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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
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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
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