Parsimony failure in AVES

Ken Kinman kinman at HOTMAIL.COM
Tue Feb 12 12:49:25 CST 2002

Dear All,
      I have come to the startling conclusion that strict parsimony has lead
many researchers astray in their efforts to discover more accurate theropod
and avian phylogenies.  The only remedy is some form of weighting, something
that many strict cladists find hard to swallow.  But the level of homoplasy
is so high that non-independent character groupings will force them to
weight or combine them sooner or later.
      It appears that "Enigmosauria" (the segnosaur-oviraptorosaur grouping)
is not even paraphyletic, but polyphyletic.  The many researchers who are
getting a holo(mono)phyletic "enigmosaur" grouping appear to be relying on
characters which are subject to functional convergences (mainly in the
vertebrae and jaws).
     My refined (simplified) definition of Aves is now:    All theropods
possessing (1) a convex coracoid glenoid, and (2) an enlarged fused
"semilunate" in adults.   Note:  the first is reversed in at least one genus
(Phasianus), and the distinctive shape of the second is partially reversed
in Protarcheopteryx and Caudipteryx.  These appear to be very rare
reversals, so these synapomorphies remain highly diagnostic.
     The contents of my classification (see below) remain the same, but I
obviously had to move caenagnathiforms and mononykiforms down below
Archaeopterygidae (and do some necessary recoding).  I doubt that
Alvarezsaurus will be put back in (but it is such a scrappy fossil, who
knows).  Many of the character distributions are beginning to make a whole
lot more sense.
        ------ Cheers,  Ken Kinman

  1  Plesion Troodontidae
  ?  Pl. Bagaraatan
  2  Archaeopterygiformes
           1  Dromaeosauridae
           B  "utahraptorid" family
           2  Pl. Pyroraptor
           3  Pl. Bambiraptor
           B  Velociraptoridae
           4  Pl. Sinornithosaurus
           ?  Pl. Unenlagia
           5  Pl. Microraptor
           6  Pl. Rahonavis
           7  Archaeopterygidae
           8  {{expanded "Metornithes"}}
_1_ Yandangornithiformes
  ?  Pl. Sapeornis
  2  Mononykiformes Kinman, 1994
           1  Patagonykidae
           2  Parvicursoridae
           3  Mononykidae
  3  Avimimiformes
  4  Pl. Protarcheopteryx
  5  Pl. Caudipteryx
  B  Pl. Nomingia
  6  Caenagnathiformes Cracraft, 1971
           1  Pl. Microvenator
           2  Caenagnathidae
           3  Oviraptoridae
           4  Confuciusornithidae
  ?  Pl. Protopteryx
  7  Longipterygiformes
  8  Pl. Jibeina
  ?  Pl. Hulsanpes
  9  Pl. Boluochia
  B  Iberomesornithiformes
10  Enantiornithiformes
 B  Gobipterygiformes
11  Plesion Vorona
12  Patagopterygiformes
 ?  Pl. Yanornis
13  Chaoyangiiformes
14  Pl. Apsaravis
 15  Hesperornithiformes
 16  Ambiortiformes
 17  Ichthyornithiformes
 18  Pl. Limenavis
 19  Lithornithiformes
20  Tinamiformes
_a_ Struthioniformes
21  Galliformes
  B  Anseriformes
22  .... other neognath orders

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