Re: Coffins

["Thomas R. Holtz, Jr." <th81@umail.umd.edu>]

At 02:55 PM 6/23/98 -0400, Ralph "Morph-man" Chapman wrote:

>I indeed intended to say that the nail was in the coffin of the non-dino
>theory of brid origins. The new beasts are incredibly strong evidence for
>birds as theropod dinosaurs. Just wanted to pick them up and take them
>home (NMNH is home here), which I told Phil at the press conference.

:-)

Too bad I didn't drive there: I could fit the slabs in the back of my Honda
Civic...

>I will go to the exhibit when I return from Connecticut for a week's
>vacation. if others go, please let us know what the other three
>specimens are. I believe at least one is Sinosauropteryx, but don't know
>what the other two are.

There will be two Sinosauropteryx specimens on display: the type and the
third (largest) specimen.  I presume the third critter will be a
Confuciusornis, but will see soon enough.

Still a bit in awe over the critters...  Given that the paper is now
computer accessible (but NOT in the "public domain", as someone said: that
is something different with regard to copyrights), here are some of the
highlights:

Neither form has a distally placed retroverted pedal digit I: these were not
perchers, and indeed had typical nonavian theropod feet.  Protarchaeopteryx
is fairly long-armed (Arm/Femur ratio of 2.5, comparable to the longest
armed dromaeosaurs), whereas Caudipteryx is very short armed (Arm/F of 1.5,
on the low end of oviraptorosaurs).  The teeth of Protarchaeopteryx look
like serrated versions of Archaeopteryx teeth, but Caudipteryx teeth are
very unusual: long and slender.  The ischium of Caudipteryx is very
dromaeosaur or oviraptorosaur like: no sign of the posterodorsal process
found in Archaeopteryx and more advanced birds.  The dentary of Caudipteryx
is reminiscent of oviraptorosaurs in shape, and to a certain degree
resembles that of Shuvosaurus (!?!?!), but this does not necessarily imply
close relationships with either.

The phylogenetic analysis Ji et al. published did not include any non-avian
theropods other than velociraptorines, nor does it include Unenlagia or
Rahonavis.  It will be interesting to see where these guys fall out in a
more inclusive analysis...

Later.

Thomas R. Holtz, Jr.
Vertebrate Paleontologist     Webpage: http://www.geol.umd.edu
Dept. of Geology              Email:th81@umail.umd.edu
University of Maryland        Phone:301-405-4084
College Park, MD  20742       Fax:  301-314-9661