Re: II CLPV talk summaries: Day 2

[dinoboygraphics@aol.com]

> > > Wasn't it recently said that *Plateosaurus* was "semiplantigrade" 
like a sauropod, based on the shape of the astragalus? In that case it 
would have needed a heel pad.  <<<

It was, but it was wrong.  The conclusion of semi-plantigady was based 
on an interpretation of the needed locomotory arc the ankle and foot 
would have to swing through, and (IMHO) the kinematics were based on 
very bad assumptions.  Also, sauropods are no more semi-plantigrade 
than elephants are (Matt Bonnan may have a different opinion here?).  
Both have digitigrade hindfeet, backed by a large pad that distributes 
the weight of the animal during locomotion.  Plantigrade animals do not 
usually have large heel pads like we see in the pes impressions of 
sauropod trackways.

Scott Hartman
Science Director
Wyoming Dinosaur Center
110 Carter Ranch Rd.
Thermopolis, WY 82443
(408) 483-9284

www.skeletaldrawing.com