Re: Seismosaurus

[Stratigraphy@aol.com]

In a message dated 5/27/00 8:57:09 AM Mountain Daylight Time, 
ceevans@home.com writes:

<< However, how can you assume that this animal didn't exceed 120'
 when pieces of the neck and tail are missing, not to mention other
 parts, and also that it is considerably larger than diplodocus, which is
 known for its great length of 90'? >>


Chris, 

    Gillette states that the vertebrae are 20% longer than those 
of_Diplodocus_.  That is 23 out of 70-80+ caudal verts, sacral, and 11 dorsal 
verts.  Granted there are only two cervicals.  But the most parsimonious 
conclusion is that_Seismosaurus_would maintain its similarity to_Diplodocus_. 
 Here are your two options: 1) _Seismosaurus_ has a unique cervical series, 
and distal caudal series in terms of length 2) _Seismosaurus_maintains its 
similarities to_Diplodocus_throught the vertebral column at 20% the length.
   Until cervicals and distal caudals are located, prepared and described, we 
must continue with the most parsimonious hypothesis, and that would be that 
it maintains its similarities to_Diplodocus_, as in the case of the other 
diplodocids.  If the vertebrae are averaging 20% the length of a 
27.5m_Diplodocus_, then the total length would be 1.2 times 27.5 m = 32.9 m 
(108').  I gave a little leeway (though according to the numbers, I don't 
need to) and said it was33.36.5m (110'-120').  There is no way with the 
evidence at hand to consider this animal to be anything greater than 
33-36.5m, certainly not the 45.7 m (150') that was claimed by Gillette (I 
don't know if he has yet rescinded that length and shortened it).  I will 
give Gillette this, his_Seismosaur_ caudals are interesting.

Hope this helps, Chris.

Regards,


Dave