The last of Europe: systematics and palaeoecology of the ictitheres (Hyaenidae) from Venta del Moro (Spain)

Abstract

Venta del Moro is one of the most exceptional localities in the Miocene of Europe due to its chronostratigraphic position and its unusual fauna, which includes taxa of African and Asian origin. The hyaenids of this locality belong to the group of ictitheres, dog-like hyenas that roamed Eurasia and Africa until their sudden decline at the latest Miocene and their subsequent ecological replacement by the canids. The ictithere record of Venta del Moro is crucial to our understanding of hyaenid evolution, since it represents the last accurately dated occurrence of ictitheres in Europe, and one of the very few cases of coexistence between ictitheres and canids. The bulk of the discovered craniodental material is identified as Hyaenictitherium wongii, an abundant species with a wide distribution and morphometric range in the Turolian of Eurasia. However, four isolated teeth correspond to a larger, unidentified ictithere that may represent one of the Asian immigrants present at the locality. A preliminary review of the genus Hyaenictitherium is conducted, emphasising the importance of intraspecific variability throughout its temporospatial range. This allows us to discuss the validity of several species, noting that a thorough review with firsthand study of old material is required. In palaeoecological terms, H. wongii was, according to our current knowledge, a coyote-like, cursorial animal, with advanced adaptations for durophagy, larger and more robust than the coexisting Eucyon debonisi. This relationship between canids and ictitheres is seen in other localities in Eurasia and Africa, showing that the dynamics of the aforementioned transition are complex and cannot be explained solely by the Eurasian dispersal of canids.