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Re: Sheesh



On 10/24/06, Jamie Stearns <stearns5@cox.net> wrote:
> Why have no birds, or indeed -as far as is known- archosaurs (sensu sort
> of
> traditional) never got around to giving birth to live young (sensu any way
> anybody chooses)?  Bearing that latter proviso in mind, some sharks, fish
> (sensu very loose indeed), frogs, reptiles of various persausions (or
> sauropsoids), scorpions...  Various lineages have manged this, but
> archosaurs seem uninterested in such experiments.
>
> My suspicion is that the hard and potentially sharp eggshell shards may be
> a
> discouragement, but it's no more than a suspicion.

As I recall, sauropterygians are considered to be archosaurs (correct me if
I'm wrong here) and ichthyosaurs managed to give live birth well enough.

Sauropterygians aren't archosaurs, but probably basal lepidosauromorphs. The ichtyosaurs are neither sauropterygians nor archosaurs, but probably stem saurians (Sauria = Lepidosauromorpha + Archosauromorpha).

--
Andreas Johansson

Why can't you be a non-conformist just like everybody else?