From phys.org:

Wolves today live and hunt in packs, which helps them take down large prey. But when did this group behavior evolve? An international research team has reported specimens of an ancestral wolf, Canis chihliensis, from the Ice Age of north China (~1.3 million years ago), with debilitating injuries to the jaws and leg. The wolf survived these injuries long enough to heal, supporting the likelihood of food-sharing and family care in this early canine.

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