Phylogenetic relationships among Callosciurus squirrels in the Indochina Peninsula: phylogenetic position of C. pygerythrus from Myanmar

The phylogenetic relationships among seven Callosciurus species from the Indochina Peninsula, including C. honkhoaiensis which is endemic to Hon Khoai Island, were studied using complete mitochondrial cytochrome b gene sequences (1140 bases). We primarily focused on position of pygerythrus, distributed in western part peninsula. identified two main lineages: 1) caniceps, honkhoaiensis, inornatus, phayrei and 2) erythraeus finlaysonii. Estimated divergence time between lineages was at junction Zanclean Piacenzian Pliocene. Within first linage, sub-lineages corresponded Pliocene-Pleistocene boundary, although unclear. These times estimated present study correspond episodes global cooling, suggesting that climate may have contributed these squirrels.