Aves vs. Avepectora (was: sensu lato)
kinman at HOTMAIL.COM
Thu Oct 24 15:26:47 CDT 2002
Riaan's question brings up a wider problem that I've been grappling
with the past few years. The phrases "sensu stricto" and "sensu lato" are
really most useful when you have ONLY two different meanings of a taxon
proposed by two different authorities. This worked well back when we had
fewer competing authorities, but in an increasingly egalitarian world with
instant communications abilities, it's gradually losing its usefulness.
This is already most notably showing up in dinosaurology where there
are many more workers in a very dynamic field, and I recently discovered the
taxon "Ornithurae" has so many meanings (even in the published literature)
that it has become very confusing. Therefore, you increasingly see phrases
like "Ornithurae sensu Sereno", or "Ornithurae sensu Gauthier", and so on.
In such cases, it looks like we will have to do this more often in the
future or risk being misunderstood (especially by future biologists).
The idea behind PhyloCode is to establish a new authoritarianism, so
that all taxa (incl. Ornithurae) have only one (strictly phylogenetic)
meaning: Ornithurae "sensu PhyloCode Central Headquarters". And while this
might not be a half bad idea for names like Ornithurae, this is going to be
a nightmare when applied to all taxa (as debates here on TAXACOM have
shown). It's a solution that creates more problems than it solves, and
establishes a whole new parallel bureaucracy that will conflict with the one
we already have.
Anyway, we will increasingly have to abandon the terms "sensu stricto"
and "sensu lato", in favor of "sensu Author 1" (sensu Author 2, and sensu
Author 3) if we are to be understood when using taxon names with conflicting
meanings (at least in groups that are particularly dynamic and crowded with
competing workers). And I think biologists in the future (who read our
literature) will be thankful we did so. This brings to mind the broadening
concept of birds:
Our concept of Aves ("birds") is changing as we discover more
maniraptoran dinosaurs are feathered (whether they could fly or were
secondarily flightless, sort of like Cretaceous ratite analogs). Gauthier's
(1986) proposed "crown group" restriction of taxon Aves (= Neornithes) has
not caught on at all. The traditional Aves (with Archaeopteryx as a sort of
anchor) is thankfully slowly being abandoned by strict cladists in favor of
Avialae (and hopefully they will give us back "Reptilia" as well).
Thus we presently have an opportunity to carefully broaden the concept
of Class Aves to include maniraptors, which should have been classified as
birds in the first place (if only we had discovered all those Chinese
feathered "dinosaurs" a long time ago). I was shocked (but delighted) to
learn that even Larry Martin has recently adopted Gregory Paul's concept
that maniraptoran "dinosaurs" are birds---an idea that was widely ridiculed
when Paul proposed it in the mid-1980's (which BTW was around the same time
that Australian doctor was being mercilessly ridiculed for suggesting
Helicobacter, or any bacterium, causes stomach ulcers).
The question now is whether to call the bird taxon: (1) Maniraptora,
(2) Avepectora (Paul, 2002), or (3) Aves (sensu consensus 2003?). I
obviously favor the latter, since the name Aves has always been associated
with birds, and my second choice would be Avepectora (although it is based
on a synapomorphy that is about as problematic as semilunate morphology has
turned out to be). I am still strongly inclined to use a broader Aves that
will be slightly nebulous at the base until we sort out the best
synapomorphies (similar to the way in which jaw and earbone morphology
became the standard for Mammmalia).
Since TAXACOM has a broad spectrum of botanists and zoologists, I would
be interested to hear whether you would prefer Class Avepectora or Class
Aves for this broadened concept of "birds". I would love to get some
feedback on this (private e-mails are welcome too).
Anyway, if workers as different as Larry Martin and Gregory Paul are
converging on a new concept of "birds" (which closely resembles the content
of my own recent avian classifications), I am confident a relatively broad
consensus could be reached in the scientific community---and I am sure the
non-scientific community would also be eternally grateful that we came to a
consensus on this very important taxon. If we procrastinate, PhyloCode
Headquarters will eventually dictate a strict phylogenetic definition, and
it will then be much harder to fight it retroactively. Let's be proactive
for a change, especially for a taxon as important as Aves (or Avepectora, if
----- Thanks, Ken Kinman
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