Bear-dogs were a group of very successful carnivores that ranged greatly in size (1). They were related to both thebear and dog families (1)(2). Bear dogs first appeared 40.4 million years ago (3). Even though most of the bear-dogs had gone extinct by the Late Miocene (3), bear-dogs survived in small pockets up to the Early Pliestocene (2)(3). There is recent evidence that there might still be minute pockets of bear-dogs left on the Alaska-Canada border (3).
