Horned Dinosaurs and Their Noses

["Jaime A. Headden" <qilongia@yahoo.com>]

Okay, everybody,

  A few questions. First, anyone out there know (or have an idea) why
centrosaurine ceratopsids (ceratopsians, aka, horned dinosaurs) had
those anteriorly-pointing nasal prongs, formed from the maxilla and
nasal bones? I sure don't. And why didn't chasmosaurines have them?

  Also, how does the pachyrhinosaur's nasal boss develops from
something like *Einiosaurus'* well developed horn into something like
*Achelousaurus'* boss? The boss was porous, but the horn not nearly
so, and while I gather that the porousness of the bone could increase
and deform the original shape, why?

  Finishing my whining,

==
Jaime A. Headden

Qilong, the website, at:
http://members.tripod.com/~Qilong/qilong.html
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All comments and criticisms are welcome!

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