July 5, 2022

Marginocephaly (Marginocephalia) - a group of dinosaurs from the order of bird-pelvis dinosaurs (from the Cerapoda suborder, from the Heterodontosauriformes group). They were all herbivores. Originally they were bipedal, later forms of very large sizes and moving on four legs appeared. They are characterized by a bony bone collar above the occipital bone of the skull and overlapping the back. The skulls of some were among the largest in vertebrates. Heads covered in such a way, often equipped with horns, could be used for deterrence or defense against predators, or for mating fights for females. They are known from the Late Jurassic until the end of the Cretaceous. They are divided into pachycephalosauria (Pachycephalosauria) and ceratopsia (Ceratopsia). Simplified group cladogram: