The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Haiyan Tong - One of the best experts on this subject based on the ideXlab platform.
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turtle remains from the Middle Jurassic xintiangou formation of yunyang sichuan basin china
Annales De Paleontologie, 2020Co-Authors: Hui Dai, Haiyan Tong, Eric Buffetaut, Ping Wang, Guangbiao Wei, Can XiongAbstract:Abstract Three turtle shells from the Middle Jurassic Xintiangou Formation of Yunyang (Chongqing, China) are described and assigned to Xinjiangchelyidae (Testudines: Eucryptodira). This is the first report of turtle remains from the Xintiangou Formation, Sichuan Basin and represents the oldest known Xinjiangchelyidae. The assemblage includes two taxa, Protoxinjiangchelys sp. and Xinjiangchelyidae indet. This discovery extends the stratigraphical distribution of Xinjiangchelyidae and improves our knowledge about the early evolution of that family. It demonstrates that by the Middle Jurassic, at the time of deposition of the Xintiangou Formation, the group was already diversified in the Sichuan Basin.
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Middle Jurassic turtles from the Sichuan Basin, China: a review
Geological Magazine, 2011Co-Authors: Haiyan Tong, Igor G. Danilov, Hui Ouyang, Guangzhao PengAbstract:The turtle fauna of the Middle Jurassic Xiashaximiao Formation in the Sichuan Basin and the type series of Chengyuchelys baenoides Young & Chow, 1953 are revised. By the absence of a mesoplastron and other shell characters, both the holotype and paratype of Chengyuchelys baenoides belong to the family Xinjiangchelyidae and come probably from the Upper Jurassic Shangshaximiao Formation. The Middle Jurassic turtle assemblage of the Sichuan Basin is composed of two entities: the Bashuchelyidae fam. nov. ( Bashuchelys gen. nov., Chuannanchelys gen. nov.) and Protoxinjiangchelys gen. nov. on the one hand, and Sichuanchelys on the other hand, with the former as the dominant group. Bashuchelyids and xinjiangchelyids are closely related to one another, while Sichuanchelys is more primitive and has no shared apomorphic features with bashuchelyids. The whole assemblage appears to be endemic to the Sichuan Basin at genus level and distinct from the Late Jurassic turtle fauna of the same basin in its relict nature and absence of the Polycryptodira.
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Middle Jurassic turtles from southern Thailand
Geological Magazine, 2002Co-Authors: Haiyan Tong, Eric Buffetaut, Varavudh SuteethornAbstract:A new genus and species of primitive cryptodiran turtle, Siamochelys peninsularis n. g. n. sp., from the Middle Jurassic Mab Ching locality, in the southern peninsula of Thailand, is described on the basis of complete shells. They are characterized by a combination of primitive features (the presence of a pair of mesoplastra meeting on the midline) and a series of derived characters (loose plastron–carapace attachment, short diamond-shaped entoplastron, dorsal thickening of the lateral edge of the second to seventh peripheral plates, expanded seventh to eleventh peripheral plates, extension of the anal scute to the hyo-hypoplastral suture or onto the hypoplastron, midline sulcus sinusoidal), and thus closely resemble Chengyuchelys , from the Middle Jurassic of China, and more particularly Xinjiangchelys and its relatives from the Middle and Late Jurassic of China and Central Asia. This supports a Middle Jurassic age for the locality and suggests that the Sibumasu (Shan-Thai) block was in contact with the Asian mainland by that time.
Guangzhao Peng - One of the best experts on this subject based on the ideXlab platform.
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new Middle Jurassic dinosaur track record from northeastern sichuan province china
Swiss Journal of Palaeontology, 2017Co-Authors: Lida Xing, Hendrik Klein, Martin G. Lockley, Yongdong Wang, Mike Pole, Guangzhao Peng, Xiaoping Xie, Guoquan Zhang, Chuntao Deng, Michael E BurnsAbstract:Two relatively small tridactyl tracks from the Middle Jurassic Xintiangou Formation of northeastern Sichuan are assigned to cf. Anomoepus based on low length/width and anterior triangle ratios, and a relatively short step and inward rotation of the footprint axes. Anomoepus is typical of many Middle Jurassic dinosaur-dominated ichnofaunas from central and southern China and appears to be allied to the globally widespread Lower Jurassic tetrapod track biochron.
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Middle Jurassic turtles from the Sichuan Basin, China: a review
Geological Magazine, 2011Co-Authors: Haiyan Tong, Igor G. Danilov, Hui Ouyang, Guangzhao PengAbstract:The turtle fauna of the Middle Jurassic Xiashaximiao Formation in the Sichuan Basin and the type series of Chengyuchelys baenoides Young & Chow, 1953 are revised. By the absence of a mesoplastron and other shell characters, both the holotype and paratype of Chengyuchelys baenoides belong to the family Xinjiangchelyidae and come probably from the Upper Jurassic Shangshaximiao Formation. The Middle Jurassic turtle assemblage of the Sichuan Basin is composed of two entities: the Bashuchelyidae fam. nov. ( Bashuchelys gen. nov., Chuannanchelys gen. nov.) and Protoxinjiangchelys gen. nov. on the one hand, and Sichuanchelys on the other hand, with the former as the dominant group. Bashuchelyids and xinjiangchelyids are closely related to one another, while Sichuanchelys is more primitive and has no shared apomorphic features with bashuchelyids. The whole assemblage appears to be endemic to the Sichuan Basin at genus level and distinct from the Late Jurassic turtle fauna of the same basin in its relict nature and absence of the Polycryptodira.
Lida Xing - One of the best experts on this subject based on the ideXlab platform.
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sauropod trackways from the Middle Jurassic chaya group of eastern tibet china
Historical Biology, 2020Co-Authors: Lida Xing, Hendrik Klein, Martin G. Lockley, Lijun Zhang, Scott W Persons, Donghao Wang, Miaoyan Wang, Xiaoqiao WanAbstract:Multiple sauropod-track-bearing horizons occur in the Middle Jurassic Shaqiaomu Formation, in the Chaya Group of Eastern Tibet. These add to the report of a previously described sauropod trackway, ...
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new Middle Jurassic dinosaur track record from northeastern sichuan province china
Swiss Journal of Palaeontology, 2017Co-Authors: Lida Xing, Hendrik Klein, Martin G. Lockley, Yongdong Wang, Mike Pole, Guangzhao Peng, Xiaoping Xie, Guoquan Zhang, Chuntao Deng, Michael E BurnsAbstract:Two relatively small tridactyl tracks from the Middle Jurassic Xintiangou Formation of northeastern Sichuan are assigned to cf. Anomoepus based on low length/width and anterior triangle ratios, and a relatively short step and inward rotation of the footprint axes. Anomoepus is typical of many Middle Jurassic dinosaur-dominated ichnofaunas from central and southern China and appears to be allied to the globally widespread Lower Jurassic tetrapod track biochron.
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Middle Jurassic theropod trackways from the Panxi region, Southwest China and a consideration of their geologic age
Palaeoworld, 2012Co-Authors: Lida Xing, Hendrik Klein, Martin G. Lockley, Jianping Zhang, Gerard D. Gierliński, W. Scott Persons, Long ZhouAbstract:Abstract Theropod footprints from the Middle Jurassic Xincun Formation in the Panxi region (Sichuan Province, Southwest China) show strong similarities to the ichnogenus Kayentapus . They are characterized by slender digits, wide digit divarication, and a characteristic pad configuration that is different from other Jurassic theropod ichnotaxa. At the Shansong tracksite, three trackways are present, each consisting of four consecutive tracks (stride and pes lengths up to 200 cm and 36 cm, respectively). The speed of the trackmakers has been calculated with values between 1.1 and 1.4 m/s. The assemblage is a further document of a Middle Jurassic occurrence of this morphotype that is basically known from the Lower Jurassic deposits elsewhere. This could be due to peculiarities of theropod communities in this region, reflecting a different paleobiogeographic distribution pattern in the Middle Jurassic. Biostratigraphically, ostracods lend support to a Middle Jurassic age of the trackbearing unit. This corresponds partly with data from the Shangshaximiao Formation that is considered to be of Middle Jurassic age based on ostracods but Late Jurassic age based on vertebrate skeletons. The ichnological record and the presence of Kayentapus -like footprints in both units support a Lower–Middle Jurassic age.
H. Philip Powell - One of the best experts on this subject based on the ideXlab platform.
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A Middle Jurassic dinosaur trackway site from Oxfordshire, UK
Palaeontology, 2004Co-Authors: Julia J. Day, David B. Norman, Andrew S. Gale, Paul Upchurch, H. Philip PowellAbstract:The Middle Jurassic (Bathonian) Ardley trackway site in Oxfordshire, UK is described in detail. The track site is extensive, containing over 40 more-or-less continuous theropod and sauropod trackways preserved together on a single bedding plane with some trackways up to 180 m in length. The trackways display reasonable preservation, with claw marks discernible. Sauropod trackways are by far the most abundant and are representative of taxa that exhibit both narrow and wide-gauge styles of locomotion. Theropod trackways are represented by large tridactyl prints and claw impressions that display exceptionally low pace angulation values during their walking phase. One theropod trackway is unique in that it reveals a gait transition associated with a temporary increase of speed. These dinosaurs were walking over a lime-mud firmground to hardground that was emergent, or locally very shallowly submerged. GPS (Global Positioning Satellite) data reveal that the tracks, preserved during a short time interval, trend in a north-easterly direction. Multi-herding behaviour is suggested for the sauropods of differing size. The discovery of this site adds significantly to our knowledge of the taxonomic composition of Middle Jurassic ecosystems. Evidence concerning locomotor styles employed by saurischian dinosaurs, footprint identification, potential trackmaker, social interactions and observations concerning estimates of Middle Jurassic faunal diversity, as well as aspects of dinosaur locomotor evolution are discussed.
Abdul Rahman Ashraf - One of the best experts on this subject based on the ideXlab platform.
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The Upper Triassic to Middle Jurassic strata and floras of the Junggar Basin, Xinjiang, Northwest China
Palaeobiodiversity and Palaeoenvironments, 2010Co-Authors: Ge Sun, Yuyan Miao, Volker Mosbrugger, Abdul Rahman AshrafAbstract:The Upper Triassic to Middle Jurassic strata are well exposed and basically continuous in the Junggar Basin of Xinjiang, Northwest China. The Upper Triassic strata include the Huangshanjie Formation (lacustrine facies mainly) and Haojiagou Formation (fluvial to fluvial-swamp facies). The Lower Jurassic consists of the coal-bearing Badaowan Formation (fluvial swamp facies) and Sangonghe Formation (lacustrine facies mainly). The Middle Jurassic is composed of the large coal-bearing Xishanyao Formation (fluvial-swamp facies mainly) and Toutunhe Formation (variegated lacustrine facies). The Late Triassic to early Middle Jurassic floras from the basin consist of four floristic assemblages, including the Danaeopsis-Nanzhangophyllum assemblage (Ass. I, Carnian-Norian) and Glossophyllum-Cycadocarpidium assemblage (Ass. II, Norian-Rhaetian), belonging to the Late Triassic “Northern China Flora” (Danaeopsis-Bernoullia Flora), and the Neocalamites-Marattiopsis assemblage (Ass. III, Early Jurassic) and Coniopteris-Raphaelia assemblage (Ass. IV, Middle Jurassic), belonging to the Early–Middle Jurassic “Siberian Flora” (Continental Floristic Province). The palaeoclimatic changes basically consisted of warming up and moistening from the Late Triassic to Early Jurassic, while the climate of the early Middle Jurassic might have been warm–temperate and humid, which was favourable for coal formation. The lower Middle Jurassic strata appear to be the largest sedimentary mineral resources for coal, oil and natural gas in the Junggar Basin area. Two new taxa from the Upper Jurassic are described, Danaeopsis tenuinervis Sun, Mosbrugger et Li sp. nov and Thinnfeldia? mirisecta Sun, Mosbrugger et Li sp. nov.
