Re: beaks and teeth

["Norton, Patrick" <Patrick.Norton@state.me.us>]

Tom Holtz wrote, in part:

<Also, some hadrosaurid specimens have been discovered with possible   
rhamphothecal material preserved.>

Can anyone provide me a reference for one or more of these finds? For   
purposes of an illustration, I'm interested in knowing where on the   
jaws(?) the possible rhamphothecal material was found preserved, the   
species on which it was found and if the animal(s) were adult or   
juvenile.

And Larry Witmer wrote, also in part:

<how does rhamphotheca differ from other specializations of the stratum   
corneum? what are the osteological correlates? etc. etc.>

One possible osteological correlate that occurs to me is the location of   
the nasal opening in the nasal bone. All extant animals with rhamphotheca   
have nasal openings located high up on the beak, and those openings are   
directly correlated to the location of the opening the nasal bone. As I   
recall, the location of the naris varies widely among the hadrosaurid   
species--some located well away from the end of the snout and others   
close to the end of the snout. Perhaps the location of the naris on those   
animals has some relationship to the presence or extent of a   
rhamphothecal covering.

Patrick.Norton@state.me.us