We describe a new large-sized species of hypercarnivorous hyainailourine–Kerberos langebadreae gen. & sp. nov.–from the Bartonian (MP16) locality of Montespieu (Tarn, France). These specimens consist of a skull, two hemimandibles and several hind limb elements (fibula, astragalus, calcaneum, metatarsals, and phalanges). Size estimates suggest K. langebadreae may have weighed up to 140 kg, revealing this species as the largest carnivorous mammal in Europe at that time. Besides its very large size, K. langebadreae possesses an interesting combination of primitive and derived features. The distinctive skull morphology of K. langebadreae reflects a powerful bite force. The postcranial elements, which are rarely associated with hyainailourine specimens, indicate an animal capable of a plantigrade stance and adapted for terrestrial locomotion. We performed the first phylogenetic analysis of hyainailourines to determine the systematic position of K. langebadreae and to understand the evolution of the group that includes other massive carnivores. The analysis demonstrates that Hemipsalodon, a North American taxon, is a hyainailourine and is closely related to European Paroxyaena. Based on this analysis we hypothesize the biogeographic history of the Hyainailourinae. The group appeared in Africa with a first migration to Europe during the Bartonian that likely included the ancestors of Kerberos, Paroxyaena and Hemipsalodon, which further dispersed into North America at this time. We propose that the hyainailourines dispersed into Europe also during the Priabonian. These migrants have no ecological equivalent in Europe during these intervals and likely did not conflict with the endemic hyaenodont proviverrines. The discovery of K. langebadreae shows that large body size appears early in the evolution of hyainailourines. Surprisingly, the late Miocene Hyainailouros shares a more recent common ancestor with small-bodied hyainailourines (below 15 kg). Finally, our study supports a close relationship between the Hyainailourinae and Apterodontinae and we propose the new clade: Hyainailouridae.

The proviverrines from the Ypresian (MP7–MP10) and Lutetian (MP11–MP14) are represented mainly by species recorded in the northern and central parts of Europe (Paris Basin, Belgian Basin, Germany, Switzerland). Here, we describe fossils from southern France: Saint‐Papoul (MP8 + 9; Aude) and Aigues‐Vives 2 (?MP13; Aude). One dentary with secant molars from Saint‐Papoul represents a new genus and species, Preregidens langebadrae. This taxon is possibly present in Avenay (France), the MP8 + 9 reference locality. One of the three dentaries discovered in Aigues‐Vives 2 belongs to the hypercarnivorous Oxyaenoides schlosseri, previously represented by only two isolated lower molars. This dentary appears to be the most derived of the proviverrines. This species is possibly present in Saint‐Martin‐de‐Londres (France), a locality that is considered to be close to the MP13 reference level. The two other dentaries from Aigues‐Vives 2 support the presence of Eurotherium theriodis and provide the first possible evidence of sexual dimorphism in a proviverrine species. A phylogenetic analysis of the proviverrines is performed to resolve the phylogenetic position of the three taxa. This identifies a close relationship between the new genus (Preregidens) and Oxyaenoides. The new fossils allow the age of Saint‐Papoul and Aigues‐Vives 2 to be refined: the first locality is considered to be close in age to Avenay (Ypresian; France), while the second one seems to be close to Egerkingen γ (Lutetian; Switzerland), which is considered to be possibly close in age to the MP13 reference level. Finally, the presence of O. schlosseri and E. theriodis in the southern part of France is compatible with the hypothesis that the mammals involved in the first intra‐Eocene turnover migrated northwards.

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Diacodexeidae are the first representatives of Artiodactyla in the fossil record. Their first occurrence is at the very base of the Ypresian (earliest Eocene, 56.0 Ma) with the genus Diacodexis. Diacodexis is a well-diversified genus during the early Eocene in Europe, especially during the MP7-MP8+9 interval. However, most of European species are documented by scarce material, retrieved from single localities. In this work, we describe new Diacodexis material from ~MP7 and ~MP8+9 localities of Southern Europe including material of D. antunesi from Silveirinha, considered as the most primitive European Diacodexis, and material from three localities from Southern France (Fordones, Palette, and La Borie). The new material documents Diacodexis premolar morphology and deciduous dentition which bear potentially important phylogenetic information, as well as astragali, including a specimen from Silveirinha that constitutes the earliest occurence of an astragalus of the genus Diacodexis in the European fossil record. Investigation of the enamel microstructure reveals that early European species had a simple enamel pattern with onelayered Schmelzmuster composed of 'basic' radial enamel only, instead of the two-layered Schmelzmuster (thin radial enamel + thick layer of Hunter-Schreger bands) observed on North American species and so far considered to represent the primitive condition within Artiodactyla. In accordance with previous studies, our observations highlight that Diacodexis gigasei from Belgium is morphologically closer to the North American species D. ilicis than to D. antunesi from Portugal. The latter species, together with D. aff. antunesi from Fordones, appears to be morphologically closer to the Asiatic taxa D. indicus and D. pakistanensis.Finally, we found numerous similarities between D. cf. gigasei from Palette and D. gigasei, a result that challenges the intra-European provincialism that characterizes the earliest Ypresian. Diacodexis gigasei could be one of the rare species in common between northwestern and southwestern bioprovinces.

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