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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
> you add another node to it, and thus two more potential supraspecific taxa
> 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
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...