Machairoceratops cronusi

Machairoceratops cronusi is a basal ceratopsian dinosaur that lived during the early Late Cretaceous , approximately 77 million years ago, in what is now southern Utah, USA. It was described in 2016 from fossil remains from the Wahweap Formation , a key geological unit for understanding the early diversification of ceratopsians in Laramidia. Its name means "bladed horned face," referring to the distinctive shape of its cranial ornamentation, while the epithet cronusi alludes to the titan Cronus, reinforcing the idea of a primitive morphology within the lineage.

From a phylogenetic perspective, Machairoceratops is considered one of the oldest known ceratopsians , close to the base of the divergence between the Centrosaurinae and the Chasmosaurinae . Recent studies and phylogenetic revisions published in the last decade position it as a key taxon for understanding how the elaborate cranial structures that characterize the more derived ceratopsians of the Late Campanian arose.

The known fossil material consists mainly of skull elements, especially parts of the frill, which exhibit a unique combination of primitive and derived features. The most striking feature of the cranial skeleton is the presence of extremely elongated and curved epoccipitals , projecting laterally and slightly backward, with a blade-like shape. These structures have no direct equivalents in other known ceratopsians and suggest a primarily visual and display function, possibly related to species recognition or sexual selection, rather than active defense.

The skull of Machairoceratops was relatively small compared to later ceratopsians. The complete animal is estimated to have reached a body length of 6 to 8 meters .

Unlike later forms such as Triceratops , it did not possess large, well-developed supraorbital horns; its horns were short and inconspicuous, reinforcing the idea that the evolutionary emphasis was on the cranial frill.

Although the postcranial skeleton of Machairoceratops is poorly understood, comparison with closely related basal ceratopsians suggests a robust body, obligate quadrupedal posture, and strong limbs, adapted to a terrestrial herbivorous lifestyle. Like other ceratopsians, it possessed a horny beak for cutting vegetation and efficient dental batteries for grinding tough plants, indicating a diet based on low-lying, fibrous vegetation.

Recent paleoecological studies suggest that Machairoceratops inhabited a subtropical environment with rivers, floodplains, and open woodlands , sharing its ecosystem with primitive hadrosaurs, medium-sized theropods, and other early ornithischians. Its coexistence with other basal ceratopsians supports the hypothesis that southern Laramidia was an important center of early diversification for the group.

Approximate measurements of the Pentaceratops:

• 1:60 Scale Complete
• Length 105 mm
• Height 64 mm
• width 28 mm
• Snout-tail length 117 mm

• 1:35 Scale Complete
• Length 180 mm
• Height 109 mm
• Width 48 mm
• Snout-tail length 200 mm

• Complete 1:20 Scale
• Length 289 mm
• Height 176 mm
• Width 100 mm
• Snout-tail length 350 mm