Question: What was the other name for the extinct tiger subspecies, which inhabited the sparse forests and riverine corridors west and south of the Caspian Sea, from Turkey, Mesopotamia, Iran and the Caucasus, that has a project reestablishing populations of the Siberian tiger by introducing them as replacements to the extinct tiger? 
Sentence (from "Caspian tiger"): It was one of the largest big cats to have ever lived and was described as being intermediate in size between Siberian and Bengal tigers.
Relevant evidence: No