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

beaks and teeth

A few questions about beaks and teeth:

1) Except for dinosaurs, including some Tertiary birds, I am not aware of   
any animal that had (or has) both a beak and teeth. Are there other   
examples of this?

2) Is the presence of beaks on some dinosaurs inferred or confirmed by   
fossil evidence? I think I recall reading somewhere of an Oviraptor skull   
that was found with bits of a fossilized beak, but I may be wrong.

3) Beaks are found among several vertebrate and invertebrate taxa,   
including dinosaurs, birds, turtles, fish and mollusks. Are the beaks of   
these animals considered examples of convergence, homologous structures,   
or what?

4) Among the vertebrates with beaks, are there any osteological features   
on the  bones of the mouth region that indicate the presence of a beak? I   
recall a talk at the last SVP meeting speculating on the presence of a   
keratinous sheath covering the buccal region in some dinosaurs instead of   
"cheeks", but the evidence presented seemed (to me) more to refute the   
existence of muscular cheeks than confirm the presence of a sheath.

Patrick Norton