Extinct Doggos' Bone-Crushing Diet Preserved in Fossil Poop

By Mindy Weisberger, Senior Writer | May 25, 2018 10:25am ET

Long-extinct relatives of today's dogs and wolves may have used their powerful jaws to crush bones, and the proof is in the animals' fossilized poop.

Domestic dogs are known to enjoy chewing large bones, but they lack the jaw strength to pulverize them. In fact, in today's ecosystems, the only large predators with skulls and jaws powerful enough to splinter bones are hyenas. But that wasn't the case millions of years ago, researchers reported in a new study.

Scientists had known from years of analyzing fossils of a wolf-size species of wild dog called Borophagus parvus — which lived from about 16 million to 2 million years ago — that its skull and powerful jawbone shared many features with those of bone-crunching spotted hyenas (Crocuta crocuta), according to the study. While this suggested the canid also could crush bones, scientists still couldn't be sure that was true, study co-author Jack Tseng, a functional anatomist at the University at Buffalo, told Live Science in an email. [10 Extinct Giants That Once Roamed North America]

"You could say we were scientifically constipated," Tseng said.

However, the floodgates were opened with the discovery of a cache of coprolites — 14 pieces of fossilized poop — at a site in California's Mehrten Formation. The location dates to the late Miocene epoch, about 5.3 million to 6.4 million years ago, and is known for being rich in Borophagus fossils; the coprolites, which are much rarer than bones, are thought to be about 2 million years old, the study authors reported.

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