[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Taxonomy and naming issues
Tim Williams writes (how *do* you write upside-down? ;) ):
>What do you define as an "avetheropod" - is it equivalent to Paul
>Sereno's Neotetanurae (Allosauroidea+Coelurosauria)?
If I recall correctly from Mayr's textbook on taxonomy,
suprafamilial taxa do not have "priority" in the traditional sense. I
didn't quite pick up what the difference was, but I am fairly
convinced that Avetheropoda has priority if such a thing exists (Paul
suspected it was the equivalent of Tetanurae (Gauthier) or
Neotheropoda (Bakker), in which instances he was more-or-less right).
To/im Holtz (of Erlic/kosaurus fame ;) ) may correct me. Avetheropoda
also just has a much more definitive name to it.
I hear (from Nick Pharris) that Tom Holtz has resurrected the
Carnosauria as Allosauroidea + Basal allosaurs. Any comment (TRH?).
Of course, the problem I see ebing that no one has proven that there
ARE basal Carnosaurs outside of Sereno's Allosauroidea (Piatnitz,
IMHO, is a Megalosaur, Torvosaur, or it's own thang).
Nick Pharris writes:
>Well, up until very recently there was some confusion over the exact
>meaning of the term "megalosaur" (and perhaps there still is). In
>1993, for instance, Currie and Zhao refer to _Monolophosaurus_ as a
>"megalosaur grade theropod" and to Sinraptor as a "related form" to
>_Megalosaurus_, although it is quite clear that neither of these is a
>member of the Megalosauridae.
> Apparently it was not realized at the time how different the
>megalosaurids are from other theropod families.
The Cryolophosaurus article also referred to it as megalosaur
grade. Grade, per that Myer text (yes, I did some reading), referrs
to animals which have developed to a comparable level of complexity.
It has been noted that in many cases, at the base of a radiation there
is often a lot of gradation (early allosauroids look like megalosaurs
look like Piatnitzkysaurus look like Afrovenator (Agree with NJP,
looks like an allosaur), hence "megalosaur grade").
This is a common phenomenon: you may have heard Tom Holtz
refer to "Homoplasy amongst basal tetanurans", which is a more
scientific way of saying the same thing (although it has cladistic
implications which go beyond this discussion). In any case, a "grade"
is *never* a valid taxon, but is good way of quickly placing that form
of a member of a well known lineage. While I personally do not aggree
with "grade is as important as clade" in taxonomy (as I do not believe
that the information added is more valuable than the phylogenteic
clarity(or lack thereof) which is lost), one of the dissapointting
aspects of cladistics is that grade is buried in a pile of data
(excepting, of course, it's preservation in the works of Gregory Paul,
BTW: Sinraptor *is* related to Megalosaurus, probably about as closely
as Tyrannosaurus is to Gallimimus (of course, that's very subjective).
P.S. Non-taxomonmic issue (individual is not a valid taxon, Meyr
FAYI (For All Y'all's information), except in abberant cases,
"Jonathan" is shortened to "Jon" (no h), while "John" is never
lengthened to "Johnathan", exceptions usually being examples of
cross-lingual mishmoshing of the sort that is all-too common in this
happy world. "Jonathan" is an ancient Hebrew name (say it
yaw-nuh-tan), and no, I doubt that it's related to Nathan, but it
could be. John is greek, I think, and is the same name as Ian (say it
yon or yan, get it?). Ergo, when gettin' all friendly like as we like
to do around here, you would address me as "Jon" (or Wagner, or "hey
you", or a dozen things I don't think we want to say out loud), and
John Bois as "John". And spell Buchholz and Tom Holtz and
Erlicosaurus, and brush your teeth after every meal! :)
[Sorry; can't resist. Along those lines, Ernst Mayr probably prefers
to have his name spelled "Mayr" every time it's written down! :-) --
! Jonathan R. Wagner ! "Camin-Sokal Pars- !
! Graduate student sans portfolio ! imony couldn't help !
! firstname.lastname@example.org ! you determine who !
! http://faraday.clas.virginia.edu/~jrw6f ! your own mother is..." !
! Check out the paleo sections!!!!!! ! * * * !