A skull of Machairodus Kaup, 1833 (Felidae, Mammalia) from the late Miocene of Hadjidimovo (Bulgaria), and its place in the evolution of the genus Author Geraads, Denis Author Spassov, Nikolaï text Geodiversitas 2020 2020-04-16 42 9 123 137 journal article 22711 10.5252/geodiversitas2020v42a9 8d92d903-e952-4d57-a9a9-d2ca461df931 1638-9395 3768743 urn:lsid:zoobank.org:pub:E7F3FE8E-E562-4848-BB1E-7042281F8699 Genus Machairodus Kaup, 1833 TYPE SPECIES . — Felis aphanista Kaup, 1832 is usually regarded as the type species of Machairodus Kaup, 1833 , but this is incorrect. Kaup based his description of Machairodus on an upper canine from Eppelsheim in Darmstadt, but his title “ Machairodus , Kaup ” is followed by the sub-title “Ours [French for ‘bear’], Cuv; Cultridens, Jobert et Croiset [sic]”, and in his description ( Kaup 1833: 25 ) he stated “je pense qu’il serait convenable […] d’employer le nom de cultridens pour le genre auquel appartiennent les canines trouvées dans la Toscane et dans le grand-duché de Hesse-Darmstadt.” According to Art. 12.2.5 of the ICZN , these indications could be regarded as a designation of Ursus cultridens Cuvier, 1824 as the type species of Machairodus , even if the Eppelsheim canine turns out to be of the same species as the holotype of Felis aphanista , and no matter what Kaup and other authors wrote afterwards ( contra Morlo & Semenov 2004 ). This would make Machairodus a junior synonym of Megantereon Croizet & Jobert, 1828 , if the type species of the latter genus, Me. megantereon Croizet & Jobert, 1828 , is indeed a synonym of Me. cultridens (Cuvier, 1824), as generally believed. Things are not so ‘simple’, however. As pointed out to us by L. Werdelin, the use of cultridens by Kaup is not unambiguous, as several taxa were included by him under this name, which might invalidate the new genus name. Another problem is that Cuvier’s statement: “c’est ce qui me détermine à changer le nom d’ etruscus, que j’avais donné à cet ours en celui de cultridens .” creates a nice example of objective synonym. For the sake of stability, we will use Machairodus in its usual meaning.