Acristavus gagslarsoni

†Acristavus gagslarsoni was a non-crested hadrosaurid dinosaur from the Late Cretaceous (~79 Ma) of Montana and Utah, USA. A large bipedal/quadrupedal herbivore, it is notable for lacking a crest, contrasting with many ornate relatives. Named by Gates et al. in 2011, it helps clarify the evolutionary transitions in hadrosaurid head ornamentation.

Diet & Feeding

Herbivore

Acristavus gagslarsoni was a plant-eating dinosaur. Herbivores typically fed on ferns, cycads, conifers, and other vegetation available during their era. Many herbivorous dinosaurs developed specialized teeth and digestive systems for processing tough plant material.

Time Period

Cretaceous Late Mesozoic Era

Acristavus gagslarsoni lived during the Cretaceous Late period of the Mesozoic Era, approximately 100.5 to 66.0 million years ago.

The final age of dinosaurs, featuring iconic species like Tyrannosaurus rex, Triceratops, and Velociraptor. Dinosaurs reached their peak diversity before the catastrophic asteroid impact at the Chicxulub crater ended the Mesozoic Era.