[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

[dinosaur] Dockum Triassic archosauromorph fragments + Yanliao Biota + coprolites + more




Ben Creisler
bcreisler@gmail.com


Some recent and not so recent papers:



Volkan Sarıgül (2017)
New archosauromorph fragments from the Dockum Group of Texas and assessment of the earliest dinosaurs in North America.
Historical Biology (advance online publication)
doi:  http://dx.doi.org/10.1080/08912963.2017.1333609   
http://www.tandfonline.com/doi/full/10.1080/08912963.2017.1333609




Three small and gracile jaw fragments are recovered from the Boren Quarry, one of the lowest fossil quarries of the Upper Triassic Dockum Group of Texas. The specimens are referred to archosauromorphs, where the morphology of the dentary and teeth of two specimens resemble what is observed in basal saurischians. Growing numbers of early dinosaur fossils from the lowest quarries of the Dockum Group of Texas which correspond to the lowermost Norian raises doubts concerning early dinosaur dispersal during the late Carnian-early Norian interval and the first occurrence of North American dinosaurs which might have happened earlier than previously suggested.



===




A number of articles in Chinese not yet mentioned. Some have free pdfs.


GAO Fuliang, JIANG Yang, ZHANG Guoren, PAN Yuqi, WU Zijie & WANG Xuan (2017)

Location and New Found of Yanliao Biota in Western Liaoning.

Geological Review 63(3): 770-780

doi:10.16509/j.georeview.2017.03.01

http://www.geojournals.cn/georev/ch/reader/view_abstract.aspx?file_no=20176303016&flag=1

 

free pdf download:

http://www.geojournals.cn/georev/ch/reader/create_pdf.aspx?file_no=20176303016&flag=1&journal_id=georev&year_id=2017

 

Abstract:


Objectives: Western Liaoning Province in our country has been an important producer of Mesozoic fossils, a large number of rare animal and plant fossils was found and had a significant impact in recent years, but the layers of fossils remains unclear, this time we are going to solve this problem.


Methods: In the past three years, the author carry out an investigation in detail for a sedimentary rock between two other volcanic rocks in Jianchang, Lingyuan, Chaoyang, Jianping of western Liaoning. First of all, according to the exposed of Tiaojishan formation, we set the main section in Daxishan Linglongta Jianchang, which located in Jinlingsi—Yangshan Basin, Moreover we measured assisted sections in Dapingfang—Meileyingzi basin and Lingyuan—Sanshijiazi basin; at the same time we excavate fossils layer by layer, in order to determine the stratigraphic horizons which has fossils; after that we researched the fossils we collecting and collected the informations of fossils in western Liaoning; at last we put fossils on the correct fossil bed and comparing fossil beds in different basin. The main methods of this investigation is sectional measurement and fossil collection systematic.


Result: Through out the sectional measurement and fossil collection, we determining a part of fossil beds of the Tiaojishan Formation Middle Jurassic, belonging middle of theYanliao Biota. In order to compare with fossil beds in other basins, we named two fossil beds——Daxishan fossil bed and Guancaishan fossil bed, corresponded fossil with stratigraphic horizons, and completed comparison of fossil beds in different basin; at the same time we excavated anumber of precious fossils.


Conclusions: By the investigation this time, we determining a series of middle Jurassic fossil beds in western Liaoning and collecting many fossils enrich the Yanliao Biota and provide informations for studying and researching for future.


===


JI Qiang (2017)

On the Cretaceous stratigraphic framework and the Cretaceous-Paleogene boundary of Eastern Shandong Province.

Journal of Geology 41(1):

doi: 10.3969/j.issn.1674-3636.2017.01.1

http://www.journalofgeology1977.com/ch/reader/view_abstract.aspx?file_no=20170101&flag=1



Eastern Shandong is a typical region for studying Late Cretaceous and Early Paleogene strata in China. Dating back to 1920s, the research has accumulated a large amount of data on the division and correlation of Cretaceous and Paleogene strata. The present study introduces the stratigraphic sequence of the Cretaceous Paleogene boundary sediments revealed in the borehole I of Shandong Cretaceous Scientific Drilling near the west suburb of Jiaozhou City. The borehole core shows that the Cretaceous-Paleogene boundary sediments can be divided into 3 formations (in ascending order): the Hongtuya Formation, the Shijiatun Formation, and the Jiaozhou Formation. The Hongtuya Formation is redefined herein, comprising a set of red pluvial and alluvial clastic sediments with rich dinosaurs between the underlying Xingezhuang Formation and the overlying Shijiatun Formation. The new definition shows the Hongtuya Formation objectively has comprised the sediments of the Jingangkou Formation. The Shijiatun Formation is a new litho-unit upgraded from the Shijiatun Member, which was originally considered as a basalt member of the Hongtuya Formation. The Shijiatun Formation, in fact, represents the uppermost part of the Wangshi Group, which is composed of volcano-sedimentary strata of more than 970 m in thickness and contacted conformably with both the underlying Hongtuya Formation and the overlying Jiaozhou Formation. The Jiaozhou Formation is mainly composed of purple red siltstones, intercalated with grayish green, yellowish green siltstones and marls, as well as rare sandstones and conglomerates. It is in conformable contact with the underlying Shijiatun Formation of the Wangshi Group, but its relationship with the overlying litho unit is unclear. Besides, this paper extensively discusses the stratigraphic division and comparison, the stratigraphic distribution of dinosaurs, geological events, paleoclimate and paleoenvironment of the Late Cretaceous in Eastern Shandong. It is proposed that this region experienced a series of events in the Cretaceous-Paleogene period: thriving, decline and disappearance of dinosaurs, fiercely volcanic eruption, extraterrestrial impact (?), forest fires, mass extinction by the end of Cretaceous, and bio-recovery at the beginning of Paleogene. The present study reveals that : (1) It is appropriate to place the Cretaceous Paleogene boundary in the interval between Bed 172 and Bed 148 of the Jiaozhou Formation in Eastern Shandong; (2) The mass extinction event by the end of Cretaceous may be closely related to extraterrestrial impacts, but non avian dinosaur extinction may be not related to those impacts; (3) Non-avian dinosaurs were extinct before extraterrestrial impacts by the end of Cretaceous worldwide, and there is no evidence that their extinction is directly related to the impacts; (4) A series of geological events in Late Cretaceous caused the changes of climate, environment and ecological system and worsened them gradually. Terrestrial creatures gradually lost their original living homeland, their diversity and numbers gradually declined, and they eventually disappeared. Non-avian dinosaurs suffered the same fate, and their disappearance could be caused by multiple events, rather than a single event.



==
Free pdfs of short articles

JI Shuan,LU Liwu,ZHANG Lifu,YUAN Chongxi,JIANG Shan,CHEN Xiaoyun,HOU Yandong (2017)

Recent progress in the study of the Early Cretaceous dinosaur fauna from the Ordos region, Inner Mongolia.

Geology in China 44(1): 196-197

http://geochina.cgs.gov.cn/ch/reader/create_pdf.aspx?file_no=20170117&flag=1&year_id=2017&quarter_id=1


**



XU Shichao,XU Huan,WANG Suozhu,YI Jian,XUE Peilin,JIA Lei (2017)

The first discovery of sauropod dinosaur tracks from the Jurassic strata in Shanxi Province]. 

Geology in China 44(1): 192-193.

http://geochina.cgs.gov.cn/ch/reader/create_pdf.aspx?file_no=20170115&flag=1&year_id=2017&quarter_id=1



==


Fábio Antônio de Oliveira & Rodrigo Miloni Santucci (2017)

Criteria for recognition and taphonomy of coprolites from the Serra da Galga Member, Marília Formation (Upper Cretaceous), Minas Gerais, Brazil.

Journal of South American Earth Sciences (advance online publication)

doi: https://doi.org/10.1016/j.jsames.2017.05.012

http://www.sciencedirect.com/science/article/pii/S0895981116303121


Highlights


The fecal masses were produced by different vertebrate types.

The coprolites underwent temporal and spatial-mixing.

Samples are mostly considered allochthonous due the presence of wear/pebble marks.


Abstract


The Cretaceous sedimentary rocks from Uberaba, Minas Gerais, have provided a rich vertebrate fauna unearthed from rocks of the Serra da Galga Member, Marília Formation, Bauru Group, of Maastrichtian age. Together with these fossils, a large number of coprolites have also been found from two main localities, here called the Peirópolis and Serra da Galga sites. During field trips carried out in the last few years, 340 samples have been collected, prepared, and analyzed in laboratory. By using parameters such as weight, density, mineralogical composition, and content, we identified 199 coprolites and 141 inorganic nodules (pseudocoprolites). The coprolites have been divided into four morphotypes, which suggest their producers varied in feeding strategies and size. The taphonomic study, based on morphological characters such as wear, presence of pebbles or pebble marks, and desiccation cracks, suggests they underwent temporal and spatial-mixing, and that the material from the Peirópolis Site were transported essentially by alluvial processes (alluvial fans), whereas the material from the Serra da Galga Site were reworked mainly by fluvial streams. The same taphonomic processes may well have affected other fossils from these sites, which are highly abundant in the rocks of this area. Because of that, this taphonomic aspect becomes an important parameter to be taken into account in future studies on the biota of the region.

 

===


Martin Qvarnström, Grzegorz Niedźwiedzki, Paul Tafforeau, Živil Žigaitė & Per E. Ahlberg (2017)

Synchrotron phase-contrast microtomography of coprolites generates novel palaeobiological data

Scientific Reports 7, Article number: 2723 (2017)

doi:10.1038/s41598-017-02893-9

https://www.nature.com/articles/s41598-017-02893-9


 

Coprolites (fossil faeces) reveal clues to ancient trophic relations, and contain inclusions representing organisms that are rarely preserved elsewhere. However, much information is lost by classical techniques of investigation, which cannot find and image the inclusions in an adequate manner. We demonstrate that propagation phase-contrast synchrotron microtomography (PPC-SRμCT) permits high-quality virtual 3D-reconstruction of coprolite inclusions, exemplified by two coprolites from the Upper Triassic locality Krasiejów, Poland; one of the coprolites contains delicate beetle remains, and the other one a partly articulated fish and fragments of bivalves.