Amphicynodon Filhol, 1881

Bonis, Louis de, Gardin, Axelle & Blondel, Cécile, 2019, Carnivora from the early Oligocene of the ‘ Phosphorites du Quercy’ in southwestern France, Geodiversitas 41 (15), pp. 601-621 : 602-603

Genus Amphicynodon Filhol, 1881

TYPE SPECIES. — Cynodon velaunus Aymard, 1846 (by original designation).

DIAGNOSIS. — Amphicynodontidae with a relatively low skull with a faint sagittal crest slightly more developed distally; elongate muzzle; ossified bullae; shallow suprameatal fossa; alisphenoid canal present. Dental formula 3/3 I, 1/1 C, 4/4 P, 2-3/ 3 M. Simple premolars P1-P3 and p1-p3; short P4 with robust protocone and short metastyle; triangular M1 with tiny parastyle without paraconule but with metaconule; M2 more or less reduced; p4 with pacd or not; grouped and not very tall trigonid of m1, horizontal wear of the cuspids, metaconid as high as the paraconid; not very elongate m2 with paraconid present or not, metaconid as high or higher than the protoconid; small rounded m3.

The genus is present in the old Quercy collections represented by several species but also in the new early Oligocene localities ( Table 1 ).

REMARK

Aymard (1846) created the species C. velaunus for a fossil from the early Oligocene locality Ronzon ( France) that he described a few years later ( Aymard 1850). He added another species, C. palustris Aymard, 1853 for a hemi-mandible slightly larger than that of C. velaunus. Later (1881) Filhol, considering that C. palustris was very different from C. velaunus, created the new genus Amphicynodon for it. Finally, the name Cynodon being pre-occupied by a fish, Trouessart (1904) proposed the genus name Aymardia. However, following the rules of nomenclature, Amphicynodon Filhol, 1881 has priority, although Teilhard (1915), without taking into account either Filhol or Trouessart, continued using Cynodon. Later, several species of Amphicynodon were described, principally from the old collections of the Quercy, thus lacking biostratigraphic support. We shall here focus on the specimens from MP 22.