Class AVES expanded (preliminary classification)

[Ken Kinman]

Dear Taxacom Members:
      Yesterday I posted the announcement below on the DML (Dinosaur Mailing
List).  I post it here for those who might be interested.  I fully expect
this to be controversial, but I am convinced this is the best way to proceed
(and to focus the muddled debate over bird origins, so we can settle it once
and for all).  This will undoubtedly benefit both the scientific community
and the public at large as well.
      The primary synapomorphy for Class Aves (sensu lato) will probably be:
  Possession of a true semilunate carpal block.  I am defining this
structure as precisely as I can in the following way:
      A distal carpal structure which (1) is enlarged so as to fully cap mcI
and II;  (2) has a distinctive semilunate shape; and (3) has a pronounced
trochlear groove on the proximal side.
       Comments are welcome,
                    Ken Kinman
*******************************************
Dear All,
      I have thought about this long and hard for well over a year, and have
come to the conclusion that Class AVES should be expanded to include
maniraptors which possess so many bird characteristics that they should be
called birds.  It will be an apomorphy-based taxon that is *approximately*
equivalent to the cladistic stem-based "Maniraptora".
      The fact that Archaeopteryx was so long considered the first bird was
just an accident of history, but new fossils (from China in particular) now
almost cry out for a paradigm shift that is reflected in our nomenclature,
both formal and informal.
     The precise synapomorphy (or group of synapomorphies) is not yet
certain, but it will involve elements of the "folded" forelimb (particularly
in the wrist and manus).  I am certainly open to suggestions on which would
be the best and most precise synapomorphies for this new definition of Class
Aves.
     This expanded Aves will now include (but *not* defined by) forms that:
(1) possess vaned feathers; (2) possess eggs with ornithoid microstructure;
(3) possess lateral shoulder joints; (4) enlargement of sterna; and various
other bird characteristics.
     Furthermore, it will now contain those forms which display various
degrees of pubic retroversion (including mesopuby).  Many of these forms
have pelvic structures that are more bird-like, and they should probably
never have been classified in Saurischia in the first place.  I believe the
time has come to expand Class Aves to include all these "birds".  I had
already classified Order Mononykiformes in Class Aves in my 1994
classification, so there are only two new Orders, namely Segnosauriformes
and Caenagnathiformes (and these are obviously just Internet-type manuscript
names).
     My preliminary classification is given below (Pl. is my abbreviation
for Plesion):
*****************************************
CLASS AVEA (AVES)

1  Segnosauriformes
        1  Pl. Beipiaosaurus
        2  Alxasauridae
        ?  Pl. Neimongosaurus
        3  Therizinosauridae
2  Caenagnathiformes
        1  Pl. Protarcheopteryx
        ?  Avimimidae
        2  Pl. Caudipteryx
        3  Pl. Microvenator
        4  Pl. Nomingia
        5  Caenagnathidae
        6  Oviraptoridae
3  Plesion Alvarezsaurus
B  Mononykiformes
        1  Patagonykidae
        2  Parvicursoridae
        3  Mononykidae
4  Plesion Troodontidae
5  Archaeopterygiformes
        1  "utahraptorid" family
        2  Pl. Pyroraptor
        3  Pl. Bambiraptor
        B  Velociraptoridae
        C  Dromaeosauridae
        4  Pl. Sinornithosaurus
        ?  Pl. Unenlagia
        5  Pl. Microraptor
        6  Pl. Rahonavis
        7  Archaeopterygidae
        8  Yandangornithidae
        9  Pl. Sapeornis
       10  Confuciusornithidae
       11  Enantiornithidae
       12  {{Euornithes}} (Patago., etc.)
_1_ Patagopterygiformes
2  Hesperornithiformes
3  Plesion Apsaravis
4  Ichthyornithiformes
5  Tinamiformes
_a_ Struthioniformes (ratites)
6  Galliformes
     .....other neognath orders

*NOTE:  I will be discussing the precise apomorphy-based definition of the
new Aves in the days to come.  All suggestions are welcome.  And also note
that I plan to add Plesion Bagaraatan once I decide the best place for it.



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