Re: AW: Heterodontosaurid with protofeathers

[Erik Boehm <erikboehm07@yahoo.com>]

What about ophiacodonts  - they had dermal belley scales at least right?

Were these homologous to the scales on a fish? such as a Queensland lungfish?

Is there any evidence that can give us an insight into when tetrapods lost 
their "fish scales"?

Might it have happened independently in saurodsids and synapsids?

I once had a leopard gecko - the skin under its throat was really soft, and 
whatever scales it had must have been really small- it didn't look obviously 
scaly/bumpy like its back - how certain is it that these skin impressions show 
naked skin, as opposed to skin with really really small and thin/flexible 
scales?

Since scales and fur are both subdermal - I can't help but think they may be 
homologous.

--- On Tue, 3/31/09, K and T Dykes <ktdykes@arcor.de> wrote:

> From: K and T Dykes <ktdykes@arcor.de>
> Subject: Re: AW: Heterodontosaurid with protofeathers
> To: keesey@gmail.com
> Cc: dinosaur@usc.edu
> Date: Tuesday, March 31, 2009, 11:21 PM
> <<We have evidence of fur in
> _Docodonta_ and (of course) in _Mammalia_, so it probably
> existed in some common ancestor of those two clades, but not
> prior to the sauropsid-synapsid split. In fact, since
> _Estemmenosuchus_, a dinocephalian stem-mammal, is supposed
> to have been scaly, it may have been after the
> dinocephalian-neotherapsid split (see: 
> http://en.wikipedia.org/wiki/Therapsida#Phylogeny)>>
> 
> /Castorocauda/ was "scaly", Mike.  The scales are on
> the tail.  Ask a mouse about synapsid scales. 
>