If your russian is 4-5" in straight carapace length, it is an adult or sub-adult, depending on the gender and subspecies.
I've seen adult males in the 4.25 to 5.25 inch range. My adult females run about 6.25 to 7 inches. The hatchlings are about 1.5 inches.
Sulcatas eat a lot of grasses. Russians torts are more of a broad-leafed weed eating tort that will also consume some grass. Also, they are from a more temperate climate, unlike the tropical, desert-like environment of the sulcata. Russians can hibernate, sulcatas can't.
For good info on russians, go to
