The specific name cronusi refers to Cronus, a Greek god who deposed his father Uranus by castrating him with a sickle or scythe based on the mythology, and as such is shown carrying a curved bladed weapon.

The maximum parsimony analysis yielded a large polytomy at the base of Centrosaurinae, with only Centrosaurini, most of Pachyrhinosaurini (Einiosaurus, Wendiceratops and Pachyrostra), and a clade formed by Avaceratops and Nasutoceratops being resolved.

[3] During the time that Machairoceratops lived, the Western Interior Seaway was at its widest extent, almost completely isolating southern Laramidia from the rest of North America.

[4] Machairoceratops shared its paleoenvironment with other dinosaurs, such as the hadrosaur Acristavus gagslarsoni,[5][6] centrosaur Diabloceratops eatoni [7] and the lambeosaur Adelolophus hutchisoni,[8] unnamed ankylosaurs and pachycephalosaurs, and the theropod Lythronax argestes, which was likely the apex predator in its ecosystem.

[9][10][6] Vertebrates present in the Wahweap Formation at the time of Machairoceratops included freshwater fish, bowfins, abundant rays and sharks, turtles like Compsemys, crocodilians,[11] and lungfish.

[15] Invertebrate activity in this formation ranged from fossilized insect burrows in petrified logs[16] to various mollusks, large crabs,[17] and a wide diversity of gastropods and ostracods.