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RE: Distributions of morphological characters and more

Nick Gardner wrote-

Additionally, I've the following character in my analysis:
Premaxillary tooth number: 0- four; 1- two; 2- three; 3- five; 4- six;
5- seven; 6- zero.

Should the sixth character state (zero premaxillary teeth) be
separated as "premaxillary teeth: 0-present; 1- absent" or is it fine
as a state within a character counting the number of premaxillary

I separate it in my coelurosaur analysis, and code taxa without premaxillary teeth as inapplicable for tooth number. That's only because I order the tooth number character, and toothlessness seems to be able to evolve from both reducing tooth number (e.g. oviraptorosaurs) and increasing it (e.g. ornithomimosaurs). So I don't want to favor or punish either possibility. But if you left it unordered, I don't see why you'd need the second character.

Also, the supratemporal and infratemporal "bars" referred to
separately by Sereno and You, what exactly are they? Is the
supratemporal "bar" the postorbital-squamosal contact separating the
laterotemporal fenestra and the supratemporal fenestra, and the
infratemporal "bar" the jugal-quadratojugal contact that forms the
ventral margin of the laterotemporal fenestra?


Additionally, You uses palatal characters describing "choanae" in his
cladistic analysis, regretably, I've not been able to find out what
these are. Can someone please point me to a figure or paper that
adequately describes what part of the palate these are?

Choanae are internal nostrils. Generally formed by the maxillae, vomer and palatines on the ventral surface of the snout. Figure 22.3 in The Dinosauria: 2nd Ed. has a good view of them.

Mickey Mortimer