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Re: Princeton Field Guide: a different take
Aside from the disputes in regards to the taxonomy in the Princeton Field Guide
to Dinosaurs (hereon abbreviated as PFGD), I am actually somewhat disappointed
in the skeletals that are contained therein for some taxa and the lack of
skeletals for some both well-documented and well-described taxa. Because my
interest is mainly in sauropods, I will focus on those taxa.
I am somewhat irked by the fact that Greg Paul argues that splitting and
of genera and species should at least be consistent, whilst his criteria for
including (or excluding) skeletals for certain taxa is not, to say the least,
consistent. Similarly inconsistent is the rigorousness with which some taxa are
restored versus other taxa. Case in point: the skeletal for *Supersaurus* shows
the state of preservation of the fossil material (such as that some skeletal
elements are incomplete or missing and are shown as such). However, other taxa,
such as *Rapetosaurus* are not restored in the same manner. For instance, many
of the caudals of *Rapetosaurus* are missing and yet are restored as being
known. Also, most of the cervical vertebrae in *Rapetosaurus* are known only
from their centra, as their neural arches are missing in many of them. Yet,
Greg's skeletal, you'd never know that since they are all shown to be
On the other hand, well-documented taxa that have been well-described and
figured are not given skeletal treatments. For instance, while we get a
restoration of the skull of *Malawisaurus*, the rest of the skeleton is not
restored even though it is known from a nearly complete postcranial skeleton
including much of the cervical, dorsal, sacral and caudal series not to mention
appendicular elements--the only thing really lacking is the ilia and pubis.
Similarly, *Phuwiangosaurus* is known from well-described and documented
(including much of the cervical, dorsal, sacral and caudal series as well as
the appendicular elements), but no skeletal treatment is given for this taxon
either. In both cases, these taxa represent a relatively basal part of the
titanosaur radiation and would give a better idea of what basal titanosaurs
looked like but are nonetheless lacking.
Similarly odd is why *Huabeisaurus* is given a skeletal treatment, yet is known
from comparatively few elements when compared to *Malawisaurus* and
*Phuwiangosaurus*. In the original description, *Huabeisaurus* is listed as
being known from only 4 cervical elements, 2 of which are figured.
*Huabeisaurus* is only known from 5 dorsal vertebrae and 21 caudal vertebrae as
well as its sacrum and pelvis and appendicular elements, and as such is no more
complete (in fact, less complete) than *Malawisaurus* and *Phuwiangosaurus*,
a skeletal is provided for it and appears to show a lot more elements than are
actually known. What it appears to me is that the skeletal of *Huabeisaurus*
drawn from photographs of the mounted skeleton, which much of its elements
appear to be sculpted to fill in the missing gaps (look at the anterior
vertebrae for instance in pictures of the mounted skeleton that are available
Flickr). This makes me wonder how accurate other skeletals are of species that
appear to be based off of mounts in which the material therein has not been
published on in any science journal of which I am aware. For instance, the 35m
long "Mamenchisaurus sinocanadorum" skeletal based off of the huge mounted
skeleton is questionable, because, as far as I am aware it has not been
described. If we're going off mounted skeletons to provide references, why is
there no skeletal based off of the 37m long *Argentinosaurus* mount at the
Fernbankn museum of natural history? Much of the material in the
*Argentinosaurus* skeletal is restored and is in general too big, we know that
*because* of the published material. In the case of "Mamenchisaurus
sinocanadorum" mount, how do we know this isn't similarly speculatively
as in the case of *Argentinosaurus*? If we were to go ff skeletal mount,
*Argentinosaurus* would mass a lot more than "M. sinocanadorum", yet the latter
is considered the largest dinosasur known from good material in PFGD.
Aside from this, at least one skeletal appears to be scaled incorrectly, and
entry for that taxon lists it as much larger than it probably was based off
known material. I speak of *Futalognkosaurus* which is shown as quite a bit
larger than the *Giraffatitan* next to it in the section on gigantism in PFGD.
Yet both from information in the paper describing the anatomy of
*Futalognkosaurus*, it is apparent it was at least smaller than the HMN SII
specimen and proabably a good deal smaller than HMN XV2. The dorsal column of
*Futalognkosaurus* was probably just under or around 3m long, yet in Greg's
paper on *G. brancai* the dorsal column was estimated to be over 3.7m long.
Furthermore, a recent abstract released in 2008 said that previous estimates of
the length of *Futalognkosaurus* were overstated, and that the length from axis
to sacrum was ~11.9 m, and that the total length of *Futalognkosaurus* was
13 m excluding the tail (which may still be a fairly liberal estimate of its
length). Yet, going off the table in Greg's 1988 paper, the HMN SII specimen of
*G. brancai* was over 14.8m excluding the tail. That means that
*Futalongnkosaurus* was almost 2 m shorter (excluding the tail) than a
not-yet-fully-grown *G. brancai*, but you'd never know that from the diagram in
Also odd is that the taxon *Uberabatitan* is nowhere listed or even referred to
anywhere in PFGD, even though it is known from reasonably good material. There
are other issues that I will not go into, but I'll leave it at that.
All-in-all, I'm not too impressed with PFGD. However, I will admit that it is
nice to see a lot of skeletals for taxa that I haven't seen before. I just
these can be vouched for better than some of the sauropods...
I also find it it odd that Greg says that a larger field guide would not be
marketable. The Sibley Guide to Birds contains 810 species and is over 540
(thats over 200 more pages than in PFGD) and has sold very well. Especially odd
since only about 400 of those are actually illustrated and the rest are given
rather cursory treatments. Even the Princeton Field Guide "Sharks of the
which contains 453 shark species--all illustrated in both color and in
white, often with multiple views---and is 368 pages, and has more information
each species of shark than each species of dinosaur has in PFGD.
----- Original Message ----
From: "Thomas R. Holtz, Jr." <firstname.lastname@example.org>
To: DML <email@example.com>
Sent: Fri, October 1, 2010 7:40:37 AM
Subject: Princeton Field Guide: a different take
My copy arrived yesterday, and thankfully was not ruined by the horrendous
rainfall we had.
I know that the DML is always WAY concerned about taxonomy, but there is a lot
more to this book than that.
As in: dozens of hitherto unpublished Greg Paul skeletal restorations!! Some of
speices which have not-to my knowledge-had actual
skeletal restorations before.
At some point in my mythical copious free time I need to spend a few hours with
a flat bed scanner: next year's GEOL 104 students
will be seeing a lot new taxa showing up on PowerPoints and tests...
Thomas R. Holtz, Jr.
Email: firstname.lastname@example.org Phone: 301-405-4084
Office: Centreville 1216
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
Faculty Director, Science & Global Change Program, College Park Scholars
Mailing Address: Thomas R. Holtz, Jr.
Department of Geology
Building 237, Room 1117
University of Maryland
College Park, MD 20742 USA