Re: Question about Segmentation

From: CurtAdams (curtadams_at_aol.com)
Date: 07/27/04 

Date: Tue, 27 Jul 2004 05:17:32 +0000 (UTC)

wirtatmar@aol.com writes:

>If you're looking for a name, no one knows with any certainty, but the
>protostome-deuterostome split is presumed to have occurred in the >Vendian
>Period. Please see:

> http://www.peripatus.gen.nz/paleontology/Vendian.html

I thought the protostome split was dated to the Vendian, implying
the protostome-deuterostome split was substantially earlier and
possibly pre-Vendian. Your citation mentions this as a possibility.
Because Protostomes and Deuterostomes develop differently (in
one the first hole is the mouth and the other the anus) I'd
consider it very plausible that the divergence preceeded having
a bilaterian body structure.

Curt Adams (curtadams@aol.com)
"It is better to be wrong than to be vague" - Freeman Dyson