Acheroraptor

Jurassic Dinos editorial · Updated 17 October 2026 · Source-based review

What was Acheroraptor?

Acheroraptor was a meat-eating dinosaur from Montana, USA, near the end of the Cretaceous Period. It belonged to the dromaeosaurids, the group often nicknamed raptors. Its best clues are jaws and teeth, rather than a complete skeleton. That makes this animal a useful example of how a small fossil can answer one question while leaving many others open.

The Royal Ontario Museum places it about 67–66 million years ago, alongside Tyrannosaurus and Triceratops. Its full species name is Acheroraptor temertyorum. The name refers to Acheron, a river of the underworld in Greek mythology, and the Hell Creek rocks where the fossils were found.

Why are its teeth important?

The 2013 description by David Evans, Derek Larson and Philip Currie identified an almost complete maxilla: the tooth-bearing part of the upper jaw. A lower jaw, called a dentary, was also associated with the discovery. These are separate pieces of evidence, not a whole animal preserved from nose to tail.

Distinct ridges run along the teeth. The researchers also compared the positions of openings and walls in the upper jaw. Together, these details helped distinguish Acheroraptor from other raptors. An isolated sharp tooth can suggest a feeding role, but a tooth still linked to its jaw supplies much more information about identity.

Was it related to Velociraptor?

The original study found similarities with long-snouted Asian raptors, including Velociraptor. This supported a possible connection between Asian and North American dinosaur communities. It does not mean that Acheroraptor was simply Velociraptor living under another name, or that a particular individual crossed between continents.

How big was it, and what did it eat?

The museum gives an estimated length of about three metres. Treat that as a reconstruction estimate, not a measurement along a complete fossil body. A meat-eating diet fits the sharp teeth. The fossils do not provide a daily menu or demonstrate coordinated pack hunting.

Does the illustration show its confirmed appearance?

No. Our AI artwork follows Nobu Tamura’s credited, complete Acheroraptor restoration. Its feathered silhouette is an artistic interpretation; the jaw fossils do not preserve a complete coat of feathers. Colour, scenery and pose are also choices made for the illustration. The image helps introduce the animal, while the evidence above explains what can actually be checked.

Continue with Velociraptor, compare the much larger Tyrannosaurus, or browse dinosaur names beginning with A.