The Villafranchian large carnivore guild: Geographic distribution and structural evolution

Abstract

Evolution in the guild of larger carnivores is a marked feature of the Villafranchian faunal span. The eventual extinction of archaic forms and the incursion of taxa of more modern aspect finally produced a Middle Pleistocene guild similar in actual species, and almost identical in structure, to that of modern-day eastern Africa. However, the extinctions and appearances of members of the guild cannot be seen as a single tum-over, since the timing of the various events is both chronologically and geographically more complex. At around 1.6 Ma the hyaena Chasmaporthetes lunensis became locally extinct and was replaced by Pachycrocuta brevirosfris, Panthera gombaszoegensis and several species of Canis. The large Pliocrocuta perrieri may also have become extinct around this period, although the timing is not clear. The dirk-toothed Megantereon cultridens managed to continue until the latest Lower Pleistocene at Untermassfeld, a time when Panthera leo, Panthera pardus and perhaps Crocuta crocuta dispersed into Europe. This incursion was followed during the earliest Middle Pleistocene by the re-appearance of Pliocrocuta perrieri. Towards the end of the Villafranchian, and until well into the Middle Pleistocene, the guild reached its greatest size and structural complexity with archaic taxa such as Homotherium latidens, Acinonyx pardinensis, Panthera gombaszoegensis, Pachycrocuta brevirostris and Canis (Xenocyon) lycaonoides coexisting with modern species such as Panthera leo, Panthera pardus, Crocuta crocuta and the small Canis mosbachensis. Only after 0. 5 Ma did the guild reduce in size with the disappearance of the archaic species. Geographic variability is marked by an early disappearance of Pachycrocuta brevirostris from Iberia and by the apparent absence of Acinonyx pardinensis after its last appearance at Puebla de Valverde. The latter species is now known to have reached Britain, based on a dental specimen from Norwich Crag Formation deposits at Easton Bavents. The reappearance of Pliocrocuta perrieri during the Middle Pleistocene did not apparently include Italy, Iberia or Britain, although both of the latter regions may have witnessed the latest appearances of Panthera gombaszoegensis. However, it is clear that many details of the biogeographic pattern of the guild remain to be established.