Re: synapsids are reptiles

[Jura <archosaur@reptilis.net>]

David Marjanovic wrote:

> About scales... at least some caecilians have scales > (though I don't know 
> whether they are more fish- or > reptile-like), so the fact that most living  
>       >  amphibians are scaleless may be their apomorphy    > (evolved 
> several times).

++++++++++++++++++++++++++++

Amphibian scales are roughly the same as those in fish (i.e. dermal in nature 
and not made from keratin ;IIRC). As I've stated before, reptile scales are a 
form of integument. They are epidermal in nature and there is skin between 
them. 

I'm not sure how unique (apomorphic) these scales are to reptilia itself 
though. I also don't know why synapsids are now considered to be scaleless. 

Do we have any actual evidence to support scalelessness, or is this based off 
of cladistic positioning (in which case, I still don't see why they would be 
considered scaleless)?

Jura

Ectoparasite: external parasites. Some common ectoparasites include: ticks, 
mites & personal injury attorneys.

The Reptipage
http://reptilis.net