Re: Seismosaurus

[Stratigraphy@aol.com]

In a message dated 5/23/00 3:31:55 PM Mountain Daylight Time, 
ceevans@home.com writes:

<< Size estimates on Seismosaurus range from about 120' to about 180' in 
length, as where
 weight estimates range from about 60-100 tons. As more bones of
 seismosaurus are discovered, more info about its size will also. >>


  Chris, um....where are you getting this information?  Gillettes book?  This 
animal would have not have exceeded 36 metres (120').  Though, as in any case 
of a partially known animal, the more information, the better off we will be. 
 I have a major problem with the mass estimates that you gave to this animal. 
 100 tonnes?  Do you realize how big that is?  That goes well beyond the 
scope of this animal.  This animal is considered to be a diplodocid. and only 
20% longer than_Diplodocus_.  Now, 70-80+caudals are the "norm" for 
diplodocids.  With only 23 caudals know, the exact tail length could not be 
determined, though, by scaling one can arive at a reasonable conclusion.  
Acording to Dave, the_Seismosaur_centra lengths are averaging 20% longer than 
those of_Diplodocus_.  However, he somehow makes the animal longer than 20% 
because the neural spine length doesn't scale isometricaly with those 
of_Diplodocus_.  Well, what difference does that make?  It is the centra 
length that determines the length of the animal.  So, going with the evidence 
at hand, with centra lengths averaging 20% longer than_Diplodocus_, the 
animal, being a diplodocid will probably scale to, hold your seats boys and 
girls, 20% longer.  That would make its length, around 33m (110').  Now, as 
for the mass estimates.  A 100 tonne animal is, well, hard to imagine.  I 
work with an new specimen that is probably_Supersaurus_, and this is a big 
critter, but it would have massed no more than 35 tonnes.  I cant imagine, 
from the papers/measurements i have, that_Seismosaurus_will mass more than 
30-35 tonnes as well.  And here are the numbers:  If_Seismosaur_is 1.2 times 
length of_Diplodocus_ , then scaling to the cube root for mass, it would be 
1.78 times as massive, or 20-21 tonnes.  So, making the assumption that  its 
more massive for its length than_Diplodocus_(more like_Apatosaurus_) that 
would make it at most 30 tonnes.  And, on that note, how 'bout them 
plesiadapids!
Regards



Dave Lovelace
Director of Education
Wyoming Paleontological Association
935 S. Melrose
Casper, Wyoming 82609
(307) 265-1045 (phone/fax)

stratigraphy@aol.com