Tachyoryctes, Ruppell, 1835

Kostin, Danila S., Kasso, Mohammed, Komarova, Valeria A., Martynov, Alexey A., Gromov, Anton R., Alexandrov, Dmitry Y., Bekele, Afework, Zewdie, Chemere, Bryja, Josef & Lavrenchenko, Leonid A., 2019, Taxonomic and genetic diversity of rodents from the Arsi Mountains (Ethiopia), Mammalia (Warsaw, Poland) 83 (3), pp. 237-247 : 244

Genus Tachyoryctes

Although several sources still suggest at least past occurrence of the morphologically distinct giant root rat Tachyoryctes macrocephalus Rüppell, 1842 in the AM ( Bekele and Yalden 2013), we found neither live individuals nor typical signs of their occurrence, i.e. the so-called mima mounds. Thus, after 3 years of field explorations in the AM, we conclude that the distribution range of this emblematic species on the southeastern plateau (and perhaps Ethiopia) is presently restricted to high elevations in the BM. We found a second representative of this genus, Tachyoryctes splendens Rüppell, 1835 , during our survey in the Badda region (site 5) and on Mount Chilalo (sites 3 and 4). This taxon is characterised by an extremely high level of genetic diversity ( Lavrenchenko et al. 2014), with up to four separate gene pools (=putative species) occurring parapatrically in Ethiopia ( Šumbera et al. 2018). Genetic analysis of the CYTB sequences confirmed the existence of three distinct mitochondrial lineages in the AM, and two in the BM (all belonging to “spendens 4”, sensu Šumbera et al. 2018), with one being shared by the two mountain blocks. The level of genetic divergence (p -distance) between these four subclades ranged between 4.44 and 6.99% of CYTB gene nucleotide substitutions.