[Taxacom] Rankless classifications
kennethkinman at webtv.net
Thu Mar 19 18:38:37 CDT 2009
I happened onto an American Museum of Natural History "rankless"
diagram/pseudocladogram showing the relationships of vertebrates. The
first thing I noticed is that there is no mention of Aves or birds at
all. They are buried within group Maniraptors. A major Class of
vertebrates doesn't even merit a mention on this large diagram.
And also look at the branch splitting off just before the
tetrapods. It is called "coelacanths, lungfish & extinct relatives of
tetrapods" (what a mouthful). That is because the name Sarcopterygii
(or sarcopterygians) for this group has been hijacked by strict cladists
and greatly expanded to include all the tetrapods as well. The funny
thing is that this grouping of tetrapod relatives is paraphyletic, and
this diagram makes it look like it is mono(holo)phyletic. The same
problem with the group "Diapsids excluding archosaurs" (no indication
that it is a paraphyletic grouping).
If they include those paraphyletic groupings, they could at the
very least split the maniraptors into two branches (birds and "other
maniraptors"). And for heaven's sake, clearly label paraphyletic groups
as such!!! Don't pretend this is a real cladogram or phylogram. This
diagram can be seen through the weblink below.
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