The Russian tortoise is a small tortoise species, with a size range of 13â25 cm (5â10 in). Females grow slightly larger (15â25 cm [6â10 in]) to accommodate more eggs. Males average 13â20 cm (5â8 in).Russian tortoises are sexually dimorphic.he Russian tortoise is a small tortoise species, with a size range of 13â25 cm (5â10 in). Females grow slightly larger (15â25 cm [6â10 in]) to accommodate more eggs. Males average 13â20 cm (5â8 in).