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    15 March 2015, Volume 53 Issue 1
    Panxianichthys imparilis gen. et sp. nov., a new ionoscopiform (Halecomorphi) from the Middle Triassic of Guizhou, China
    XU Guang-Hui, SHEN Chen-Chen
    2015, 53(1):  1-15. 
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    The Ionoscopiformes are a fossil lineage of halecomorphs known only from the Mesozoic marine deposits. Because of their close relationships with the Amiiformes, the Ionoscopiformes are phylogenetically important in investigating the early evolution and biogeography of the Halecomorphi. However, fossil evidence of early ionoscopiforms was scarce; until recently,Robustichthys from the Middle Triassic Luoping Biota, eastern Yunnan,China, represents the oldest and only known ionoscopiform in the Triassic. Here we report the discovery of a new ionoscopiform, Panxianichthys imparilis gen. et sp. nov., on the basis of two well preserved specimens from the Middle Triassic Panxian Biota, western Guizhou, China. The discovery documents the second ionoscopiform in the Middle Triassic; although Panxianichthys is slightly younger than Robustichthys, it is significantly older than other members of this group from the Late Jurassic of Europe, and Early Cretaceous of North and South America. Panxianichthys possesses an important synapomorphy of the Ionoscopiformes: a sensory canal in the maxilla, but retains some primitive characters unknown in other ionoscopiforms. Results of our phylogenetic analysis recover Panxianichthys as the most primitive ionoscopiform, and provide new insight on the early evolution of this clade. The interrelationships of the Ionoscopidae have been reassessed;Quetzalichthysis regarded more closely related to Ionoscopus than to Oshunia. In addition, our analysis supports the reassessment of Furo muensteri as an ophiopsid ionoscopiform. The successive discoveries of Robustichthys andPanxianichthys from China indicate that the early diversification of the Ionoscopiformes is more rapid than previously thought.
    New discoveries from the Sinokannemeyeria-Shansisuchus Assemblage Zone: 1.Kannemeyeriiformes from Shanxi, China
    Liu Jun
    2015, 53(1):  16-28. 
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    Recently, some new tetrapod fossils were collected alongthe Yellow River in Shanxi Province. From the Member I of the Tongchuan Formation at Baidaoyu in Linxian County, at least one species of Parakannemeyeria, and one new species ofSinokannemeyeria, S. baidaoyuensis, are identified. The new species is characterized by prefrontal anterior extension level to posterior margin of postnarial excavation. From the Ermaying Formation inLinxian County, a third kannemeyeriid genus is identified for theSinokannemeyeria-Shansisuchus Assemblage. The new findings increase the content and time extension of the Sinokannemeyeria-Shansisuchus Assemblage.
    The taxonomic status of the Late Cretaceous dromaeosaurid Linheraptor exquisitus and its implications for dromaeosaurid systematics
    XU Xing, Michael PITTMAN, Corwin SULLIVAN, Jonah N. CHOINIERE, TAN Qing-Wei,  James M. CLARK, Mark A. NORELL,WANG Shuo
    2015, 53(1):  29-62. 
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    The dromaeosaurid Linheraptor exquisitus was named in 2010 based on a nearly complete skeleton recovered from the Upper Cretaceous Wulansuhai Formation at the Gate Locality, in Bayan Mandahu, western Nei Mongol, China. However, three recent studies regarded L. exquisitus as a subjective junior synonym of Tsaagan mangas, a dromaeosaurid from the Upper Cretaceous Djadokhta Formation of the Ukhaa Tolgod locality, Mongolia.Here we refute this synonymy based on 61 morphological features that distinguish L. exquisitus from T. mangas. Many of these features are based on new observations from previously unprepared areas of the L. exquisitus holotype, most notably from the left lateral side of the skull. These observations underscore and strengthen our original taxonomic separation of L. exquisitus and T.mangas. Evidence from L. exquisitus points to an unexpectedly complex distribution of derived osteological features amongst dromaeosaurids, because this species possesses features that were previously identified as autapomorphies of T. mangas or indeed of various other dromaeosaurids. Our review demonstrates that the proposed synonymy between L. exquisitus and T. mangas ignores many subtle morphological variations. Increased taxonomic sampling breaks down seemingly obvious diagnostic differences into more subtle morphological variations, which are potentially of great importance for fine-scale phylogenetic analyses. Rigorous quantitative methods using continuous data represent a promising way to exploit this type of information in future systematic studies.
    Large theropod teeth from the Upper Cretaceous of Jiangxi, southern China
    MO Jin-You, XU Xing
    2015, 53(1):  63-72. 
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    Two isolated, large theropod teeth from the Upper Cretaceous Nanxiong Formation of Nankang County, Jiangxi Province, southern China, are described. Their crown heights (CH) are 76 and 91 mm, respectively. The smaller tooth is referable to the Tyrannosauridae based on its size and sub-oval cross-section (the crown base ratio (CBR) is about 0.72). The larger tooth is moderately laterally compressed (the CBR is about 0.47), with well defined longitudinal oriented enamel wrinkles at the basal halves of the mesial and distal margins, probably represents a previously unknown large theropod inhabited Asiaduring the Late Cretaceous. The recovered large theropod teeth add to the known diversity of vertebrates from the Upper Cretaceous Nanxiong Formation, southern China.
    Morphology through ontogeny of ChineseProboscidipparion and Plesiohipparion and observations on their Eurasian and African relatives
    Raymond L. BERNOR, SUN Bo-Yang
    2015, 53(1):  73-92. 
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    We analyse and figure a total of 18 sectioned cheek teeth ofPlesiohipparion houfenense, Proboscidipparion pater andProboscidipparion sinense to digitally document and characterize the morphologic changes through their ontology and to discover possible synapomorphies between these Chinese taxa and other Eurasian and African hipparion lineages. The maxillary and mandibular cheek teeth of P. houfenense are found to likely share characters in common with Spanish Plesiohipparion crusafonti, Turkish Plesiohipparion aff. P.huangheense and the African Eurygnathohippus lineage. In turn, these Eurasian and African lineages may in fact have their evolutionary roots in the Siwalik Sivalhippus lineage. The two Proboscidipparionspecies, P. pater and P. sinense are clearly related to each other, and likely related to Turkish “Proboscidipparion” heintzi. Likewise, our analysis of P. pater and P. sinense maxillary and mandibular cheek teeth support this genus’ relationships with the Plesiohipparion andSivalhippus clades previous argued by other authors.