Re: BAD vs. BADD (was: Re: Most popular/common dinosaur misconceptions)

[Tony Canning <tonyc@foe.co.uk>]

Jaime A. Headden wrote:

>Jura (pristichampsus@yahoo.com) wrote:
>
><I’m afraid I don’t quite get what you are saying here. Why is it okay 
to call
>a bird a dinosaur, but it’s not okay to call a snake a lizard? 
Especially when
>you seem to be in agreement with Pianka & Vitt on just that, further 
down in
>the post.>
>
> A lizard, unfortunately, entails the idea of a sprawling legged animal.
>Although it is technically correct to refer to snakes as "legless 
lizards",
>which is true almost of moasaurs as well. Additionally, birds are in most
>respects flighted dinosaurs, since there are no flight-worthy dinosaurs
>(powered, that is) that are not also thought of in some way as birds, from
>*Archaeopteryx* or *Ichthyornis* to *Anser* or *Passer*.
>

But limb reduction has occurred more than 60 times in squamates, once in the
ancestor of snakes and 60+ times in other 'lizards' (I'm including 
partial loss,
digit reduction etc., but there are many examples almost as extreme as 
snakes).
And although there have been several proposals regarding the placement 
of snakes
within squamata, no one suggests that they are the sister group of all 
other
lizards, so I think the situation is no different to the bird/dinosaur 
distinction.

I do sometimes talk to the general public about British wildlife, and I 
do describe
snakes as legless lizards (I don't think legless squamates or 
lepidosaurs would be
comprehensible). Many people are surprised to learn that snake ancestors 
had four
limbs, and I see no conflict between technical accuracy and educational 
value,
quite the opposite.

I recently heard a young biologist tour guide in Mexico describe 
crocodilian
parental care as "unusual, for reptiles". However, it is far from 
unusual for
archosaurs, perhaps ancestral, so this is another example where employing
paraphyletic taxa impedes education, in my view.

regards

Tony

Tony Canning