Largest sauropods

[theropod]

This should be second in our considerations, first should be "is there evidence for its existence". How hard its life may have been (not too hard certainly, Fragillimus showed it could have easily found enough food, and nobody denies such giants would be rare) should be figured in as an argument against speculations, not agaisnt fossil evidence.

[Fragillimus335]

Jun 27, 2013 21:10:50 GMT 5 creature386 said:

What about Supercommunist's points? Such an animal would have a very hard life.

Animal bones seem to have levels of safety built into them, both elephant and mouse femurs experience similar stress levels, regardless of size!

[theropod]

That's probably also the reason why foot size seems to scale isometrically in dinosaurs (Wedel, SVPOW/Paul, DML)

[coherentsheaf]

Jun 27, 2013 21:18:40 GMT 5 theropod said:

That's probably also the reason why foot size seems to scale isometrically in dinosaurs (Wedel, SVPOW/Paul, DML)

Very unikel as the stress would increase that way. Wedel and Paul never substantiated their claims regarding this neither did anyone else. There is clear allometric tend in extant animals.

[creature386]

Jun 27, 2013 21:14:37 GMT 5 Fragillimus335 said:

Jun 27, 2013 21:10:50 GMT 5 creature386 said:

What about Supercommunist's points? Such an animal would have a very hard life.

Animal bones seem to have levels of safety built into them, both elephant and mouse femurs experience similar stress levels, regardless of size!

I wasn't only talking about supporting the mass. There are more problems than that (like food).
Also, why should a sauropod grow to 200 t+, when it is already pretty much invincible at 100 t?

[coherentsheaf]

Jun 27, 2013 21:35:25 GMT 5 creature386 said:

Jun 27, 2013 21:14:37 GMT 5 Fragillimus335 said:

Animal bones seem to have levels of safety built into them, both elephant and mouse femurs experience similar stress levels, regardless of size!

I wasn't only talking about supporting the mass. There are more problems than that (like food).
Also, why should a sauropod grow to 200 t+, when it is already pretty much invincible at 100 t?

Being invincible is onlyone reason for becoming gigantic. Others include: Being able to produce much larger/more children, being more efficient due to scaling of metabolism, reaching more food sources or simply even faster growth as juveniles that if unchecked makes you larger.

[theropod]

It might never have fully stopped growing and so (very) old individuals turned out that size.

coherentsheaf: Anyway, the change would have to be substantial to matter much for the size, as Wedel states. But obviously, an animal cannot change the strenght of its structures directly proportional to mass (otherwise, elephants would be the fastest animals on earth), so the built-in safety-levels hold true, don't they?

[Fragillimus335]

Jun 27, 2013 21:35:25 GMT 5 creature386 said:

Jun 27, 2013 21:14:37 GMT 5 Fragillimus335 said:

Animal bones seem to have levels of safety built into them, both elephant and mouse femurs experience similar stress levels, regardless of size!

I wasn't only talking about supporting the mass. There are more problems than that (like food).
Also, why should a sauropod grow to 200 t+, when it is already pretty much invincible at 100 t?

I adressed the food part a few posts back, and size may have kept going up due to sexual selection or efficiency needs. Bigger animals are more efficient.

[coherentsheaf]

Jun 27, 2013 21:39:53 GMT 5 theropod said:

It might never have fully stopped growing and so (very) old individuals turned out that size.

coherentsheaf: Anyway, the change would have to be substantial to matter much for the size, as Wedel states. But obviously, an animal cannot change the strenght of its structures directly proportional to mass (otherwise, elephants would be the fastest animals on earth), so the built-in safety-levels hold true, don't they?

the safety is achieved by changing limb direction, gait and increasing limb thickness beyond isometry. All are observed in extant animals. It would be strange if e would not see the same in sauropods. However the it is close to ismoetry in extant animals and scaling by a factor 2 will not change that much: E.g. the Broome trackmaker would weigh about 85 tonnes based on isometry with Giraffatitan and 75 tonnes if I try to account for allometry.

[theropod]

Some further explanation on the broome tracks and a mention of 1,7m in lenght by Thulborn: dml.cmnh.org/1997Aug/msg00778.html

And here's the mention of the 2m print, I suppose width means lenght in this regard: greatcretaceouswalk.blogspot.co.at/2011/06/dinosaur-tracks-of-western-australia.html

Would be interesting to know how much there is to this. perhaps just uprounded to the nearest metre from 1,7m?

[Fragillimus335]

Jun 28, 2013 0:47:40 GMT 5 theropod said:

Some further explanation on the broome tracks and a mention of 1,7m in lenght by Thulborn: dml.cmnh.org/1997Aug/msg00778.html

And here's the mention of the 2m print, I suppose width means lenght in this regard: greatcretaceouswalk.blogspot.co.at/2011/06/dinosaur-tracks-of-western-australia.html

Would be interesting to know how much there is to this. perhaps just uprounded to the nearest metre from 1,7m?

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...

[coherentsheaf]

Jun 28, 2013 1:22:53 GMT 5 Fragillimus335 said:

Jun 28, 2013 0:47:40 GMT 5 theropod said:

Some further explanation on the broome tracks and a mention of 1,7m in lenght by Thulborn: dml.cmnh.org/1997Aug/msg00778.html

And here's the mention of the 2m print, I suppose width means lenght in this regard: greatcretaceouswalk.blogspot.co.at/2011/06/dinosaur-tracks-of-western-australia.html

Would be interesting to know how much there is to this. perhaps just uprounded to the nearest metre from 1,7m?

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.

[Grey]

The guys don't take one inch of safety with that kind of informations, any optimistic statement is necessary true.

[Supercommunist]

I dont see them as too bad, recent studies find that give a mixed diet of dry forage a 70 metric ton sauropod would "only" need about 120kg of food per day! That makes a mere 350kg for a 200 ton Amphicoelias. An average acre of mature conifer forest during peak growing season may support 8-9 metric tons of foliage. Thus one 200t Amphicoelias could sustain itself for nearly a month on a single acre of land, not factoring in regrowth of plant matter, or ground plants.

What about issues dealing with water sources? I believe some of these supposedly massive sauropods lived in areas that may have suffered from droughts time to time. Elephants I believe need to drink fifty liters of water a day to remain healthy(correct me if I am wrong) imagine what a herd of one hundred fifty ton giants would have to drink in a day. If a bad drought did occur, competing with other giant herbivores for food and water would have probably weeded out the larger specimens out of the gene pool.

[coherentsheaf]

Jun 28, 2013 2:32:06 GMT 5 Supercommunist said:

I dont see them as too bad, recent studies find that give a mixed diet of dry forage a 70 metric ton sauropod would "only" need about 120kg of food per day! That makes a mere 350kg for a 200 ton Amphicoelias. An average acre of mature conifer forest during peak growing season may support 8-9 metric tons of foliage. Thus one 200t Amphicoelias could sustain itself for nearly a month on a single acre of land, not factoring in regrowth of plant matter, or ground plants.

What about issues dealing with water sources? I believe some of these supposedly massive sauropods lived in areas that may have suffered from droughts time to time. Elephants I believe need to drink fifty liters of water a day to remain healthy(correct me if I am wrong) imagine what a herd of one hundred fifty ton giants would have to drink in a day. If a bad drought did occur, competing with other giant herbivores for food and water would have probably weeded out the larger specimens out of the gene pool.

depending on the environment water would not be a limiting factor at all! If you disagree cnsider the fact that even millions zebras and wildebeast cant empty the nile. So if it lived in a water rich environment this is not a problem.