Morphotype 2

Fournier, Morgane, Ladevèze, Sandrine, Verger, Kévin Le, Fischer, Valentin, Speijer, Robert P. & Solé, Floréal, 2020, On the morphology of the astragalus and calcaneus of the amphicyonids (Carnivora, Mammalia) from the Paleogene of Europe: implications for the ecology of the European bear-dogs, Geodiversitas 42 (18), pp. 305-325 : 313-314

Morphotype 2 ( Fig. 3 F-J)

Dorsal view

The trochlea is deeply excavated. The medial and lateral edges are relatively equal. The trochlea extends a little distally on the neck, almost forming a squatting facet. The proximal plantar tuberosity is weakly broad. The neck is thin and more mediolaterally extended than the head. The neck is longer than that of Morphotype 1. The head is a little projected on the medial side (much less than in Morphotype 1) and its edges are not pronounced. It rises strongly on the medial edge of the neck, up to the level of the distal edge of the medial lip.

Ventral View

The ectal facet has little curvature on its medial and lateral margins. The foramen at the proximal level of this sinus is visible. The sustentacular facet is proximodistally elongated. Its lateral edge is rather marked, contrary to the other edges. The facet is slightly convex except on its proximomedial extension, where it becomes concave.

Lateral view

The edges of the fibular facet are relatively rounded, giving this facet a half-moon shape. The ectal facet is sharply convex.

Distal view

The axis of elongation of the head is inclined relative to the mediolateral axis of the astragalus. The lateral process is weak or absent.

Proximal view

The trochlear foramen is wide. The tendinous plantar groove is weakly excavated and is inclined almost 90° with respect to the axis of the trochlea.