Welcome to Visited Vertebrata Palasiatica, Today is Share:

Table of Content

    20 October 2020, Volume 58 Issue 4
    Subdivision and age of the Silurian fish-bearing Kuanti Formation in Qujing, Yunnan Province
    CAI Jia-Chen, ZHAO Wen-Jin, ZHU Min
    2020, 58(4):  249-266.  DOI: 10.19615/j.cnki.1000-3118.200513
    Asbtract ( )   HTML ( )   PDF (5890KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    The continuous Silurian strata are well developed and exposed with abundant fossils in Qujing Area of Yunnan Province, which makes Qujing as one of ideal areas in China for the research of Silurian stratigraphy and paleontology for a long time. The Kuanti Formation has become the focus of attention for early vertebrate researchers in the world, since tremendous amount of fossil fishes were found in the formation exposed in the surrounding areas of Qujing in 2007, which eventually led to the discovery and establishment of the Xiaoxiang Vertebrate Fauna in 2009. However, the stratigraphic subdivision, correlation and the geological age of the Kuanti Formation in Qujing still remain contentious, although many biostratigraphic and lithostratigraphic attempts have been made since the formation was named in 1914. Based on the detailed field geological investigation in recent years in the surrounding areas of Xiaoxiang Reservoir and the measured data of one continuous section (Shangtielu-Dongpo Section), together with many previous paleontological and stratigraphic works, this paper redefines the Kuanti Formation containing abundant Silurian fishes in Qujing Area and further discusses its geological age. According to the main lithological changes and paleontological characteristics, the Yuejiashan Formation which was separated by some researchers from the lower part of the Kuanti Formation is abandoned here. In the paper, the redefined Kuanti Formation can be subdivided into four members in ascending order. Member I (Yuejiashan Member) is characterised by yellow-green and gray-green shales intercalated with thin-bedded fine sandstones or siltstones and several thin-bedded fine-grained conglomerates bearing fragments of fossil fishes in its lower and middle parts. Member II (Chongjiawan Member) is represented by gray-green and purple-red shales, intercalated with light grey middle- to thin-bedded or lenticular limestones or bioclastic limestones containing many brachiopod fossils. Member III (Cailian Member) is dominated by purple-red and gray-green silty and calcareous mudstones or marls intercalated with minor purple-red or yellow-green shales or siltstones, containing brachiopods, fossil fishes and stout tubular trace fossils. A set of middle-thick-bedded fine sandstone with small thickness is usually developed in the bottom of the member, which becomes the obvious marker of the boundary between Member III and Member II. Member IV (Dongpo Member) is composed of gray-green and yellow-green mudstones and shales intercalated with thin-bedded or lenticular argillaceous limestones and marlites. Abundant fossil fishes of the Xiaoxiang Vertebrate Fauna were found in the argillaceous limestones in the lower part, and coral fossils in the upper part. Mainly based on the records of fossil fishes, conodonts and other paleontological data, the age of Member III to Member IV of the Kuanti Formation, containing the main fish-bearing strata of the Xiaoxiang Vertebrate Fauna and conodont Ozarkodina crispa, should be assigned to the Ludfordian Stage of the Ludlow, and Member I to Member II can be referred to the Gorstian Stage of the Ludlow, Silurian. Based on the current stratigraphic data, the possibility of its bottom extending down to Wenlock is not excluded.

    A new species of Luganoia (Luganoiidae, Neopterygii) from the Middle Triassic Xingyi Biota, Guizhou, China
    XU Guang-Hui
    2020, 58(4):  267-282.  DOI: 10.19615/j.cnki.1000-3118.200624
    Asbtract ( )   HTML ( )   PDF (8471KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    Neopterygii is the largest known group of ray-finned fishes today, and the Luganoiidae, recognized by its specialized skull and greatly deepened flank scales, is a stem lineage of this group in the Middle Triassic. Since its naming in 1939, the Luganoiidae has been represented solely by the marine species Luganoia lepidosteoides found near the Ladinian/Anisian boundary of the southern and eastern Switzerland, northern Italy and southeastern Spain. Here, I report the discovery of a new species of this genus, Luganoia fortuna sp. nov. based on a nearly complete specimen from the late Middle Triassic (Ladinian) marine deposits exposed near Xingyi, Guizhou, China. The discovery represents the first record of the Luganoiidae in Asia, indicating that the biogeographical distribution of this family is much wider than previously recognized. Comparative studies of the new species with the type species from Europe reveal some anatomical features previously unnoticed in Luganoia, e.g., the presence of antorbitals, absence of a plate-like quadratojugal, presence of a narrow naked region of the body at the base of the dorsal fin, presence of a small anal fin closer to the caudal fin than to the pelvic fin, and absence of postcleithra. An amended diagnosis of the genus is presented. Moreover, the distinguishable features between the Chinese and European species are highlighted in this study, and they provide valuable information on the morphological diversification of Luganoia.

    New chroniosuchian materials from Xinjiang, China
    LIU Jun
    2020, 58(4):  283-292.  DOI: 10.19615/j.cnki.1000-3118.200415
    Asbtract ( )   HTML ( )   PDF (2246KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    Chroniosuchians have the earliest representatives in Gansu, China, but the Chinese records were scarcer compared to Russia, especially the Triassic one. In Xinjiang, there was only one specimen reported from the upper part of the Guodikeng Formation. Here three new chroniosuchian specimens are reported from three new stratigraphic horizons: the Quanzijie Formation (middle Permian), the base of the Guodikeng Formation (upper Permian), and the Jiucaiyuan Formation (Lower Triassic). The osteoderm from the Jiucaiyuan Formation represents the first definite Triassic chroniosuchian from China. The new findings increase the chroniosuchian diversity and their time range in China. The bystrowianid chroniosuchian specimens from the Guodikeng and Jiucaiyuan formations demonstrated that this group survived in the end-Permian mass extinction in Xinjiang, China.

    Taxonomic revision of Anthracokeryx thailandicus Ducrocq, 1999 (Anthracotheriidae, Microbunodontinae) from the Upper Eocene of Thailand
    DUCROCQ Stéphane
    2020, 58(4):  293-304.  DOI: 10.19615/j.cnki.1000-3118.200618
    Asbtract ( )   HTML ( )   PDF (1864KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    The anthracotheriid (Mammalia, Cetartiodactyla) species Anthracokeryx thailandicus from the Upper Eocene of Thailand is redescribed in details and a revision of its phylogenetic position within the family is proposed. A combination of important dental differences has been observed that led to attribute the Thai form to a distinct genus, Geniokeryx gen. nov., which represents the third genus included into the Microbunodontinae. The new genus is characterized mainly by its unfused short and deep mandibular symphysis, massive lower and upper premolars, weakly selenodont upper molars that exhibit a protostyle and lack an ectometacristule. The peculiar morphology of its symphysis might have been a sexually dimorphic feature that provided the role of a lateral protection for the enlarged upper canine in males as seen in some Paleogene nimravid carnivorans like Eusmilus. A short review of some Anthracokeryx species from China suggests that A. dawsoni might be synonymous to A. sinensis.

    New skulls of ctenodactyloids from the Early Oligocene of Ulantatal, Nei Mongol, China
    XU Ran-Cheng, LI Qian
    2020, 58(4):  305-327.  DOI: 10.19615/j.cnki.1000-3118.200413
    Asbtract ( )   HTML ( )   PDF (24187KB) ( )  
    Figures and Tables | References | Related Articles | Metrics
    Ancient DNA molecular identification and phylogenetic analysis of Cervinae subfossils from Northeast China
    XIAO Bo, SHENG Gui-Lian, YUAN Jun-Xia, WANG Si-Ren, HU Jia-Ming, CHEN Shun-Gang, JI Hai-Long, HOU Xin-Dong, LAI Xu-Long
    2020, 58(4):  328-337.  DOI: 10.19615/j.cnki.1000-3118.200722
    Asbtract ( )   HTML ( )   PDF (1569KB) ( )  
    Figures and Tables | References | Related Articles | Metrics

    The deer resources in China are abundant, with seven species in the sub-family Cervinae distributing in various areas. The intraspecific phylogeny of Cervinae has been widely explored, while the evolutionary relationship among different species requires further efforts, in which only few molecular studies on ancient materials have been performed. In this study, we carried out ancient DNA research on two Cervinae subfossils from northeastern China, dating of 3800 and 5100 aBP. Through ancient DNA extraction, double-stranded sequencing libraries construction, next-generation sequencing and bioinformatics data analysis, we reconstructed two mitochondria sequences with lengths of 16475 bp (GenBank accession number: MT784751, sequence integrity: 99.83%) and 16167 bp (GenBank accession numberh: MT784752, sequence integrity: 97.96%), respectively. Based on the mitochondrial homologous sequences of the extant Cervinae species in GenBank, we constructed a phylogenetic tree. The results show that: 1) both the average length and the C-to-T substitution frequencies at 5’- end of the NGS short reads indicate the data are from ancient specimens; 2) the two ancient individuals clustered with Cervus elaphus in the phylogenetic tree, and were molecularly identified as C. elaphus; 3) the two ancient samples from Heilongjiang are phylogenetically close to the extant C. elaphus alxaicus, but far from the extant C. elaphus xanthopygus. Combining the dates of the samples, we suggest that these two samples represent a population of ancient C. elaphus in Heilongjiang, which was not the direct maternal ancestor of the extant C. elaphus xanthopygus.