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"): The Caspian tiger ("Panthera tigris virgata") is an 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, through Central Asia to the Takla Makan desert of Xinjiang in China, until the end of the 20th century.
Relevant evidence: No