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Re: Rex's cloaca, Hypsi's tail, Neo's nose and Bary's jaw!



Michael,

> Finally, Colin McHenry mentioned Baryonyx's jaw festooning in a recent
post.
> Forgive my ignorance, but what is jaw festooning?
>

In this context, festooning describes a jaw line that is not straight in the
dorso-ventral plane.  Think of the jaws of a large Nile or salt water
crocodile, seen from side on - there is a wave-line to the jaw which
exaggerates the pseudo-heterdont (or anisodont, whichever term you prefer)
appearance of the teeth.  I think the term was first applied to crocs by
Iordansky, but I'll have to check.

Note that not all crocs have festooned jaws - longirostrine taxa, such as
_Gavialis_, _Tomistoma_, _Crocodylus cataphractus_, and _C. johnstoni_ have
a straight jawline.  They also have a homodont (isodont) dentition - there's
a farily strong correlation of festooning to anisodonty in crocodiles.

The reason I was asking about _Baryonyx_  and _Spinosaurus_ was because I
understand that they have festooned jawlines but homodont dentition.  I had
a feeling that the assertions of piscivory in these animals were to do with
the fact they have festooned jaws (but no-one has commented on this).

Lastly, from my dictionary (Collins):
Festoon: n. 1. a decorative chain of flowers, ribbons, etc., suspended in
loops; garland.  2. a carved or painted representation of this, as in
architecture, furniture, or pottery.  3. a. the scalloped appearance of the
gums where they meet the teeth.  b. a design carved on the base material of
a denture to simulate this......


Cheers
Colin