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Re: Fossil Discovery Threatens Theory of Birds' Evolution
In a message dated 6/25/00 8:13:10 PM, firstname.lastname@example.org writes:
<< Cuttlefish are a sort of squid, or at least a member of the Decapoda. The
shell of Spirula bears some resemblance to that of an ammonite but is
hardly "exactly" like one (for example, it does not have the extremely
complex folding of the septa that is very much a distinguishing feature of
ammonites). Anyway its spiral shape is a pretty basic one in nature, and
ammonites and spirula belong in the same class anyway, so the convergence
involved seems to me interesting but not all that remarkable. Anyway, I
still do not see the relevance of your point in bringing it up. >>
Just to show that convergance of the kind I've talked about is indeed a
possiblilty. That is relevent. BTW. If cuttlefish are squids, so are octopi.
If they are the same class anyway, which they indeed are, and the convergence
involved seems "interesting but not all that remarkable," which is also the
case, then convergence between two anmiotes, which are the same superclass,
shouldn't be either.
<<>The graphotite-like colonies we've both mentioned is another example of
>convergance. I've never said that these look anything like theropods as you
>seem to be saying. Can nearly exact duplicates evolve completely seperately?
Um... I didn't say that either, and the term is "graptolite". And what are
graptolites supposed to be convergent to?>>
Okay, it's a thingie that was found near New Guinea a decade or so back.
There was a possibility of a ghost lineage of four hundred million years if
it wasn't convergance.