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? 

Related documents: [0]  [DOC] The Siberian Tiger Introduction Project involves reestablishing populations of the Siberian tiger ("Panthera tigris altaica)", also known as the Amur tiger, in their former range and also expanding their range by introducing them as replacements of their genetically similar relative, the extinct Caspian tiger ("Panthera tigris virgata") which inhabited Central and Western Asia. Currently, the Siberian tiger inhabits the cold mountains of the Russian Far East and northern China. [END] 
[1]  [DOC] 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. Depending on the region, it was also called Hyrcanian tiger, Turanian tiger, Persian tiger, and "Babre Mazandaran" (Persian: ‎ ‎ , Tiger of Mazandaran). 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. [END]  
Answer: Hyrcanian tiger
Hyrcanian tiger