[Taxacom] Kinman System, dinosaurs, and bird classification
Ken Kinman
kinman at hotmail.com
Fri Jul 28 23:12:42 CDT 2006
Pierre and Christopher,
Before I get into the Kinman System, I thought I would answer Pierre's
question about where dinosaurs end and birds (Class Aves) begin. Exactly
where to draw the line between Reptilia and Aves is no longer easy (and
increasingly arbitrary to a degree with so many more intermediates being
known now). However, Archaeopteryx and its deinonychosaur relatives
(Archaeopterygiformes) should clearly be placed near the base of Class Aves
since Archaeopteryx has been recognized as a bird from the time of its
discovery.
These are the forms where we see the beginnings of the true semilunate
carpal block (in the wrist) and also eggs with ornithoid microstructure. It
is also fairly close to the origin of lateral shoulder joints, vaned
feathers, enlargement of the sternum, and other birdlike characteristics.
The immediate outgroups are the bird-like dinosaurs, such as families
Segnosauridae, Ornithomimidae, and even Tyrannosauridae. We can quibble
about the details of a precise synapomorphy for the origin of birds, but the
wrist morphology and eggshell microstructure seem to show an excellent area
in which to make the division. Deinonychosaur "dinosaurs" would have been
immediately classified as birds had we known about their feathers and
ornithoid eggs.
Below is the classification of Class Aves which I posted on Taxacom
earlier this year. It is divided into two subclasses, a paraphyletic
Archaeornithes giving rise to Neornithes. As I have stated many times, I
see no advantage whatsoever in restricting taxon Aves to only the Neornithes
(modern birds) as Gauthier and other strict cladists have proposed (mainly
because it is a "crown clade"). It just seems silly and arbitrary to me to
exclude Archaeopteryx from Aves, and it is also redundant to equate Aves
with Neornithes.
I have explained the Kinman System and its coding at various times
(using various taxa) for about 8 years now (see the Taxacom archives), but
here are the highlights. My 1994 book explains it in more detail, but there
are no copies in the Sacramento area. Paraphyletic groups are allowed
(actually necessary, although I use them sparingly), and their names marked
by a % sign. The descendant exgroups of such paraphyletic groups are coded
by an underlined alphanumeric symbol (usually _1_ or _a_).
The main cladistic code is alphanumeric, with numbers showing the main
branching of clades in the order that they split off (and subsidiary
subclades coded by letters). Phylogenetic uncertainty is obviously
indicated by a question mark coding. Neornithes clade 3 (Pterocliformes
through Eurypygiformes) is still not fully coded as their phylogeny is still
very uncertain. Note that among the extinct groups within Archaeornithes,
there are some genera not formally assigned to families, and therefore still
referred to as "Plesion" (usually abbreviated Pl.). Note that I broke down
Order Archaeopterygiformes to family level here because it is very
paraphyletic and has been expanded to include what are normally classified
as dinosaurs). Velociraptorids and Dromaeosaurids are increasingly being
recognized as large flightless birds, and their much smaller flying
ancestors will no doubt be discovered in the future.
CLASS AVES
1 ARCHAEORNITHES%
1 Archaeopterygiformes%
1 Troodontidae
2 Velociraptoridae
B Dromaeosauridae
3 Microraptoridae
? Plesion Sinovenator
? Pl. Mei
4 Scansoriopterygidae
? Pl. Unenlagia
? Pl. Buitreraptor
5 Pl. Rahonavis
6 Archaeopterygidae
? Pl. Protarchaeopteryx
7 {{expanded Avebrevicauda}}
_1_ Yandangornithiformes
? Pl. Shenzhouraptor
2 Omnivoropterygiformes
B Pl. Sapeornis
? Pl. Caudipteryx
3 Oviraptoriformes
4 Caenagnathiformes
? Pl. Nomingia
? Avimimiformes
5 Mononykiformes
6 Confuciusornithiformes
7 Longipterygiformes
B Iberomesornithiformes
C Enantiornithiformes
D Gobipterygiformes
8 Chaoyangiiformes
9 Patagopterygiformes
? Pl. Hongshanornis
10 Yanornithiformes
11 Ambiortiformes
12 Hesperornithiformes
13 Ichthyornithiformes
14 Pl. Limenavis
15 Lithornithiformes
16 {{Neornithes}}
_a_ NEORNITHES (crown clade, "modern" birds)
1 Tinamiformes%
_a_ Struthioniformes (ratites)
2 Galliformes
B Anseriformes
3 Pterocliformes
B Columbiformes
Opisthocomiformes
C Caprimulgiformes%
_a_ Apodiformes
D Mesitornithiformes
Phoenicopteriformes
Podicipediformes
Phaethontiformes
Rhynochetiformes
Eurypygiformes
4 Turniciformes
B Charadriiformes
C Gruiformes (sensu stricto)
5 Ciconiiformes
B Pelecaniformes
C Procellariformes
6 Falconiformes
B Strigiformes
7 Cuculiformes
8 Coliiformes
B Psittaciformes
9 Coraciiformes (sensu stricto)
10 Alcediniformes
11 Bucerotiformes
12 Piciformes
13 Passeriformes
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