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Bridget Jones' New Papers

Hi All -

   A few new tidbits:

Canudo, J.I., Barco, J.L., Pereda-Suberbiola, X., Ruiz-Omeñaca, J.I., and Salgado, L. 2007. On the Iberian dinosaurs said to exist bridge between Gondwana and Laurasia in the Lower Cretaceous. Poster presentation, First International Paleobiogeography Symposium, July 10-13. http://www.aragosaurus.com/secciones/publicaciones/panel/artic/Canudo_etal2007Paris.pdf.

Ipas, J., Aurell, M., Bádenas, B., Canudo, J.I., Liesa, C., Mas, J.R., and Soria, A.R. 2007. Caracterización de la Formación Villar del Arzobispo al sur de Zaragoza (Titónico, Cordillera Ibérica). Geogaceta 41:111-114.

ABSTRACT: The Villar del Arzobispo Formation (middle Tithonian-lowermost Berriasian) has been recognized for the first time in the two classical outcrops of Villanueva de Huerva and Aguilón (Zaragoza, nor thern Iberian Chain). It consists of a 40-70 m thick detritial succession, with scarce carbonate levels (ooidal and skeletal packstone with echinoderms, miliolids and other marine fossils). In previous works, this uppermost Jurassic unit was considered to form the lower part of the Villanueva de Huerva Formation (late Valanginian-Hauterivian). However, a low-angle angular unconformity between the Villar del Arzobispo and Villanueva de Huerva formations is described here. The new interpretation gives an explanation to the occasional marine influence observed in the nearby Cameros basin (i.e., Matute Formation, middle-upper Tithonian).

Dzemski, G., and Christian, A. 2007. Flexibility along the neck of the ostrich (Struthio camelus) and consequences for the reconstruction of dinosaurs with extreme neck length. Journal of Morphology 268(8):701-714. doi: 10.1002/jmor.10542.

ABSTRACT: The gross morphology and the flexibility along the neck of the ostrich (Struthio camelus) were examined using fresh tissue as well as neck skeletons. The results of the morphologic studies were compared with results from observations of living ostriches. The investigation was focused on differences in the morphology and the function between different sections of the neck. Additionally, the function of major dorsal neck ligaments was examined, including measurements of force-strain-relations. Comparative studies of giraffes (Giraffa camelopardalis) and camels (Camelus bactrianus) were conducted to find relations between the flexibility along the neck and the general feeding strategy. The examinations revealed that the neck of the ostrich can be divided into four sections with different functions. The first is the atlas-axis-complex which is responsible for torsion. The adjacent cranial section of the neck is flexible in dorsoventral and lateral directions but this part of the neck is usually kept straight at rest and during feeding. Dorsoventral flexibility is highest in the middle section of the neck, whereas the base of the neck is primarily used for lateral excursions of the neck. For giraffes and camels, the posture and utilization of the neck are also reflected in the flexibility of the neck. For all three species, it is possible to reconstruct the pattern of flexibility of the neck by using the neck skeletons alone. Therefore, it appears reasonable to reconstruct the neck utilization and the feeding strategies of dinosaurs with long necks by deriving the flexibility of the neck from preserved vertebrae. For Diplodocus carnegii the neck posture and the feeding strategy were reconstructed. Two neck regions, one around the 9th neck vertebra and the second at the base of the neck, indicate that Diplodocus, like the ostrich, adopted different neck postures. The neck was probably kept very low during feeding. During interruptions of the feeding, e.g., in an alert, the head could have been lifted in an economic way by raising the cranial section of the neck. During standing and locomotion the head was probably located well above the shoulders.

Not dinosaurs, but perhaps of interest to some...certainly, this is the kind of cool thing that can be proffered as a good example of how paleontological and evolutionary thinking can be really beneficial to all kinds of sciences applicable to humans; dunno why there hasn't been press coverage of this (of course, if it were, it'd probably have all kinds of god-awful titles like "Cancer caused by having cells," which would be followed by all sorts of moronic attempts to have cells banned...):

Saul, J.M. and Schwartz, L. 2007. Cancer as a consequence of the rising level of oxygen in the Late Precambrian. Lethaia 40(3): 211-220.

ABSTRACT: The origin of multicelled animal life required collagen-family molecules whose own formation depended on the availability of molecular oxygen. Cancers, by contrast, are characterized by their low use of oxygen. In discussing the relationship between the origin of multicelled life and the origin of cancer, it is useful to think in terms of tissues rather than individual cells or complete animals. When animal tissues are disturbed, their constituent cells may be partially released from the constraints of multicellularity. This permits or obliges cells to reactivate anaerobic metabolic ways used by their single-celled ancestors in the oxygen-deficient Precambrian seas. Inhibition or loss of cell respiration under such circumstances may cause reversion to glycolytic fermentation, a less efficient metabolic style that generates waste products that are retained, thereby producing excess cell-growth. Distortion of tissue architecture may ensue with impairment of cell-to-cell adhesion, thereby liberating individual cells. Cells freed from tissue constraints undergo Darwinian variation which leads to loss of differentiation and produces cell types that are incompatible with the normal functioning of tissues. These steps, which may manifest themselves as carcinogenesis, are not reversible by restoration of oxygen and in effect constitute a demergence from the metazoan state. The existence of cancer among diverse phyla and especially among domesticated animals, suggests that the risk of cancer may be an initial condition of complex multicellular life and that it remains preferentially associated with newly modified designs. If so, there would be therapeutic strategies that have not yet been adequately considered.

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


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