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Re: Law Abiding New Papers
For the Tatankacephalus paper:
ABSTRACT: A cranium and other associated skeletal elements representing a
new ankylosaurid dinosaur, Tatankacephalus cooneyorum gen. et sp. nov.
possess several diagnostic features that indicate that this new taxon
differs from the only other known ankylosaur from the Cloverly Formation,
Sauropelta edwardsorum. These features include a frontoparietal dome, an
enlarged nuchal ridge that obscures the occipital region, a circular orbit,
ventral curvature in the posterolaterally directed paroccipital processes, a
posteroventrally directed foramen magnum, and a number of features on the
braincase. The phylogenetic analysis positions Tatankacephalus with
Ankylosauridae based on its sharing of several characters with other members
of this clade, including an enlarged nuchal segment that obscures the
occiput in dorsal view, a ventrally curving lateral profile of the cranium
anterior to the orbit, pyramidal postorbital boss, laterally projecting
pyramidal quadratojugal boss, the presence of a postocular shelf, the
presence of paranasal sinuses, and the lack of a cingulum on a maxillary (or
dentary) tooth. It is considered a basal member of Ankylosauridae because it
retains premaxillary teeth and a visible lateral temporal fenestra, in
contrast to the absence of premaxillary teeth and an obscured lateral
temporal fenestra in younger members of this clade.
(Typed, rather than a copy and paste job, so hopefully no typos!)
Regards,
Rob Taylor
----- Original Message -----
From: "Harris, Jerald" <jharris@dixie.edu>
To: <dinosaur@usc.edu>
Sent: Friday, October 23, 2009 12:04 AM
Subject: Law Abiding New Papers
Peters, W.S., and Peters, D.S. 2009. Life history, sexual dimorphism and
'ornamental' feathers in the Mesozoic bird Confuciusornis sanctus. Biology
Letters. doi: 10.1098/rsbl.2009.0574.
ABSTRACT: The life history of Confuciusornis sanctus is controversial.
Recently, the species’ body size spectrum was claimed to contradict
osteohistological evidence for a rapid, bird-like development. Moreover,
sexual size dimorphism was rejected as an explanation for the observed
bimodal size distribution since the presence of elongated rectrices, an
assumed ‘male’ trait, was uncorrelated with size. However, this
interpretation (i) fails to explain the size spectrum of C. sanctus which
is trimodal rather than bimodal, (ii) requires implausible neonate masses
and (iii) is not supported by analogy with sexual dimorphisms in modern
birds, in which elongated central rectrices are mostly sex-independent.
Available information on C. sanctus is readily reconciled if we assume a
bird-like life history, as well as a pronounced sexual size dimorphism and
sexually isomorphic extravagant feathers as frequently observed in extant
species.
Knoll, F. 2009. On the name Stormbergia dangershoeki Butler. Annales de
Paléontologie. doi: 10.1016/j.annpal.2009.09.001.
ABSTRACT: Imperfection in the formation of the name Stormbergia
dangershoeki Butler is taken as an example so as to warn future taxon
authors to repeat it.
Prevosti, F.J., and Chemisquy, M.A. 2009. The impact of missing data on
real morphological phylogenies: influence of the number and distribution
of missing entries. Cladistics. doi: 10.1111/j.1096-0031.2009.00289.x.
ABSTRACT: Here we explore the effect of missing data in phylogenetic
analyses using a large number of real morphological matrices. Different
percentages and patterns of missing entries were added to each matrix, and
their influence was evaluated by comparing the accuracy and error of most
parsimonious trees. The relationships between accuracy and error and
different parameters (e.g. the number of taxa and characters, homoplasy,
support) were also evaluated. Our findings, based on real matrices, agree
with the simulation studies, i.e. the negative effect increases with the
percentage of missing entries, and decreases with the addition of more
characters. This indicates that the main problem is the lack of
information, not just the presence of missing data per se. Accuracy varies
with different distribution patterns of missing entries; the worst case is
when missing data are concentrated in a few taxa, while the best is when
the missing entries are restricted to just a few characters. The results
expand our knowledge of the missing data problem, corroborate many of the
findings previously published using simulations, and could be useful for
empirical or theoretical studies.
Csiki, Z., Grigorescu, D., Codrea, V., and Therrien, F. 2009. Taphonomic
modes in the Maastrichtian continental deposits of the Haţeg Basin,
Romania – palaeoecological and palaeobiological inferences.
Palaeogeography, Palaeoclimatology, Palaeoecology. doi:
10.1016/j.palaeo.2009.10.013.
ABSTRACT: The uppermost Cretaceous continental deposits of the Haţeg Basin
(SW Romania) have yielded a high-diversity vertebrate assemblage,
including the "dwarf" insular dinosaurs of Nopcsa. In 1902, Franz Nopcsa
was the first to comment on the preservation patterns of vertebrate
fossils, suggesting that the most important fossil accumulations, which he
simply referred to as "fossiliferous pockets", were the result of the
predatory activity of crocodilians ("crocodilian feeding grounds"). Recent
investigations of the fossil occurrences within the Haţeg Basin revealed a
much wider range of taphonomic modes, from microfossil bonebeds to
isolated, partially- articulated skeletons, than previously believed. The
survey of the vertebrate accumulation types and their sedimentary context
documents a wide range of processes responsible for their genesis,
operating within a fluvial-dominated upland setting. Study of the
individual fossil accumulations yields important informations on the
palaeoecology (composition of local biocenoses, trophic interactions) and
palaeobiology (social behaviour, habitat preferences) of the Haţeg fossil
assemblage.
Castle, J.W., and Rodgers, J.H., Jr. 2009. Hypothesis for the role of
toxin-producing algae in Phanerozoic mass extinctions based on evidence
from the geologic record and modern environments. Environmental
Geosciences 16(1):1-23. doi: 10.1306/eg.08110808003.
ABSTRACT: Mass mortalities of invertebrates, fish, birds, and mammals
caused by algal-produced toxins are occurring in modern environments. In
addition to direct effects of these toxins, the large mass of organic
material produced by algal blooms can lead to oxygen depletion during
decay, which indirectly causes death of some biota. Toxin-producing algae
occupy a wide range of modern marine, brackish, and freshwater
environments. Their growth is favored by warm water temperatures,
increased inorganic carbon concentrations (e.g., CO2), and abundant
nutrient supplies in aquatic environments. Cyanobacteria (blue-green
algae) are responsible for most of the disease and death caused by algal
toxicity today.
Based on characteristics and occurrences of algae in modern aquatic
environments and on observations from the fossil record, we propose that
toxin-producing algae were present in the geologic past and were an
important factor in Phanerozoic mass extinctions. The geologic record
demonstrates a pronounced increase in abundance and environmental range of
algae, including stromatolitic cyanobacterial mats, coincident with major
Phanerozoic mass extinctions. During these past events of algal expansion,
population decline of metazoan taxa could have been caused by effects of
algal blooms, including algal-produced toxins, at a scale sufficient to
generate a fossil record of mass extinction. Environmental changes such as
climatic warming, sea level fluctuation, and increased nutrient supply may
have promoted algal blooms over vast expanses of marine to freshwater
environments. From the increasing frequency of modern, toxin-producing
algal blooms, which may be related to global warming, another massive
biotic crisis could be forthcoming.
Parsons, W.L., and Parsons, K.M. 2009. A new ankylosaur (Dinosauria:
Ankylosauria) from the Lower Cretaceous Cloverly Formation of central
Montana. Canadian Journal of Earth Sciences 46(10):721-738. doi:
10.1139/E09-045.
(Sorry -- couldn't grab the abstract for this because CJES is a bit
slow updating their web site, but it introduces the basal ankylosaurid
_Tatankacephalus cooneyorum_ -- "tatanka" is Oglala for "bison.")
Parsons, W.L., and Parsons, K.M. 2009. Further descriptions of the
osteology of Deinonychus antirrhopus (Saurischia, Theropoda). Bulletin of
the Buffalo Society of Natural Sciences 38:43-54.
ABSTRACT: Developmental and/or functional implications are described for
aspects of Deinonychus antirrhopus scapula, pedal, and long bone
morphology. Differences in claw curvature are identified as indicators of
juvenile development, and the presence of periosteal rest lines as
evidence for determinate growth is confirmed. The asymmetric ventral keel
morphology that is characteristic of certain tree-climbing birds is also
documented for the penultimate phalanx of the second pedal digit. The
lateral orientation of the scapula glenoid and the presence of a
scapulohumeral ligament would allow the forelimb an arc of movement that
would reach angles extensively above and below the horizontal plane. Like
Archaeopteryx, Deinonychus has a robust deltopectoral crest anchoring a
robust pectoralis muscle. Proximal lateral flanges are present on the
first phalanx of second manual digit. These features provide additional
evidence concerning the behavioral morphology of Deinonychus and some
other members of Dromaeosauridae.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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/
"Education is the only thing people
shell out a lot of money for...and
then do everything possible to avoid
getting their money's worth."
-- unknown