Some recent (mainly non-dino) articles:
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Free pdf:
WANG Baopeng & LI Jianjun (2020)
Review of dinosaur footprints research in Shaanxi Province.
Mineral Exploration Â11(2): 403-410
http://www.kckc.org.cn/ch/reader/view_abstract.aspx?file_no=20200226&flag=1
Free pdf:
Shaanxi is the cradle of dinosaur footprints research in China. The earliest reported dinosaur footprint in China was discovered by Mr. Yang Zhongjian and Pierre Teilhard de Chardin in Shenmu, Shaanxi in 1929. In recent years,the discoveries of dinosaur tracks have been reported from Tongchuan, Shenmu, Shangluo, Zizhou and Zhongji. In addition, fish swimming trails and lizards tracks have been found in Hengxian and Zizhou County. Only a small number of dinosaur bone fossils have been found in Shangluo area in Shaanxi Province. Therefore, as a branch of dinosaur research,dinosaur footprint research can make up for the deficiency of dinosaur bone fossils. It is of great significance in studying the population distribution of dinosaurs and restoring the Mesozoic paleoenvironment and paleogeography of Shaanxi Province. The study of geological age of footprint-bearing strata in Shaanxi is weak and controversial,which is the focus of the next research.
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Free pdf:
Zhu Ning, Xu Yadong, Wu Rui, Han Fenglu, Huang Leqing & Tong Qianming (2020)
The Age and Sedimentary Environment of Late Cretaceous Dinosaur Fossils Layer in the Tianyuan Area of Zhuzhou City, Hunan Province.
Earth Science-Journal of China University of Geosciences 45(3): 752-763
doi: https://doi.org/10.3799/dqkx.2019.054
http://www.earth-science.net/cn/article/doi/10.3799/dqkx.2019.054
Free pdf:
New dinosaur fossils were found from the Late Cretaceous Daijiaping Formation in the Zhuzhou Basin recently. However, the age of the dinosaur fossil formation remains controvercial. Based on the analysis of palynological types and detrital zircon U-Pb data, the age and geological background of the dinosaur fossils from the Tianyuan area, Zhuzhou City, Hunan Province, are reported here. 18 species of 15 genera of the main palynomorphs could obtain a concurrent-range Aquilapollenites coriaceus-Betpakdalina pentaoculoides zone. Through comparison of the typical palynomorphs from the Daijiaping Formation,the age of the formation can be accurately defined as Campanian-Maastrichtian. A series of detrital zircon samples are collected and analyzed from the key layers of dinosaur fossils, and the detrital zircon U-Pb age peaks can be divided into six stages: 200-320 Ma, 390-450 Ma, 740-950 Ma, 1 020-1 100 Ma, 1 640-2 000 Ma and 2 440-2 600 Ma. On the basis of detrital zircon and paleogeography analysis, coarse sediments of the Daijiaping Formation were mainly from the southeastern surrounding mountains, whereas parts of the fine-grained debris came from the northwestern Huangling area.
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Worapong Singchat, Siwapech Sillapaprayoon, Narongrit Muangmai, Sudarath Baicharoen, Chantra Indananda, Prateep Duengkae, Surin Peyachoknagul, Rebecca E. O'Connor, Darren K. Griffin & Kornsorn Srikulnath (2020)
Do sex chromosomes of snakes, monitor lizards,and iguanian lizards result from multiple fission of an "ancestral amniote super-sex chromosome"?
Chromosome Research (advance online publication)
DOI: https://doi.org/10.1007/s10577-020-09631-4https://link.springer.com/article/10.1007/s10577-020-09631-4
Sex chromosomes in some amniotes share linkage homologies with distantly related taxa in regions orthologous to squamate reptile chromosome 2 (SR2) and the snake W sex chromosome. Thus, the SR2 and W chromosomes may formerly have been part of a larger ancestral amniote super-sex chromosome. Comparison of various sex chromosomal linkage homologies in Toxicofera with those in other amniotes offers an excellent model to assess key cytological differences, to understand the mechanisms of amniote sex chromosome evolution in each lineage and the existence of an ancestral amniote super-sex chromosome. Chromosome maps of four species of Toxicofera were constructed using bacterial artificial chromosomes (BACs) derived from chicken and zebrafinch libraries containing amniote sex chromosomal linkages. Different macrochromosome linkage homologies were highly conserved among Toxicofera, and at least two BACs (CH261-125F1 and CH261-40D6) showed partial homology with sex chromosomes of amniotes associated with SR2, which supports the hypothesis of an ancestral super-sex chromosome with overlaps of partial linkage homologies. The present data also suggest a possible multiple fission mechanism of an ancestral super-sex chromosome, which resulted in further development of various sex chromosomal linkages of Toxicofera based on particular properties that favored the role of sex chromosomes.Â
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Free pdf:
Paul M Hime, Alan R Lemmon, Emily C Moriarty Lemmon, Elizabeth Prendini, Jeremy M Brown, Robert C Thomson, Justin D Kratovil, Brice P Noonan, R Alexander Pyron, Pedro L V Peloso, Michelle L Kortyna, J Scott Keogh, Stephen C Donnellan, Rachel Lockridge Mueller, Christopher J Raxworthy, Krushnamegh Kunte, Santiago R Ron, Sandeep Das, Nikhil Gaitonde, David M Green, Jim Labisko, Jing Che & David W Weisrock (2020)
Phylogenomics Reveals Ancient Gene Tree Discordance in the Amphibian Tree of Life.
Systematic Biology, syaa034 (advance online publication)
doi: https://doi.org/10.1093/sysbio/syaa034
https://academic.oup.com/sysbio/advance-article/doi/10.1093/sysbio/syaa034/5828236
Phylogenomics Reveals Ancient Gene Tree Discordance in the Amphibian Tree of Life.
Systematic Biology, syaa034 (advance online publication)
doi: https://doi.org/10.1093/sysbio/syaa034
https://academic.oup.com/sysbio/advance-article/doi/10.1093/sysbio/syaa034/5828236
Molecular phylogenies have yielded strong support for many parts of the amphibian Tree of Life, but poor support for the resolution of deeper nodes, including relationships among families and orders. To clarify these relationships, we provide a phylogenomic perspective on amphibian relationships by developing a taxon-specific Anchored Hybrid Enrichment protocol targeting hundreds of conserved exons which are effective across the class. After obtaining data from 220 loci for 286 species (representing 94% of the families and 44% of the genera), we estimate a phylogeny for extant amphibians and identify gene tree-species tree conflict across the deepest branches of the amphibian phylogeny. We perform locus-by-locus genealogical interrogation of alternative topological hypotheses for amphibian monophyly, focusing on interordinal relationships. We find that phylogenetic signal deep in the amphibian phylogeny varies greatly across loci in a manner that is consistent with incomplete lineage sorting in the ancestral lineage of extant amphibians. Our results overwhelmingly support amphibian monophyly and a sister relationship between frogs and salamanders, consistent with the Batrachia hypothesis. Species tree analyses converge on a small set of topological hypotheses for the relationships among extant amphibian families. These results clarify several contentious portions of the amphibian Tree of Life, which in conjunction with a set of vetted fossil calibrations, support a surprisingly younger timescale for crown and ordinal amphibian diversification than previously reported. More broadly, our study provides insight into the sources, magnitudes, and heterogeneity of support across loci in phylogenomic data sets.
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Victoria E. McCoy, Jasmina Wiemann, James C. Lamsdell, Christopher D. Whalen, Scott Lidgard, Paul Mayer, Holger Petermann & Derek E. G. Briggs (2020)
Chemical signatures of soft tissues distinguish between vertebrates and invertebrates from the Carboniferous Mazon Creek LagerstÃtte of Illinois.
Gebiology (advance online publication)
doi: https://doi.org/10.1111/gbi.12397
https://onlinelibrary.wiley.com/doi/10.1111/gbi.12397
The chemical composition of fossil soft tissues is a potentially powerful and yet underutilized tool for elucidating the affinity of problematic fossil organisms. In some cases, it has proven difficult to assign a problematic fossil even to the invertebrates or vertebrates (more generally chordates) based on often incompletely preserved morphology alone, and chemical composition may help to resolve such questions. Here, we use in situ Raman microspectroscopy to investigate the chemistry of a diverse array of invertebrate and vertebrate fossils from the Pennsylvanian Mazon Creek LagerstÃtte of Illinois, and we generate a ChemoSpace through principal component analysis (PCA) of the in situ Raman spectra. Invertebrate soft tissues characterized by chitin (polysaccharide) fossilization products and vertebrate soft tissues characterized by protein fossilization products plot in completely separate, nonâoverlapping regions of the ChemoSpace, demonstrating the utility of certain soft tissue molecular signatures as biomarkers for the original soft tissue composition of fossil organisms. The controversial problematicum Tullimonstrum, known as the Tully Monster, groups with the vertebrates, providing strong evidence of a vertebrate rather than invertebrate affinity.
Chemical signatures of soft tissues distinguish between vertebrates and invertebrates from the Carboniferous Mazon Creek LagerstÃtte of Illinois.
Gebiology (advance online publication)
doi: https://doi.org/10.1111/gbi.12397
https://onlinelibrary.wiley.com/doi/10.1111/gbi.12397
The chemical composition of fossil soft tissues is a potentially powerful and yet underutilized tool for elucidating the affinity of problematic fossil organisms. In some cases, it has proven difficult to assign a problematic fossil even to the invertebrates or vertebrates (more generally chordates) based on often incompletely preserved morphology alone, and chemical composition may help to resolve such questions. Here, we use in situ Raman microspectroscopy to investigate the chemistry of a diverse array of invertebrate and vertebrate fossils from the Pennsylvanian Mazon Creek LagerstÃtte of Illinois, and we generate a ChemoSpace through principal component analysis (PCA) of the in situ Raman spectra. Invertebrate soft tissues characterized by chitin (polysaccharide) fossilization products and vertebrate soft tissues characterized by protein fossilization products plot in completely separate, nonâoverlapping regions of the ChemoSpace, demonstrating the utility of certain soft tissue molecular signatures as biomarkers for the original soft tissue composition of fossil organisms. The controversial problematicum Tullimonstrum, known as the Tully Monster, groups with the vertebrates, providing strong evidence of a vertebrate rather than invertebrate affinity.