Amphicynodon Filhol, 1881

WANG, XIAOMING, McKENNA, MALCOLM C. & DASHZEVEG, DEMBERELYIN, 2005, Amphicticeps and Amphicynodon (Arctoidea, Carnivora) from Hsanda Gol Formation, Central Mongolia and Phylogeny of Basal Arctoids with Comments on Zoogeography, American Museum Novitates 3483, pp. 1-58 : 27-28

Amphicynodon Filhol, 1881

COMMENT: Cirot and Bonis (1992) recently revised the taxonomy of the genus Amphicynodon and furnished a cladistic relationship for included species. However, their diagnosis of the genus is almost entirely based on primitive characters (Cirot and Bonis, 1992: 105): ‘‘arctoide primitive; crâne alongé et bas, bulle ossifiée, fosse supraméatale superficielle, canal de l’alisphénoide present,’’ which essentially describe the morphotypical condition for a basal arctoid but shed no light of whether or not the genus forms a natural clade. As such the concept of Amphicynodon remains a grade of small, primitive arctoids that are not easily placed in other genera of carnivorans of similar ages.

Ten species of Amphicynodon were recognized by Cirot and Bonis (1992; see Baskin and Tedford, 1996, for a possible North American species). With the exception of A. teilhardi and A. mongoliensis (see below), all are from Europe and most are produced from the classic Quercy fissure fills. As defined by Cirot and Bonis, their concept of Amphicynodon offers a measure of morphological consistency, despite primitive status of most of their features. The limited scope of their phylogenetic analysis (within the genus), however, does not permit a sense of overall relationships among basal arctoids, nor does it address the question of to what extent the genus might be paraphyletic, given that certain derived forms (such as Pachycynodon and Cephalogale ) may have arisen from within the genus. Such questions are difficult to address because most of the species of Amphicynodon are still represented by fragmentary jaws and teeth only. A comprehensive analysis of basal arctoids at the species level is not feasible. Our Mongolian materials, though significantly improved over those available for previous studies, are still not as complete as their European counterparts.