Historical Biology An International Journal of Paleobiology ISSN: 0891-2963 (Print) 1029-2381 (Online) Journal homepage: https://www.tandfonline.com/loi/ghbi20 Pleistocene fossil snakes (Squamata, Reptilia) from Shanyangzhai Cave, Hebei, China Yu Chen, Yong-Xiang Li, Jing-Song Shi, Yun-Xiang Zhang & Kun Xie To cite this article: Yu Chen, Yong-Xiang Li, Jing-Song Shi, Yun-Xiang Zhang & Kun Xie (2019): Pleistocene fossil snakes (Squamata, Reptilia) from Shanyangzhai Cave, Hebei, China, Historical Biology, DOI: 10.1080/08912963.2019.1658094 To link to this article: https://doi.org/10.1080/08912963.2019.1658094 Published online: 02 Sep 2019. Submit your article to this journal Article views: 23 View related articles View Crossmark data Full Terms & Conditions of access and use can be found at https://www.tandfonline.com/action/journalInformation?journalCode=ghbi20 HISTORICAL BIOLOGY https://doi.org/10.1080/08912963.2019.1658094 ARTICLE Pleistocene fossil snakes (Squamata, Reptilia) from Shanyangzhai Cave, Hebei, China Yu Chena, Yong-Xiang Lia, Jing-Song Shib, Yun-Xiang Zhanga and Kun Xiea aState Key Laboratory of Continental Dynamics, Department of Geology, National Demonstration Center for Experimental Geology Education (Northwest University), Xi’an, China; bChinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Beijing, China ABSTRACT ARTICLE HISTORY Shanyangzhai Cave, located in Hebei Province, North China, has yielded a large number of snake bones Received 21 April 2019 dated back to the late middle Pleistocene and late Pleistocene. These snakes are represented by at least Accepted 17 August 2019 six taxa: three colubrids (Elaphe cf. schrenckii, Elaphe cf. dione, Lycodon sp.), one natricid (Rhabdophis KEYWORDS fi tigrinus), and two viperids (Gloydius sp1. and Gloydius sp2.). Most of the identi ed taxa still occur on the China; Pleistocene; Elaphe; research area, except for Elaphe schrenckii. The snake fauna of Shanyangzhai Cave represents the first Lycodon; Rhabdophis; Pleistocene snake remains described in any detail from a cave locality in North China. The bones in Gloydius Shanyangzhai Cave also represent the first fossil record of pit vipers in China. Introduction fauna in Shanyangzhai Cave, discussing the age and environ- ment of these fauna (Niu et al. 1999, 2003). However, none of In Eurasia, fossil snakes from the Pleistocene are well docu- these studies mentioned snake fossils. The snake remains mented in western and central Europe, but they are very studied here come from numerous excavations of Northwest poorly known in East Asia. To date, only four localities (or University since 2005 (Wang 2009; Zhang et al. 2010;Li2012; complexes of localities) have yielded fossils of Pleistocene Xie 2017). The purpose of this paper is to provide a detailed snakes: Zhoukoudian location 1 and 3 (Bien 1934), Haimao description of these snake fossils and discuss the paleoenvir- Cave (Sun 1992), Okinawajima Island (Otsuka 2002; Ikeda onment and snake distribution changes since the Pleistocene et al. 2016) and Renzidong Cave (Mead et al. 2016). This may in this region. be due to the lack of an adequate comprehensive skeletal collection of living snake species. Furthermore, snake fossil materials are usually disjointed when they are discovered, Material and methods consisting of fragmentary vertebrae and ribs, which makes it The Shanyangzhai fossil site has been subdivided into four difficult to collect these small fossils. However, snakes are locations by the latest research: SYZ 1 (discovered in 2005 useful in the reconstruction of terrestrial paleoenvironments (Xie 2017)), SYZ 2(discovered in 2000, named as location 2 of the Quaternary, since they are poikilothermal animals with by Niu et al. (2003)), SYZ 3 (discovered in 2000, named as relatively reduced mobility (Bailon 1991). Moreover, their location 1 by Niu et al. (2003)), and SYZ 4(discovered in 2015 fossil record promotes a better understanding of paleofaunis- (Xie 2017)). The snake remains described in this paper come tic and paleobiogeographic events during the Pleistocene from SYZ 2 and SYZ 4. (Venczel 2000), and an implicit understanding of the origin By comparing it with other Pleistocene fauna in North of the modern East Asia snake fauna. China (Niu et al. 2003; Zhang et al. 2010), the fauna of SYZ This paper reports on a snake fauna from the Pleistocene 2 indicates a middle to late Pleistocene age. Work by Xie in Shanyangzhai Cave. This cave is located at 119°31ʹ50″E, (2017) has also assigned SYZ 2 to the top of the middle 40°5ʹ13″N (165 m elevation) (Figure 1), near the village of Pleistocene, with an age of 270–330 ka estimated by Shanyangzhai, approximately 20 km north of Qinhuangdao, Electron Spin Resonance (ESR) dating. Considering that the Hebei Province, North China (Zhang et al. 2010). Since the test sample was collected from a lower layer than the fossil 1980s, the diverse fauna from this location have been site, the age of SYZ 2 should be slightly later than 270 ka. The described in several studies. The first mention of fossil bones of mammals from SYZ 4 were dated by the Accelerator remains a presence in Shanyangzhai Cave dates from Kong Mass Spectrometry (AMS) method, and the age obtained for (2009) who made the first excavation. Then, in the early these specimens was 22,287–22,753a B.P. (δ13C = 20.95). 1980s, a team from the Institute of Vertebrate Paleontology The collected sample included 905 fragments. Among and Paleoanthropology (IVPP), Chinese Academy of Sciences them, 472 fragments were from SYZ 2, and 433 fragments (Beijing) joined the excavation (Huang 1989). In approxi- were from SYZ 4. All of the abovementioned fossil specimens mately 2000, another team described some of the mammalian CONTACT Yong-Xiang Li [email protected] State Key Laboratory of Continental Dynamics, Department of Geology, National Demonstration Center for Experimental Geology Education (Northwest University), Xi’an China © 2019 Informa UK Limited, trading as Taylor & Francis Group Published online 02 Sep 2019 2 Y. CHEN ET AL. Figure 1. Location of Shanyangzhai Cave. are preserved in the Vertebrate Palaeontology Collection, have epizygapophyseal spines on the posterior tips of the Geology Department of Northwest University (NWUV). postzygapophyses (Holman 2000). The identifications of fossils described here were mainly based on the taxa presently inhabiting in the Palearctic Subfamily Colubrinae OPPEL, 1811 Realm of China (3 families, 11 genera, and 19 species), but the extant species only living in the Oriental Realm of China (3 families, 18 genera, and 26 species) were also Diagnosis considered. Skeletons of all 45 species (each species is Hypapophyses lack trunk vertebrae; the haemal keels are well represented by one specimen) were housed in the specimen projected from the centrum; subcentral ridges and grooves room of IVPP (the number of all 45 specimens are listed in are usually distinct; prezygapophyseal processes prominent Appendix 1 and Appendix 2). Furthermore, we also and well projected (Holman 2000). referred to the descriptions in some studies (Szyndlar 1984, 1991a, 1991b; Ratnikov 2004; Ikeda 2007). The dis- Genus Elaphe FITZINGER, 1833 tribution and the habitat of present species were mainly derived from Zhao et al. (1999)andZhao(2006). The Elaphe cf. schrenckii BOULENGER, 1916 vertebrae of snakes were measured according to (Figures 2 & 3) Auffenberg (1963)’s methods. All measurements and photo- graphy were performed with an Automated Digital Material Microscope ZEISS Smartzoom5 to the nearest 0.01 mm. Nineteen specimens from SYZ 4, including 14 mid-trunk The morphological characters and abbreviations used to vertebrae (NWUV 1492-1506) and 5 posterior-trunk verteb- describe the vertebrae follow Auffenberg (1963), Szyndlar rae(NWUV 1507-1510); most are complete or slightly (1984), LaDuke (1991) and Holman (2000). All terminology damaged. Specimens NWUV 1492 (Figure 2) and NWUV follows Holman (2000). The classification of taxa mostly 1507 (Figure 3) are the primary basis for our morphological follows Holman (2000). The regional subdivision of the descriptions. whole snake vertebral column follows LaDuke (1991). Description NWUV 1492 is a mid-trunk vertebra; CL = 7.93 mm; NAW = Systematic palaeontology 5.71 mm; CL/NAW = 1.39. In dorsal view, the anterior edge Family Colubridae OPPEL, 1811 of the zygosphene is concave; the prezygapophyseal articular facet oval; prezygapophyseal accessory process projects 1.33 mm beyond the facet and is directed laterally; the distal Diagnosis tip of the prezygapophyseal accessory process is pointed; Trunk vertebrae are usually lightly built and longer than wide; epizygapophyseal spines are absent. In ventral view, the hae- the centrum usually has prominent subcentral ridges; the mal keel is prominent, spatulate, extending from cotyle to prezygapophyseal processes are prominent; some species condyle, and gradually narrowed anteriorly; the HISTORICAL BIOLOGY 3 Figure 2. Middle-trunk vertebra of Elaphe cf. schrenckii (NWUV 1492). (a) – lateral view, (b) – anterior view, (c) – posterior view, (d) – dorsal view, (e) – ventral view. Scale bar = 2 mm. Figure 3. Posterior-trunk vertebra of Elaphe cf. schrenckii (NWUV 1507). (a) – lateral view, (b) – anterior view, (c) – posterior view, (d) – dorsal view, (e) – ventral view. Scale bar = 2 mm. postzygapophyseal articular facet is oval; subcentral ridges are slightly narrower than the zygosphene; the prezygapophyseal well developed and straight, with adjacent small subcentral accessory process is developed. In the posterior view, the foramina. In lateral view, the neural spine is 5.83 mm long neural arch is vaulted; the condyle is oval and larger than with a height of 3.08 mm; the anterior end of the neural spine the neural canal. NWUV 1493-1506 have the same morphol- is approximately vertical, and the posterior part of the neural ogy and are similar-sized vertebrae. spine overhangs posteriorly; the parapophyseal process is NWUV 1507 is a slightly damaged trunk vertebra that is undeveloped. In the anterior view, the cotyle is oval and quite similar to NWUV 1492, except for a distinct subcentral 4 Y. CHEN ET AL.