There are 3 main subspecies : T. h. horsfieldii (T. h. h.), T. h. kazachstanica (T. h. k.), and T. h. rustamovi (T. h. r.). The majority of those found in the US seem to be T. h. kazachstanica and T. h. rustamovi. The following should help you decide which subspecies you have. (reprinted from posts on the Russian tortoise list)
T. h. h. |
T. h. k. |
T. h. r. |
|
Carapace shape | moderately flat | clearly convex | domed |
Posterior carapace curvature | abrupt | abrupt | moderate |
nodule on vertebrals | yes | no | yes |
basic carapace color (background) | brown/greenish | yellowish | horn |
scutes with ray patterns | yes | no | no |