Re: Back-evolution of limbs.

[Jack <jconrad@lib.drury.edu>]

On Sun, 28 Jun 1998, Earl Wood wrote:

> I would like to insert a question here........ was the original limb composed
> of five digits
> before going onshore , or developed after becoming terrestrial ?
> Earl Wood
> candles@jps.net
> 

This is not so simple a question as it may, at first, appear if you are
discussing basal tetrapods.  The original tetrapod, _Acanthostega_ or
something related, possessed as many as eight digits.  However, it has
been suggested that this animal never left the water and only used its
digits to help it remain still while under water or to "crawl" along the
bottom.  I don't know much a _Tulerpeton_ (sic?), but I have seen the
monograph on _Ichthyostega_.  This animal possessed at least six digits
and was probably a semiterrestrial form.  Therefore, the five-digit
tetrapod limb probably did develop on land.  

Hope that I didn't miss the point of your question.  

Jack Conrad
jconrad@lib.drury.edu