metabolism and respiratory system, they are entirely possible. That droughts are problematic for all animals is out of the question tough. coherentsheaf: the problem is, futalognkosaurus has no appendicular elements preserved. Maybe have a try with a creature that has, eg. Brachiosaurus. Grey: And you automatically assume the "worst case" scenario, that everything above the minimum estimate is too liberal. That's not viable either. You have to accept it, 200t is part of the proposed range (proposed by scientists which is what you were asking for), and bases on evidence. You have no argument for favouring the lower range here, yet you yell at people who don't. It makes perfect sense that the biggest dinosaurs may be ichnotaxa, it seems more likely for such an animal to leave trace fossils than to fossilise itself. Alamosaurus has apendicular elements and should be the first thing you compare- what I did and came up with a hip height of about 6.5m for the Broome print maker. Hartmans Futalongkosaurus does only reinforce the point. Other reasons to doubt this nonsense of 8m hip height are: nothing published, just hearsay. Print width rather consistent with an 80 tonne animal. No sauropod remains that indicate that animals in excess of 60 tonnes were in any way frequent I would contend this is rather overwelming reason to set a prima facie estimate of the Broome trackmaker below 100 tonnes. Edit: Last sentence a little too strong. I would say there is no reason to believe it is somehow far greater than other sauropods we know of. |
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Post by theropod on Jun 28, 2013 17:19:14 GMT 5
I wasn't arguing about the size, just noting Hartmans Futalognkosaurus is of no use in this regard. It is difficult to judge how large broome was, due to the missing comparative data on foot lenght. I only know the print is about 1,7 times longer than those usually regarded as large (eg. the Lourhinhan tracks). I'm also not sure whether Alamosaurus is a good comparison, it is latest-cretaceous while the Australian tracks were said to be lower Cretaceous.
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Post by Grey on Jun 28, 2013 18:51:18 GMT 5
Theropod read again the quote by Taylor dating backing a month ago and let's put a end to this discussion. If you want to make facts of multiple gigapods bigger than anything that's not my problem. Respectfully, I don't take you seriously on these matters.
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Post by coherentsheaf on Jun 28, 2013 19:59:33 GMT 5
I wasn't arguing about the size, just noting Hartmans Futalognkosaurus is of no use in this regard. It is difficult to judge how large broome was, due to the missing comparative data on foot lenght. I only know the print is about 1,7 times longer than those usually regarded as large (eg. the Lourhinhan tracks). I'm also not sure whether Alamosaurus is a good comparison, it is latest-cretaceous while the Australian tracks were said to be lower Cretaceous. Alamosaurus was my first reference point because it is a rather well known giant titanosaur. |
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Post by theropod on Jun 28, 2013 20:05:22 GMT 5
Grey: I know. And you don't read my posts and quotes, but expect me to read yours for some reason... Taylor's estimate for Amphicoelias is a downscaled Carpenter-estimate. The apparently wrong assumption about Diplodocus' was not checked and therefore not corrected. So it fits the size Wedel proposes for the plagne trackmaker perfectly (since with Taylor's and Carpenter's reconstruction of the vert it would make it 120 and 200t respectively), if you correct the size of the dippy vert in the equation. Nobody rejects sauropods in that size range, and the evidence does suggest them. SVPOW backs them too, not as factual, but as possible; obviously just as possible as the lower range. Biomechanical or ecological factors do not seem to limit the growth of animals that much, at least nothing we have to data indicates it. You don't always have to call suggestions you don't like made-up facts, especially when they are actual propositions from scientists. The 100-200t gigapods are no myth, they are very real, and their upper-end is a valid figure.
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Fragillimus335
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Post by Fragillimus335 on Jun 28, 2013 20:35:13 GMT 5
I doubt the largest gigapods would have been social, rather solitary like elephant bulls. Water doesn't seem to be that problematic, as already pointed out. Even huge herds constituting a tremendous amount of biomass can survive in dry environments. Also, due to their lower surface area relative to volume, larger animals should have an advantage in keeping the water where it is needed. With an efficient metabolism and respiratory system, they are entirely possible. That droughts are problematic for all animals is out of the question tough. coherentsheaf: the problem is, futalognkosaurus has no appendicular elements preserved. Maybe have a try with a creature that has, eg. Brachiosaurus. Grey: And you automatically assume the "worst case" scenario, that everything above the minimum estimate is too liberal. That's not viable either. You have to accept it, 200t is part of the proposed range (proposed by scientists which is what you were asking for), and bases on evidence. You have no argument for favouring the lower range here, yet you yell at people who don't. It makes perfect sense that the biggest dinosaurs may be ichnotaxa, it seems more likely for such an animal to leave trace fossils than to fossilise itself. Alamosaurus has apendicular elements and should be the first thing you compare- what I did and came up with a hip height of about 6.5m for the Broome print maker. Hartmans Futalongkosaurus does only reinforce the point. Other reasons to doubt this nonsense of 8m hip height are: nothing published, just hearsay. Print width rather consistent with an 80 tonne animal. No sauropod remains that indicate that animals in excess of 60 tonnes were in any way frequent I would contend this is rather overwelming reason to set a prima facie estimate of the Broome trackmaker below 100 tonnes. I need to make this clear. We have no idea how wide the prints are...the outline I made was a guess, I could have easily misinterpreted them. The only thing we have going is length, and as you say, even with Hartman's exceptionally long sauropod feet hip heights of 6 meters are obtained (to the acetabulum), compared to argentinosaurus's 4.95, which would indicate an animal of at least 115 tons. Assuming Argentinosaurus was 65 tons. And all the most recent literature on sauropod tracks and locomotion suggest that sauropod hip heights fell in the 4.5-5.9x foot length range, which is 7.6-10 meters. ( I doubt the ratio was actually above 5x, and 4.5-4.8 seems the most likely.) Here is the paper: www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652011000100016 |
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Post by coherentsheaf on Jun 28, 2013 20:50:45 GMT 5
Alamosaurus has apendicular elements and should be the first thing you compare- what I did and came up with a hip height of about 6.5m for the Broome print maker. Hartmans Futalongkosaurus does only reinforce the point. Other reasons to doubt this nonsense of 8m hip height are: nothing published, just hearsay. Print width rather consistent with an 80 tonne animal. No sauropod remains that indicate that animals in excess of 60 tonnes were in any way frequent I would contend this is rather overwelming reason to set a prima facie estimate of the Broome trackmaker below 100 tonnes. I need to make this clear. We have no idea how wide the prints are...the outline I made was a guess, I could have easily misinterpreted them. The only thing we have going is length, and as you say, even with Hartman's exceptionally long sauropod feet hip heights of 6 meters are obtained (to the acetabulum), compared to argentinosaurus's 4.95, which would indicate an animal of at least 115 tons. Assuming Argentinosaurus was 65 tons. And all the most recent literature on sauropod tracks and locomotion suggest that sauropod hip heights fell in the 4.5-5.9x foot length range, which is 7.6-10 meters. ( I doubt the ratio was actually above 5x, and 4.5-4.8 seems the most likely.) Here is the paper: www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652011000100016Directly comparing it with the giant Alamosaurus results in 100 tonnes assuming that the Alamosaurus weighs 75 tonnes, which is rather high in itself. The 4.95m for Argentinosaurus is a lot lower than the around 5.75m I got for the Alamosaurus at the hip as well. I will read the paper later. Read it. It is strongly depedent on the reconstruction. I will nt judge which reconstruction is better but suspect that Hartman's is. I have left a comment at his Alamosaurus Puertasaurus pic at deviant art: coherentsheaf.deviantart.com/art/Clash-of-the-Titans-378125466 |
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stomatopod
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Post by stomatopod on Jun 28, 2013 21:04:31 GMT 5
You don't always have to call suggestions you don't like made-up facts, especially when they are actual propositions from scientists. The 100-200t gigapods are no myth, they are very real, and their upper-end is a valid figure. Pardon, which scientist proposed 200 t for a sauropod? Those 200t are proposed by a few amateurs based on the assumption that Carpenter used vertebral height to get his estimate. We are speking of a scrappy neural arch that was lost decades ago, along other material from the quarry, so saying that any estimates based on it are real is a bit far fetched. There are also multiple reconstructions of the vertebrae (at least 3 made by palaeontologists), so nothing is certain. |
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