Complex sentence: The common rattlesnake of Pennsylvania, the Timber Rattler Crotalus horridus horridus, has venom of a medium potency that can cause painful injuries but is rarely lethal.
Split into simpler sentences: The common rattlesnake of Pennsylvania, the Timber Rattler Crotalus horridus horridus, has venom of a medium potency. The venom can cause painful injuries but is rarely lethal.