Description and Classification

Anchiceratops was a four-legged, plant-eating dinosaur, typical of the Ceratopsidae family. It was a medium-sized ceratopsian, estimated to be about 4.5 to 5 meters (15 to 16 feet) long and weighing around 1.5 to 2 metric tons (1.7 to 2.2 short tons). Like other ceratopsids, it had a large skull featuring a prominent frill and horns. It possessed two long brow horns above its eyes, which often showed a tendency to curve forwards, and a shorter, sometimes more rounded, horn on its nose. Its mouth ended in a strong, toothless beak, ideal for gripping and plucking tough vegetation, with batteries of shearing teeth located further back in its jaws for processing food.

The frill of Anchiceratops was long and somewhat rectangular, a characteristic feature of the Chasmosaurinae subfamily to which it belongs. This subfamily also includes well-known dinosaurs such as Chasmosaurus and Triceratops. The frill of Anchiceratops had two large openings, called fenestrae, which would have reduced the skull’s overall weight and provided attachment points for powerful jaw muscles. The edges of its frill were adorned with distinctive, large, pointed, triangular bony knobs known as epoccipitals (or episquamosals), which were particularly prominent along the back edge and corners of the frill.

In the broader classification of dinosaurs, Anchiceratops belongs to the order Ornithischia (bird-hipped dinosaurs), the suborder Marginocephalia (dinosaurs with a bony shelf or frill at the back of the skull), and the infraorder Ceratopsia (horned dinosaurs). Within the Ceratopsidae family, it is firmly placed in the Chasmosaurinae, which are generally characterized by their longer frills and often more prominent brow horns compared to the Centrosaurinae subfamily (like Centrosaurus or Styracosaurus), which typically have shorter frills and larger nasal horns or bosses.

Distinguishing Features

Anchiceratops can be identified by several key characteristics that set it apart from other ceratopsian dinosaurs:

• A long, somewhat rectangular frill, typical of chasmosaurines.
• Large, distinctively pointed, triangular bony knobs (epoccipitals/episquamosals) lining the side and rear edges of the frill. These were often more pronounced than in its close relative Chasmosaurus.
• Two long brow horns situated above the eyes, which frequently curved forward or slightly outward.
• A relatively small horn on the nose, which could vary in shape.
• Some specimens exhibit a unique pattern of smaller bumps or hornlets along the midline of the frill, just behind the main brow horns.

Paleoenvironment and Diet

Fossils of Anchiceratops are primarily found in the Horseshoe Canyon Formation of Alberta, Canada, dating to the early Maastrichtian age of the Late Cretaceous. This geological formation indicates that Anchiceratops lived in a coastal plain environment. The region featured extensive river systems, floodplains, swamps, and estuaries, located near the western edge of the Western Interior Seaway, a large inland sea that once divided North America.

The climate during this time was generally warm and humid, supporting a rich diversity of plant life. Anchiceratops was a herbivore, using its powerful beak to crop low-lying vegetation such as ferns, cycads, and possibly early flowering plants. Its dental batteries would have effectively shredded these tough plant materials. It shared its habitat with a variety of other dinosaurs, including hadrosaurs like Edmontosaurus, other ceratopsians such as Pachyrhinosaurus (found in different layers of the same broader formations), armored ankylosaurs like Anodontosaurus, and predatory theropods, notably tyrannosaurids like Albertosaurus, as well as smaller carnivores.

Significance and Ongoing Research

Anchiceratops is an important dinosaur for understanding the diversity and evolution of chasmosaurine ceratopsids during the Late Cretaceous period in North America. Its fossils help paleontologists reconstruct ancient ecosystems and provide data for biostratigraphy, which involves using fossils to date and correlate different rock layers. The variations observed in the frill ornamentation and horn structure among Anchiceratops specimens contribute to discussions about individual variation, growth stages (ontogeny), and possibly sexual dimorphism within ceratopsian species. These frills and horns are widely believed to have played roles in display for species recognition or attracting mates, and potentially in defense against predators or in contests between individuals.

Ongoing research continues to refine our understanding of Anchiceratops. Paleontologists work to clarify the exact number of valid species within the genus (the type species being Anchiceratops ornatus) and its precise evolutionary relationships with other chasmosaurines, such as Arrhinoceratops and the later, larger Triceratops. Detailed studies of existing and newly discovered fossil material focus on anatomical variations and how these might relate to the animal’s life and behavior. Further discoveries could shed more light on aspects such as its social behavior, though large bonebeds indicating herding, common for some centrosaurines, are not as well-documented for Anchiceratops.