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[dinosaur] Early Jurassic sauropods of Thailand + Pu’an dinosaur find + Diictodon skull neutron scan + Chicxulub peak rings





Ben Creisler
bcreisler@gmail.com


Some recent papers with free pdfs:


Contents for new issue of Acta Geologica Sinica 91(4)  (English edition) at free pdf link


http://www.geojournals.cn/dzxben/ch/reader/issue_list.aspx?year_id=2017&quarter_id=4


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For now, I'll post this ref as-is. Unfortunately, there is currently some seriously technical issue with the link and the website. I have been unable to download the free pdf (only the last page seems to work) and so I do not have the abstract for now.

 

LAOJUMPON Chalida,SUTEETHORN Varavudh,CHANTHASIT Phornphen,LAUPRASERT Komsorn & SUTEETHORN Suravech (2017).

New Evidence of Sauropod Dinosaurs from the Early Jurassic Period of Thailand.

Acta Geologica Sinica 91(4): 1169-1178

http://www.geojournals.cn/dzxben/ch/reader/view_abstract.aspx?file_no=2017endzxb04001&flag=1



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This short item from the same issue works, however:


HAO Ziguo,FEI Hongcai,HAO Qingqing & LIU Lian (2017)

A Large Dinosaur Assemblage has been Discovered in Pu’an, Yunyang County, Chongqing, China.

Acta Geologica Sinica 91(4): 1487-1488 (English edition)

http://www.geojournals.cn/dzxben/ch/reader/view_abstract.aspx?file_no=2017endzxb04025&flag=1


pdf:


http://www.geojournals.cn/dzxben/ch/reader/create_pdf.aspx?file_no=2017endzxb04025&flag=1&journal_id=dzxben&year_id=2017



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Michael Laaß, Burkhard Schillinger & Ingmar Werneburg (2017)

Neutron Tomography and X-ray Tomography as Tools for the Morphological Investigation of Non-mammalian Synapsids.

Physics Procedia 88: 100-108

https://doi.org/10.1016/j.phpro.2017.06.013

http://www.sciencedirect.com/science/article/pii/S1875389217300639




As having evolved on the stem line of mammals, the taxonomy and phylogeny of therapsids (Synapsida) are of special interest with respect to early mammalian evolution. Due to the fact that in most cases soft tissue of fossil vertebrates is not preserved, species can only be distinguished by diagnosis of morphological features of the skeleton. Moreover, investigations of vertebrate fossils are often obstructed, because internal cranial anatomy is usually hidden and parts of the fossils may be embedded in stone matrix. As a consequence, most species of non-mammalian synapsids were only defined on the basis of external skeletal features. Our investigations on Diictodon skulls (Therapsida, Anomodontia) show that non-destructive methods are very useful to clearly distinguish fossil species. We, therefore, propose using modern non-destructive techniques such as neutron tomography, synchrotron tomography, and micro-computed tomography (μCT) as standard tools for the investigation and virtual reconstruction of fossils and to include features of the internal cranial anatomy into morphological descriptions and phylogenetic analyses of fossil vertebrates.


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Chen Chen & Wei-dong Sun (2017) 

Tracing the origin of peak rings at Chicxulub.

Solid Earth Sciences (advance online publication)

https://doi.org/10.1016/j.sesci.2017.08.001

http://www.sciencedirect.com/science/article/pii/S2451912X17300454


Large impacts play an important role in planetary and biologic evolutions. For example, the Moon may have been formed through massive comet impacts on Earth (Taylor, 2016 ;  Sun, 2016). The large impacts are also responsible for modifying planetary surfaces (Morgan et al., 2016) and can even cause mass extinctions (Alvarez et al., 1980). However, it remains unclear how materials were transported during large impacts and how powerful the catastrophic crashes were.


The Chicxulub impactor is well-known for the potential association with the mass extinction of dinosaurs and about three-quarters of genera on Earth (Schulte et al., 2010), in which the Deccan eruptions may have took an effect to a certain extent. Because of the similar period of the disasters and weak constraints on both climate effects, it is difficult to answer who is/are the dinosaurs' true killer (s) — impact, volcanism or both (Renne et al., 2015). In addition, the crater at Chicxulub is the only terrestrial one with an unequivocal and intact peak ring, a rugged ring of rocky hills within the bowl-shaped crater (Fig. 1). Nevertheless, the origins of the peak rings are still debated. Some studies attribute to the collapse of over-heightened central peaks (Murray, 1980 ;  Alexopoulos and McKinnon, 1994), namely dynamic collapse model. According to this scenario, the peak-ring rocks are derived from the deep crystalline basement. Alternatively, the nested melt-cavity hypothesis argues that the ring have a less deep origin, forming from near-surface materials (Baker et al., 2016 ;  Head, 2010). Therefore, getting hold of the rocks inside the Chicxulub crater can offer the critical evidence to validate the origin of peak rings.






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