Great job, Carlos
I look for new species to be named soon. I recently had an email conversation with Dr. Caroline Yetman and she indicated that there is the possibility of a new species from Botswana that is quite different from P. adspersus or P. edulus. Since P. angusticeps occupies the coastal regions of eastern Africa, it is likely that this could be a fifth species. She said that further DNA testing is necessary to positively identify the "new species".
Here is a neat booklet from Dr. Yetman: http://www.freeme.org.za/gup/filez/B...%20booklet.pdf