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RE: the tonight show



> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> King, Norm R
>
> >And from Ronald Orenstein:
> >Calling a cassowary a "dino-bird" will imply to a
> >general audience not that it is marginally more
> >like a Velociraptor than a sparrow is (and I am
> >not sure I buy this either), but that it is some sort
> >of halfway-house between birds and (other) dinosaurs.
>
> The latter point reopens that can of worms that seems to be inherent in
> phylogenetic taxonomy, and really comes home to roost in the birds as
> dinosaurs scenario.  What would the public envision when the term
> "dino-bird" comes up?  Probably some big marauding monster that growls
> rather then chirps, peeps, or quacks. So, does it really help
> communication
> by labeling any birds this way?
>
> Then, what does it mean in PT to say that paleognaths are more like
> dinosaurs than neognaths (and thus might be called "dino-birds" or a
> "half-way house"), when the distance between them is phylogenetic
> (number of
> evolutionary novelties) rather than morphological?

Actually, the above is nonsense: in PT paleognaths and neognaths are BOTH
dinosaur groups, and NEITHER is more closely related to _Velociraptor_ than
is the other.  See Dinogeorge's original comments for more details.

"Dino-birds" is NOT a term from phylogenetic taxonomy: it is instead a
pop-term introduced by people who are not willing to embrace a phylogenetic
frame of mind.

I think the confusion here lies in your association with the terms "halfway
house" and "dino-birds" with phylogenetic taxonomy: these are in fact
gradistic rather than cladistic terms!

> Might it be true that
> the most derived members of a lineage that split off early might, in fact,
> have developed as many, if not more, novelties on the way to being derived
> forms in their own lineage than the most derived members of the original
> branch (now a separate lineage) which we might characterize as more
> advanced?  In other words, aren't some paleognaths as advanced (i.e., as
> distant from dinosaurs) as some neognaths, even while retaining some
> primitive feature which allows us to identify them as paleognaths?  Surely
> Ron is correct in saying "It is a perfectly good modern bird, though a
> palaeognath."

Yes, and the above is wholly within a phylogenetic framework (other than to
add that paleognaths, despite their name, can be characterized by derived
rather than primitive features).  (Oh, and change "distant from dinosaurs"
to "distant from _Velociraptor_" or some such...).

> And the poor ichthyorniths had the misfortune of becoming extinct.  But if
> they had survived, they would also be just as distant from dinosaurs, and
> perfectly good, modern birds.  Therefore, I am not sure what significance
> there is in referring to such "half-way houses."

And if dromaeosaurids and oviraptorosaurs survived, we'd have primitive
fully fingered feathered bipeds running around, which everybody and their
brother would recognize as members of the same larger group as ichthyorniths
and paleognaths and neognaths.  (And, no doubt, some folks would have been
arguing that we have to put all members of Class Maniraptora in a different
group than dinosaurs like _Triceratops_ and _Stegosaurus_ and
_Diplodocus_...).

> Maybe it's the word "house" that has me hung up.  Am I quibbling?  I'm
> struggling with cladistics as it is.  I don't need to be confused
> even more!

I think that might be the case.

                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
                College Park, MD  20742
http://www.geol.umd.edu/~tholtz/tholtz.htm
http://www.geol.umd.edu/~jmerck/eltsite
Phone:  301-405-4084    Email:  tholtz@geol.umd.edu
Fax (Geol):  301-314-9661       Fax (CPS-ELT): 301-405-0796