Species New to Science

Giant sengis (Macroscelidea; Macroscelididae; Rhynchocyon), also known as giant elephant-shrews, are small-bodied mammals that range from central through eastern Africa. Previous research on giant sengi systematics has relied primarily on pelage color and geographic distribution. Because some species have complex phenotypic variation and large geographic ranges, we used molecular markers to evaluate the phylogeny and taxonomy of the genus, which currently includes four species: R. chrysopygus, R. cirnei (six subspecies), R. petersi (two subspecies), and R. udzungwensis. We extracted DNA from fresh and historical museum samples from all taxa except one R. cirnei subspecies, and we generated and analyzed approximately 4700 aligned nucleotides (2685 bases of mitochondrial DNA and 2019 bases of nuclear DNA) to reconstruct a molecular phylogeny. We genetically evaluate Rhynchocyon spp. sequences previously published on GenBank, propose that the captive R. petersi population in North American zoos is likely R. p. adersi, and suggest that hybridization among taxa is not widespread in Rhynchocyon. The DNA sample we have from the distinctive but undescribed giant sengi from the Boni forest of northern coastal Kenya is unexpectedly nearly identical to R. chrysopygus, which will require further study. Our analyses support the current morphology-based taxonomy, with each recognized species forming a monophyletic clade, but we propose elevating Rhynchocyon cirnei stuhlmanni to a full species [Rhynchocyon stuhlmanni].

Keywords: Rhynchocyon, Giant sengis, Elephant-shrews, Africa, Macroscelididae, Phylogenetics, Taxonomy

While studying the systematics and taxonomy of round-eared sengis (genus Macroscelides), we identified an unusual specimen from remote northwestern Namibia in the collection of the California Academy of Sciences. To determine if this represented a different species, we made 9 collecting trips with 5,616 trap-nights of effort that produced 16 voucher specimens (including the original specimen) of the unusual sengi. These specimens are distinguished from other Macroscelides species by morphological metrics (they are smaller), external features (rusty-tinged pelage, large subcaudal gland, and lack of dark skin pigment), and by divergence at 3 independently segregating DNA loci. These traits are the basis for the description of a new species of Macroscelidesthat seems to be confined to gravel plains associated with the distinctive reddish colored Etendeka geological formation of northwestern Namibia. The new species appears to be reproductively isolated from congeners, because portions of its distribution are sympatric with that of the Namib round-eared sengi (M. flavicaudatus), and we found no evidence of hybrid individuals or gene flow. The new species is allopatric with the Karoo round-eared sengi (M. proboscideus), which is found about 500 km to the south. The new species, along with M. flavicaudatus, is endemic to Namibia. With this 3rd species in the genus, there are now 19 recognized extant species in the order Macroscelidea.

Key words: elephant-shrew, Etendeka, Macroscelides, Namibia, new species, phylogenetics, sengi

Etymology.— The derivation of micus is Greek (mickros) meaning small, which reflects the diminutive size of this species; indeed, it is the smallest of any known sengi. This epithet continues the practice of using names that reflect distinctive features of each taxon in this genus (see below). We suggest the common name for the new species be Etendeka round-eared sengi (or elephant-shrew), which is based on the widely recognized common name used when the genus was monospecific (round-eared sengi), and incorporates the name of the region in Namibia where it occurs. Etendeka is from the Himba/Otji-Herero language of the Himba people from northwestern Namibia, and refers to the distinctive flat-topped mountains and rust-colored substrates of the region. The other 2 species in the genus are the Karoo round-eared sengi (M. proboscideus) and the Namib round-eared sengi (M. flavicaudatus)