Pakistan J. Zool., vol. 39(5), pp. 333-338, 2007. New Fossil Remains of Selenoportax vexillarius From The Late Miocene of Hasnot MUHAMMAD AKBAR KHAN*, ABDUL GHAFFAR, UMAR FAROOQ AND MUHAMMAD AKHTAR Department of Zoology, University of the Punjab (Quaid-e-Azam Campus), Lahore, Pakistan (MAK, UF, MA), Department of Meteorology, COMSATS, Institute of Information Technology, Islamabad (AG) Abstract.- First and second lower molars of Selenoportax vexillarius, collected from the late Miocene of Hasnot (Middle Siwaliks) are described in this paper. The studied specimens were collected during previous decades by palaeontological expeditions working in the late Miocene sediments of Hasnot, and are housed in the Abu Bakr Fossil Display and Research Center of Zoology Department, Punjab University, Lahore, Pakistan. The studied specimens are compared with relevant specimens at the American Museum of Natural History (AMNH) and the Punjab University Palaeontological Collection (PUPC). The variation in size in the dentition of S. vexillarius is also observed. The sediments of Hasnot comprise a late Miocene vertebrate fauna constrained to between 7 and 5 million years ago, including a variety of boselaphine bovids which distinguish the sediments from the other sediments of the Siwaliks. Key words: S. vexillarius, Middle Siwaliks, Late Miocene, Hasnot, Molars. INTRODUCTION Pecorans, ruminants with cranial appendages such as horns, became widespread in the early Miocene. Subfamilies and tribes within the horned families began to differentiate in the Middle Miocene, but some modern groups of these ranks are known only from the late Miocene onward (Gentry, 2000). Bovids have no upper incisors, and vestigial minute upper canines occur in only a minority of individuals. The cheek teeth are selenodont and the crescentic cusps join to one another earlier in wear than in cervids and giraffids. A canon bone comprising fused metapodials III and IV is absent or more reduced than in cervids. Compared with cervids or giraffids, many bovids show more hypsodont teeth, stronger cursorial characters in their limb bones and territorial behavior (Gentry, 1990). By the latter Middle Miocene it is apparent that the Siwaliks region was inhabited by various boselaphines, caprines and the smaller Gazella. Bovids and giraffids are best known from Africa and southern Asia (Gentry, 1994). The large boselaphines in the Siwaliks * Corresponding author: Curator, Department of Zoology, University of the Punjab, Lahore. E-mail: akbaar111@yahoo.ca 0030-9923/2007/0005-0331 $ 8.00/0 Copyright 2007 Zoological Society of Pakistan. include Selenoportax and Pachyportax, which were present in the Middle and Upper Siwaliks (Pilgrim, 1937, 1939; Akhtar, 1992, 1995, 1996). Selenoportax was a bovid abundant in the late Miocene of the Siwaliks. The fossils described in this paper come from Hasnot about 70 kilometers west of Jhelum in the fresh water deposits of the Middle Siwaliks (Fig. 1). Lithostratigraphically the sediments belong to the Dhok Pathan Formation (Middle Siwaliks) which is characterized by sandstones with orange brown alternating clays and scattered conglomerates in lower part and more conglomerates with sandstones and clays in the upper part. The clays are orange brown in colour and the time of deposition ranges from 10.1-3.5 Ma (Pilbeam et al., 1977; Johnson et al., 1982; Barry et al., 1982, 2002; Barry, 1987). The aim of the paper is to describe the new findings of the Selenoportax dental remains from Hasnot. ABBREVIATIONS PUPC, Punjab University Palaeontological Collection, housed in the Department of Zoology, Punjab University, Lahore, Pakistan; AMNH, American Museum of Natural History, New York, United States of America; Ma, Million years ago; H, Hasnot; M 1 , first lower Molar; M 2 2 , second upper