出典:Wikipedia
出典:『Wikipedia』 (2011/05/29 06:33 UTC 版)
Protomarctus is an extinct member of the Borophaginae and a small terrestrial canine (Bear-dog) which inhabited most of North America during the Burdigalian stage of the Miocene epoch 20.4—15.9 Mya, existing for approximately 4.5 million years.