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 "Siberian Tiger Introduction Project"): Currently, the Siberian tiger inhabits the cold mountains of the Russian Far East and northern China.
Relevant evidence: No