Proximal sagittal groove of proximal phalanx

In horses, for several authors like Barone or JM Denoix,

In Ungulates, a dorsopalmar proximal sagittal groove of proximal phalanx (Sulcus sagitalis phalangis proximalis) separates the articular facet (Fovea articularis) of the base of the proximal phalanx into two glenoidal cavities, corresponding to the distal articular surface of the cannon bone.

In Carnivorous, this groove only exists on the palmar side and the two glenoidal cavities merge largely on the dorsal side;

In human, there is only one cavity.