Allosaurus Roar’s Fossil of the Week (2/6/17)

This week’s Fossil of the Week comes from the great Miocene fossil trove at Agate Fossil Beds National Monument near Harrison, Nebraska.  Daeodon, commonly nicknamed “hell pig,” was one of the fiercest and most interesting mammals of this ancient environment around 19 million years ago.

Daeodon, Agate Fossil Beds National Monument, Harrison, NE

These huge omnivores looked like giant boars, although they were not actually related to modern pigs.  Daeodon was one of the largest mammals in its era, about the size of a modern bison, with a huge head and very large teeth capable of crushing and tearing. Daeodon lived in the open grasslands of western North America, and fossils, while rare, have been found from Oregon to Nebraska.  Named for the Greek “dreadful tooth,” Daeodon indeed had a frightening mouthful, with a mix of teeth, including large canine tusks, for eating a wide variety of foods.  Its diet probably included live prey, carrion, plants, and tubers.  It is likely that Daeodon was an apex predator, but similar to omnivores today was probably an opportunist that ate whatever edible things it could find.

The nearly complete Daeodon found at Agate Springs Ranch (which later became Agate Fossil Beds National Monument) and first described in 1905, was known for over 90 years as Dinohyus.  A 1998 study, however, found that Dinohyus was indistinguishable from the Daeodon, a fossil named by famed “Bone Wars” paleontologist Edward Drinker Cope in 1878.  Dinohyus then became Daeodon, which was named earlier and whose name therefore took precedence.  It was the largest member of an extinct group of mammals known as entelodonts, and the huge beast could reach a height of over 6 feet at the shoulder, and weigh over 900 pounds.

The many animals fossilized at Agate Fossil Beds National Monument are theorized to have died around a water source, probably during a drought.  Mammals such as Moropus (an unusual extinct relative of the horse and rhino) and Menoceras (a medium-sized ancient rhino) have been found in small herds at the fossil beds.  As carcasses of these large animals piled up, predators such as the beardog Daphoenodon and omnivores such as Daeodon came to scavenge the remains, but also eventually fell victim to the drought.

Entelodonts went extinct around 16 million years ago, but fortunately the great fossil remains of Daeodon found at Agate Fossil Beds give us a good understanding of this frightful and amazing animal of the past.