Crocidura munissii, Stanley & Hutterer & Giarla & Esselstyn, 2015

Stanley, William T., Hutterer, Rainer, Giarla, Thomas C. & Esselstyn, Jacob A., 2015, Phylogeny, phylogeography and geographical variation in the Crocidura monax (Soricidae) species complex from the montane islands of Tanzania, with descriptions of three new species, Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 174 (1), pp. 185-215 : 207-208

CROCIDURA MUNISSII SP. NOV.

( FIGS 7 , 9 , 14 ; TABLES 3, 4, 6)

Holotype: FMNH 158290, an adult male with slightly worn molars (age class II; see Methods and Materials), prepared as a round skin, skull and skeleton, and frozen tissue (liver, heart and kidney) collected by W. T. Stanley (original field number W.T.S. 2651) on 11 August 1996. The condition of the skin, skull and post-cranial skeleton are good.

Paratypes: We designate nine specimens from Tanzania as paratypes: Morogoro Region, Morogoro District, Uluguru Mts, Uluguru North Forest Reserve, 3 km W, 1.3 km N Tegetero, 6.9292°S, 37.7056°E, 1345 m (FMNH 158280–158281, 158283); Uluguru Mts , Uluguru North Forest Reserve , 5.1 km W, 2.3 km N Tegetero, 6.92°S, 37.6833°E, 1535 m (FMNH 158287–158289); Uluguru Mts , Uluguru North Forest Reserve , 6 km W, 3 km N Tegetero, 6.9167°S, 37.675°E, 1850 m (FMNH 158410–158412). See Appendix for additional specimens examined .

Type locality: Tanzania, Morogoro Region, Morogoro District, Uluguru Mts, Uluguru North Forest Reserve , 5.1 km W, 2.3 km N Tegetero, 6.92°S, 37.6833°E, 1535 m .

Measurements of holotype: TL: 166; HB: 86; TV: 80; tail pilosity: 11%; HF: 17; EAR: 10; WT: 11.5 g; CI: 24.69; BL: 22.37; PPL: 10.91; PGW: 7.24; UTRL: 10.91; LIW: 5.14; BW: 7.21; NW: 2.19; GW: 10.25; HBC: 6.88; I 3 -W: 0.88; CW: 0.98; M 3 -L: 1.58; M 3 -W: 0.83; MP: 1.15; MI: 15.62; LTR: 10.06.

Diagnosis: Large Crocidura with a long tail (91% of HB in the Uluguru population) covered by only a few bristle hairs over 8–15% of its basal length ( Table 6); hindfoot long and narrow (17–19 mm), distance between thenar and interdigital pad 1 relatively larger ( Fig 7 ) than in C. monax , C. usambarae and C. tansaniana ; skull large (CI 22.7–25.8), braincase long with pronounced anterior facets; first upper incisor long and hook-like.

Description: Large shrews with a head and body length of 75–106 mm, a long tail of 66–95 mm and mass of 9.5–19.5 g ( Table 3). Ear pinnae are short, as in other species of this study. The longest mystacial vibrissae are about 24 mm in length. There are very few short bristles (3 mm) on the basal 8–15% of the tail (which is 85–93% of the length of head and body; Table 6). Dorsal and ventral pelage is rich brown in colour and hairs of the back are 6–7 mm in length. The hairs of the dorsum are steel grey with brown tips (with the exception of FMNH 166739 from Ukaguru which represents a light grey colour variant). The tail is equally brown. Front and hind feet are slightly paler, and covered by short brown to whitish hairs. The hindfoot of C. munissii differs from all other taxa treated here by its slenderness; it is rather long but narrow; digit 5 is longer than digit 1. The medial plantar surface is only glandular in its anterior part; there is more space between the thenar and the interdigital pad 1, and the interdigital pads 1–4 are situated more closely together than in C. monax and the other species ( Fig. 7 ).

The cranium is long (CI 22.70–25.76) as in C. tansaniana , but slightly smaller and narrower, with a narrow maxillary, a short broad interorbital region and a squarish braincase with prominent superior articular facets ( Fig. 14 ). The dorsal profile of the skull is flat from the rostrum to the interorbital region, but slightly domed over the braincase. The maxillary plate is large and bears a large foramen at its anterior rim. The lambdoidal crest is well developed. The first upper incisor is a long hook ( Figs 9 , 14 ) and extends beyond the tip of the second upper incisor and the fourth upper premolar. The upper unicuspids are wide, with broad cingula ( Fig. 14 ).

Comparisons: Crocidura munissii is best distinguished from all other Tanzanian species of the C. monax group by its relatively long tail (84–94% of HB), in combination with a low pilosity (means of 7–15% in all four populations; Table 6). The few scattered bristles are short. In overall size C. munissii equals C. tansaniana ; both species are larger than all other taxa of this study ( Table 1). Mean hindfoot measurements of all four populations are larger than all other species, but there is overlap with C. monax and C. tansaniana ( Table 3). The hindfoot of C. munissii differs by the close arrangement of the plantar pads ( Fig. 7 ).

In skull size, C. munissii resembles C. tansaniana , although East Usambara populations of the latter species tend to be larger ( Table 4). The length of the third upper molar is also larger in C. tansaniana . The first upper incisors are very long in all four populations of C. munissii , but are similar to those of C. tansaniana . The upper unicuspids are wide with broad cingula.

Distribution: The species occurs on four southern mountains of the Eastern Arc: Rubeho, Udzungwa, Ukaguru and Uluguru Mountains.

Etymology: The species is named in honour of Maiko J. Munissi in recognition of his contribution to our understanding of the natural history of montane mammals in Tanzania. This study, and many others, could not have happened without Munissi’s tireless efforts during faunal inventories of each of the mountains covered here. We suggest the common name Munissi’s shrew.

Ecological notes: Crocidura munissii is found in submontane and montane habitats (sensu Lovett & Pocs, 1993) of the Rubeho, Udzungwa, Ukaguru and Uluguru Mountains. Syntopic soricids include Crocidura hildegardeae , C. desperata , C. elgonius , C. olivieri , C. telfordi , Myosorex geata and M. kihaulei , Suncus lixus , S. megalura and Sylvisorex howelli . Stanley & Hutterer (2007) documented C. munissii (reported as C. monax ) in habitats above 1450 m in the Udzungwa Scarp forests, but not below in drier forests.

Figures

Figure 7. Plantar view of the right hindfoot of (A) Crocidura monax (FMNH 173789), (B) C. newmarki sp. nov. (FMNH 208012) and (C) C. munissii sp. nov. (FMNH 158407); scale is 5 mm. Note differences in the relative distance between thenar (T), hypothenar (H) and interdigital pads (I1–4).

Figure 9. Lateral views of the first upper incisor of populations of the C. monax species group; scale is 1 mm: A, Ngorongoro FMNH 211332 (= C. mdumai sp. nov.); B, Uluguru FMNH 158280 (= C. munissii sp. nov.); C, Udzungwa FMNH 155501 (= C. munissii sp. nov.); D, Ruhebo FMNH 197660 (= C. munissii sp. nov.); E, Ukaguru FMNH 166705 (= C. munissii sp. nov.); F, Meru FMNH 208424 (= C. newmarki sp. nov.); G, Kilimanjaro FMNH 174109; H, North Pare FMNH 192665 (= C. monax); I, South Pare FMNH 153918; J, Magamba FMNH 27429 (= C. usambarae); K, West Usambara FMNH 151099; L, East Usambara FMNH 149970 (= C. tansaniana).

Figure 14. Dorsal, ventral and lateral views of adult cranium and mandible of Crocidura munissii [FMNH 158290 (holotype); CI = 24.69 mm], a male from 5.1 km west, 2.3 km north of Tegetero in the Uluguru Mountains (1535 m).