Of snakes and Tyrannosaurs

[rowe@lepomis.psych.upenn.edu (Mickey Rowe)]

I was in the process of writing about Jack Horner and T. rex, but
George Pesely beat me to it.  Being a sore loser, I'll move on to a
side issue :-)

Steve Showalter says:

>Snakes do not have "noses" per se, they have nasal openings, 

Although I could be wrong, I'm pretty confident that snakes have
"real" noses associated with their nostrils.

>but the olfactory organ is in their tongue.

That's not right.

>It is called a Jacobsen's (sp?) organ, 

Call it by its alternate name, the vomeronasal organ and you won't
have to worry about how Jacobson (sp?) spelled his name :-).  The organ is
*not* on the tongue, however.  The organ is in the roof of the mouth.
Snakes sample the air with their tongues, and then insert the tongue's
tips into recesses in their palate.  That's were the vomeronasal organ
resides. 

>and can sense taste, smell and temperature.  Some large cats have
>this organ (Felis concolor, the mountain lion) also.

I'm slightly more familiar with the struture in mammals than in
snakes, but I think you're stretching it with "taste, smell and
temperature".  The vomeronasal organ is specialized for detecting
non-volatile chemicals, typically proteins.  It's not exactly like
human smell or taste, so it's probably not fair to refer to it as
both.  It's just different.  And I'm not sure where the temperature
sensation bit is coming from... snakes which prey on mammals (and can
thus rely on temperature cues) typically use heat sensors in pits on
their faces.

-- 
Mickey Rowe     (rowe@lepomis.psych.upenn.edu)