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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
http://cactus.dixie.edu/jharris/
STORIES IN SIX WORDS OR LESS:
"Machine. Unexpectedly, I'd invented
a time"
-- Alan Moore
"Easy. Just touch the match to"
-- Ursula K. Le Guin
"Batman Sues Batsignal: Demands
Trademark Royalties."
-- Cory Doctorow