Volume 61,Issue 1,2022 Table of Contents

1 Discovery of early proasaphiscid trilobites in Tangshan area, North China, and revision of some genera and species

GAO Jian , YUAN Jin-liang , WANG Ping-li

2022, 61(1):1-19. DOI: DOI:10.19800/j.cnki.aps.2020020 CSTR:

[Abstract](371) [HTML](0) [PDF 5.94 M](1855)

Abstract:
This study of proasaphiscid trilobites is based on some type specimens and new materials (topotypes) collected from the type sections at Longwangmiao, Qujing in eastern Yunnan as well as at Sanwan, Nangao, Danzhai, Kaili and Meitan in Guizhou. The diagnoses and occurrences of Kuetsingocephalus and Danzhaiaspis have been revised, and the ratio of preglabellar field to glabellar length is here considered as the main crucial distinction between the two genera. In Kuetsingocephalus the ratio of preglabellar field to glabellar length is less than 24%, but in Dan-zhaiaspis it is more than 30%. In Danzhaiaspis all pleural ribs are visible, while in Kuetsingocephalus only the first pair of pleural ribs is visible. One new genus and three new species have been established herein: Qizuoshania tang-shanensis gen. et sp. nov., Danzhaiaspis intermedius sp. nov., and Kuetsingocephalus fengrunensis sp. nov. With exception of oryctocephalids, the proasaphiscid trilobites are of very important significance for defining the boundary of Cambrian Series 2 and Miaolingian Series in North China Platform and the Yangtze Platform owing to its wide distribution and rapid evolution in China.

2 Coupling variation of microbially induced sedimentary structures and metazoan bioturbation structures in the Permian–Triassic successions, western Henan Province

ZHENG Wei , WU Pan-pan , XU Xin , XING Zhi-feng , QI Yong-an , LIU Yun-long , LI Wan-ying

2022, 61(1):20-35. DOI: 10.19800/j.cnki.aps.2020008 CSTR:

[Abstract](282) [HTML](0) [PDF 8.79 M](1771)

Abstract:
Microbially induced sedimentary structures (MISS) and metazoan bioturbation structures (trace fossils) are abundant in Upper Permian–Lower Triassic Sunjiagou, Liujiagou and Heshanggou formations in Xingyang, Jiyuan, Dengfeng, Yiyang and Gongyi areas, western Henan, North China. The MISS can be divided into 25 subtypes belonging to three major groups, i.e., mat growth, mat destruction and mat decay structures. Thirteen ichnospecies of 6 ichnogenera are recognized from the Liujiagou and Heshanggou formations. The MISS and metazoan bioturbation structures (trace fossils) vary from the bottom to the top of the strata with some patterns. The MISS first appeared in the Sunjiagou Formation, became abundant in the Liujiagou Formation and disappeared completely in the Heshanggou Formation. The metazoan bioturbation structures first appeared in the middle and upper parts of the Liujiagou Formation, gradually increased in the upper part of the Heshanggou Formation, and basically recovered to the diversity level of the pre-Permian–Triassic catastrophe in the Middle Triassic Youfangzhuang Formation. The MISS and the metazoan bioturbation structures cooccur only in the Liujiagou Formation. The results show that, in general, there is a negative correlation between the development of the MISS and the metazoan bioturbation structures in the study area, and there is a coupling variation of the two types of structures.

3 Coprolites from the Ladinian (Middle Triassic) Xingyi Fauna, Xingyi, Guizhou Province

CHANG Xi-yuan , SUN Zuo-yu , LU Hao , JI Cheng , ZHOU Min , JIANG Da-yong

2022, 61(1):36-50. DOI: 10.19800/j.cnki.aps.2021011 CSTR:

[Abstract](283) [HTML](0) [PDF 5.32 M](1678)

Abstract:
Coprolites (fossilized faeces) are important paleobiological sources for inferring diet, behavior and physi-ology of animals that produced them and predator-prey interactions among animals. Therefore, coprolites are pivotal in reconstructing the trophic structure of a paleoecosystem. Abundantly and exceptionally preserved coprolites are documented from the 35th layer of the Ladinian (Middle Triassic) Xingyi Fauna in the Nimaigu section, Xingyi, Guizhou Province and are categorized into seven morphotypes for the first time. Information about the inclusions was obtained by an optical microscope and a scanning electron microscope. The inclusions mainly consist of bone fragments of Keichousaurus hui and fish scales. Fragments of invertebrates are rare. The size of the coprolites and the absence of spiral-shaped structure, together with relatively small fragments of the inclusions in the coprolites, suggest that the producers are carnivorous marine reptiles. Taking the information of the lower marine reptile assemblage of Xingyi Fauna into account, the producers might include Nothosaurus, Lariosaurus or Thalattosauria. The seven morphotypes of coprolites indicate the existence of at least one trophic level discrepancy among marine reptiles. This result provides important information for the reconstruction of the marine ecosystem in the Ladinian. In addition, the presence of bacteria and the anaerobic environment with high content of mud may have enhanced the preservation of coprolites.

4 Conodont biostratigraphy and sedimentary facies of the Sanhedong Formation (Norian, Upper Triassic) in Weishan, western Yunnan Province

WU Qiang-wang , DU Yi-xing , JIN Xin , SHI Zhi-qiang

2022, 61(1):51-64. DOI: 10.19800/j.cnki.aps.2021006 CSTR:

[Abstract](285) [HTML](0) [PDF 7.82 M](1879)

Abstract:
The Norian (Upper Triassic) marine carbonate successions of the Sanhedong Formation were formed in the Lanping-Simao Block, western Yunnan Province. In this study, conodont fossils from the Sanhedong Formation were collected and identified. The conodont assemblage, dated as early Norian (Lacian), consists of Epigondolella vialovi,Epigondolella uniformis and Epigondolella aff. Triangularis. Facies and microfacies analyses of the Sanhedong Formation, in combination with field observation at the Sanhedong section, reveal three main facies, i.e., restricted-marine platform, open-marine platform and platform-margin reefs. They are further subdivided into nine microfacies. The presence of hydrothermal minerals, such as garnets, and the high conodont alteration index (CAI = 5) throughout the Sanhedong Formation indicate that hydrothermal actions may have affected the diagenetic process. The hydrothermal activities may be related to the upwelling of geothermal brine resulted from the subsidence of the continental rift margin and tectonic plate collision during the post-diagenetic process.

5 Palaeontological characteristics and sedimentary environments of the Jurassic Buqu Formation in the Northern Qiangtang Basin

BAI Pei-rong , XIONG Xing-guo , JIANG Kai-yuan , MA De-sheng , ZENG Yu-ren , CHEN Qi-fei , LI Yue-sen , WU Tao

2022, 61(1):65-87. DOI: 10.19800/j.cnki.aps.2020046 CSTR:

[Abstract](211) [HTML](0) [PDF 28.51 M](1754)

Abstract:
Based on studies of the six sections of the Jurassic Buqu Formation in Shenglihe, Donghu and Maomaoshan areas in the south central parts of the North Depression of the Northern Qiangtang Basin, their lithological characters, and their rich paleontological data (including abundant brachiopods and bivalves), we propose that the age of the Buqu Formation is constrained to the Middle Jurassic Bathonian to early Callovian (probably extending to early Bajocian). Results from our observations and regional correlations indicate that the Buqu Formation in the Northern Qiangtang Basin is diachronic. Characteristics of rock assemblages of the Buqu Formation indicates that the sediments can obviously divided into three parts. Both the lower and upper parts consist of a series of low-energy carbonate rocks dominated by microcrystalline and grain-muddy structures, and the middle part consists of a series of high-energy carbonate rocks dominated by pelsparite. Combined with the palaeoecological habits of the paleontological, the overall depositional environments of the Buqu Formation are considered as a near-shore shallow water open platform and a platform margin carbonate sedimentary system, which constitute multiple depositional cycles. This basic data provides a foundation for further analysis of the lithofacies paleogeography of the Buqu Formation in the south central parts of the Northern Qiangtang Depression.

6 Vertebrate diversity of the Yanliao Biota and comparison with other biotas

LIU Fan , WU Rui , HAN Feng-lu

2022, 61(1):88-106. DOI: 10.19800/j.cnki.aps.2020027 CSTR:

[Abstract](590) [HTML](0) [PDF 2.22 M](2300)

Abstract:
A total of 54 genera and 58 species of vertebrates, including fishes, amphibians, reptiles and mammals, have been reported from the Yanliao Biota, but the diversity and formation mechanism of vertebrates have not been well-studied in detail based on biological analysis. Here, a statistical analysis of the vertebrates in the Yanliao Biota and a detailed comparison with other biotas of similar age are present, which provides significant evidence for the diversity of vertebrates and the formation of the Yanliao Biota. Although the early Daohugou Biota and the late Linglongta Biota are continuous in time, they show different characteristics of biological combination of vertebrates, respectively. Yanliao Biota including a large number of invertebrates and vertebrates and plant fossils is significantly different from other biotas of similar age, such as the Wucaiwan Fauna from Xinjiang and Dashanpu Dinosaur Fauna from Sichuan Basin. Dinosaurs from the Yanliao Biota only contain small theropods and some early ornithischians. But Yanliao Biota is very rich in pterosaurs and mammals. Vertebrates from the Yanliao Biota have high ecological diversity and a unique combination of taxa groups. Some evidence indicates that there may exist geographic isolation between East Asia and other regions during this period. Combined with the characteristics of terrestrial vertebrate assemblage, it can be inferred that there may have been some obstacles in the communication between vertebrates of the Yanliao Biota and the outside world.

7 Application of bromalites in palaeoecological research: A review

YIN Ya-fei , LUO Mao , HUANG Jin-yuan

2022, 61(1):107-122. DOI: 10.19800/j.cnki.aps.2021031 CSTR:

[Abstract](370) [HTML](0) [PDF 10.26 M](2072)

Abstract:
Coprolites are the fossilized animal faeces while bromalites are the fossilized food remains ingested by ancient animals. As an important type of trace fossils, bromalites carry copious palaeoecological information that is not available through the study of body fossils. Therefore, studying these fossils opens a window for understanding the behavioral ecology and predator-prey relationship of ancient animals and food chain/web structures of ancient ecosystems. Further, fossilized parasites within coprolites provide direct evidence on the origin and evolution of intestinal parasites. Besides, coprolites produced by potential hominins in Cenozoic caves provides pivotal clues in elucidating the recipes and health conditions of ancient humans. In addition, plant remains (pollen and phytoliths) within Mesozoic and Cenozoic coprolites supply crucial evidence from which palaeo-vegetation, climate and animal-plant relationships can be well reconstructed. This paper reviews the history of bromalite studies and sums up the recent advances of applying bromalite to various aspects of palaeoecologic interpretations mentioned above. It is concluded that bromalites serve as significant proxies in palaeoecological interpretations. Finally, we sum up new techniques (such as CT scan technology) used in bromalite studies and propose possible future development directions, which we hope may boost the bromalite studies in China.

8 Quantitative reconstruction of paleoclimate—A new understanding of the normal distribution method for coexistence likelihood estimation

XIANG Ming-xing , MIAO Yun-fa , WANG Xue-lian

2022, 61(1):123-135. DOI: 10.19800/j.cnki.aps.2021056 CSTR:

[Abstract](323) [HTML](0) [PDF 7.07 M](1790)

Abstract:
Using plants as a proxy to estimate climate is one of the main approaches to quantitatively reconstructing past climate parameters. The parametric function of Climate Reconstruction Analysis using Coexistence Likelihood Estimation (P-CRACLE) is a quantitative climate reconstruction method based on biological taxonomy. P-CRACLE uses worldwide plant distribution data to obtain corresponding climate parameters. This method assumes that the occurrence of a species is normally distributed along the variables of the climate to calculate the climate intervals where plants coexist. Based on 165 modern floras of the world, the reliability of this method is well verified, but there are still controversies over the acquisition and processing of plant distribution and climate data. To further verify the reliability of this method, we selected 26 research sites of modern floras, obtained plant distribution data from the Global Biodiversity Information Facility (GBIF) database and the climate parameters by using the meteorological grid data (WorldClim 2.1) with two different resolutions (0.5 arcminute and 2.5 arcminute). We apply the traditional mutual climate range (MCR) and P-CRACLE to jointly calculate the climate parameters for all research sites. The results show no apparent difference when using different resolutions of climate grid data. Annual average temperatures obtained using MCR and P-CRACLE are 8.3 ℃ and 1.7 ℃, respectively, and the average resolutions of annual average precipitation are 1120 mm and 280 mm, respectively. Therefore, the resolution of climate intervals obtained by P-CRACLE is far more accurate than that by MCR. Then, based on the percentile of each plant taxon’s given climate parameter to the observed value of the research site, the plant taxon with a percentile higher than 10% and lower than 90% was selected to re-analyze the coexistence of P-CRACLE. Comparison with the coexistence results of previous studies shows that the accuracy of the reconstruction is significantly improved, providing a direction for increased accuracy of quantitative paleoclimate reconstruction in the future. This study suggests that P-CRACLE can be applied to the quantitative reconstruction of paleoclimate since the Cenozoic with very high resolution and reliability.

9 Experimental taphonomy on the degradation of guts and ventral nerve cords of arthropods

MA Ying-yue , SHENG Yi-di , WANG De-qi , LIU Jian-ni

2022, 61(1):136-150. DOI: 10.19800/j.cnki.aps.2021037 CSTR:

[Abstract](221) [HTML](0) [PDF 10.35 M](2105)

Abstract:

The delicate internal organs of the Cambrian arthropods, such as the digestive and nervous systems, provide significant insights into the evolution of early life and the Cambrian ecosystems. As such, their original morphology and preservation mechanisms have been the focus of research in recent years, indicating that the exploration on the preservation mechanisms of soft tissues requires a variety of textural experiments and theories. As a branch of taphonomy, the experimental taphonomy provides important theoretical supports and empirical means for interpreting anatomical structures during fossilization of dead bodies and the formation of a Lagerst?tte. We present this experimental means on the guts and ventral nerve cords of the arthropod Penaeus vannamei under different temperatures and combined conditions in order to observe the degradation process of these soft tissues. The result shows that the degradation trends of guts and ventral nerve cords are similar at different temperatures, but at different rates. The rate and degree of degradations of gut and ventral nerve cord materials at 25 ℃ are significantly higher than those at 10 ℃. At the same temperature, the degradations of guts and ventral nerve cords are different in the early stage. The morphology and the amount of biofilms produced by the degradation at 10 ℃ are totally different. The amount of biofilms produced by the combination of guts and ventral nerve cords is much higher than those produced separately by guts and ventral nerve cords. It is also difficult to distinguish the biofilms produced by the guts and ventral nerve cords. Therefore, temperature is an important factor affecting the speed and degree of gut and ventral nerve cord degradation. In addition, microorganisms play an important biochemical role during the degradation process of biological organs and tissues. The degradation process of biological organs and tissues, associated with the formation of biofilm, has a great influence on the morphological characteristics of fossils, especially the preservation and interpretation of delicate internal structures

10 Study on weathering mechanism of dinosaur tracks from Early Cretaceous in tracksite No. 8, Otog, Inner Mongolia

HAN Xiang-na , ZHAO Wen-hua , LI Chen-yuan , HUA GE GE Gen , ZHANG Li-fu , WANG Li-xia , Li Yang , WANG Xiao-lin

2022, 61(1):151-164. DOI: 10.19800/j.cnki.aps.2021044 CSTR:

[Abstract](368) [HTML](0) [PDF 21.37 M](1848)

Abstract:
Chabu area in Otog Qi, Inner Mongolia, is a rare fossil producing area of dinosaur footprints in the world, which is rich of dinosaur tracks from Early Cretaceous. However, these footprint fossils are experiencing different degrees of weathering in the field. In order to protect these fossils in-situ , the Otog Field Museum of Geological Vestige was built on the Tracksite No. 8. Whereas, it was found that the weathering degree of indoor footprints was more serious than that in the field, especially the area within the museum near the surrounding walls, and the surface of the footprints gradually became efflorescence and broken, and some even completely disappeared. In order to understand this weathering phenomenon, fossil rocks of the same stratum inside and outside the museum were tested by means of polarized light microscope (PM) observation, X-ray diffraction (XRD) analysis, mercury intrusion test (MIP), ion chromatography (IC) analysis, Raman spectroscopy (Raman) analysis, Fourier transform infrared spectroscopy (FTIR) analysis and scanning electron microscopy (SEM-EDS) analysis in this article. It is found that the indoor rock has a higher porosity and larger pore size, and soluble salts content is 2 times that of the surface rock as well as 11 times of subsurface rock. The soluble salts are mainly NaCl and Na₂SO₄. Though simulated aging tests, it is found that the damage of soluble salt is greater than freeze-thaw, and Na₂SO₄ is the most damage salt. Therefore, it is indicated that the weathering mechanism of dinosaur tracks in the museum is the combined action of groundwater and surface water formed by rainfall, which leads to strong water-salt activity of Na₂SO₄. It is found that the nitrocellulose varnish, which was used as consolidant and sealing material, did not have a good protective effect. Some suggestions are put forward to deal with this problem.

Volume 61,Issue 1,2022 Table of Contents

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