A juvenile Diabloceratops would be noticeably smaller than adults, which could reach lengths of up to 5.5 meters (18 feet). As in many dinosaurs, juveniles would display different proportions than adults: their head would be relatively larger compared to their body, and their horns and frill would not be as developed or prominent as in adults.
In juvenile Diabloceratops, the frontal horns, located above the eyes, and the nasal horns would be present but not fully formed, probably shorter and less sharp. The ruff or bony shield would also have been less elaborate, with the characteristic smaller and less pronounced protuberances. As they grew, these horns and ruff would have developed, taking on the more imposing and defensive shapes that characterized adults.
Its body would have been robust and low, with powerful limbs that would have allowed it to move agilely through its environment, searching for food and avoiding predators. Juvenile Diabloceratops would have fed on low plants, such as ferns and cycads, using its sharp beak to cut vegetation.
The social behavior of juvenile Diabloceratops might have included living in herds, where younger individuals would have been protected by adults. Forming herds would have offered greater safety from predators, such as the tyrannosaurids that also inhabited the region.
Approximate measurements of Diabloceratops:
- Complete 1:35 scale
- Length 34 mm
- Height 17 mm
- Width 24 mm
- Snout-tail length 55 mm
- Complete 1:10 scale
- Length 115 mm
- Height 56 mm
- Width 82 mm
- Snout-tail length 192 mm