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Re: T-J Extinction event article (more media errors?)



> << This problem can be nipped in the bud (as it were): Don't have
>  paraphyletic taxa. >>
>
> The reason to have paraphyletic taxa is to avoid having 2n higher taxa for
> every n species. Consider: no matter where you add a species to a
cladogram,
> you add another node to it, and thus two more potential supraspecific taxa
to
> your taxonomy (one node-based and one stem-based). Who needs so many taxa?

This is a moot question as long as nobody names them all. In earlier times
(mid-late 20th century B-) ) some cladists did state that "every node must
be named", but nowadays this is agreed to be total nonsense for exactly the
reasons you write.
        Example -- still nobody has named, AFAIK, the node
(*Pseudolagosuchus* + Dinosauria), even though people agree about its
contents. It is just not discussed so often that we would gain something
from a name.

> (And I won't even go into the problems that >incorrect placement< of a
> species could generate.) Better to group the multitude of clades into a
> simple, partitioned hierarchy of larger groups that aid in general
scientific
> discourse.

Such taxa are, or can easily become, wastebaskets, the internal branching
sequence of which is not investigated. Remember the times when
paleontologists derived short of everything from Thecodontia and
Cotylosauria? I don't want to have this back...