[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Ceratopsian leg position



>> [But this is true for *most* quadrupedal dinosaurs, not just
>> ceratopsians].

>I'm curious. Is this "in between" track evidence true for quadrupedal 
>mammals as well (such as an elephant or rhino)? In a lot of quadrupedal 
>animals, isn't the width of the shoulders generally greater than the width 
>of the hips, which might account for the difference?

Mammals do (I think) have wider hips than dinosaurs (possibly because live
young are bigger than eggs). Since the fore-legs are attached to the outside
of the ribcage (and plant-eating dinosaurs had a large ribcage to house a
large digestive system), this limits how close they can be to each other.
The hind-legs, on the other hand, are only limited by the width of the
pelvis, so they can be set closer together.

Mammals tend to have fore and hind-legs roughly the same distance apart. The
only exceptions I can think of are primates, which have opted for a wider,
flatter rib-cage, therefore wider shoulders, and girafes, which I have seen
standing with their front legs splayed out to feed from bales of hay (Which
I don't think is their natural feeding position).

James Shields  -  jshields@iol.ie  -  http://www.iol.ie/~jshields
-------------------------------------------------------------------------------
And when the ark was finished Noah said unto Elvis, "What do you reckin?"
And Elvis checked out his own cabin and shook his head saying "poky".
And so did they knock several walls through and install a jaccuzzi.
And when it was all done Noah scratched his beard and said, "We don't have
room for all the animals now."
And Elvis perused the livestock list and in his wisdom said, "Lose the
dinosaurs."
        -Robert Rankin, The Suburban Book of the Dead