Re: New Paper

[Rahul Daryanani <rahul721@hotmail.com>]

Might seem strange to go back to a 90 day old topic, but whatever.....

> So the best we can do is compare the long figure of _A. fragillmus_ with 
> the _A. altus_ remains, and that's exactly what Ken did in his paper. So 
> what you've just read is the state of the art concerning _Amphicoelias_ 
> species synonymy.

I guess you're right. :-) Since A. fragillmus'  bones are lost, we can only 
compare Cope's old drawings with A. altus' remains. But Cope's drawings were 
pretty detailed and good aren't they (unlike Bruhathkayosaurus' drawings, 
LOL), so we could come to a more or less solid conclusion. Looks like Ken 
did that, meaning that if, a big if here, his theory is correct, then A. 
altus is the well 'normal' species of Amphicoelias. That means that the 
giant 60 m one is an abnormal species. If that's true, Amphicoelias isn't in 
the list of the largest dinosaurs. This is really your branch, Mike.

> Nope -- it's a difference of 100%; it's a _factor_ of 200%. (Sorry to be 
> picky, but this mistake is an easy habit to get into).

I was talking about the difference between 65 and 205 feet. The difference 
is 140 ft, which is actually like 215%. Doesn't really matter.

> Why? Variation even _within_ species can be far greater than that -- 
> compare a great dane with a toy poodle. Size is very subject to 
> evolutionary pressure, and tends to change quickly in all sorts of 
> circumstances. For this reason, it's not much used in systematics.

You're right on that count. I guess that that the environment back then was 
far more complex than today, so all kinds of circumstances could change the 
biological features of the dinosaurs. Th example of dogs was pretty true. 
Although I still find it hard to think about the evolutionary pressures that 
would triple a creature in size.

On that topic, what about this theory? I had posted a thread on 
Bruhathkayosaurus a few months ago, and got an idea. If Amphicoelias might 
be an abnormal species of a normally smaller genus, could the same be for B. 
matelyi, assuming it is a dinosaur? I mean, I've done a few calculations, 
comparing the estimated size of Bruhathkayosaurus' tibia (2 m) to 
Argentinosaurus (1.55 m).
2000 mm/ 1550 mm gives 1.29, cubed, equals 2.14. If you multiply it by the 
old Argentinosaurus estimate of 80-100 tons, it gives you 172-214 tons, 
similar to Mickey's old estimates. If you're using the newer estimate of 73 
tons (who did that one again?), you get 157 tons. If I'm correct, 140 tons 
is the theoretical limit for the weight of a land animal. Maybe this species 
was a freak mutation of a genus that hasn't been found yet. Maybe it even 
died due to it's huge size. I'd say it's a possibility.

Also, how accurate is Ken's paper? It resized most of the sauropods, putting 
Sauroposeidon at 34 m, Argentinosaurus at 30 m, Supersaurus at 32 m, 
Paralititan at 26 m (this one might be going to far) and Amphicoelias at a 
huge 58 m and 122.4 tons. Some of them are a bit drastic, and I have no idea 
what to believe.

Thanks,
Rahul

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