New Fossils of Gaindatherium (Rhinocerotidae, Mammalia) from the Middle Miocene of Pakistan

Turkish Journal of Earth Sciences Turkish J Earth Sci (2014) 23: 452-461 http://journals.tubitak.gov.tr/earth/ © TÜBİTAK Research Article doi:10.3906/yer-1312-24 New fossils of Gaindatherium (Rhinocerotidae, Mammalia) from the Middle Miocene of Pakistan 1 2 1 Abdul Majid KHAN , Esperanza CERDEÑO , Muhammad AKHTAR , 1 1 3 Muhammad Akbar KHAN , Ayesha IQBAL , Muhammad MUBASHIR 1 Paleontology Laboratory, Department of Zoology, University of the Punjab, Lahore, Pakistan 2 Department of Paleontology, The Argentine Institute of Snow Research, Glaciology, and Environmental Sciences (IANIGLA), Science and Technology Center- National Scientific and Technical Research Council (CCT-CONICET), Mendoza, Argentina 3 Department of Zoology, Government College University Faisalabad, Faisalabad, Pakistan Received: 30.12.2013 Accepted: 24.04.2014 Published Online: 17.06.2014 Printed: 16.07.2014 Abstract: New isolated teeth with maxillary and mandibular fragments from the Chinji Formation of the Lower Siwaliks are described and determined as Gaindatherium browni and Gaindatherium vidali. This material comes from the Middle Miocene of Lava and Dhok Bun Ameer Khatoon localities, northern Pakistan, and significantly increases the number of remains previously known for this rhinocerotid genus. Specimens from the Lava site determined as G. vidali present morphological differences with respect to those of G. browni, being similar to those of G. vidali from the Nagri Formation, showing a greater size. Previously, G. vidali was reported only from the Nagri Formation of the Middle Siwaliks and the new material thus significantly widens the chronological distribution of this species in the continental deposits of the Siwaliks. This record implies that both species are not successive but rather coeval during the late Middle Miocene. Key words: Rhinocerotinae, Chinji Formation, Siwaliks, Potwar Plateau, biostratigraphy 1. Introduction the mammal assemblage recovered from the Lava site. The Fossil vertebrates from Pakistan and particularly the whole sample is a significant increase of known remains Tertiary deposits of the Siwalik Group (Pakistan and assigned to Gaindatherium since Heissig’s (1972) work. India) have been studied for more than a century (e.g., The genus Gaindatherium was described by Colbert Lydekker, 1883, 1884; Pilgrim, 1913, 1917; Matthew, 1929; (1934) with the species G. browni from the Chinji Pilbeam et al., 1979, 1996; Flynn et al., 1995; Barry et al., Formation. A second species was later added, G. vidali, 2002). Among mammals, fossil rhinocerotids from the characterizing the overlying Nagri Formation (Heissig, Siwaliks and other Pakistani areas are very abundant and 1972); that author identified this species from one of diversified (Lydekker, 1881, 1884; Colbert, 1934, 1935; the specimens included previously in G. browni by Forster-Cooper, 1934; Heissig, 1972; Cerdeño and Hussain, Colbert (1934), namely the mandible AMNH 19471 1997; Antoine and Welcomme, 2000; Antoine et al., 2003, that also comes from the Nagri Formation. Antunes and 2010). The recent revision of unpublished specimens from Ginsburg (1983) recognized the genus Gaindatherium in the Siwaliks (Khan, 2009) revealed the presence of new West Europe, describing the new subgenus and species material of Alicornops, Chilotherium, and Gaindatherium Gaindatherium (Iberotherium) rexmanueli from several from different areas of the Potwar Plateau. Chilotherium localities in the Lisbon area (Portugal). Later, Ginsburg et and Alicornops remains have been already studied in al. (1987) assigned to the same species 8 isolated teeth from detail (Khan MA et al., 2011; Khan et al. 2013), and this Beaugency-Tavers (France). However, Cerdeño (1996) contribution presents the comparative description of the considered G. rexmanueli as belonging to Prosantorhinus, material identified asGaindatherium , coming from the a Miocene genus known from Germany and France and Chinji Formation at 2 different localities, Lava and Dhok then extended to Spain and Portugal. She proposed the Bun Ameer Khatoon. Two of the included specimens were species Gaindatherium rexmanueli as synonymous with preliminarily studied by Khan MA et al. (2011b) as part of Prosantorhinus douvillei. * Correspondence: [email protected] 452 KHAN et al. / Turkish J Earth Sci Gaindatherium has a wide geographic as well as Ginsburg and Tassy, 1985; Ducrocq et al., 1994, 1995; stratigraphic range in and outside Pakistan. In Baluchistan Peigné et al., 2006). (Pakistan) it is known from the Early Miocene of the Vihowa and Chitarwata Formations and it was living in 2. Geographic and stratigraphic context association with a diversified and exceptionally large The studied material comes from 2 fossil localities found rhinoceros assemblage, very rich in diceratheriines, nearby Lava and Dhok Bun Ameer Khatoon villages, rhinocerotines, elasmotheriines, and teleoceratines Chakwal district, northern Pakistan (Figure 1). The (Antoine and Welcomme, 2000; Metais et al., 2009). geography and geology of the areas were described by The Manchar Formation in Sindh has also yielded Khan MA et al. (2008, 2011b). Gaindatherium sp. from strata equivalent to the Kamlial The Lava locality (32°62′N, 71°98′E) is located 11 and Chinji Formations in the Potwar Plateau (Raza et al., km southeast of Lava village; the fossiliferous section is 1984). characterized by sandstone and reddish shale characteristic The Lower Siwaliks of the Ramnagar region, of the Chinji Formation in the Siwaliks (Khan MA et al., Jammu, India, have yielded Gaindatherium browni, 2011b). Brachypotherium perimense, and Chilotherium sp., Dhok Bun Ameer Khatoon (32°47′N, 72°55′E) is along with other mammals representing small- and situated about 16 km northeast of Chua Saydan Shah medium-sized browsing forms, very similar to the Chinji (Figure 1). It constitutes one of the most famous fossiliferous mammalian fauna (Middle Miocene) of the Potwar localities of the Siwaliks, comprising a panorama of Plateau, Pakistan (Basu, 2004). The assemblage indicates sedimentary exposures of all the 5 component formations a woodland-type ecosystem having a substantial forest (Kamlial, Chinji, Nagri, Dhok Pathan, and Soan) of the component and subordinately developed grassy subareas Siwalik group (Johnson et al., 1982; Cheema, 2003; Khan (Basu, 2004). et al., 2008; Khan MA et al., 2011a). The stratigraphic and According to Chavasseau et al. (2009), in the sedimentological details can be found in the works of Raza Middle Miocene fossiliferous Li and Pong basins (1983) and Friend et al. (2001). of northwestern Thailand, Gaindatherium lived in association with Stegolophodon (Tassy et al., 1992) as well 3. Materials and methods as the anthracothere Brachyodus and the suid Conohyus The fossils described herein were collected by some of (Ducrocq et al., 1994, 1997). Gaindatherium has also the authors (AMK, MAK, MA) and are housed in the been collected from the Mae Moh basin of Thailand in Dr Abu Bakr Fossil Display and Research Center of the association with Stegolophodon, the mustelid Siamogale, Department of Zoology, University of the Punjab, Lahore, and the amphicyonid Maemohcyon (Ginsburg et al., 1983; Pakistan. The specimens are cataloged into 2 series: the Figure 1. Geographic locations and chronostratigraphic correspondences of Lava and Dhok Bun Ameer Khatoon localities of the Chinji Formation (middle Miocene; 14.2–11.2 Ma) in northern Pakistan. 453 KHAN et al. / Turkish J Earth Sci first figure denotes the collection year, while the second Subfamily Rhinocerotinae GRAY, 1821 denotes the serial number of the respective specimen. Tribe Rhinocerotini GRAY, 1821 They are detailed in Section 4. Subtribe Rhinocerotina OWEN, 1845 For morphological descriptions, tooth cusp Genus Gaindatherium COLBERT, 1934 nomenclature follows Heissig (1972). Tooth length and Type species: Gaindatherium browni COLBERT, 1934 width were measured at maximum level and dimensions Gaindatherium browni COLBERT, 1934 are given in millimeters. The comparative study was (Figures 2 and 3; Table 1) mainly based on data from Colbert (1934, 1935) and 1934 Gaindatherium browni. – Colbert, pp. 1–13; figures Heissig (1972) for previous material from the Lower 1–5; tables 1 and 2. and Middle Siwalik localities. Suprageneric classification 1972 Rhinoceros (Gaindatherium) browni. – Heissig, follows Antoine et al. (2003). pp. 18–24; plates 1 and 2; plate 4, figure 5. Abbreviations: AMNH – American Museum of Holotype. – AMNH 19409, an almost complete skull. Natural History; D – deciduous; Fm. – Formation; H – Stratigraphic Level. – Chinji Formation (14.2–11.2 height; i – lower incisor; l – left; L – length; M – upper Ma), the Lower Siwaliks. molar; m – lower molar; Ma – million years; P – upper Diagnosis [after Colbert (1934) and Heissig (1972)]. premolar; p – lower premolar; Pl. – plate; PUPC – Punjab – An Upper Tertiary rhinoceros of medium size, with a University Paleontological Collection; r – right; W – width. saddle-shaped skull having a single horn on the nasals, and with brachydont, simple molar teeth. The orbit is located 4. Systematic paleontology in an approximately central position above the first molar; Order Perissodactyla OWEN, 1848 the occiput is vertical; the postglenoid and posttympanic Family Rhinocerotidae GRAY, 1825 processes are fused, forming a closed tube for the external Figure 2. Gaindatherium browni (Rhinocerotini, Rhinocerotidae, Mammalia). 1, PUPC 02/146, rP1; 2, PUPC 08/122, lP2; 3, PUPC 08/123, rP3; 4, PUPC 08/124,

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