Re: Pterosaur diversity (was: Re: Waimanu)

[Tim Williams <twilliams_alpha@hotmail.com>]

David Marjanovic wrote:

> Interestingly, I do get an increase for presacral length over 
> Sauropodomorpha as a whole, but the probability that this is a random 
> outcome of random data is _88 %_.

I may be reading too much into your statement, but are you using "presacral 
length" as a proxy for body size in your calculations?  I can't help but 
wonder what effect those absurdly long-necked sauropods have on your 
analyses - like _Mamenchisaurus_, _Omeisaurus_, and _Erketu_ and even 
_Diplodocus_, all of which appear to have been rather lightweight relative 
to body length.

BTW, in a previous post I wrote that Barrett & Upchurch (2005) determined 
that sauropods underwent a trend of body-size decrease in the later 
Cretaceous.  My mistake; it was actually Carrano (2005) who did this work.  
(Sorry, Matt!)  They are both really neat studies, and both in the same 
great volume.  Carrano found that most of the body-size increase in 
sauropods had occurred by the Late Jurassic, and "smaller sauropods tend to 
be the end points of their respective lineages."  This trend is especially 
evident in the Macronaria.

Cheers

Tim