Scarturus tetradactylus
Creators: name: Don E. Wilson
name: Russell A. Mittermeier
name: Thomas E. Lacher, Jr
Publisher: name: Lynx Edicions
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Rodentia
Dipodidae
Scarturus
Scarturus tetradactylus

description: 21.
Four-toed Jerboa
Scarturus tetradactylus
French: Gerboise a quatre doigts / German: Vierzehen-Pferdespringer / Spanish: Jerbo tetradactilo
Taxonomy. Dipus tetradactylus Lichtenstein, 1823,
Libyan Desert between Siwa and Alexandria, Egypt.
Previously included in the genus Allactaga and later Paralactaga, which has recently been found to be a junior synonym of Scarturus. Phyllogenetically, it is in the subgenus Scarturus. Monotypic.
Distribution. Coastal NE Libya and NW Egypt.
Descriptive notes. Head-body 102-119 mm, tail 154-180 mm, ear 37-43 mm, hindfoot 51-59 mm; weight 48-56 g. There is no significant secondary sexual dimorphism. Condylo-basal lengths of skulls are 27-3-30-4 mm, zygomatic breadths are 19-1-22-6 mm, and maxillary tooth row lengths are 5-2-6-2 mm. Head and dorsum are dark grayish orange; sides and ventral pelage are pure white; and tail banner is wide and well flattened, with short fuzzy whitish basal ring, long black subterminal field, and short white terminal tuft. Hindfeet have four toes. Toes of hindfeet are covered from below with medium-length soft blackish hairs not forming brushes; conic calluses at bases of toes are large and high, with wide bases and rounded apexes. Auditory bullae are weakly inflated. Mastoid cavity is medium-sized and not subdivided into sections; tympanic cavity is extremely small. Front surfaces of incisors are white; incisors are weakly deflected forward. P' is three times smaller in diameter than M®. Molars are medium-crowned, with terraced masticatory surfaces; crown heights of unworn molars are 80-90% of their lengths. Glans penis is heart-shaped, somewhat compressed in dorso-ventral direction, subdivided by deep longitudinal dorsal fold into two lateral lobes; surfaces of lobes are covered by single-vertex, backward-directed aciculae slightly increasing in size in backward direction; and aciculae cover all surfaces of lobes and are arranged in 10-12 concentric rows, with 12-16 aciculae in each row. Os penis (baculum) is absent. Chromosomal complement has 2n = 48 and FN = 96.
Habitat. Only coastal salt marshes and “hamadas” (barren, hard, rocky plateaus) and inland flat clay desert along the Mediterranean coast.
Food and Feeding. Little is known, but molar morphology of the Four-toedJerboa suggests that its diet contains seeds and green plant material, particularly from succulent vegetation.
Breeding. No information.
Activity patterns. The Four-toedJerboa is nocturnal, but it is not known if it hibernates.
Movements, Home range and Social organization. Burrows are simple, 60-150 cm deep.
Status and Conservation. Classified as Vulnerable on The IUCN Red List (as Allactaga tetradactyla). The Four-toed Jerboa has disappeared from certain coastal valleys near Alexandria, Egypt (where it was originally collected). Its status could change in the near future, so there is an urgent need for new survey work to clarify its conservation status. It could be threatened by desert reclamation, so assessment of remaining habitat is essential.
Bibliography. Moore et al. (2015), Osborn & Helmy (1980), Ranck (1968), Shahin & Ata (2001).
description: Published as part of Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Dipodidae, pp. 81-100 in Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona :Lynx Edicions on page 93, DOI: 10.5281/zenodo.6591722