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Re: Yay! Cladobabble! :-)



David Marjanovic wrote:
- Is cladistics a good thing? (The cladistic method to find phylogenetic
trees, I mean.)


Yes.

- Is phylogenetic nomenclature a good thing? (The young art of defining
names. It seems to be true that all followers of PN are cladists, but by no
means vice versa.)


Yes.

- How, if at all, should Aves be defined? (An extra complicated example of
the above. -- Because it _means_ "birds", no way around this, _I_'d like a
complicated stem-based definition, one so complicated that it'll survive
several decades with hardly changed contents: e. g. "everything more closely
related to *Passer domesticus* [or perhaps *Turdus merula*... or both... and
adding *Struthio camelus* wouldn't hurt either...] than [to] *Velociraptor
mongoliensis*, *Adasaurus mongoliensis*, *Microraptor zhaoianus*, *Troodon
formosus*, *Sinovenator changii*, *Ornithomimus velox*, *Tyrannosaurus rex*,
*Ornitholestes hermanni*, *Beipiaosaurus inexpectus*, *Oviraptor
philoceratops*, *Caudipteryx zoui*, *Protarchaeopteryx robusta*,
*Sinosauropteryx prima*, *Scansoriopteryx heilmanni*, *Crocodylus
niloticus*, *Euparkeria capensis*, *Longisquama insignis* and
*Megalancosaurus preonensis*". Add a bat if you like to prevent
Haem[at]othermia. Don't add Archie or an alvarezsaur, I wouldn't like that.
:-) )



I would like to see the continued use of the node-based definition of the clade containing both Archaeopteryx lithographica and Vultur gryphus. However, I would like to make a suggestion, and that is to define Aves as the most clade containing Archaeopteryx lithographica, Wellnhoferia grandis, Archaeornis siemensii, Jurapteryx recurva, Archaeopteryx bavarica, and Vultur gryphus (perhaps a few more neornithines could be added for fun). Even though I personally am not convinced that A. siemensii or Jurapteryx recurva are separate species from A. lithographica, I include them, so that if somehow, they are found to be separate species and these former Archaeopteryx species do not fall together in a polytomy with each other, but instead serially to the rest of Aves, that they would not be excluded. Of course, TMK, no one has proposed where they might fall relative to other taxa in a phylogenetic analysis, so I'm uncertain of this altogether. And also, even if they are synonymous, then it'll still be referring to the holotypes (presumedly) which will be referred specimens under Archaeopteryx (like with Caenagnathus being used in definitions of a few oviraptorosaur clades).


David, is there something in particular you are aiming for? In phylogenies that have been proposed by GSP (1988, 2002) and CMIIW, yourself, these taxa were considered more derived than Archaeopteryx. If this is the case, then Archaeopteryx is not a member of Aves. Of course, GSP (1988) states: "As for myself, since most theropods are usually excluded from Aves, I feel it is all right to exclude protobirds too, even a flying one like Archaeopteryx, and I prefer to restrict Aves to true birds, including the toothy ones. One advantage is that Aves is then a morphologically uniform group, and protobirds are left in the group that matches their anatomical grade." (206) I am curious now, if GSP still agrees with his last statement in light of the discovery of various new birds like the confuciusornithids, Longipteryx, Boluochia, Protopteryx, Sapeornis, Yandangornis, Omnivoropteryx, etc. which are certainly not morphologically uniform. Of course, he did describe the enantiornithines as "mysterious and bizzare". In his phylogenetic chart (224-225), he does not show where the enantiornithines would have been placed. Instead, he has the "Las Hoyas bird" (Iberomesornis romeralli), Ganius, Ambiortus, Ichthyornis, Hesperornis, and other birds (presumedly neornithines?) within a group labelled "birds".

Also, why do you include Scansoriopteryx heilmanni as a taxon that should be excluded from Aves?


- Is phylogenetic nomenclature useful, how useful should a classification
be, and is Linnaean classification more useful than phylogenetic
nomenclature? (Note the constant confusion of nomenclature and
classification. Also note that Benton's famous critique of the PhyloCode is
IMHO not worth much, because it attacks partly a very old version of the
draft PhyloCode, partly a strawman. See
http://dino.eu.tc/Benton-Phylocode.htm [case-sensitive!] for details. [The
cladograms there are all outdated.])


I find PhyloCode to be interesting, however, I have a few problems. Currently, I would like to know why they want all proper taxa to be italicized, as opposed to only species, and I suppose the "arbitrary" genus as well.



Nick Gardner

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