Re: Do beavers have baby teeth prior to using their adult teeth?

Thanks to my colleague, Steve Myers, for finding this Encarta article 
on teeth.
 http://encarta.msn.com/text_761561931__1/Teeth.html

There you will find that Beavers are monophydont (although the more 
accepted spelling seems to be monophyodont), having a single set 
of teeth that grow for their entire lives. Humans (and apparently most  
mammals) are diphyodont, with 2 sets of teeth in a lifetime; one 
deciduous (falling out) and one permanent. Other animals may have 
polyphyodont dentition with regular replacement throughout their 
lives.

The Web is a bit short on examples but polyphyodont animals are 
found among fish and reptiles, with sharks and alligators being 
specific examples of polyphyodont kinds.

Hope this helps.