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Re: Partly-scientific answer to question about cats
Since this topic is reasonably relevant to dinosaur facial expressions (or the
lack there-of), I
suppose I'll throw in my 2 cents.
Whether or not any creature can smile depends very much on what you mean by
'smile'. Dogs can
certainly appear to turn the corners of their mouths slightly upwards when the
mouth is open,
however it's unlikely this is a direct attempt to communicate mood. An angry
pit-bull with it's mouth
open may well mimic a human smile as well (although perhaps more of a 'Jack
Nicholson' smile
than anything else). An over-heated dog with it's mouth hanging open may also
mimic a smile,
despite a neutral mood.
Smiling to communicate mood seems to be unique to humans. Other great apes
don't seem to do
it, despite facial muscles similar to ours. The facial expression we teach to
chimps or orangs to
mimic a big toothy smile in the movies is actually an expression of fear in
wild apes. It's been
suggested that the human smile is also a co-opted fear expression.
When humans smile, we seem to contract muscles between the corners of our
mouths and our
cheek bones, pulling the corners of our mouth upwards. Communicating using
facial expressions is
a subtle art however, depending on the context of other facial movements. A
grimace of pain might
also pull the corners of the mouth upwards, and a lunatic 'Jack Nicholson'
smile may well
communicate a mood quite different to friendliness. It's the complex and subtle
combination of
various facial movements that communicate mood in humans, and that
differentiate honest
emotion from the cold professional smiles of models, entertainers or
politicians.
Facial expressions in dogs and cats appear to be limited to movements of the
ears, upper lip, and
the eye region. It's no coincidence that many breeds of dog have colour
differentiation above the
eyes, which seem to be roughly analogous to our eyebrows. One of the reason why
humans and
canids have formed such a close symbiotic bond may be because both are able to
interpret each
others' facial expressions to a degree.
Archosaurs in general tend to have (or have had) even fewer facial muscles,
making it unlikely
that theropods ever curled their lips as menacingly as a canid (despite what
you see in some
movies), and reducing the chance of them ever smiling to virtually nill.
Dinosaurs probably used
body stance and vocalisation to communicate mood, much as modern birds do.
Feathered
theropods might also have raised their body feathers to increase their apparent
size. Flushing
blood into wattles, combs, or just bare skin might also have been a possibile
means of visual
communication.
Quoting Scott <hmwh@together.net>:
> We have a samoyed. They are known as the dog with a smile.
> ----- Original Message -----
> From: "PLDT FOA- Edmundo S. Ancog" <rayancog@pldtdsl.net>
>
> I;ve always thought that, in order to smile the way humans do, a mammal
> would have to: a. have the muscles to pull the lips upwards; and b. have
> cheeks wherein the mouthline doesn't extend past the front teeth. While
> ungulates, rodents and lagomorphs have cheeks (some with well-developed
> cheek pouches), carnivores like my pet dogs have mouthlines extending all
> the way to the molars. Dogs can pull their raggedy lips upward, and looking
> at pictures of cats all over the Internet it does seem that they are capable
> of doing so, although to a lesser extent. Their faces are also foreshortened
> compared to the average dog breed, so they have fewer muscles and a shorter
> mouthline to begin with, AFAIK.
>
> It makes me wonder now where Lewis Carroll got the inspiration for the
> grinning Cheshire Car.
--
___________________________________________________________________
Dann Pigdon
GIS / Archaeologist http://geo_cities.com/dannsdinosaurs
Melbourne, Australia http://heretichides.soffiles.com
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