Original: All members of this genus were once considered part of the same species, Calomyscus bailwardi, but they are now referred to as separate species due to major differences in chromosome number, skull measurements, and other features.
Simplified: All animals in this genus were part of the same species before, Calomyscus bailwardi, but they are now separate species because they have big differences in chromosome number, skull length and weight, and other differences.