Spermophilopsis leptodactylus (Lichtenstein)

Kryštufek, Boris, Mahmoudi, Ahmad, Tesakov, Alexey S., Matějů, Jan & Hutterer, Rainer, 2016, A review of bristly ground squirrels Xerini and a generic revision in the African genus Xerus, Mammalia (Warsaw, Poland) 80 (5), pp. 521-540 : 535-536

Spermophilopsis leptodactylus (Lichtenstein) : Long-clawed ground squirrel

Arctomys leptodactylus Lichtenstein, 1823, p. 119 . Type locality is “140 Werst diesseits Buchara”, interpreted as “vicinity of Kara-Ata, 140 km north-west from Buchara, Uzbekistan ” ( Ognev 1940: 452). Thorington et al. (2012: 202) erroneously fixed the type locality to “ Dagestan, Russia ”.

Gromov and Erbajeva (1995) recognized three subspecies which differ in size and color.

Etymology. – “ Spermophilus ” (a genus of ground squirrels) from “sperma” (seed) and “phylos” (loving; both Greek) in allusion to the animal’s principal food+“opis” (Greek) “of appearance”; i.e. “of same appearance as ground squirrel”. The species name is from “leptos” (slender)+“dactylos” (finger, both Greek), on allusion on slender fingers bearing excessively long claws.

Diagnosis. – A large and short-tailed bristly ground squirrel with a seasonally dimorphic pelage (bristly and sparse in summer, long, dense and silky in winter); dorsal color is plain, with no stripes ( Figure 3 ). The external ear is extremely reduced to a rounded thickened rim, the tragus and the antitragus however are present. Soles and plants are densely clothed with hair; the pollex is clawed; claws on the remaining digits are heavily thickened and enlarged (> 10 mm in length) ( Figure 4 ); 1 tuft of supraorbital vibrissae. Melanocits are present in the cerebral dura mater ( Sokolov 1963). Skull is wide and deep, with short braincase ( Figure 6 ); external meatus acusticus has a bony tube; the parieto-interparietal suture is retained in adults; jugal bone has a short wedge-like extension between the lacrimal and maxillary ( Figure 10 ); buccinator and masticatory foramina fused. Cheek-teeth are strongly hypsodont; the 3 rd upper premolar is present ( Figure 8 ).

Distribution. – The long-clawed ground squirrel is restricted to sandy deserts (“peski” in Russian) of Central Asia, from the Caspian Sea in the west to Lake Balkash in the east, and from the Sea of Aral in the north to northern Afghanistan in the south ( Figure 9 ). The majority of distributional area is in Turkmenistan, Uzbekistan and southern Kazakhstan.

Remarks. – Abundant information on various biological issues of Spermophilopsis leptodactylus exists in Russian ( Sludskiy et al. 1969, Komarova 1980, Zubov and Svidenko 2005) which however is unknown to the English speaking community (cf. Thorington et al. 2012). For general review in English see Ognev (1966) and for a study of the ecology (in French) see RuŽić (1967).

Figures

Figure 3: Long-clawed ground squirrel SPermoPhiloPSiS lePtodactylUS (Kyzyl Kum, Kazakhstan; photo courtesy Nedko Nedyalkov).

Figure 4: Right front paw (ventral view) in (1) SPermoPhiloPSiS lePtodactylUS (ZFMK 92.478) and (2) AtlantoxerUS getUlUS (NMW 28084). Roman numerals correspond to digits (No. I is the thumb); a.v. – antebrachial vibrissae. Note that digit III is longer than either digits II and IV. Also note differences in length of claws (decidedly longer in SPermoPhiloPSiS) and in hairiness of the palm (nude in AtlantoxerUS). Not to scale.

Figure 6: Bivariate plot of six Xerini species onto the first two principal components (PC) derived from ordination of nine cranial measurements (transformed to log10). Percentage of variance explained by individual PC is in parentheses. 95% confidence ellipses show the dispersion of all specimens within each species and letters indicate group centroids. Skulls (in dorsal view) are depicted to scale: A – AtlantoxerUS getUlUS (PMS 19301); E – EUxerUS erythroPUS (ZFMK 47.972); Gi – GeoSciUrUS inaUriS (NMW 32092); GP – GeoSciUrUS PrincePS (NMW 32097); S – SPermoPhiloPSiS lePtodactylUS (NMW 25782); X – XerUS rUtilUS (ZFMK 81.234).

Figure 8: Left maxillary (above) and right mandibular (below) toothrows in Xerini: 1 – EUxerUS erythroPUS (NHML 69.10.24.18/ZFMK 97.467), 2 – XerUS rUtilUS (ZFMK 81.234/ZFMK 96.251); 3 – GeoSciUrUS inaUriS (ZFMK 55.147); 4 – AtlantoxerUS getUlUS (PMS 19301 / ZFMK 88.195); 5 – SPermoPhiloPSiS lePtodactylUS (ZFMK 92.497/ ZFMK 92.496). Abbreviations for cheek-teeth: P/p – upper/lower premolar, M/m – upper/lower molar; numbers refer to a position in the tooth-row. Scale bar=2 mm.

Figure 9: Distributional ranges of Xerini. Fossil (Late Oligocene to Early Pleistocene) records (top inset) are based on Fortelius (2015) with corrections and additions from Gromov and Erbajeva (1995), Kozhamkulova and Bendukidze (2005), Winkler et al. (2010), Flynn and Wessels (2013), and Maridet et al. (2014). Map of recent ranges (inset below) does not show the isolate of EUxerUS erythroPUS in Morocco, and the population of AtlantoxerUS getUlUS introduced to Fuerteventura, Canary Islands.

Figure 10: Anterior zygomatic arch in three genera of Xerini to show differences in a suture between the lacrimal (lac), the maxillary (max) and the jugal (ju) bones. 1 – SPermoPhiloPSiS lePtodactylUS (NMW 32092); 2 – AtlantoxerUS getUlUS (NMW 43000); 3 – EUxerUS erythroPUS (ZFMK 97.472). Arrow points on a wedge-like extension of the jugal between the lacrimal and maxillary in SPermoPhiloPSiS and AtlantoxerUS. A bluntly truncated top of jugal bone at the lacrimal bone which is distinctive of sub-Saharan Xerina, is shown by triangle. Not to scale.