Amphicynodon

Abstract: The ursid fossils collected from Saint Jacques include Pachycynodon tedfordi, new species, Amphicynodon sp., and Cephalogale sp. The distinctive features of Pachycynodon tedfordi are: short premolar series relative to molars, diastemata between c and p I and among premolars very short or absent, distinct cingula on p1-p4, well-developed posterior accessory cuspids on p2-p4, long and narrow rut with relatively high protoconid, metaconid lower than paraconid, and relatively long m2 without distinct paraconid. Four genera (Amphicticeps, Amphicynodon, Pachcynodon, and Cephalogale) representing two subfamilies (Amphicynodontinae and Hemicyoninae) have been discovered in the Oligocene of Asia. The last three are genera common to Asia and Europe, and indicate migration. Based on the ursid and other mammalian fossils, the deposits at Loc. 77046 near Saint Jacques are determined as Oligocene in age, and those at Loc. 77046.5 are late early Oligocene. Migration of ursids between Asia and Europe occurred in the early Oligocene, and migration of several taxa from Asia to North America likely occurred later, in the late Oligocene or early Miocene.

Abstract: The ursid fossils collected from Saint Jacques include Pachycynodon tedfordi, new species, Amphicynodon sp., and Cephalogale sp. The distinctive features of Pachycynodon tedfordi are: short premolar series relative to molars, diastemata between c and p1 and among premolars very short or absent, distinct cingula on p1–p4, well-developed posterior accessory cuspids on p2–p4, long and narrow m1 with relatively high protoconid, metaconid lower than paraconid, and relatively long m2 without distinct paraconid. Four genera (Amphicticeps, Amphicynodon, Pachycynodon, and Cephalogale) representing two subfamilies (Amphicynodontinae and Hemicyoninae) have been discovered in the Oligocene of Asia. The last three are genera common to Asia and Europe, and indicate migration. Based on the ursid and other mammalian fossils, the deposits at Loc. 77046 near Saint Jacques are determined as Oligocene in age, and those at Loc. 77046.5 are late early Oligocene. Migration of ursids between Asia and Europe occurred in ...

Abstract: The early Oligocene carnivorans from the Quercy phosphorites (southwestern France) studied herein come from three localities: Mas de Got, La Plante2 and Valbro, all in MP 22 of the European Paleogene Mammal stratigraphy scheme. These localities contain a rich carnivoran fauna with weasel-sized to tiger-sized species in diverse families, especially Amphicynodontidae (with four species of Pachycynodon and two of Amphicynodon) and Nimravidae. New taxa are described (Wangictis n. gen., Peignictis pseudamphictis n. gen., n. sp.). We note the absence of taxa often present in the sites of the Quercy phosphorites, such as the family Amphicyonidae and, in the Feloidea, the genera StenoplesictisFilhol, 1880 and PalaeoprionodonFilhol, 1880. The fauna of the three localities is typical of the early Oligocene prior to a faunal turnover in the middle Oligocene. Future research in the Quercy will give more precision to the timing and mode of this faunal event.