Re: Crest or Horn? was RE: Ornitholestes

["T. Mike Keesey" <tmk@dinosauricon.com>]

On Mon, 17 Dec 2001, goose zilla wrote:
(Welcome, Katy!)

> Id say if its durable enough for an animal to hit
> other animals with it and bear the load of multiple
> collisions.
> Crests I wouldnt assume to be used for trauma of any
> kind. While horns, antlers, etc. are definately
> designed to butt and puncture against things.
> So if the structure is delicate it is a crest of sorts
> and if quite durable it is a horns of sorts. For
> instance, a horn shaped crest would still be a crest
> if it was brittle in structure.

Not bad, although I'd add Steve's criterion of being conical.
(_Pachyrhinosaurus_' bump may have been used to butt, but it's not a horn
-- err, unless the big bony knob really *was* the support of a huge
keratinous horn.)

By these criteria, _Allosaurus_, _Proceratosaurus_, and _Ceratosaurus_
seem to have crests, not horns. _Carnotaurus_ ... I'm not sure ... crests?
Would any theropod have true horns? Would any dinosaur besides
ceratopsomorphs and the occasional ankylosaur or pachycephalosaur have
true horns? (Or would it be just the ceratopsomorphs?)

_____________________________________________________________________________
T. MICHAEL KEESEY
 The Dinosauricon        <http://dinosauricon.com>
  BloodySteak             <http://www.bloodysteak.com>
   personal                <keesey@bigfoot.com> --> <tmk@dinosauricon.com>
    Dinosauricon-related    <dinosaur@dinosauricon.com>
     AOL Instant Messenger   <Ric Blayze>
      ICQ                     <77314901>
       Yahoo! Messenger        <Mighty Odinn>