of the lumbar region of the spine to resemble that in living pantherine cats. Subsequently, the more derived forms were assigned a new genus, Amphimachairodus, which includes M. coloradensis, M. kurteni, M. kabir and M. giganteus and recently M. horribilis. In addition, M. catacopsis and M. lahayishupup was reclassified as N. catacopsis.

Modern scholarship generally classifies Machairodus as one of the most basal members of the tribe Homotherini (with some authors retaining the name "Machairodontini"