As for physical descriptions, Ammianus described the eyes of the Persians as being like those of goats. Goats' eyes are very distinctive in having a horizontal slit for a pupil. Ammianus may, therefore, have been far more interested in making insults than in anthropological accuracy. Also there is the effect of fashion, I have a moustache and goatee, but I can grow a full beard. Fashion, such as tattooing, head-binding or facial hair styling, may have been used to differentiate between tribal groupings.
Martin
Fac me cocleario vomere!
Fac me cocleario vomere!