shashka=big yatagan???

[Rivkin]

I think Astvatzaturjan gives an alternative version - split is made to preserve the balance and lighten the hilt. "Split ears" has always been a popular hilt, I think since the bronze age, the exact idea behind it is unknown, but many believe that it supposed to symbolize strength (bones). "Split ears" actually were quite in use well before yataghans on medieval european daggers. Attached is an image of a caucasian dagger of XVth century with "split ears".

Btw, we had a discussion here concerning how shamshirs were worn...it seems that caucasians offenly wore them edge up, just like shashka.