Dipodidae Author Don E. Wilson Author Russell A. Mittermeier Author Thomas E. Lacher, Jr text 2017 2017-11-30 Lynx Edicions Barcelona Handbook of the Mammals of the World – Volume 7 Rodents II 81 100 book chapter 60686 10.5281/zenodo.6591722 9d33d7df-dc06-426e-8945-d99b967af193 978-84-16728-04-6 6591722 7. Balochistan Pygmy Jerboa Salpingotus michaelis French: Gerboise du Baloutchistan / German: Belutschistan-Dreizehenzwergspringmaus / Spanish: Jerbo pigmeo de Beluchistan Other common names: Dwarf Three-toed Jerboa Taxonomy. Salpingotus michaelis FitzGibbon, 1966 , “Desert plateau of Nushki , north-western Baluchistan , approximately 29° N , 66° E , 3,500 feet [ 1067 m ],” Pakistan . Salpingotus michaelis is in the subgenus Salpingotulus . It is considered by some authors to be in a separate genus, but its position on the phylogenetic tree constructed with use of morphological characteristics place it in the genus Salpingotus , being sister group of Anguistodontus. Monotypic. Distribution. SW Pakistan (Balochistan). Descriptive notes. Head-body 41-45 mm, tail 72-94 mm, ear 6-11 mm, hindfoot 18— 19 mm; weight 4 g. The Balochistan PygmyJerboa is very small. Condylo-basal lengths of skulls are 12:8-14-3 mm, mastoid breadths are 13-3-14-7 mm, and maxillary tooth row lengths are 2-6-2-8 mm. Head and dorsum are pale yellow-ocher or sandy buff; sides and ventral pelage are pure white. Tail is fatty, with relatively long black terminal tuft; fat deposits in tail are greatest in anterior one-third and rapidly become thinner toward tip. Hindfeet have three toes, covered below with brushes of white hairs; toes do not have conic calluses at bases. Ears are short and tubiform. Auditory bullae are greatly inflated and strongly project from under braincase laterally and caudally. Mastoid cavity is large and completely subdivided into three sections by septum. In volume, mastoid cavity is about twice as large as tympanic cavity. Front surfaces of incisors are yellow. P' is present and slightly smaller in diameter than M®. Molars are low-crowned, with tuberculous surfaces; crown heights of unworn molars are ¢.70% of their lengths. Glans penis is small, thin, elongated, cone-shaped, and not subdivided into lobes, with surface covered by very small single-vertex, backward-directed aciculae not differentiated in size. Os penis (baculum) is rudimentary and rachis-like; its length about equal to one-tenth of the length of glans penis. Habitat. Rolling sand dunes, sandy plains,orflat gravel plains with wind-moving sand layer in hot deserts at elevations of 1000-1600 m. Food and Feeding. The Balochistan Pygmy Jerboa mainly eats grass seeds and some other plant material. Breeding. Pregnant Balochistan Pygmy Jerboas were recorded in June-August. Females produce two litters per year. Litters have 2—4 young. Activity patterns. The Balochistan PygmyJerboa is nocturnal. It does not hibernate but can become torpid at low temperatures. Movements, Home range and Social organization. In captivity, social interactions of Balochistan PygmyJerboas are amicable; up to 5-6 adults can sleep huddled together during the day. Status and Conservation. Classified as Data Deficient on The IUCN Red List (as Salpingotulus michaelis ). The Balochistan Pygmy Jerboa is known from only nine localities in Chagai District (Balochistan) in ¢.3000 km?. Bibliography. FitzGibbon (1966), Roberts (1997).