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Observe and New Papers



Walker, J.D., and Geissman, J.W. 2009. 2009 GSA Geologic Time Scale. GSA
Today 19(4/5):60-61.

     (Includes a major revision to the Triassic time scale -- note, however,
that this is NOT [AFAIK] the internationally accepted version issued by the
ICS.)




Senter, P. 2009. Pedal function in deinonychosaurs (Dinosauria: Theropoda):
a comparative study. Bulletin of the Gunma Museum of Natural History
13:1-14.

ABSTRACT: Members of the Cretaceous theropod clade Deinonychosauria have a
highly modified second toe with an enlarged, recurved ungual. Here I present
the first comparative study of pedal function in deinonychosaurs and other
theropods to test hypotheses of function for this toe. I manually
manipulated bones and casts to determine pedal range of motion in the
non-deinonychosaurian theropods Dilophosaurus, Allosaurus, Mononykus, and
Chirostenotes; and the deinonychosaurs Troodon, Neuquenraptor, Rahonavis,
Bambiraptor, Deinonychus, and Dromaeosaurus. I also used movies of walking
bird feet for comparison. The results of the study show that: (1) contrary
to previous suggestions, the distodorsal eminence of pedal phalanx II-1 of
deinonychosaurs is not correlated with greater hyperextensibility of phalanx
II-2 than in other theropods; (2) the proximoplantar process of phalanx II-2
of deinonychosaurs limits flexion, as previously suggested (3) movement of
the second toe is sub-orthal in dromaeosaurids, the toe remains adducted
(angled toward the animal's midline) through hyperextension and flexion in
Troodon, and in other theropods the second and fourth toes diverge during
hyperextension and converge during flexion; (4) pedal phalanx I-1 is
immobile in Chirostenotes and the examined deinonychosaurs but has a wide
range of motion in other theropods; (5) contrary to a previous suggestion,
the hallux of Rahonavis was not retroverted; (6) range of motion in the
second toe is consistent with opening tough insect nests in dromaeosaurids
but not Troodon; (7) the deinonychosaurian second toe was hyperextended, not
flexed, during locomotion.




Kolosov, P.N., Ivensen, G.V., Mikhailova, T.E., Kurzanov, S.M., Efimov,
M.B., and Gubin, Y.M. 2009. Taphonomy of the Upper Mesozoic tetrapod Teete
locality (Yakutia). Paleontological Journal 43(2):201-207. doi:
10.1134/S0031030109020129.

ABSTRACT: The fauna of the Teete locality (Neocomian, Yakutia) includes
bivalve and gastropod mollusks, palaeoniscid and chondrostean fishes,
caudate and anuran amphibians, choristoderes, lizards, phytophagous and
predatory dinosaurs, and theromorphs (cynodonts). The flora includes mosses,
horsetails, lycopods, ferns, and conifers. The petrographic study showed the
prevalence in the section of volcano-sedimentary rocks. The Teete paleobiota
dwelled on the alluvial-lacustrine plain in conditions of warm humid climate
influenced by intense volcanic activity.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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/

"Life is the art of drawing
sufficient conclusions from
insufficient premises."
               -- Samuel Butler