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New Papers Strikes Back



Some stuff for the sauropodophile in all of us...

Salgado, L., García, R.A., and Daza, J.D. 2006. Consideraciones sobre las láminas neurales de los dinosaurios saurópodos y su significado morfofunctional. Revista del Museo Argentino de Ciencias Naturales, n.s. 8(1):69-79.

González Riga, B.J., and Astini, R.A. 2007. Preservation of large titanosaur sauropods in overbank fluvial facies: a case study in the Cretaceous of Argentina. Journal of South American Earth Sciences 23(4):290-303. doi: 10.1016/j.jsames.2007.02.005.

ABSTRACT: Patagonia exhibits a particularly abundant record of Cretaceous dinosaurs with worldwide relevance. Although paleontological studies are relatively numerous, few include taphonomic information about these faunas. This contribution provides the first detailed sedimentological and taphonomical analyses of a dinosaur bone quarry from northern Neuquén Basin. At Arroyo Seco (Mendoza Province, Argentina), a large parautochthonous/autochthonous accumulation of articulated and disarticulated bones that represent several sauropod individuals has been discovered. The fossil remains, assigned to Mendozasaurus neguyelap González Riga, correspond to a large (18-27-m long) sauropod titanosaur collected in the strata of the Río Neuquén Subgroup (late Turoronian-late Coniacian). A taphonomic viewpoint recognizes a two-fold division into biostratinomic and fossil-diagenetic processes. Biostratinomic processes include (1) subaerial biodegradation of sauropod carcasses on well-drained floodplains, (2) partial or total skeletal disarticulation, (3) reorientation of bones by sporadic overbank flows, and (4) subaerial weathering. Fossil-diagenetic processes include (1) plastic deformation of bones, (2) initial permineralization with hematite, (3) fracturing and brittle deformation due to lithostatic pressure; (4) secondary permineralization with calcite in vascular canals and fractures, and (5) postfossilization bone weathering. This type of bone concentration, also present in Rincón de los Sauces (northern Patagonia), suggests that overbank facies tended to accumulate large titanosaur bones. This taphonomic mode, referred to as "overbank bone assemblages", outlines the potential of crevasse splay facies as important sources of paleontological data in Cretaceous meandering fluvial systems.


...and the theropodophile...

Maxwell, E.E., and Larsson, H.C.E. 2007. Osteology and myology of the wing of the emu (Dromaius novaehollandiae), and its bearing on the evolution of vestigial structures. Journal of Morphology 268(5):423-441. doi: 10.1002/jmor.10527.

ABSTRACT: Emus have reduced their wing skeleton to only a single functional digit, but the myological changes associated with this reduction have never been properly described. Moreover, the intraspecific variability associated with these changes has not previously been examined, dissections having been restricted in the past to only one or two individuals. In this paper, the myology and osteology of the emu wing is described for a sample of five female birds. The emu showed a marked reduction in the number of muscles in the wing, even compared with other ratites. Many wing muscles showed diversity in structure, origin and insertion sites, number of heads, as well as presence-absence variation. This variability dramatically exceeds that found in flying birds. Evolutionary theory predicts that relaxed selection on vestigial organs should allow more variation to persist in the population, and corresponds to what is observed here. A large amount of fluctuating asymmetry was also detected, indicating reduced canalization of the wing during development.


...and, lastly, the, uh, champsosaurophile.

Vandermark, D., Tarduno, J.A., and Brinkman, D.B. 2007. A fossil champsosaur population from the high Arctic: implications for Late Cretaceous paleotemperatures. Palaeogeography, Palaeoclimatology, Palaeoecology 248(1-2):49-59. doi: 10.1016/j.palaeo.2006.11.008.

ABSTRACT: During the Late Cretaceous, Axel Heiberg Island of the high Canadian Arctic supported a sizable population of champsosaurs, a basal archosauromorph, amongst a community including turtles and a variety of freshwater fishes. Here we report that a large portion of the available champsosaur fossil assemblage is comprised of elements from subadults. This dominance of subadults is similar to that seen from low latitude sites and suggests that the champsosaur population was a well-established facet of the ecological community. Because of the sensitivity of juveniles to ice formation, the make-up of the Arctic champsosaur population further indicates that the Late Cretaceous (Coniacian-Turonian) saw an interval of extreme warmth and low seasonality. The Coniacian-Turonian date makes these choristoderes amongst the earliest in North America, apart from the Jurassic Cteniogenys and a single limb bone from the mid-Cretaceous.


I've also finally managed to lay my hands on the book from the 2005 Heyuan Dinosaur Symposium, and for those interested, here's the contents in alphabetical order by author (I couldn't find that these had been posted previously except a few individual papers, so forgive me if this is redundant!):


Buffetaut, E., Suteethorn, V., and Tong, H. 2006. Dinosaur assemblages from Thailand: a comparison with Chinese faunas; pp. 19-37 in Lü, J., Kobayashi, Y., Huang, D., and Lee, Y.-N. (eds.), Papers from the 2005 Heyuan International Dinosaur Symposium. Geological Publishing House, Beijing.



Currie, P.J. 2006. The dinosaurs of Alberta; pp. 61-86 in Lü, J., Kobayashi, Y., Huang, D., and Lee, Y.-N. (eds.), Papers from the 2005 Heyuan International Dinosaur Symposium. Geological Publishing House, Beijing.



Dong, H. 2006. Brief introduction to vertebrate fossils from the Heyuan Basin, Guangdong Province; pp. 1-9 in Lü, J., Kobayashi, Y., Huang, D., and Lee, Y.-N. (eds.), Papers from the 2005 Heyuan International Dinosaur Symposium. Geological Publishing House, Beijing.



Godefroit, P. 2006. Latest Cretaceous hadrosaurid dinosaurs from Heilongjiang Province (P.R. China) and Amur region (far eastern Russia); pp. 103-114 in Lü, J., Kobayashi, Y., Huang, D., and Lee, Y.-N. (eds.), Papers from the 2005 Heyuan International Dinosaur Symposium. Geological Publishing House, Beijing.



Ji, S. 2006. Furculae of non-avian theropods and basal birds; pp. 115-128 in Lü, J., Kobayashi, Y., Huang, D., and Lee, Y.-N. (eds.), Papers from the 2005 Heyuan International Dinosaur Symposium. Geological Publishing House, Beijing.



Kobayashi, Y., Manabe, M., Ikegami, N., Tomida, Y., and Hayakawa, H. 2006. Dinosaurs from Japan; pp. 87-102 in Lü, J., Kobayashi, Y., Huang, D., and Lee, Y.-N. (eds.), Papers from the 2005 Heyuan International Dinosaur Symposium. Geological Publishing House, Beijing.



Lee, Y.-N., and Lee, H.-J. 2006. Hasandong vertebrate fossils in South Korea; pp. 129-139 in Lü, J., Kobayashi, Y., Huang, D., and Lee, Y.-N. (eds.), Papers from the 2005 Heyuan International Dinosaur Symposium. Geological Publishing House, Beijing.



Lü, J., Azuma, Y., Dong, H., Noda, Y., and Qiu, L. 2006a. New troodontid dinosaur eggs from the Heyuan Basin of Guangdong Province, southern China; pp. 11-18 in Lü, J., Kobayashi, Y., Huang, D., and Lee, Y.-N. (eds.), Papers from the 2005 Heyuan International Dinosaur Symposium. Geological Publishing House, Beijing.



Lü, J., Ji, S., Yuan, C., Gao, Y., Sun, Z., and Ji, Q. 2006b. New pterodactyloid pterosaur from the Lower Cretaceous Yixian Formation of western Liaoning; pp. 195-203 in Lü, J., Kobayashi, Y., Huang, D., and Lee, Y.-N. (eds.), Papers from the 2005 Heyuan International Dinosaur Symposium. Geological Publishing House, Beijing.



Polcyn, M.J., Jacobs, L.L., and Lü, J. 2006. Unraveling distortion: an overivew of techniques for reconstructing flattened fossils; pp. 205-215 in Lü, J., Kobayashi, Y., Huang, D., and Lee, Y.-N. (eds.), Papers from the 2005 Heyuan International Dinosaur Symposium. Geological Publishing House, Beijing.



Taylor, L.H., Jacobs, L.L., and Downs, W.R. 2006. A review of the Cretaceous-Paleogene boundary in the Nanxiong Basin; pp. 39-59 in Lü, J., Kobayashi, Y., Huang, D., and Lee, Y.-N. (eds.), Papers from the 2005 Heyuan International Dinosaur Symposium. Geological Publishing House, Beijing.



Tong, H., Claude, J., Buffetaut, E., Suteethorn, V., Naksri, W., and Chitsing, S. 2006. Fossil turtles of Thailand: an updated review; pp. 183-194 in Lü, J., Kobayashi, Y., Huang, D., and Lee, Y.-N. (eds.), Papers from the 2005 Heyuan International Dinosaur Symposium. Geological Publishing House, Beijing.



Winkler, D.A. 2006. Ornithopod dinosaurs from the Early Cretaceous Trinity Group, Texas, USA; pp. 169-181 in Lü, J., Kobayashi, Y., Huang, D., and Lee, Y.-N. (eds.), Papers from the 2005 Heyuan International Dinosaur Symposium. Geological Publishing House, Beijing.



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

"Trying to estimate the divergence times
of fungal, algal or prokaryotic groups on
the basis of a partial reptilian fossil and
protein sequences from mice and humans
is like trying to decipher Demotic Egyptian with
the help of an odometer and the Oxford
English Dictionary."
              -- D. Graur & W. Martin (_Trends
                  in Genetics_ 20[2], 2004)