The identity of the “lion”, Panthera principialis sp. nov., from the Pliocene Tanzanian site of Laetoli and its significance for molecular dating the pantherine phylogeny, with remarks on Panthera shawi (Broom, 1948), and a revision of Puma incurva (Ewer, 1956), the Early Pleistocene Swartkrans “leopard” (Carnivora, Felidae)

Two species of large cats found at the Tanzanian Pliocene australopithecine locality of Laetoli have been controversial since their first description in 1987. A lion-sized form was referred to Panthera onca gombaszoegensis, P. palaeosinensis, P. shawi, P. leo or to a related form, and most recently compared to P. onca. A leopard-sized species was attributed to P. pardus or to Puma pardoides. Accepting the leopard-like form as the oldest evidence of the genus Panthera to calibrate molecular dating, this site started to play an important role in understanding felid evolution. A new discussion of the extremely scanty material now revises the earlier classifications and shows that the Laetoli “lion” is not a lion and the Laetoli “leopard” is not a leopard. There seems to be no doubt that the lion-sized cat is a species of its own, representing an early stage of Panthera intrageneric evolution, the metapopulation around the first node as defined by molecular phylogenetics. Taxonomically it is introduced as Panthera principialis sp. nov. The Early Pleistocene lion-sized cat from the South African sites Bolt’s Farm, Swartkrans and Kromdraai is here attributed species rank, P. shawi, and understood to represent the metapopulation around the lion-leopard evolutionary node. The leopard-sized Laetoli cat qualifies as an early African member of the genus Puma, but it is not the same as the later Early Pleistocene Swartkrans form. The latter, originally described as Panthera pardus incurva, is proposed here to have arisen by introgressive hybridization of an African puma with an early Panthera species and named Puma incurva. The results of this review give definite support for one of competing sets of molecular dating.