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New Papers Wide Shut



Well, all the latest movies either have been used or have unusable titles,
so...


Chin, K., Hartman, J.H., and Roth, B. 2009. Opportunistic exploitation of
dinosaur dung: fossil snails in coprolites from the Upper Cretaceous Two
Medicine Formation of Montana. Lethaia 42(2):185-198. doi:
10.1111/j.1502-3931.2008.00131.x.

ABSTRACT: Multiple associations of fossil snails with dinosaur coprolites
demonstrate that snails and dinosaurs not only shared ancient habitats but
were trophically linked via dinosaur dung. Over 130 fossil snails
representing at least seven different taxa have been found on or within
herbivorous dinosaur coprolites from the Upper Cretaceous Two Medicine
Formation of Montana. The terrestrial snail Megomphix is the most common
taxon, but three other terrestrial taxa (Prograngerella, Hendersonia and
Polygyrella) and three aquatic snails (Lioplacodes, ?Viviparus and a physid)
also occur in coprolites. At least 46% of the shells in the faeces are whole
or nearly so, indicating that most (if not all) of the snails were not
ingested by dinosaurs, but were post-depositional visitors to the dung pats.
The sizeable, moist and microbially enriched dinosaur faeces would have
provided both food and roosting sites for the ancient snails, and the large
number of snail?coprolite associations reflect recurring, opportunistic
exploitation of dung.
     The terrestrial taxa in the coprolites suggest that this Late
Cretaceous locality included sufficiently moist detrital or vegetative cover
for snails when dinosaur dung was not present. The aquatic snails probably
entered the faeces during flood events. Dinosaur dung would have provided an
abundant but patchy influx of resources that was probably seasonally
available in the ancient environment.




Maidment, S.C.R., and Porro, L.B. 2009. Homology of the palpebral and origin
of supraorbital ossifications in ornithischian dinosaurs. Lethaia. doi:
10.1111/j.1502-3931.2009.00172.x.

ABSTRACT: The palpebral is a small ossification that projects across the
orbit in some ornithischian dinosaurs and its presence is considered a
synapomorphy of the clade. By contrast, other ornithischians lack the
palpebral but possess accessory ossifications, commonly termed
supraorbitals, which form the dorsal margin of the orbit. The homology of
the ornithischian palpebral to one or more of the supraorbitals is widely
accepted in the literature, but this homology has never been explicitly
tested and no hypotheses have been proposed regarding the function of the
palpebral or why it was incorporated into the orbital margin. As homology is
synonymous with synapomorphy, incorrect homology statements can lead to
incorrect hypotheses of relationships being obtained during cladistic
analysis. The primary and secondary homologies of the ornithischian
palpebral and the anterior supraorbital of more derived members of the major
ornithischian clades are tested and we demonstrate that these homology
hypotheses can be accepted. Osteological correlates indicate that the
palpebral supported a layer of connective tissue that roofed the orbit;
ossification of this connective tissue resulted in the incorporation of the
palpebral into the skull roof and gave rise to additional supraorbital
elements, which are neomorphic ossifications. Large-scale structural changes
in the ornithischian skull, including dermal ossifications associated with
display or defence and the development of complex feeding mechanisms, may
have led to the incorporation of the palpebral into the skull roof.




Nicolas, M., and Rubidge, B.S. 2009. Changes in Permo-Triassic terrestrial
tetrapod ecological representation in the Beaufort Group (Karoo Supergroup)
of South Africa. Lethaia. doi: 10.1111/j.1502-3931.2009.00171.x.

ABSTRACT: For more than a century, large collections of fossils from the
Beaufort Group have been built up at various museums in South Africa and
have been handled as separate databases in the individual museums. Because
of the unique time-extensive record of continental vertebrate biodiversity
represented by the fossils of the Beaufort Group, a single standardized
database has been compiled for the fossils collected from the Beaufort Group
housed in South African museums. This unique data set has enabled the
determination of terrestrial tetrapod ecological representation from the
Middle Permian to Middle Triassic Beaufort Group of South Africa.




Gates, T.A., and Farke, A.A. 2009. Biostratigraphic and biogeographic
implications of a hadrosaurid (Ornithopoda: Dinosauria) from the Upper
Cretaceous Almond Formation of Wyoming, USA. Cretaceous Research. doi:
10.1016/j.cretres.2009.05.001.

ABSTRACT: The results of Barnum Brown's 1937 expedition to the Almond
Formation of Wyoming consisted of two unidentified ceratopsian skulls and a
partial hadrosaurid specimen (AMNH 3651). The hadrosaurid is here attributed
to the Maastrichtian genus Saurolophus, verifying previous biostratigraphic
correlations of this formation using ammonite zones. Fossiliferous lower
Maastrichtian formations occurring latitudinally between those of Alberta,
Canada, and southwestern Texas, USA, such as the Almond Formation, are
essential for testing the effects and duration of apparent hadrosaurid
faunal segregation earlier in the Campanian, and indirectly aiding in the
placement of faunal boundaries that are currently unknown for the late
Campanian. The discovery of Saurolophus in Wyoming, a close relative of the
Campanian genus Prosaurolophus, affirms that the segregation of hadrosaurid
faunas established in the late Campanian (~75 Ma) continued for at least 3
million years. Combining occurrences of Saurolophus from Mongolia and the
Moreno Formation of California with those of Alberta, Canada, this genus
appears to have had one of the largest geographic ranges of any equivalent
clade of hadrosaurid dinosaur, although species level distributions are
still uncertain.




Zhang, H., Wei, Z.-L., Liu, X.-M., and Li, D. 2009. Constraints on the age
of the Tuchengzi Formation by LA-ICP-MS dating in northern Hebei-western
Liaoning, China. Science in China D 52(4):461-470. doi:
10.1007/s11430-009-0052-9.

ABSTRACT: Accurately determining the age of the Tuchengzi Formation has
direct influence on confirming the boundary between the Jurassic and the
Cretaceous systems in northern Hebei-western Liaoning, and on related
geological problems in China. However, the Tuchengzi Formation mainly
consists of sedimentary rocks, with a poor fossil record and especially lack
of index fossils. The Tuchengzi Formation is also lack of the type of
volcanic rocks that can provide an isotopic age. Therefore, the age of the
Tuchengzi Formation has been uncertain. Based on our systematic dating of
the tuff interbedded in the Tuchengzi Formation of Chengde and
Jinlingsi-Yangshan basins in northern Hebei-western Liaoning, combined with
the dating results of previous researchers, here we suggest that the age
range of the Tuchengzi Formation in northern Hebei-western Liaoning is from
147 Ma to 136 Ma. It implied that the Tuchengzi Formation was mainly formed
in the Early Cretaceous.




Moratalla, J.J., and Hernán, J. 2008. Los Cayos S y D: dos afloramientos con
icnitas de saurópodos, terópodos y ornitópodos en el Cretácico Inferior del
área de Los Cayos (Cornago, La Rioja, España). Estudios Geológicos
64(2):161-173. doi: 10.3989/egeol.08642.043.

ABSTRACT: Although most part of the Los Cayos area track-bearing layers have
yielded almost non-avian theropod footprints, Los Cayos S and D have
revealed the presence of fossil prints belonging to sauropods and
ornithopods respectively.
     Los Cayos S contains ten track-bearing layers, but the most significant
one shows a short sauropod trackway that, based on manus print morphology,
it is identified with the ichnogenus Titanosaurimanus. This trackway was
caused by a titanosaurid sauropod or at least by a titanosauriform. On the
contrary, Los Cayos D has yielded abundant footprints ?most of them
isolated? that have been produced by relatively big ornithopod dinosaurs. We
identify these tracks with the ichnogenus Iguanodontipus.
     The existence of both footprint morphotypes is very interesting for the
Los Cayos area due to it represents the presence of large herbivorous
dinosaurs in those Cretaceous ecosystems that produced the sediments of the
Enciso Group.




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

"It's no wonder that truth is stranger
than fiction. Fiction has to make
sense."
                          -- Mark Twain