[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: semilunate carpal

Well, seems this has developed into the old BADD vs. BCF thread.  :-) But
there are a few interesting points I'd like to respond to-

George Olshevsky wrote-

> The skull of Archaeopteryx is much more birdlike than the skull of any
> dromaeosaurid.

Really?  I wonder, are you including Sinornithosaurus or Microraptor in the
Dromaeosauridae?  I don't know of a single cranial character that
Archaeopteryx shares with pygostylians that isn't found in some other
theropod lineage.  In fact, I know of only two postcranial characters shared
by Archaeopteryx and pygostylians and not seen in other theropods, and one
is problematic.  The first is the presence of less than nine caudal
vertebrae with transverse processes (also seen in Rahonavis, which maybe
avian).  The second is the presence of a reversed hallux.  Again, this is
present in Rahonavis.  Additionally, both Microraptor and Caudipteryx have
been said to exhibit the condition, although I'm wary of the reality of
this.  Finally, such a character is no doubt lost easily once a taxon
becomes flightless, as Patagopteryx (a euornithine) has an unreversed hallux
(Chiappe, 1996).  I would have to agree that Archaeopteryx has extremely few
characters more birdlike than derived eumaniraptorans, although using
Dromaeosauridae sensu stricto (limited to Dromaeosaurus, Deinonychus,
Saurornitholestes and Velociraptor, perhaps Adasaurus and Achillobator),
you'd find several.

Mike Keesey wrote-

> Has _Proceratosaurus_ ever been considered a maniraptor?

No.  It's a very basal coelurosaur in both Holtz's (2000) and Rauhut's
(2000) studies, the only two it's been included in.  I would be interested
in comparison of the Bathonian paravian-like teeth to it though.
..... Then Tom had to post that he found Proceratosaurus to be a
maniraptoran in some of his unpublished trees. :-)  To this I would respond
that several Jurassic taxa (Coelurus, Ornitholestes, Compsognathus, this new
German skull, many teeth) could very easily be maniraptorans.  We just
usually ignore them when discussing Jurassic maniraptorans for some reason.

Tim Williams wrote-

> There is tantalizing evidence of Jurassic maniraptorans
> (sensu Sereno, 1999 - oviraptorosaurs + deinonychosaurs + birds)...
> _Palaeopteryx_, _Nuthetes_ (though the paper has yet to come out, AFAIK),
> perhaps _Ozraptor_.

Nuthetes is Early Cretaceous (Beriassian).  Besides Paleopteryx and
Ozraptor, here are some other Jurassic maniraptorans based on non-dental
unnamed Morrison segnosaur-oviraptorosaur (Kimmeridgian-Tithonian)
unnamed Lufeng segnosaur (Hettangian-Pliensbachian)
(Clark (pers. comm.) says the majority of evidence indicates it's not a
unnamed Morrison paravian(?) femur (Jensen, 1981)
By the way, a quick comparison of Paleopteryx to other coelurosaurs makes me
near certain it is paravian and probably avialan.

Josh Smith wrote-

> Oh good.  Let's take and throw out an entire class of putative data simply
> because no one has sat down and examined what can really be done with

I completely agree.  Go dental evidence!

Randall Irmis wrote-

> This is a problem even if Protoavis is a valid taxon (which we should not
discuss here
> because that would be beating a very dead horse).

Actually, I think it should be discussed- but with actual study of the
published photos and comparison to supposedly related taxa (birds,
coelophysoids, herrerasaurids, megalancosaurs, etc).  Nearly all discussion
on the list to this point has been vague or reiterations of what has been
published (furcula may be chevron, metacarpus may be metatarsus, etc.).
I've started to look into it, but need the photos from Chatterjee's 1999
paper, as I don't trust the line reconstructions.

Mickey Mortimer