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Re: Sauropodz r kewl WAS silly ramble
Am 17.04.2012 14:09, schrieb Jaime Headden:
It was not my intention to be hostile, so the tone of the response I
received from Mike seems particularly odd.
But apparently it wasn't sent to the list (I haven't received it), so
there's probably no point in discussing it here...
Consider that the commentary of this entire thread has been on the
efficacy of certain names, especially referring to *Brachiosaurus* as
an equivalence to *Brachiosaurus altithorax*, which in zoological
terms would be just *B. altithorax* for the most part.
(Point taken, but even neontologists don't abbreviate genus names before
they've spelled them out once.)
[...] *Brachiosaurus*, being capitalized, it the primary element of
the name, a fault I'd rather lay at the feet of Linnaeus than anyone
else, but a typical effect in the classical language he was using.
It's not simply a side effect of the default word order of Latin;
Linnaeus deliberately employed it because of his philosophy. To him, the
genus really was the basic _general_ unit, and the species was
_specific_. It was an additional subdivision diagnosed by "less
important", less "general", more "specific" characters. The modern
emphasis on species as units of biodiversity and genera as a
biologically meaningless rank is much younger; Linnaeus thought that
genera were real.
and even the ICZN doesn't tolerate or regard anything higher than
Not true. Most rules (such as priority) don't extend above the family
group of ranks, but the use of higher ranks is not at all discouraged.
Growing is the movement to abandon ranks, and their concordant
problems. I've written on this on my blog ad nauseam, and of course
many of the offenders have defended their choices, but all of them
have and will continue to use "genus" without any care for its lack
of scientific value. When Mike argues about what I'm talking about,
his very message is ripe with the problem I speak of, his continuing
demonstration that despite knowing a genus means nothing, _he's still
He's using a genus _name_ as a _clade name_. I really can't see why he
When Mike says "[t]hey're just names on characteristic specimens",
then he really doesn't understand the problem to its extreme:
scientific nomenclature names the specimens as proxies for a set of
organisms, but the "genus" and the "species" are completely different
from the _specimens_,
The names are attached to the type specimens; the set of organisms
consists of the type specimen and, in practice (at least in
paleontology), all others that are similar enough to it.
and intend to describe instead a set without any concordant value.
_They have no intrinsic value_.
Please explain what you mean by "concordant value" and "intrinsic value".
I similarly have no problem with a taxon named *Giraffatitan* or
another named *Brachiosaurus*. What I have a problem with is people
determining that a taxon named *brancai* MUST or SHOULD be divided
from *altithorax* in a fixed fashion that can be comapred to other
issues, like how to divide *Psittacosaurus* into neat, clean "genera"
These two cases are the same as far as the ICZN is concerned, but not as
far as the practice of the last few decades is concerned.
*Psittacosaurus* as currently understood is, apparently, monophyletic.
*Brachiosaurus* as it used to be understood is probably not
monophyletic; in addition to Mike's own phylogenetic analysis which
showed a lack of evidence for monophyly, there's one that finds it to be
para- or polyphyletic (I don't remember) and was presented at last
year's SVP meeting. The ICZN is fine with para- and even polyphyletic
genera; but few biologists these days are. Given the high probability
that *Brachiosaurus* and *Giraffatitan* are not sister-groups, it was a
good move to separate them nomenclaturally.
[...] paleontologists and zoologists may have directly contradicting
views on species identification, despite using the same nomenclatural
Different neontologists have very different views on species
identification, too. There is much controversy over many individual
cases and over general questions like whether subspecies should be
recognized at all (as opposed to promoting them to species rank).