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Re: Ichthyornis paper



Excellent.  I like the GSP illustrations.  Goodbye Ornithurae OTU, hello
Ichthyornis and Hesperornithes OTU's.  Unfortunate that Clarke cut the
character discussions and inclusion of Songlingornis, Gansus and Chaoyangia
from her analysis though (compared to her dissertation).  Perhaps those are
waiting for the Yixianornis paper suggested by her SVP presentation.
Evidence of Gansus' prior inclusion was not completely erased though, as
seen on page 26- "However, because this optimization is currently ambiguous
(due to missing data in Limenavis patagonica and Gansus yumenensis..." :)

Also, note the phylogenetic definition for several clades-

Hesperornithes Furbringer, 1888 - (Hesperornis regalis <- Aves)
Eat that, Hesperornithiformes!

Hesperornithidae Marsh, 1872 - (Hesperornis regalis <-Baptornis advenus)

Ichthyornithes Marsh, 1873 - (YPM 1450 <- Aves)

Ichthyornis Marsh, 1872 - clade stemming from an ancestor that possessed all
of the morphologies described by apomorphies 2, 5, 6, 7, 8 (in the
Ichthyornis dispar Diagnosis) homologous (sensu Patterson, 1982) with those
in YPM 1450 (holotype of Ichthyornis dispar Marsh, 1872b) and more closely
related to YPM 1450 than to Aves (internal specifiers of Gauthier and de
Queiroz, 2001; see Introduction).
Oy.

dispar Marsh, 1872 - the species that includes YPM 1450.

Guildavis Clarke 2004 - (YPM 1760 <- Ichthyornis dispar, Vultur gryphus,
Struthio camelus, Tetrao major, Vultur gryphus [yes, again])

tener Marsh, 1880 - the species that includes YMP 1880.

Apatornis Marsh, 1873 - (YPM 1451 <- Ichthyornis dispar, Vultur gryphus,
Struthio camelus, Tetrao major, Vultur gryphus)

celer Marsh, 1873 - the species that includes YPM 1451.

Iaceornis Clarke, 2004 - (YPM 1451 <- Ichthyornis dispar, Vultur gryphus,
Struthio camelus, Tetrao major, Vultur gryphus)
HAHAHA!  Through a typo, Clarke inadvertently defined her new taxon
Iaceornis as a junior synonym of Apatornis!  And unlike the other defined
genera, she never specifies what species the reference specimen is the type
specimen of in the definition.

marshi Clarke, 2004 - the species that includes YPM 1734.
Poor, poor genusless marshi.

Pangalliformes Clarke, 2004 - provisionally (Gallus gallus <- Anser anser)

Austinornis Clarke, 2004 - provisionally (YPM 1796 <- Gallus gallus, Crax
rubra, Megapodius freycinet)

lentus Marsh, 1877 - the species that includes YPM 1796.

So, we have our first phylogenetic definitions for a Mesozoic dinosaur genus
and species.  What does everyone think?

Mickey Mortimer
Undergraduate, Earth and Space Sciences
University of Washington
The Theropod Database - http://students.washington.edu/eoraptor/Home.html