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Re: Are dinosaurs really reptiles?

On Mon, Apr 28, 2008 at 2:53 PM, David Marjanovic
<david.marjanovic@gmx.at> wrote:
> > That would indeed be an excellent name for the sauropsid crown group!
>  Perhaps it should be reserved for something apomorphy-based, though,
> because many early amniotes are preserved in materials that might
> occasionally preserve skin impressions (and regularly preserve the relief of
> ossified dermal, as opposed to epidermal, scales).

Four points to make:
1) If we found vague impressions in a "stem-scutellate", could we
really be sure they were homologous?
2) Just because it might be preserved doesn't mean that most fossils
preserve it.
3) Isn't there some osteological character that suggests the presence
of an amniotic sac in embryos? I can't quite recall what it is at the
moment, but I'm sure I've heard of something along those lines.
4) "Apo-Scutellata" would be available for the apomorphy-based clade, anyway.

T. Michael Keesey
Director of Technology
Exopolis, Inc.
2894 Rowena Avenue Ste. B
Los Angeles, California 90039