Crocidura australis, Esselstyn & Achmadi & Handika & Swanson & Giarla & Rowe, 2021

Esselstyn, Jacob A., Achmadi, Anang S., Handika, Heru, Swanson, Mark T., Giarla, Thomas C. & Rowe, Kevin C., 2021, Fourteen New, Endemic Species Of Shrew (Genus Crocidura) From Sulawesi Reveal A Spectacular Island Radiation, Bulletin of the American Museum of Natural History 2021 (454), pp. 1-109 : 48-49

Crocidura australis , new species

LSID: urn:lsid:zoobank.org:act:3ABC433E-7C35-47DD-B52B-D33CC37F8F62

HOLOTYPE: MZB 43003 (= MVZ 237610 ), an adult of unknown sex collected by K.C. Rowe on 30 October 2016. The specimen was preserved as a study skin, cleaned skull ( fig. 24 ) and skeleton, and frozen tissues. External measurements from the holotype are: 141 mm × 65 mm × 16 mm × 11 mm = 9.8 g. The voucher specimen and a tissue sample will be permanently curated at MZB, with another tissue sample retained at MVZ.

TYPE LOCALITY: Indonesia, Sulawesi Selatan, Sinjai, Sinjai Barat, Gunung Perak Village , Mt. Bawakaraeng ; 5.308463° S, 119.948661° E, 2390– 2550 m elevation.

ETYMOLOGY: We use the Latin for “southern,” as this species is the most southern member of the Rhoditis Group.

GEOGRAPHIC DISTRIBUTION: This species is known only from the south-west area of endemism and was only collected from Mt. Bawakaraeng, South Sulawesi Province ( fig. 20 ) on traplines placed around 1660–2040 and 2390– 2550 m elevation ( fig. 13 ; table 3 ).

DIAGNOSIS: Crocidura australis is a mediumsized shrew ( tables 2 , 7 ) with a thick, mediumbrown dorsal pelage and slightly paler venter. Hairs of the middorsum are 6–7 mm long. The color of the tail matches that of the dorsal pelage, but the feet are paler than the surrounding fur, particularly on the digits ( fig. 21A ). The tail is slightly shorter than the head-and-body length and not distinctly bicolored. Applied hairs on the tail are inconspicuous and bristles are sparsely distributed along the proximal half of tail length. The claws are translucent and surrounded by small tufts of white hairs. On the hind foot, the claws are long and the tufts more prominent than on the forefoot. The foot pads are more darkly pigmented than the surrounding plantar and palmar surfaces, but the difference is greater on the hind foot than on the forefoot. The external ears, though not small, are indistinct from the surrounding fur, due to the matching color, length, and density of the pelage. The mystacial vibrissae are relatively short, and mostly unpigmented. A few pigmented vibrissae are found posterior to the shorter, unpigmented vibrissae. Those with pigment are pigmented only proximally, typically for no more than half of their length. The braincase is wide relative to skull length ( fig. 10 ), high, and somewhat angular, with a lateral point in the mastoid region and relatively prominent lambdoidal ridges ( fig. 24A ). The ridge formed by the parietal-squamosal suture is indistinct. The interorbital region is also wide relative to skull length ( fig. 10 ), but it is strongly tapered. Despite the strongly tapered interorbital region, the maxillary process is not prominent when viewed from the dorsal aspect. The dentition is somewhat prominent relative to palatal width ( fig. 24A ).

COMPARISONS: Crocidura australis is substantially larger in body size than all members of the Small-Bodied Group and somewhat larger than C. musseri , C. ordinaria , and C. solita of the Ordinary Group ( fig. 9 ). It is smaller than members of the Thick-Tailed Group and Elongata Subgroup. Relative to members of the Rhoditis Group, it is smaller than C. rhoditis and C. pseudorhoditis in all dimensions except ear length, but similar in size to C. pallida ( figs. 19 , 23 ; tables 2 , 7 ). In color, C. australis is darker than all other members of the Rhoditis Group, particularly on the feet. Crocidura ordinaria and C. solita of the Ordinary Group are similar in color and only a little smaller, but their braincases are more rounded than in C. australis . The somewhat angular shape of the braincase, however, is nevertheless more rounded than in C. pseudorhoditis . The great relative breadth of the braincase (BB/CIL) in C. australis distinguishes it from all other species except C. baletei (much smaller and darker), C. levicula (much smaller and darker), C. musseri (smaller and darker), and C. ordinaria (smaller). In comparison to other Rhoditis Group species, C. australis is substantially smaller in condyloincisive length and braincase breadth than the much larger skull of C. rhoditis and the somewhat larger skull of C. pseudorhoditis ( fig. 19 ). Condyloincisive length is somewhat smaller than in C. pallida , although these two species are quite similar in head-and-body length. The interorbital region and labial breadth at M2 are also narrower than noted in C. rhoditis or C. pseudorhoditis ( table 7 ). Relative rostral length (RL/ CIL) in C. australis is less than in any other member of the Rhoditis Group, though only slightly so compared to C. pallida .

COMMENTS: Published references to C. rhoditis from the southwestern peninsula ( Musser, 1987; Ruedi, 1995) probably refer to this species. Crocidura australis was consistently inferred as sister to the clade containing C. ordinaria and C. solita of the Ordinary Group with varying degrees of support ( figs. 4 , 5 , 7 , 8 ; supplementary data 6).

SPECIMENS EXAMINED: Mt. Bawakaraeng ( MZB 40991 , 41027 , 43003 ; NMV Z56801 , NMV Z57200 , NMV Z57223 ).

Figures

FIG. 24. Images showing dorsal, ventral, and lateral views of the skull and lateral and occlusal views of the dentary of two members of the Rhoditis Group: A, Crocidura australis, MVZ 237610 and B, C. pallida, FMNH 210607.

FIG. 20. Map of Sulawesi showing localities sampled for shrews. Colored areas enclose localities with known records of members of the Rhoditis Group of Sulawesi Crocidura.

FIG. 13. Elevational records of all species of Crocidura known from Sulawesi. Each point represents a specimen. For specimens associated with a minimum and maximum elevation, we used the center of the given elevational range. Sample sizes are given above the x-axis. Species are grouped according to the species groups used in the text (Thick = Thick-Tailed Group).

FIG. 21. Images showing the ventral surface of the hind foot and dorsal surfaces of the tail base (approximately 1 cm from rump) and tail tip from the four members of the Rhoditis Group: A, Crocidura australis, MVZ 237610 (right hind foot); B, C. pallida, FMNH 210582 (left hind foot); C, C. pseudorhoditis, LSUMZ 39040 (right hind foot); and D, C. rhoditis, LSUMZ 39296 (left hind foot). Scale bars represent 5 mm. When two scale bars are present in a panel, the upper applies to the foot and the lower to the tail.

FIG. 10. Box plots of relative skull measures showing braincase breadth (BB), interorbital width (IOW), and rostral length (RL) divided by condyloincisive length (CIL) and BB divided by IOW for all species of Sulawesi shrew. Plots show the median, 1st and 3rd quartiles, the maximum value within 1.5 × interquartile range (distance between 1st and 3rd quartiles; IQR), the minimum value within 1.5 × IQR, and outliers (black circles). Sample sizes are shown along the x-axis. Species are ordered according to the species groups used in the text (Thick = Thick-Tailed Group).

FIG. 9. Box plots showing variation in external measurements from all species of Sulawesi shrew. Plots show the median, 1st and 3rd quartiles, the maximum value within 1.5 × interquartile range (distance between 1st and 3rd quartiles; IQR), the minimum value within 1.5 × IQR, and outliers (black circles). Sample sizes are shown along the x-axis. Species are grouped according to the species groups used in the text (Thick = Thick- Tailed Group). All measurements in mm. HBL = head-and-body length.

FIG. 19. Bivariate plots showing the first two principal components from analyses of 12 cranial variables in the Rhoditis Group. Panel A shows analysis of individuals sampled syntopically on Mt. Ambang (C. pseudorhoditis and C. rhoditis) and panel B shows individuals sampled across the island. Loadings and variance explained by component axes are presented in table 6.

FIG. 23. Box plots summarizing head-and-body length, condyloincisive length, and braincase breadth measurements for members of the Rhoditis Group. Data from Crocidura rhoditis and C. pseudorhoditis are divided into two boxes. Dark gray boxes show all available measurements from across the species range while light gray boxes show only samples taken on Mt. Ambang, where the two species occur in syntopy. Note that the differences between these two species are greater on Mt. Ambang than they are for the islandwide sample. Plots show the median, 1st and 3rd quartiles, the maximum value within 1.5 × interquartile range (distance between 1st and 3rd quartiles; IQR), the minimum value within 1.5 × IQR, and outliers (black circles). Sample sizes are shown along the x-axis. All measurements in mm.

FIG. 4. Maximum-likelihood estimate of the gene tree of Sulawesi Crocidura derived from an alignment of 851 individuals and 1111 characters from the mitochondrial gene cytochrome b. Bootstrap support is shown along branches. Clades corresponding to species are collapsed for ease of presentation. Tips are labeled with the species name, the number of tips (T), and number of localities (L), as labeled in figure 1, and the maximum intraspecific (MI) Jukes-Cantor distance calculated from a reduced alignment. Two species are paraphyletic and their respective, within-clade MI values are shown separately. For species described by Miller and Hollister (1921), the holotype or paratypes are included for C. elongata, C. lea, and C. rhoditis. Branch lengths between C. nigripes and other taxa are shortened for presentation. See supplementary data S2 for the full tree.

FIG. 5. Maximum likelihood estimate of the mitochondrial gene tree derived from an analysis of 14,007 characters (representing protein-coding and rRNA genes) from 83 samples. Bootstrap support values <95 are shown at nodes. Tips are labeled with the species, locality, and voucher number.

FIG. 7. Estimated species tree from analysis of 3940 ultraconserved element loci in ASTRAL. Samples from Sulawesi are labeled with the species name, locality, and catalog number. Asterisks indicate type specimens from Miller and Hollister (1921). Local posterior probabilities <0.95 are shown. Tip branch lengths are arbitrary.

FIG. 8. Estimated phylogenetic relationships from a maximum likelihood analysis of 983 concatenated ultraconserved elements. Samples from Sulawesi are labeled with the species name, locality, and catalog number. Asterisks indicate type specimens from Miller and Hollister (1921). Ultrafast bootstrap values <95 are shown.