Aquilops

Aquilops: An Early North American Ceratopsian

Aquilops is an early herbivorous ceratopsian dinosaur that inhabited North America during the Early Cretaceous period, approximately 109 to 104 million years ago. The discovery of a single partial skull in Montana has provided valuable insights into the evolutionary history of neoceratopsian dinosaurs.

Discovery and Naming

The fossil specimen, a partial skull, was discovered in 1997 by paleontologist Scott Madsen in Carbon County, southern Montana. Initially thought to belong to another species, further examination revealed it to be a new species to science. In 2014, the species was formally named and described by Andrew Farke and colleagues. The genus name, Aquilops, is a combination of the Latin "aquila" (eagle) and Greek "ops" (face), referring to its beaked snout. The species name, americanus, highlights its significance as the first unequivocal basal neoceratopsian found in America.

Physical Characteristics and Classification

The skull of Aquilops is relatively small, measuring 84.2 mm (3.3 inches) in length. Based on comparisons with related species, the individual specimen is believed to have been a subadult, potentially representing about 60% of its adult size. Estimates suggest an adult Aquilops would have reached a body length of approximately 60 cm (23.6 inches) and weighed around 1.5 kg (3.3 lb). Distinctive features include a downward-curving rostral bone forming the beak, a keel on its upper surface, and a concave upper jaw rim. Its classification places it as a basal neoceratopsian, meaning it was an early member of the group that would later include the more familiar horned dinosaurs like Triceratops. The presence of such an early neoceratopsian in North America suggests a migration event from Asia during the late Early Cretaceous.