Sullivan, R.M. and Lucas, S.G., eds., 2016, Fossil Record 5. New Mexico Museum of Natural History and Science Bulletin 74. 345 EUBRONTES AND ANOMOEPUS TRACK ASSEMBLAGES FROM THE MIDDLE JURASSIC XIASHAXIMIAO FORMATION OF ZIZHONG COUNTY, SICHUAN, CHINA: REVIEW, ICHNOTAXONOMY AND NOTES ON PRESERVED TAIL TRACES LIDA XING1, MARTIN G. LOCKLEY2, GUANGZHAO PENG3, YONG YE3, JIANPING ZHANG1, MASAKI MATSUKAWA4, HENDRIK KLEIN5, RICHARD T. MCCREA6 and W. SCOTT PERSONS IV7 1School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China; -email: [email protected]; 2Dinosaur Trackers Research Group, University of Colorado Denver, P.O. Box 173364, Denver, CO 80217; 3 Zigong Dinosaur Museum, Zigong 643013, Sichuan, China; 4 Department of Environmental Sciences, Tokyo Gakugei University, Koganei, Tokyo 184-8501, Japan; 5 Saurierwelt Paläontologisches Museum Alte Richt 7, D-92318 Neumarkt, Germany; 6 Peace Region Palaeontology Research Centre, Box 1540, Tumbler Ridge, British Columbia V0C 2W0, Canada; 7 Department of Biological Sciences, University of Alberta 11455 Saskatchewan Drive, Edmonton, Alberta T6G 2E9, Canada Abstract—The Nianpanshan dinosaur tracksite, first studied in the 1980s, was designated as the type locality of the monospecific ichnogenus Jinlijingpus, and the source of another tridactyl track, Chuanchengpus, both presumably of theropod affinity. After the site was mapped in 2001, these two ichnotaxa were considered synonyms of Eubrontes and Anomoepus, respectively, the latter designation being the first identification of this ichnogenus in China. The assemblage indicates a typical Jurassic ichnofauna. The present study reinvestigates the site in the light of the purported new ichnospecies Chuanchengpus shenglingensis that was introduced in 2012. After re- evaluation of the morphological and extramorphological features, C. shenglingensis is considered here as a nomen dubium. The present study also provides details of tail traces associated with two of the Anomoepus trackways and adds additional detail to the 2001 tracksite map. INTRODUCTION theropods and small ornithopods (Lockley and Matsukawa, 2009). The Saurischian-dominated dinosaur assemblages are typical of Nianpanshan site also preserves the first reportedAnomoepus trackways Jurassic deposits in China (Matsukawa et al., 2006; Xing et al., from China (Lockley and Matsukawa, 2009). Here, we offer the first 2014a), North America (Lockley and Hunt, 1995) and elsewhere. detailed re-description and re-evaluation of the Nianpanshan site, based After the skeletal record, this is the case also in the Sichuan Basin, on the first author’s field investigation in April 2015. where sauropods dominate the Middle to Late Jurassic records, while ornithischians, including stegosaurs and small-sized ornithopods (Peng HISTORICAL BACKGROUND et al., 2005), are rare. The composition of Jurassic ichnoassemblages in In the 1970s, the upper layers of a mountain in Nianpan Village the Sichuan Basin is partly different. The Nianpanshan site (previously of Jinlijing Town were removed in order to reduce shade and benefit known as the Jinlijing site, GPS: 29°47’39.03”N, 104°38’29.49”E) local agriculture. A smooth lower rock layer was left, and this exposure near Jinlijing Town, Zizhong County (Fig .1), preserves tracks of large revealed numerous fossil tracks. Local superstition regarded the tracks FIGURE 1. Geographic map indicating the location of dinosaur footprint localities in Jinlijing, Sichuan Province, P.R. China. 346 as those of a “divine crane.” Investigations conducted between 1981 Mineral Resources confirmed that the track-bearing unit belongs to the and 1982, by researchers from Chongqing Museum of Natural History, Middle Jurassic Xiashaximiao Formation (Geochemical Exploration identified the tracks as those of dinosaurs. In 1987, Xinglong Yang Team of Sichuan Bureau of Geology and Mineral Resources, 2006; and Daihuan Yang, from the Chongqing Museum of Natural History, Yang, 2009; Yang et al., 2013). described theropod tracks from the Nianpanshan site. Yang and Yang The Nianpanshan tracks are preserved on reddish-brown (1987) suggested that one large track and two medium-sized tracks feldspathic quartz sandstone. The lower member of the Xiashaximiao were left by different individuals of the Jinlijingpus nianpanshanensis Formation is 650–2500 m thick (Fig. 3), comprising cyclothemic trackmaker, and that another smaller footprint was similar to the interbedding of yellow-gray and purplish-gray feldspathic quartz theropod track Chuanchengpus. sandstone and purplish-red and purplish-gray shale of differing Although numerous tracks were collected from other Sichuan thicknesses. The basal part of the Xiashaximiao Formation consists of Basin localities throughout the1980s, villagers from Nianpan Village medium-grain sandstone with large oblique bedding. At the top of this strongly opposed specimen collection, and no footprint material could formation, a layer of grayish-green shale, rich in conchostracans, occurs be obtained from the Nianpan site. Moreover, the Nianpan site was (Stratigraphic Paleobiology Research Center of China Geological protected in Shenglingshan National Geological Park. Survey, 2004; Peng et al., 2005; Xing et al., 2014a). Lockley and Matsukawa (2009) mapped the site in 2001 The plant and invertebrate assemblage includes fresh water (Fig. 2) and concluded that the large tridactyl tracks, Jinlijingpus bivalves, conchostracans, ostracods, and sporopollen. The vertebrate nianpanshanensis, were similar to Eubrontes, whereas the small assemblage (i.e., Shunosaurus fauna) is typical of Middle Jurassic tridactyl tracks were similar to Anomoepus. Three Anomoepus isp. strata of China (Peng et al., 2005). trackways were labelled by these authors as A1-A3, being the first identification of this ichnogenus from China. Two trackways with MATERIALS AND METHODS large tridactyl pes imprints (including Eubrontes) were left unlabeled. The Nianpanshan site preserves six trackways: T1–T6. T6 and Li et al. (2011) suggested Jinlijingpus nianpanshanensis should be one well-preserved isolated track (TI1) were not previously reported. referred to the theropod ichnogenus Eubrontes, and Lockley et al. Trackways originally labeled A1-A3 in Lockley and Matsukawa (2013) assigned J. nianpanshanensis to the new combination Eubrontes (2009) are here referred to as T1–T3. Three main trackways (T1, T4 nianpanshanensis. Shortly after, Yang et al. (2013) put forth the same and T5) are oriented toward the northwest. The total track surface is taxonomic conclusion. presently surrounded by a protective wall. During the investigation, Without knowing/citing the conclusion from Lockley and each track was outlined with chalk, photographed, and measured, after Matsukawa (2009), Yang et al. (2011) followed the point from weeds and surface debris were cleared. In 2001, the site was partially Yang and Yang (1987), named a new ichnospecies Chuanchengpus covered by harvested crops, which were removed from the trackways shenglingensis based on a trackway with small pes imprints from so they could be mapped using compass and tape measures. At that the Nianpanshan site, and considered the trackmaker to have been a time selected tracks were photographed and traced on acetate film coelurosaur. In the following year, this trackway was described in more (Fig. 2). During the present study the entire tracksite was mapped on detail (Yang et al., 2012). It’s worth noting that the type ichnospecies of Chuanchengpus, C. wuhuangensis, was named by Yang and Yang (1987) based on a trackway from the Middle Jurassic Xintiangou Formation of Wuma Village, Zizhong Township. Lockley et al. (2013) re-assigned the Wuma Chuanchengpus wuhuangensis to Grallator, whereas, according to Lockley and Matsukawa (2009), the small trackway from the Nianpanshan site is still referred to Anomoepus. GEOLOGICAL SETTING Strata at the Nianpanshan site were initially thought to be part of the Middle Jurassic Xintiangou Formation (Yang and Yang, 1987). In 2006, a survey of Shenglingshan National Geological Park by the Geochemical Exploration Team of Sichuan Bureau of Geology and FIGURE 2. Map and detail of tracks from the Nianpanshan dinosaur tracksite near Jilijing village, and other sites near Chongqing, after Lockley and Matsukawa (2009, fig. 6). A1–A3 were identified as Anomoepus trackways (white arrows), corresponding to T1-T3 in the present study. A1 and A2 show detail of trackways with elongate traces. B, 2001 map of the site. C, Anomoepus tracks from the Chongqing Natural History Museum. D, detail of Jinlijingpus nianpanshanensis (= Eubrontes nianpanshanensis) from trackway T4 corresponding to NPS FIGURE 3. Stratigraphic section of Mesozoic sedimentary sequences T4 R9, L9 and R10 of the present study. in the Jinlijing area with the position of the footprint level. 347 a large plastic sheet. Photogrammetric images were produced from the Middle Jurassic Sanjianfang Formation is 0.46, and in Changpeipus multiple digital photographs (Canon EOS 5D Mark III), which were carbonicus (Young, 1960; Xing et al., 2009a) from the Middle or the converted into scaled, highly accurate 3D textured mesh models using Lower Jurassic Tuntianying Formation is 0.47. Agisoft Photoscan Professional. The mesh models were then imported For theropods, Thulborn (1990) first suggested that hip height into Cloud Compare, where the models were rendered with color h = 4.9×foot length. The relative stride length (SL/h) may be used to topographic