Re: Jeholornis prima discussion

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

David Marjanovic wrote-

> > (so the fact dromaeosaurids lack several of these is not mentioned
because it would be
> > a reversal in any reasonable phylogeny)
>
> Do *Archaeopteryx* and *Rahonavis* lack the same ones?

Well, those maniraptoriform characters of Norell et al. (2001) lacking in
some dromaeosaurids were as follows.  Those marked with an asterisk are ones
which I have examined for my analysis, the rest are taken directly from
Norell et al.-
1. maxillary fenestra situated posterior to anterior border of antorbital
fossa
Absent in Dromaeosaurus and IGM 100/1015, but Archaeopteryx has it.
3. exits of cranial nerves X-XII flush with surface of exoccipital
Absent in IGM 100/1015 and Velociraptor, but Archaeopteryx has it.
4. basipterygoid recesses on dorsolateral surfaces of basipterygoid
processes absent
Absent in Dromaeosaurus, unknown in Archaeopteryx.
5. subotic recess present
Absent in Dromaeosaurus, Velociraptor and IGM 1001/1015, but Archaeopteryx
has it.
6. dorsal tympanic recess present
Absent in Dromaeosaurus, but Archaeopteryx has it.
*8. no enlarged lacrimal foramina
Absent in Deinonychus and Velociraptor, but Archaeopteryx has it.
*10. coronoid reduced or absent
I already said I don't see a difference in size between Dromaeosaurus
(Currie, 1995) and tyrannosaurids (Hurum and Currie, 2000).  The maximum
distance between the two posterior corners is 6% of mandibular length in
both Dromaeosaurus and Tyrannosaurus.  The coronoid structure is virtually
identical between Dromaeosaurus and T. bataar, except the latter's is more
concave dorsally.  Archaeopteryx supposedly lacks a coronoid.
*11. interdental plates fused/absent
Bambiraptor and Sinornithosaurus only develop this partially, but
Archaeopteryx has unfused interdental plates.
*12. axial epipophyses not extending posteriorly past postzygopophyses
Achillobator, Deinonychus, Saurornitholestes and Velociraptor lack this, but
Archaeopteryx has it.  I include Achillobator (despite the fact its axis is
unknown) because I found the presence of this kind of epipophysis in the
post-axial cervicals to be correlated with its presence in the axis.
*14. cervical epipophyses placed anterior to postzygopophyseal facets
Absent in Achillobator, Deinonychus, Saurornitholestes and Archaeopteryx.
*15. anterior cervical centra extending posteriorly past neural arch
(only valid for third and fourth cervicals- Makovicky, 1995)
Absent in Deinonychus, Velociraptor, Saurornitholestes, IGM 100/1015, but
Archaeopteryx has it.
18. ventral surface of sacral centra flattened, sometimes with sulcus
Dromaeosaurids have it, but Rahonavis lacks this.
20. cervical ribs broad and shorter than vertebrae
Dromaeosaurids have it, but Archaeopteryx lacks this.

And to David regarding his private reply to this post, I can't send e-mail
to your address, it just bounces.  In any case, the answer is "Not that I
know of".  The rest of you can ponder what the question was ;-)

Mickey Mortimer