Trigonodontids

Trigonodontids are a family of herbivorous ornithopod dinosaurs that lived during the Late Cretaceous period, approximately 99 to 66 million years ago. They are known from fossils found in North America, Europe, and Asia. Trigonodontids are characterized by their distinctive, triangular teeth, which are unique among ornithopods. These teeth are adapted for grinding plant material, and the family is believed to have fed on a variety of plants, including ferns, conifers, and angiosperms.

The most well-known genus within the Trigonodontidae is Trigonosaurus, which was first described in 1877. Other genera include Triceratops, although this dinosaur is more commonly associated with the Ceratopsia. Trigonodontids are generally small to medium-sized dinosaurs, with lengths ranging from 2 to 7 meters. They had a relatively short snout and a pair of small horns on their skull, which may have been used for defense or display.

Trigonodontids are thought to have been social animals, with evidence suggesting that they may have lived in herds. Their teeth and jaw structure indicate that they were adapted for a diet of tough, fibrous plants, and their small size may have allowed them to exploit niche habitats that were inaccessible to larger herbivores.

The family Trigonodontidae is part of the larger group of ornithopods, which also includes hadrosaurs and iguanodons. They are believed to have evolved from earlier ornithopods and diversified during the Late Cretaceous, filling various ecological niches. Despite their distinctive features, trigonodontids are not as well-known as some other groups of dinosaurs, but they play an important role in our understanding of the diversity and evolution of ornithopods during the Cretaceous period.