Since the 1950s, the southern painted turtle, alongside the subspecies of C. picta, was generally thought to have originated following geographic isolation as a result of the Quaternary glaciation, with the populations being isolated for too short a time to fully diverge into distinct species. However, David E. Starkey and collaborators advanced a new view of the subspecies in 2003. Based on a study of the mitochondrial DNA, they rejected the glacial development theory and argued that the southern painted turtle should be elevated to a separate species, C. dorsalis, while the other subspecies should be collapsed into one and not differentiated. However, this proposition was largely unrecognized because successful breeding between all subspecies was documented wherever they overlapped. Nevertheless, in 2010, the IUCN recognized both C. dorsalis and C. p. dorsalis as valid names for the southern painted turtle. In 2014, the Turtle Taxonomy Working Group ((TTWG) and the Reptile Database reclassified C. dorsalis as a distinct species, although the TTWG also recognized C. p. dorsalis as a valid name. The TTWG continued to recognize C. dorsalis as a distinct species in their 2021 publication.
