Re: Acrocanthosaurus photos for you

[Mike Taylor <mike@seatbooker.net>]

> Date: Tue, 20 Aug 2002 17:23:12 -0400
> From: MariusRomanus@aol.com
> 
> http://hometown.aol.com/jerrydandridgevv/Acrocanthosaurus.html

Nice job, Kris.

I notice from the very bottom picture (left lateral view of the whole
skeelton) that the _Acrocanthosaurus_ femur looks really feeble,
especially when compared with, for example the _T. rex_ femur from
Kris's similarish left-lateral photo about two thirds of the way down
on the RHS of his other page,
        http://hometown.aol.com/mariusromanus/TheCarnegieGiants.html

Is that just a preservation/preparation artifact, or does it represent
a significant morphological difference between these animals?  If the
latter, it presumably implies a big, big difference in lifestyle and
in hunting strategy.

I seem to recall from McNeill Alexander's _Dynamics of Dinosaurs and
Other Extinct Giants_ that _T. rex_'s althetic index [probably not the
right term, but you know what I mean(*)] comes out pretty poor -- more
or less the same as an elephants.  If that's so, then the poor old
_Acrocanth_, with its matchstick legs, must have been reduced to a
zimmer-frame shuffle.  Can't be right, can it?

 _/|_    _______________________________________________________________
/o ) \/  Mike Taylor   <mike@miketaylor.org.uk>   www.miketaylor.org.uk
)_v__/\  "Where's the Cheesecloth?" -- Steven Sondheim, "So Happy"


(*) The measurement I'm referring to as "athletic index" is defined as
    the cross-sectional area of the narrowest part of an animal's
    femur divided by its mass.  It represents something like the
    inverse of the pressure that would have been brought to bear on
    the bone in "normal" locomotion, with the implication that higher
    values hive more "headroom" for more athletic behaviour like fast
    running and turning, jumping, etc.  Sorry for lack of
    detail/rigour: my books are at home so this is from memory.