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The Men Who Stare At New Papers



(Best.movie.title.ever.)



Vullo, R. 2009. Taphonomy of vertebrate microfossil assemblages in coastal
environments: in search of a modern analogous model. Palaios 24(11):723-725.





Peterson, J.E., Henderson, M.D., Scherer, R.P., and Vittore, C.P. 2009. Face
biting on a juvenile tyrannosaurid and behavioral implications. Palaios
24(11):780-784.

ABSTRACT: The juvenile tyrannosaurid specimen BMR P2002.4.1 possesses a
series of four partially healed, oblong lesions along the left maxilla and
nasal bones. The morphology of the lesions and their positioning and
orientation are compatible with the jaws of the specimen, suggesting that
the lesions may have been the result of a bite from an attacker of similar
size and species as the bite victim. Bone remodeling of the lesions
indicates partial healing and demonstrates that the injury was not fatal.
The injury appears to have affected the growth of the skull, causing a
slight warping of the left maxilla and a slight leftward curvature of the
nasal. Previous examples of intraspecific behavior in theropods have noted
various injuries on skulls; the majority of documented injuries are in
adults. The presence and nature of these wounds suggests that juvenile
tyrannosaurid behavior included intraspecific aggression among similar-sized
individuals, as has been observed in modern crocodilians. Although it is not
possible to unequivocally infer behavior from a fossil specimen, as a
juvenile animal it is unlikely that the behavior directly reflects sexual
competition or conflict, although it may represent learning behavior for
later conflict as competing adults or territoriality over food or spatial
resources.





Fritz, J., Hummel, J., Kienzle, E., Arnold, C., Nunn, C., and Clauss, M.
2009. Comparative chewing efficiency in mammalian herbivores. Oikos
118(11):1623-1632. doi: 10.1111/j.1600-0706.2009.17807.x.

ABSTRACT: Although the relevance of particle size reduction in herbivore
digestion is widely appreciated, few studies have investigated digesta
particle size across species in relation to body mass or digestive strategy.
We investigated faecal particle size, which reflects the size of ingesta
particles after both mastication and specialized processes such as
rumination. Particle size was measured by wet sieving samples from more than
700 captive individuals representing 193 mammalian species. Using
phylogenetic generalized least squares, faecal particle size scaled to body
mass with an exponent of 0.22 (95% confidence interval: 0.16-0.28). In
comparisons among different digestive strategies, we found that (1) equids
had smaller faecal particles than other hindgut fermenters, (2) non-ruminant
foregut fermenters and hindgut fermenters had similar-sized faecal particles
(not significantly different), and (3) ruminants had finer faecal particles
than non-ruminants. These results confirm that the relationship between
chewing efficiency and body mass is modified by morphological adaptations in
dental design and physiological adaptations to chewing, such as rumination.
This allometric relationship should be considered when investigating the
effect of body size on digestive physiology, and digestion studies should
include a measure of faecal particle size.

     (mentioned here for its potential applicability to large dinosaurian
herbivores...)





Slater, F.J., and Van Valkenburgh, B. 2009. Allometry and performance: the
evolution of skull form and function in felids. Journal of Evolutionary
Biology 22(11):2278-2287. doi: 10.1111/j.1420-9101.2009.01845.x.

 ABSTRACT: Allometric patterns of skull-shape variation can have significant
impacts on cranial mechanics and feeding performance, but have received
little attention in previous studies. Here, we examine the impacts of
allometric skull-shape variation on feeding capabilities in the cat family
(Felidae) with linear morphometrics and finite element analysis. Our results
reveal that relative bite force diminishes slightly with increasing skull
size, and that the skulls of the smallest species undergo the least strain
during biting. However, larger felids are able to produce greater gapes for
a given angle of jaw opening, and they have overall stronger skulls. The two
large felids in this study achieved increased cranial strength by increasing
skull bone volume relative to surface area. Allometry of skull geometry in
large felids reflects a trade-off between the need to increase gape to
access larger prey while maintaining the ability to resist unpredictable
loading when taking large, struggling prey.

     (mentioned here for its potential comparative information to theropods)




Kavanau, J.L. 2009. Secondarily flightless birds or Cretaceous non-avian
theropods? Medical Hypotheses. doi: 10.1016/j.mehy.2009.09.015.

ABSTRACT: Recent studies by Varricchio et al. reveal that males cared for
the eggs of troodontids and oviraptorids, so-called "non-avian theropods" of
the Cretaceous, just as do those of most Paleognathic birds (ratites and
tinamous) today. Further, the clutches of both groups have large relative
volumes, and consist of many eggs of relatively large size. By comparison,
clutch care by most extant birds is biparental and the clutches are of small
relative volume, and consist of but few small eggs. Varricchio et al.
propose that troodontids and oviraptorids were pre-avian and that paternal
egg care preceded the origin of birds. On the contrary, unmentioned by them
is that abundant paleontological evidence has led several workers to
conclude that troodontids and oviraptorids were secondary flightless birds.
This evidence ranges from bird-like bodies and bone designs, adapted for
climbing, perching, gliding, and ultimately flight, to relatively large,
highly developed brains, poor sense of smell, and their feeding habits.
Because ratites also are secondarily flightless and tinamous are reluctant,
clumsy fliers, the new evidence strengthens the view that troodontids and
oviraptorids were secondarily flightless.
     Although secondary flightlessness apparently favors paternal care of
clutches of large, abundant eggs, such care is not likely to have been
primitive. There are a suite of previously unknown independent findings that
point to the evolution of, first, maternal, followed by biparental egg care
in earliest ancestors of birds. This follows from the discovery of
remarkable relict avian reproductive behaviors preserved by virtue of the
highly conservative nature of vertebrate brain evolution. These behaviors
can be elicited readily by exposing breeding birds to appropriate
conditions, both environmental and with respect to their eggs and chicks.
They give significant new clues for a coherent theory of avian origin and
early evolution.

    (this one seriously makes me wonder...I mean, _Medical Hypotheses_...?!?
Did this one get rejected by all the journals with qualified referees only
to end up there?!?)




~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Jerry D. Harris
Director of Paleontology
Dixie State College
Science Building
225 South 700 East
St. George, UT  84770   USA
Phone: (435) 652-7758
Fax: (435) 656-4022
E-mail: jharris@dixie.edu
 and     dinogami@gmail.com
http://cactus.dixie.edu/jharris/

"Education is the only thing people
shell out a lot of money for...and
then do everything possible to avoid
getting their money's worth."

                            -- unknown