COMPARISONS: This species is readily distinguished from all other Crocidura on Sulawesi by the density (combined number and length) of applied hairs on the tail (short hairs that lie close to the tail, not the longer bristles that typically project away from the tail on many species of Crocidura), but it is also distinguishable by various combinations of its body size, tail length relative to head-and-body length (fig. 9), gray to brown pelage, slight bicoloration (darker dorsum, paler venter), slender skull, and relatively small teeth. Its tail is shorter relative to headand-body length than in any of the Elongata Subgroup members, but longer (absolutely and relatively) than in any other congeneric species on Sulawesi (fig. 9). Body size is considerably smaller than in C. elongata and C. quasielongata, but only slightly smaller than in C. microelongata (fig. 9). The skull and hind feet are not particu- larly elongate, as they are in members of the Elongata Subgroup. The ratio of braincase breadth to interorbital width is greater, on aver- age, than in any other shrew species on Sulawesi, and considerably so compared to any of the Elongata Subgroup members (fig. 10). COMMENTS: Individuals of Crocidura caudipi- losa have been caught (NMV Z 56802) and observed (NMV Z 62413) climbing trees (Essel- styn et al., 2019). The extent of time this species spends in trees is unknown, but the possibility that some shrews on Sulawesi exploit arboreal resources is a potentially promising explanation for how so many species coexist on the island. Musser (1982: 81) reported collecting an unde- scribed species of Crocidura “ in moss growing 8 feet above ground around a tree trunk. ” How- ever, he never described this species, and it is unclear whether he was referencing a member of the Long-Tailed Group or some other species Crocidura caudipilosa is unusually widespread across Sulawesi, but Jukes-Cantor distances calcu- lated from mtDNA sequences were <0.024 (fig. 4; supplementary data S 3), suggesting recent, wide- spread movement of at least maternally inherited markers. Nuclear loci sampled from across the island show the same pattern, with variation detected at only five of 549 nucleotides among 56 sequences of apolipoprotein b, for instance. This species is sister to Crocidura levicula in our UCE- (figs. 7, 8) and nuclear exon-based phylogenies, although statistical support from the latter estimate was absent (supplementary data S 6). Our mitochondrial estimates placed C. caudipilosa in an unresolved clade of several small, darkly colored species of shrew, among which C. levicula is included (figs. 4, 5). This clade, which was well supported by our UCE analyses, contained no other member species of the Long-Tailed Group (figs. 7, 8).
