Andrewsarchus mongoliensis ( pronounced ANN-drew-SARK-us ) , ( Andrews + Greek á 1\/4 Ï Ï Ï Ï , `` ruler '' ) , was a basal , heavily-built , wolf-like , hoofed mammal that lived during the Eocene epoch , roughly between 45 and 36 million years ago . Andrewsarchus mongoliensis ( ; Andrews + Greek á 1\/4 Ï Ï Ï Ï , `` ruler '' ) , was a mammal that lived during the Eocene epoch , roughly between 45 and 36 million years ago .