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theropod lungs



After reading messages from the list, we (Terry Jones, John Ruben, and Nick
Geist) realized that we had inadvertently sent out the draft of our message
rather than the final copy.  We did not intend to imply that we are in any
way above anyone else, or that responding to comments from members of the
list was not worth our time.  Our intention was to show, by answering a few
of GSP's criticisms, that his comments were invalid (most of which  are
dealt with directly in the text of our paper or in the the notes and
references).  We apologize if our gaff offended anyone.

For those of you who do not have access to peer review literature, I (TDJ)
will be happy to send you a reprint of our paper when we receive them.

The following is the posting we thought we had sent.

Terry D. Jones
John Ruben
Nick Geist
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We urge that readers of the dino-list regard GSP's recent novella ("theropod
lung unreality") with the skepticism it deserves.  All of the
objections/issues raised by him (as well as others) were easily dealt with
in the course of  peer-review before the paper appeared in the 14 November
SCIENCE.  Thus, for example:

1. ** The dorsal "imperfection" in the otherwise domelike outline of the
anterior portion of the abdominal compartment (see especially the Bejing
slab)** -- This imperfection actually represents an artifact (actually a
gouge on the Bejing slab and a corresponding raised area on the Nanjing
counter slab) created by local disruption of the otherwise mostly regular
plane in which the specimen was split.  Thus, the apparently "missing"
portion of the border of the dome-shaped liver is probably contained within
the small raised area on the Nanjing counter slab.  Additionally, note that
fairly distinct remnants of fecal material can be seen in both slabs of the
cloacal region of this individual-- further evidence that the darkened
region of this specimen's trunk probably reflects the outline of the
abdominal cavity subdivision with a fairly high degree of fidelity.  Members
of the "dream team"  (all of whom had the opportunity to study these
specimens under 'scopes) have corroborated all of these observations.  It is
also important  that dinolist readers realize that at least two distinct
individuals of Sinosauropteryx  (one's not published) exhibit similar
diaphragm-related partitioning of the visceral cavity.
2.  **(i) Mobility of  the crocodilian pubis and (ii) variation in pelvic
girdle proportions between theropods and crocodilians**-- (i)
Mobility--unlike the theropod pubis, the croc pelvis is somewhat mobile (it
doesn't participate in formation of the acetabulum).  However, during
diaphragmatic muscle contraction, the crocodilian pubis is functionally just
as rigid as the pubis of theropod dinosaurs.  This is because a stout
ligament runs between the ischium and pubis and quite effectively prevents
any anterior excursion of the pubic bones.  The need for posterior mobility
of the croc pubis is probably related to the combination of the forward
projecting nature of the elongated pubis and the lateral undulatory motion
utlized by these animal's during swimming/walking. Alternately, theropods
probably maintained a fair amount of trunk rigidity during locomotion and
required no pubic mobility.  (ii) Variation in croc/theropod pelvic girdle
proportions-- remember, we specifically mention that the key here is the
pubis in all hepatic-piston breathers must be "...at least as long as the
liver is deep..."  in order to properly accommodate the ventral
diaphragmatic muscles (which insert on the ventral aspect of the liver).
Thus,  the fact that the pubis in a markedly dorsoventrally flattened animal
(i.e., crocs) is relatively shorter than the pubis in a markedly
laterally-compressed group (theropods) is irrelevant.
        We could go on to refute the rest of  GSP's objections but, at this 
point,
it seems unnecessary. 
TDJ
:-{)>
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    Terry D. Jones                             Voice:  541/737-6120     
    Oregon State University              Fax:      541/737-0501          
    Dept. of Zoology                         JONEST@bcc.orst.edu
    3029 Cordley Hall
    Corvallis, OR  97331-2914
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