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Mesozoic Vertebrate Life: Introduction and Theropoda

  I appologize for the cross-posting; this arrived today, and I
thought I'd summarize the contents.

Tanke, D.H. & Carpenter, K. (eds.); Skrepnick, M.W. (art ed.)
2001. _Mesozoic Vertebrate Life: New Research Inspired by the
Paleontology of Philip J. Currie_. Indiana University Press
(Bloomington & Indianapolis [Indiana]) 577 pp.

[As acknowledged by Darren Tanke on the list, this book was
meant to be more inclusive of other vertebrates, but what you
see it what you get. Even so, it is nearly 600pp, and an
impressive work in itself.]

There are a number of technical and scientific papers regarding
the nomenclature and general dinosaurian topology. I'll tackle
these first, including the new species, starting with the first
paper and working my way down. Short descriptions will follow,
and I'll try to be comprehensive to the new dinosaurs (there are
four, and those familiar with George's post last month will be
aware of these to some degree). I must say, of all the people in
paleontology (a delay in Canada prevented him from coming to SVP
in '99, Denver, or I would have certainly talked to him in
person) Phil Currie is one man who I intrinsically respect
utterly. Currie is one of the most prominent paleontologist of
this and the last century, standing next to Huxley and Ostrom
and Carroll, and yet has never let the fame go to his head.

We begin with a foreword by Robert Carroll, Currie's grad
supervisor and long-time friend and colleague. A second is from
John Lazendorf, long-time friend of Currie's and collector of
art extraordinaire. Included are a section of prints in color of
some of the best art on animals Currie has had the fortune of
working on. *Monolophosaurus* graces the cover, though
*Sinraptor* is missing from within. Brian Cooley's almost freaky
*Protarchaeopteryx* is inside, several of Henderson's work
including the *Centrosaurus* in a flooded river,
*Struthiomimus*, and two hunting *Velociraptor*; more than a few
shots of the *Pachyrhinosaurus sp.* (one by Hargrove, another
sculpture by Lorusso); *Troodon* chasing *Othneilia* by Bindon;
Greg Paul has his Horseshoe Canyon oxbow painting, where several
*Anchiceratops* surge at the edge as a group of *Albertosaurus*
provoke them and *Hypacrosaurus* to stampede. John Sibbick
offers a well done *Hypacrosaurus*, and Luis Rey has both his
*Ciripati* as "Oviraptor" and hunting *Giganotosaurus* and
*Amargasaurus*; Skrepnick offers several including the cover,
and a pair of adult *Diplodocus* with "chick", his *Caudipteryx*
by the lakeshore, the *Sinosauropteryx* from the _Encyclopedia
of Dinosaurs_ cover, and a study from bone to muscle to flesh of
the same, and a very, very well done piece on a pack of juvenile
*Albertosaurus* herding a *Hypacrosaurus* into the jaws of an
adult *Albertosaurus*. Sovak also renders *Sinosauropteryx*, and
then lastly we have two bronzes of Trcic's tyrannosaurines
*Daspletosaurus* and *Tyrannosaurus*.

The first section is on theropods, of course:

1 ---

Coria, R.A. 2001. New theropod from the Late Cretaceous of
Patagonia. p. 3-9.
  This paper describes the new theropod *Quilmesaurus curriei*,
and the statistics are as follows (all text pretty much
fromCoria, 2001, my comments will be in corner brackets " [ ] "
or otherwise indicated):

--  Holotype: MPCA-PV-100, distal end (~1/4) of the right femur,
and a complete right tibia (lacking the margin of the shaft
preserving the fibular crest).
--  Horizon: Allen Formation, Campanian--Maastrichtian, Upper
Cretaceous (roughly contemporaneous to the Milk River, Judith
River, and Two Medicine Formations). The specimen was recovered
from Salitral Ojo de Agua, 40km S of Roca City, in Provincio de
Río Negro, Argentina.
--  Diagnosis: femur with strong, well-developed mediodistal
crest; tibia with hook-shaped cnemial crest, lateral malleolus
of tibia twice the size of the medial, the distal end being
assymetrical (the lateral malleolus is not just longer, but
extends further distally than the medial).
--  Measurements: preserved femur length, 350mm; tibia length,
520mm; the tibia is 59mm across at the midshaft, 124mm in
circumference at the same point, transverse distal width is
105mm, transverse proximal width is 74mm, without the cnemial
--  Discussion: Coria does not place *Q. curriei* any higher
than Theropoda, but does offer possible relationships. One thing
to note is that the facet for the ascending process of the
astragalus is relatively high, 1/5 (20.5%) the tibial length,
though the depression (indistinct) extends a little more
proximally. The distal end is not perpendicular to the tibial
shaft, but deeper laterally [this is seen in most tetanurans].
The cnemial crest is expanded distally dorsoventrally [see
below], and turned strongly laterally so that it would cover the
proximal fibula in cranial view [not many theropods have this,
so this is apomorphic for the species].   The tibial fossa is
long, over 1/3 (36.8%) of the tibial length. The distal end
bears a notch cranially, present also in *Giganotosaurus* and
*Sinraptor*, but not in *Allosaurus*, *Piatnitzkysaurus*, or
other theropods, including ceratosaurs and coelurosaurs; lastly,
the tibia lacks a groove between femoral condyles, but rather a
prominent rounded tableau. The femur has a large, mediodistal
crest [as prominent as in *Elaphrosaurus*, *Masiakasaurus*,
*Xenotarsosaurus*, and *Carnotaurus*], a rounded, globular
tibiofibular crest (not mediolaterally compressed) [one sees
this in ceratosaurs], positioned well lateral to the medial
condyle and within the flexor groove instead of to the side of
it, and a distal femoral shaft strongly flexed caudally, but
apparently straiter more proximally [similar to *Ceratosaurus*];
the femur has no cranial extension of the femoral flexor groove,
and a shallow, U-shaped caudal flexor groove.
--  Jaime's Opinion: this is a ceratosaur, and a neoceratosaur
at that. It appears to be an abelisaur, based on the form of the
cnemial crest, proximal tibial form, and extent of the
mediodistal femoral crest. Unlike Mickey Mortimer, I can't send
figures over the scanner to anyone, but those of us with the
book will make the papers available (some for a fee :) ). It is
strange that Coria does not provide an etymology for
*Quilmesaurus*, so unless this name is Mapute or other native
language in origin, the name appears to be a pun: in Spanish,
the pronounciation follows KEEL-may-SAWR-us, or possibly
"kill-me-saurus" may be cuter....

2 ---

Chure, D. 2001. On the type and referred material of *Laelaps
trihedrodon* Cope 1877 (Dinosauria: Theropoda). p. 10-18.
  Dan Chure redscribes the species as belonging to *Allosaurus*.
Yet another species of *Laelaps* being sunk.... you go, Dan. :)
The bulk of the paper is a technical meander through how one
finds lost material, through photographs, journal notes,
shipping records, and museum records. Only five teeth of AMNH
5780, originally eight, remain, of a referred specimen. All
other material cannot be located.

3 ---

Larsson, H.C.E. 2001. Endocranial anatomy of
*Carcharodontosaurus saharicus* (Theropoda: Allosauroidea) and
its implications for theropod brain evolution. p. 19-33.
  Hans got his hands on the *Carcharodontosaurus* braincase
collected in 1995 in the Kem Kem of Morocco, and finally
publishes the results. Not what you expected. The shark-toothed
guy fits on a regression line with *Allosaurus* similar to other
non-avian reptiles, but *Tyrannosaurus* is closer to birds, and
*Troodon* closer still, based on computed cerebrum to
endocranium volume ratios. Some detailed cranial anatomy is
offered, but this is generally congruous with *Allosaurus*.

4 ---

Hurum, J. 2001. Lower jaw of *Gallimimus bullatus*. p. 34-41.
  Well, something that's come up recently, the form of the lower
jaw in ornithomimids, this one especially.... Hurum is studying
many theropods in the ZPAL collection, the type of *Gallimimus*
and an osteology of *Tarbosaurus* with a perspective to function
in the jaw of tyrannosaurids (with Currie) involved. Some
surprises, so discard your Osmólska, Roniewicz, and Barsbold,
1972 discussion of it in favor of this: there is no coronoid or
supradentary, but the jaw was locked at the intramandibular
joint by the form of the dentary and surangular contact; the
prearticular occludes the articular from view medially, and
because of the lack of a coronoid, the prearticular is
apomorphically expanded distally/dorsally; the splenial does not
persist to the symphysis, and ends cranially at the mylohyoid
foramen, instead of tapering [the condition is the same for
oviraptorids, though the splenial continues to the symphysis.]

5 ---

Varricchio, D.J. 2001. Late Cretaceous oviraptorosaur
(Theropoda) dinosaurs from Montana. p. 42-57.
  Two specimens are described, an articular (MOR 1107) referred
to *Chirostenotes sternbergi* from the Two Medicine Formation of
Montana, and the first non-Canadian record of the species,
identified by the nearly circular form of the articular when
viewed from above, the strong dorsal arch, and the absence of a
slot for the chorda tympani. The second is referred to
*Elmisaurus elegans* (MOR 752), and is the most extensive
material of the species known, including the second metatarsal
lacking most of the the proximal 1/3, but with portions of the
hollow shaft extending to the proximal extent, the third and
fourth pedal digits (complete) and one partial and one complete
phalanx from the second digit, as well as a portion of the
astragalus, and an indeterminate metatarsal fragment. Varricchio
also separates Elmisauridae and Caenagnathidae, but does not
provide a reason, and from the material, I cannot see any
autapomorphies of *E. elegans* in MOR 752, as the type and other
referred material are  more complete tarsometatarsi; Varricchio
refers MOR 752 to *E. elegans* based on the size and
slenderness, and one possible autapomorphy: a distinct,
anterolateral process proximal to the distal condyle.

6 ---

Jacobsen, A.R. 2001. Tooth-marked small theropod bone: An
extremely rare trace. p. 58-63.
  A Saurornitholestes dentary (RTMP 88.121.39) possesses
apparent tooth-made scratches (there is a distinct, deep
v-shaped incisions, and another scrape with even sections in the
groove suggesting the tooth serrations were dragged across the
bone. Analysis of the serration pattern indicate the masticator
was a tyrannosaurid (probably a juvenile), as they are the wrong
shape and too fine for *Dromaeosaurus*, and the serrations are
not the same pattern in *Saurornitholestes*, ruling out
intraspecific or cannibalistic behavior. [*Ricardoestesia* is
not discussed].

7 ---

Holtz, T.R., Jr. 2001. The phylogeny and taxonomy of the
Tyrannosauridae. p. 64-83.
  Well, I think Tom can cover this pretty well... but let me
try. Tom gives a short explanation at the end that really must
be applied to most phylogenies one finds published (or one
publishes): "As with all studies, the results of the
phylogenetic analysis presented here are tentative and subject
to change with addition of new characters and new taxa." The
phylogeny, as his Tree of Life page shows, is:

--+=?=Siamotyrannus isanensis
      |   |--Aublysodon molnari
      |   |--Kirtland Aublysodontine
      |   `--Alectrosaurus olseni
          |--Alioramus remotus
          `--+=?=Shanshanosaurus houyanshanensis
             `--+--Gorgosaurus libratus
                |--Albertosaurus sarcophagus [may also be sister
to G. libratus]
                `--+--Daspletosaurus torosus
                   |--Two Medicine tyrannosaurine
                   `--+--Tyrannosaurus rex
                      `--Tyrannosaurus bataar

*Nanotyrannus* and *Maleevosaurus* were included seperately and
fell in next to *T. rex* and *T. bataar*, respectively.
*Siamotyrannus* and *Shanshanosaurus* were run in a separate
matrix and did not change the topology of the tree. Tree is 150
steps with 111 characters [not bad] (152 steps with the two
other species included -- other stats will have the more
inclusive tree in parentheses); consistency index (CI) is .860
(.855), retention index (RI) is .761 (.768), and homoplasy index
.273 (.164). Outgroups were Maniraptora and Ornithomimosauria.
The phylogeny was designed to test internal relationships,
rather than position within Coelurosauria.

8 ---

Abler, W.L. 2001. A kerf-and-drill model of tyrannosaur tooth
serrations. p. 84-89.

  A kerf is an incision as a saw bites into wood, and the drill
is pretty explanatory. The extent of the paper, as in his 1994
paper on the function of tyrannosaurid teeth ["With teeth the
shape of bananas" as Avery Brooks says in WWD ... ugh], is to
described the form of the serrations, but whereas the previous
paper focused on the form of the denticulations themselves, this
focuses on the spaces between them [I'm singing Dave Matthews
Band now....]. To summarize, the space between the denticles
(referred to as corbels in architechture) is a narrow slot,
essentially a crack between adjacant denticles, that extent into
an ampulla, or pocket. Compared to more primitive predators,
such as *Dimetrodon*, these are mechanically more capable, as
*Dimetrodon* lack ampulae: force when the denticles draw on
flesh transmit into the core of the tooth, and this has the
effect of increasing stress in the direction of the crack,
lengthening it; the ampula provides an even distribution of
force around it's edge, rather than into the tooth. This is
required for an animal that pulls at its foods as much as
tyrannosaurids seem to do, where pressures on the tooth  cause
compression on the mesial margin and tension on the distal
(posterior) margin.
  Well, I can't right his paper for you ... :) Needless to say,
very cool stuff. What with Hurum and Currie and Tom working on
jaws, and Abler on teeth, and Farlow on the biomechanics, and
the next paper, we are growing more and more knowledgeable about

9 ---

Carpenter, K. & Smith, M. 2001. Forelimb osteology and
biomechanics of *Tyrannosaurus rex*. p. 90-116.

  Describes the nearly complete forelimbs of the "Wankle" rex
(MOR 555) and "Sue" (FMNH PR 2081). Muscle groups and
attachments are delineated, so that people wanting to
reconstruct the forelimb of *T. rex* should refer to this paper.
The material includes a true semilunate carpal, and only
metacarpals I and II, with no indication there was a third (the
lateral surface of the second metacarpal has a deep incisure
that probably held the tendon for the _retinaculum m. extensor
et flexor metacarpi ulnaris_. Forelimb orientation is discussed:
from the side, the humerus could move from just below horizontal
to about 45degrees below, and from in front, the humerus can
adduct to about 10degrees inward, but could not abduct well; the
ulna/radius has a strong degree of rotation, from 45degrees of
the humeral long axis through 100degrees or so flexed; the manal
digits are permanently set apart at about 30degrees, and had a
strong flexion/weak extension sequence, where the fingers flex
slightly inward, but the points of the claws face outward during
extension, slightly....

10 ---

Padian, K.; Ji Q.; & Ji S.-a. 2001. Feathered dinosaurs and the
origin of flight. p. 117-135. [several pages of plates are also
available for this, as high-definition photographs in color].

  Currie would normally have been a part of this ... but as we
all know, it was provided in his favor, so his absence is
understood, I think. *Sinosauropteryx*, *Caudipteryx*, and
*Protarchaeopteryx* are discussed, they integument reviewed.
These structures are called feathers throughout. It is
essentially a detailed description of the flight-related or
avian-style features in the anatomy, and a detail of the type of
structures each has. Function is considered and whereas the
brooding  function is observed, Hopp and Orsen's theory is not
referenced. The primary function adopted is those features
relating to the flight stroke. The paper is too detailed for me
to offer a quick summary. You'll have to read it for yourself

  I will continue with the other papers when I get them written
out; sauropods and ornithopods are next, but are less together
than the theropod section.

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