Re: Revising Hou et al, 96 (very very long)

["Mickey Mortimer" <Mickey_Mortimer111@msn.com>]

Nicholas Gardner wrote-

> Okay.  So for this situation, mesopuby is the plesiomorphic state?

Perhaps, but it's complicated.  First I should note that the "propubic >
mesopubic > opisthopubic" trichotomy is probably oversimplified.  We should
look for actual angles between the pubis and ilium, the direction the base
points and other such things.  But assuming we utilize the simple method for
the moment, look at the distribution-

propubic (0)- Microvenator, Chirostenotes, Oviraptoridae, Bagaraatan,
Avimimus, Troodon
mesopubic (1)- Caudipteryx, Nomingia, Patagonykus, Sinornithoides,
Achillobator, Archaeopteryx, Rahonavis
opisthopubic (2)- Therizinosauroidea, Mononykinae, Sinovenator, Bambiraptor,
Dromaeosauridae, Sinornithosaurus, Pygostylia

Using my current best guess at maniraptoran phylogeny, we get the following
distribution-
|--+--2 Ther
|  `--+--+--1 Caud
|     |  `--1 Nomi
|     `--+--0 Micro
|        `--+--0 Chir
|           `--0 Ovir
`--+--0 Bagar
   `--+--+--0 Avim
      |  `--+--1 Patag
      |     `--2 Monon
      `--+--+--2 Sinov
         |  `--+--1 Sinornithoi
         |     `--0 Trood
         `--+--+--2 Bambi
            |  `--+--2 Dromae
            |     `--1 Achillo
            `--+--2 Sinornithos
               `--+--1 Archae
                  `--+--1 Rahon
                     `--2 Pygosty
I personally think troodontids + eumaniraptorans were primitively
opisthopubic, with reversals in derived troodontids, Achillobator,
Archaeopteryx and Rahonavis.  Unenlagia also reversed somewhere in there,
but exactly where it goes I'm uncertain.  I think it's less likely that
paravians or all maniraptorans were primitively opisthopubic, but it is
possible.

> Aren't we supposed to code "?" if the structure is absent? AFAIK,
> Hesperornis had only a humerus.  Maybe I'm wrong.

Yes, Hesperornis' forelimb is only known from the humerus, which doesn't
look capable of supporting many other bones.  The exact way in which to deal
with these situations is often subjectively decided.  For instance should
"posterior tooth serrations enlarged" be coded as absent in a taxon with
serrationless teeth?  We can't tell the size of the serrations when they
were not present, or does that mean they are infinitely small?  In this
example I probably should have coded Hesperornis as "?" for "manual
phalanges III-2, III-3 and III-4 absent".

Mickey Mortimer