+Model PALWOR-407; No. of Pages 15 ARTICLE IN PRESS Available online at www.sciencedirect.com ScienceDirect Palaeoworld xxx (2017) xxx–xxx A new species of Tetralophodon from the Linxia Basin and the biostratigraphic significance of tetralophodont gomphotheres from the Upper Miocene of northern China Shi-Qi Wang a,b,∗, Haruo Saegusa c, Jaroon Duangkrayom a,d, Wen He e, Shan-Qin Chen e a Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China b CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China c Division of Earth Sciences, Institute of Nature and Environmental Sciences, University of Hyogo/Museum of Nature and Human Activities, Hyogo, Yayoigaoka 6, Sanda 669-1546, Japan d Northeastern Research Institute of Petrified Wood and Mineral Resources, Nakhon Ratchasima Rajabhat University, Nakhon Ratchasima 30000, Thailand e Hezheng Paleozoological Museum, Hezheng, Gansu 731200, China Received 1 December 2016; accepted 30 March 2017 Abstract Tetralophodont gomphotheres, i.e., Tetralophodon, Paratetralophodon, and Anancus, show significant morphological diversity and are of great importance for the biostratigraphy of the Upper Miocene. However, material of this group from the Upper Miocene of northern China is rare and easily to be confused with the similar taxa such as Konobelodon and Stegolophodon. The stratigraphy of this group is also unclear in China. Here we described the first mandible from northern China that can be definitely attributed to Tetralophodon, and erected a new species Tetralophodon euryrostris n. sp. Furthermore, we amended the previously reported tetralophodont gomphotheres from northern China. We attributed the type material of “Tetralophodon exoletus”to?Paratetralophodon exoletus, the material from Lantian region (“Tetralophodon exoletus”) to Paratetralophodon sp., and the material from the Qaidam Basin (Tetralophodon sp.) to Tetralophodon aff. xiaolongtanensis. We also discussed the stratigraphic ranges of the tetralophodont proboscideans from the Upper Miocene of China, that is, Tetralophodon aff. xiaolongtanensis from MN9, Tetralophodon cf. euryrostris from MN10, Konobelodon robustus from MN9–MN10, Paratetralophodon sp. from MN11, ?Paratetralophodon exoletus from MN12, and Stegolophodon licenti from MN13. This work is important for the study of the taxonomy and biostratigraphy of tetralophodont gomphotheres from the Upper Miocene of northern China. © 2017 Elsevier Ireland Ltd Elsevier B.V.and Nanjing Institute of Geology and Palaeontology, CAS. Published by Elsevier B.V.All rights reserved. Keywords: Tetralophodont gomphotheres; Tetralophodon; Upper Miocene; Northern China; Biostratigraphy 1. Introduction elephants (Tassy, 1985, 1988, 1996; Shoshani, 1996). Because tetralophodont gomphotheres are a paraphyletic group, the fam- Tetralophodont gomphotheres are an important group in the ily hierarchy of this group is undetermined (Shoshani and evolution of proboscideans, and proximally related to the true Tassy, 2005) or they are attributed to the paraphyletic Gom- photheriidae (Gheerbrant and Tassy, 2009). They were dominant proboscideans in the Late Miocene of Eurasia (Göhlich, 1999). ∗ Corresponding author at: Key Laboratory of Vertebrate Evolution and However, fossil records of tetralophodont gomphotheres from Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleon- the Upper Miocene of northern China are rare, relatively to tology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, Western Europe and southern Asia, and the taxonomy of China. Fax: +86 10 68337001. these specimens is controversial. For example, the classical E-mail addresses: [email protected] (S.Q. Wang), taxon “Tetralophodon exoletus Hopwood, 1935” was erected [email protected] (H. Saegusa), [email protected] (J. Duangkrayom), hzbwg [email protected] (W. He), based on the type material from the Baode region (Hopwood, hzbwg [email protected] (S.Q. Chen). 1935)(Fig. 1), and Liu et al. (1978) reported other speci- http://dx.doi.org/10.1016/j.palwor.2017.03.005 1871-174X/© 2017 Elsevier Ireland Ltd Elsevier B.V. and Nanjing Institute of Geology and Palaeontology, CAS. Published by Elsevier B.V. All rights reserved. Please cite this article in press as: Wang, S.Q., et al., A new species of Tetralophodon from the Linxia Basin and the biostratigraphic significance of tetralophodont gomphotheres from the Upper Miocene of northern China. Palaeoworld (2017), http://dx.doi.org/10.1016/j.palwor.2017.03.005 +Model PALWOR-407; No. of Pages 15 ARTICLE IN PRESS 2 S.Q. Wang et al. / Palaeoworld xxx (2017) xxx–xxx Fig. 1. Map showing the fossil localities in China bearing tetralophodont proboscideans mentioned in the present article. mens from the Lantian region (Fig. 1). However, Tobien et al. In the Hezheng Palaeozoological Museum, there is a com- (1988) attributed the hypodigm to “Stegotetrabelodon exoletus” plete mandible of a tetralophodont gomphothere (HMV 1427). and referred the Lantian material to “Tetralophodon (Parate- It is the first complete mandible of a tetralophodont gomphothere tralophodon) cf. hasnotensis”. Other researchers debated on the from China, and is clearly distinguishable from K. robustus occurrence of Stegotetrabelodon in eastern Asia (Tassy, 1999; from the Liushu Formation of the Linxia Basin. On the basis Ferreti et al., 2003). Recently recognized tetralophodont ame- of the morphology of the mandible, we attributed this speci- belodontid Konobelodon robustus from the Upper Miocene of men to Tetralophodon and erected a new species Tetralophodon the Linxia Basin (Wang et al., 2016a), which had been identi- euryrostris n. sp. This is definitive evidence for the occurrence fied as “Tetralophodon sp.” and “Tetralophodon exoletus”(Deng of the genus Tetralophodon in northern China. Furthermore, et al., 2004, 2013), further complicated this problem (Fig. 1). For we amended the other material of tetralophodont gomphotheres example, can Konobelodon be used to name other material of from northern China, compared their tooth morphology with the Tetralophodon from northern China? And if so, is Tetralophodon related taxa such as Konobelodon and Stegolophodon. The strati- really present in northern China? These questions remain to be graphic occurrences of the tetralophodont proboscideans were resolved. also discussed based on the newly established Asian biochrono- Besides the above material, there are other two records of logical framework (Qiu et al., 2013; Wang et al., 2013). Hence tetralophodont gomphotheres from the Upper Miocene of north- this work improves the study of systematic evolution and bios- ern China with known horizon: Tetralophodon sp. from the tratigraphy of tetralophodont gomphotheres, an important group Qaidam Basin (Bohlin, 1937), Tetralophodon cf. exoletus from of proboscideans, from the Upper Miocene of northern China. Wuzhong (Qiu et al., 1987)(Fig. 1). The remaining speci- mens of tetralophodont gomphotheres, i.e., “Gomphotherium 2. Material and methods watzeensis”(Hu, 1962) and “Gomphotherium quinanensis” (Chow and Chang, 1961) (attributed to “Tetralophodon (Parate- 2.1. Institutional abbreviations tralophodon) cf. hasnotensis” and “Stegotetrabelodon exoletus” by Tobien et al. (1988), respectively), are represented only by molar fragments, and their precise localities and horizons are GPAHLD: Geologisch-Paläontologische Abteilung des Hessis- unknown. chen Landesmuseums, Darmstadt, Germany. Please cite this article in press as: Wang, S.Q., et al., A new species of Tetralophodon from the Linxia Basin and the biostratigraphic significance of tetralophodont gomphotheres from the Upper Miocene of northern China. Palaeoworld (2017), http://dx.doi.org/10.1016/j.palwor.2017.03.005 +Model PALWOR-407; No. of Pages 15 ARTICLE IN PRESS S.Q. Wang et al. / Palaeoworld xxx (2017) xxx–xxx 3 HMV: Hezheng Paleozoological Museum, Hezheng, China. Occurrences: ? early Late Miocene,? MN10 (reasons see below, IVPP: Institute of Vertebrate Paleontology and Paleoanthropol- Section 4.3), northern China. ogy, Beijing, China. Diagnosis: medium-sized Tetralophodon; mandibular symph- NMHW: Naturhistorisches Museum, Vienna, Austria. ysis and mandibular tusks relatively wide and long with a marked symphyseal groove; mandibular symphysis moderately MSB: Museo del Seminario, Barcelona, Spain. ventrally deflected; mandibular tusks dorsally concave, oval MNM: Naturhistorisches Museum, Mainz, Germany. cross-sectioned, and with a faint dorsal groove; exposed length of mandibular tusks subequal to symphyseal length; mandibular PMU: Palaeontological Museum, Uppsala. angular process blunt, slightly higher than the occlusal plane; UZ: Palaeontological collection in the Zoology Department, ascending ramus perpendicular to the occlusal plane; cheek University of the Panjab, Lahore, Pakistan. teeth showing convergent features with Stegolophodon, i.e., lophid straight, anterior pretrite central conules (except in the 2.2. Material first lophids) nearly absent, posterior central conule small and low, and mesoconelets enlarged. Differing from Tetralophodon The material with respect to T. euryrostris n. sp. is housed in longirostris in wider, stronger, and more ventrally defected HMV.It was collected by a local villager, and the precise locality mandibular symphysis, and in thicker and longer mandibular cannot be traced. Judged from the sediments attached