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Achelousaurus horneri

OLogy Series
extinct animal
card
011

Achelousaurus horneri

OLogy Series
extinct animal

Unlike its relative Triceratops, this lesser-known horned dinosaur had no horns on its brow. Instead, it had two long spikes on the back of its frill, the bony extension behind its skull. Fossils of this plant-eater have been found in Montana.

Achelousaurus gets its name from "Achelous," a river god in Greek and Roman mythology. This god had the power to change shape. While fighting the god Hercules, Achelous changed into a bull. But Hercules defeated him by tearing off one of its horns. Because this hornless ceratopian is thought to have evolved from ceratopians with horns, the name Achelousaurus was chosen.

When trying to identify a ceratopian dinosaur, the most important body part is the:

feet

skull

tail

Are you right?

Correct!

Ceratopians have very distinct skulls. Each one's horns and frills have different arrangements and sizes. Otherwise, their bodies are similar.

The second part of this dinosaur's name, horneri, was chosen:

because this dinosaur has no brow horns

because this dinosaur was thought to make horn-like noises

to honor the paleontologist John Horner

Are you right?

Correct!

Paleontologist John Horner is known for his work on dinosaur eggs and nesting grounds.

The Achelousaurus had a knob of bone called a "boss" on its snout.

Fact
or
Fiction
?

Fact

Scientists disagree about the purpose of the Achelousaurus' "boss." They don't know if it once supported a horn.

Scientific Name: Achelousaurus horneri
Pronunciation: ah-kee-LOH-uh-SAW-rus HOR-ner-eye
Named for: Mythological river god plus lizard
Locality Found: Montana
Age: Late Cretaceous, 75 million years ago
Size: 6 meters (20 feet) long
Characteristics: Instead of having skulls with horns like other ceratopsians, these dinosaurs had bosses (large, irregular bony bumps) above their eyes and nose.

Image credits: Rick Spears.