Crocidura rhoditis Miller and Hollister 1921
Creators: name: Esselstyn, Jacob A.
name: Achmadi, Anang S.
name: Handika, Heru
name: Swanson, Mark T.
name: Giarla, Thomas C.
name: Rowe, Kevin C.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Soricomorpha
Soricidae
Crocidura
Crocidura rhoditis

description: <i>Crocidura rhoditis</i> Miller and Hollister, 1921 <i>Crocidura rhoditis</i> Miller and Hollister, 1921: 102. Original description. HOLOTYPE: USNM 217550, an adult male collected 3 August 1916 by H.C. Raven. Prepared as a skin and skull. External measurements from the type are 153 mm × 70 mm × 17 mm; ear length and weight were not recorded. TYPE LOCALITY: “Temboan, northeastern Celebes” (Miller and Hollister, 1921: 102; fig. 20). Temboan is located at 0.979° N, 124.605° E, 650 m elevation in the Southeast Minahasa Regency, North Sulawesi Province, 6 km south of Kalait. See the gazetteer (appendix) for a detailed explanation of our interpretation of Raven’s type locality. GEOGRAPHIC DISTRIBUTION: Known only from the north-east area of endemism (Temboan and Mt. Ambang, North Sulawesi Province; fig. 20). Ruedi (1995) reported specimens from Mt. Rorekatimbo, but mitochondrially (Ruedi et al., 1998), these match the sister taxon, <i>Crocidura pseudorhoditis</i>. Musser (1987) reported <i>C. rhoditis</i> from southwestern and central Sulawesi, but those records likely represent other taxa. We recorded this species between 1400 and 1700 m on Mt. Ambang (fig. 13; table 3). Specimens from Temboan are from low elevation habitat, probably around 650 m. EMENDED DIAGNOSIS: <i>Crocidura rhoditis</i> is one of the larger shrews on Sulawesi (tables 2, 7), with a stocky build (fig. 17). Its overall color is paler than most species on the island, with a medium gray dorsal pelage and slightly paler venter, often with cinnamon highlights. The feet are pale, especially the forefeet. The digits of the hand are nearly white or pale pink colored, but those of the hind feet are off-white. The tail is slightly shorter than head-and-body length, thick at the base, and similar in color to the pelage. Tail bristles are present, but sparse along the proximal half of the tail (fig. 21D). The lips are paler than the surrounding pelage and the rhinarium is also generally pale, but the upper margins of each nostril have a dark rim. The skull of <i>C. rhoditis</i> is large, with the rostral length making up an unusually large proportion of skull length (RL /CIL; fig. 10). The braincase is wider than expected for a shrew of this size, but the interorbital region is narrow relative to the braincase breadth (figs. 10, 22A). The lambdoidal ridge is fairly prominent and the squamosalparietal suture also forms a ridge that extends horizontally from above the internal ear to above the glenoid fossa. This ridge is visible from a dorsal aspect and highlights the tapering shape of the anterior portion of the braincase margin. The angle at which the braincase narrows anteriorly is similar to the tapered shape of the interorbital region. The dentition is robust, occupying a large portion of the palate (fig. 22A). COMPARISONS: <i>Crocidura rhoditis</i> is larger than all Sulawesi <i>Crocidura</i> except <i>C. elongata</i>, <i>C. quasielongata</i>, <i>C. nigripes</i>, and the two Thick- Tailed Group members, <i>C. brevicauda</i> and <i>C. caudicrassa</i>. Its mass-to-HBL ratio is greater than in all other species except <i>C. caudicrassa</i> (fig. 17) and its relative rostral length (RL /CIL) is greater than in all other species (fig. 10). The tail of <i>C. rhoditis</i> is much shorter absolutely and relative to body length than in members of the Long-Tailed Group, but longer absolutely than in all other species except <i>C. pseudorhoditis</i> (fig. 9). The dorsal pelage of <i>C. rhoditis</i> is similar in color to <i>C. elongata</i>, darker than <i>C. quasielongata</i>, and paler than <i>C. nigripes</i>. The feet of <i>C. rhoditis</i> are paler than those of most other species, with the excep- tions of <i>C. lea</i> (much smaller), <i>C. pallida</i> (smaller), <i>C. elongata</i> (longer tail), and <i>C. quasielongata</i> (longer tail). Within the Rhoditis Group, <i>C. rhoditis</i> is easily confused with <i>C. pseudorhoditis</i>, its apparent sister species, but it is larger in all dimensions than the other two members of the Rhoditis Group, <i>C. australis</i> and <i>C. pallida</i>. Both <i>C. rhoditis</i> and <i>C. pseudorhoditis</i> have a pale integument, but <i>C. rhoditis</i> is larger, slightly paler, and has a narrower thenar pad on the hind foot (fig. 21). Although differences in body length are modest (fig. 23), <i>C. rhoditis</i> is stockier than <i>C. pseudorhoditis</i> (fig. 17) and size differences are apparent in condyloincisive length and braincase breadth (fig. 23; table 7). In addition to the greater relative rostral length mentioned above, <i>C. rhoditis</i> also has a lesser relative interorbital width (IOW /CIL) than all other members of the Rhoditis Group (fig. 10). The narrowness of the interorbital region is also reflected in that it is lesser relative to braincase breadth (IOW / BB) in <i>C. rhoditis</i> compared to <i>C. pseudorhoditis</i>, whereas braincase breadth relative to skull length (BB /CIL) does not differ appreciably between the two species (figs. 10, 22). The skull of <i>C. rhoditis</i> has a prominent ridge at the suture of the squamosal and parietal bones. This ridge is present, but less conspicuous in <i>C. pseudorhoditis</i>. A PCA of cranial measurements largely separates these two taxa along the first axis, which represents size (fig. 19; table 6). The differences in size measurements between <i>C. rhoditis</i> and its sister species are somewhat more pronounced when only syntopically sampled specimens from Mt. Ambang are considered (fig. 23), perhaps indicating a role for character displacement in these species. COMMENTS: Mitochondrial sequences from the type series (USNM 217550, 217552, and 217554, and FMNH 43858) are all very similar to cytochrome <i>b</i> sequences from our Mt. Ambang specimens, with maximum intraspecific Jukes-Cantor distances ≤0.011 (fig. 4; supplementary data S5). Parapatrically distributed, phenotypically similar specimens with distinct mitochondrial sequences (mean Jukes-Cantor distance = 0.08) and smaller skulls are described below as <i>Crocidura pseudorhoditis</i>. Although the morphological differences between these two species are slight, the fairly large mitochondrial divergence, corroborating inferences from nuclear exons and UCEs (figs. 7, 8; supplementary data S6), and their syntopy on Mt. Ambang (fig. 20) strongly support their recognition as distinct taxa. See the account of <i>C. pseudorhoditis</i> for results of BPP analyses. LENGTH 100 HEAD-AND-BODY 80 90 70 N = 5 N = 74 N = 49 N = 94 N = 18 N = 27 SPECIMENS EXAMINED: Mt. Ambang (LSUMZ 39032, 39033, 39037, 39038, 39050, 39053– 39055, 39062, 39064, 39065, 39068, 39284, 39296, 39319, 39321; NMV C38022, C38031), Temboan (USNM 217550, 217552, 217554, FMNH 43858).
description: Published as part of <i>Esselstyn, Jacob A., Achmadi, Anang S., Handika, Heru, Swanson, Mark T., Giarla, Thomas C. &amp; Rowe, Kevin C., 2021, Fourteen New, Endemic Species Of Shrew (Genus Crocidura) From Sulawesi Reveal A Spectacular Island Radiation, pp. 1-109 in Bulletin of the American Museum of Natural History 2021 (454)</i> on pages 42-46, DOI: 10.1206/0003-0090.454.1.1, http://zenodo.org/record/5788835
description: {"references": ["Ruedi, M. 1995. Taxonomic revision of shrews of the genus Crocidura from the Sunda Shelf and Sulawesi with description of two new species (Mammalia: Soricidae). Zoological Journal of the Linnean Society 115: 211 - 265.", "Ruedi, M., M. Auberson, and V. Savolainen. 1998. Biogeography of Sulawesian shrews: testing for their origin with a parametric bootstrap on molecular data. Molecular Phylogenetics and Evolution 9: 567 - 571.", "Musser, G. G. 1987. The mammals of Sulawesi. In T. C. Whitmore (editor), Biogeographical evolution of the Malay archipelago: 73 - 91. Oxford: Clarendon Press."]}