RE: Serration variation

[christopher robert noto <crnoto@midway.uchicago.edu>]

Could it also correspond then to a shift in prey and/or predatory
behavior?  Then the paedomorphosis hypothesis may have some weight. A  
small animal won't need serrations if it's eating insects or disgorged,
partially digested meat.  Serrations may be necessary in larger animals in
order for them to be effective predators.

-Chris

On Thu, 10 Feb 2000, Thomas R. Holtz, Jr. wrote:

> > From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> > Dinogeorge@aol.com
> > Sent: Wednesday, February 09, 2000 7:48 PM
> >
> > In a message dated 2/9/00 7:35:38 PM EST, dbensen@gotnet.net writes:
> <
> > Neither behavior nor tooth shape has been shown to be independent of
> > phylogeny. So who knows what "more" means in this context. Also,
> > I don't know
> > of any theropod group in which >lost< tooth serrations were
> > >regained<. But
> > there were surely theropods that evolved serrated teeth
> > independently of one
> > another, from smaller (birdlike) theropods that had tiny, unserrated
> > teeth--the same kind as seen in Archaeopteryx.
> 
> One thing to be concerned with is developmental constraints: some authors
> have suggested that  the constructional mechanisms required to place the
> serrations on teeth may only operate after the tooth is a certain size.
> Absence of serrations on very small teeth *might* thus be of developmental
> rather than phylogenetic significance.
> 
>               Thomas R. Holtz, Jr.
>               Vertebrate Paleontologist
> Department of Geology         Director, Earth, Life & Time Program
> University of Maryland                College Park Scholars
>               College Park, MD  20742
> http://www.geol.umd.edu/~tholtz/tholtz.htm
> http://www.geol.umd.edu/~jmerck/eltsite
> Phone:        301-405-4084    Email:  tholtz@geol.umd.edu
> Fax (Geol):  301-314-9661     Fax (CPS-ELT): 301-314-7843
>