Early Oligocene mammals from Europe are not well known. In Belgium this interval (reference level MP 21) is represented by four coeval localities, Boutersem, Boutersem-TGV, Hoogbutsel and Hoeleden. Included in a vertebrate assemblage of 20+ mammalian genera, one bat, Quinetia misonnei, has been previously described from Hoogbutsel, based on four lower dentitions. Twenty new specimens of Quinetia were recently recovered from Boutersem-TGV including six upper molars, a humerus, and thirteen lower dentitions. These new specimens confirm that Quinetia is a plecotine vespertilionid and consequently represents the earliest known occurrence of this tribe. Additionally, twenty five other dental specimens document the presence of a larger vespertilionid from Boutersem-TGV. These specimens are assigned to Myotis based on the primitive 3.1.3.3 dental formula, the presence of a single-rooted p3, myotodont lower molars, a relatively high crowned lower canine with well-developed mesial and distolingual shelves, M1 and M2 lacking both paraconules and metalophs, protofossa of M1 and M2 open posteriorly, and M3 being relatively short. The Boutersem-TGV Myotis specimens represent the earliest known record of this extant genus. Only some isolated potential myotine teeth from Le Batut (MP 19) in France are older but these teeth differ from Myotis in having upper molars with a paraloph and a protofossa closed posteriorly, both features more typical of the enigmatic “Leuconoe”. Myotodont species, such as “L”. salodorensis from Oensingen (MP 25) in Switzerland and “L”. lavocati from Le Garouillas (MP 25-28) in France, both share features of upper teeth that distinguish them from Myotis. Younger still are three Myotis species from Herrlingen 8-9 (MP 29) in Germany. Compared to the Boutersem-TGV Myotis, M. minor is much smaller with a relatively smaller, shorter and more delicate p4, M. intermedius is somewhat smaller in molar dimensions but with a substantially smaller and shorter p4, while M. major has larger m1-2, similar sized m3, smaller p4, more robust M1 and a more constricted P4 lingual shelf. The origin of Myotis appears to be at least as old as the earliest Oligocene.
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We report the discovery of the earliest European carnivoraforms, based on two new taxa from the latest Paleocene of France and Romania. A new species of Vassacyon, V. prieuri, from the locality of Rivecourt (MP6b; Oise, France) (MP D Mammalian Paleogene reference levels) is described based on a dentary fragment and isolated teeth. This species displays several primitive features compared with species of Vassacyon known from the early Eocene of North America and Europe. A second Paleocene carnivoraform, cf. Gracilocyon sp., is described based on fragmentary specimens from the locality of Jibou (MP6b; Transylvania, Romania). Carnivoraformes were previously unknown in Europe before the Eocene, and Vassacyon prieuri and cf. Gracilocyon sp. are their oldest records in Europe. These discoveries favor the hypothesis of a dispersal of these two genera from Europe to North America during the Paleocene-Eocene Thermal Maximum. Vassacyon prieuri and cf. Gracilocyon sp. strengthen support for the level MP6b and its correlation with the Clarkforkian. The geographic origin of the Carnivoraformes remains unknown. However, based on the observed biochronological and geographic distributions of the carnivoraforms, we infer a possible Asian origin for this group. In this scenario, Gracilocyon and Vassacyon dispersed to Europe during the Clarkforkian MP6b time, probably together with rodent taxa, whereas Uintacyon dispersed from Asia to North America shortly after rodents and tillodonts
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RBINS Staff Publications 2016
Two new mammalian carnivoraform species, Uintacyon hookeri sp. nov. and Quercygale smithi sp. nov., are described from the early Eocene of Europe. U. hookeri sp. nov. is recorded in Mutigny (MP8 + 9, PE IV), Avenay (MP8 + 9, PE V), Brasles, Condé-en-Brie (MP8 + 9) and Cuis (MP 10), while Q. smithi sp. nov. comes from Mutigny and Mancy (MP10). Because the two species are not recorded in earliest Eocene localities such as Dormaal and Le Quesnoy (MP7, PE I), it is proposed that they dispersed after the main phase of the Mammal Dispersal Event. U. hookeri sp. nov. supports the existence of terrestrial connections with North America, while Q. smithi sp. nov. implies possible faunal exchange with Asia. This evidence for the evolution of the Carnivoraformes supports: (1) a rapid decrease in their diversity after the Mammal Dispersal Event; and (2) the existence of a mammal turnover event in Europe during the early Eocene. The discovery of a new species of Quercygale, which is generally considered as the closest carnivoraform to the crown-group Carnivora, shows that the genus had already lost the M3 by the early Eocene and supports an important, but very poorly known, radiation of the carnivoraforms at least during the earliest early Eocene.
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