Centrosaurinae

Centrosaurinae (from Greek, meaning "pointed lizards") is a subfamily of ceratopsids, a group of large four-legged ornithischian dinosaurs. Centrosaurine fossils are mostly known from the northern region of Laramidia (modern day Alberta, Montana, and Alaska) but isolated taxa have also been found in China and Utah.

Centrosaurines often have a large nose horn, short horns above the eyes, and a complex frill sticking out of the back of the skull. Except for Centrosaurus apertus, all adult centrosaurines have spike-like bumps in the middle of the skull. By measuring parts of their skulls, scientists have found that centrosaurines differ from other ceratopsian groups in skull, snout, and frill shapes. Male centrosaurines might have taken a long time to mature, and sexual ornamentation did not appear until they were adults.

Centrosaurinae was named by paleontologist Lawrence Lambe in 1915 after Centrosaurus, which became its type genus. The centrosaurines are further divided into three tribes: the Nasutoceratopsini, the Centrosaurini, and the Pachyrhinosaurini by Ryan et al (2016). Nasutoceratopsins are defined as centrosaurines closer to Nasutoceratops titusi than to Centrosaurus apertus and centrosaurins are defined as centrosaurines closer to Centrosaurus apertus than to Pachyrhinosaurus canadensis. Until 2016, the only division used was Pachyrhinosaurini, which is defined as centrosaurines closer to Pachyrhinosaurus canadensis than to Centrosaurus apertus. Together, centrosaurins and pachyrhinosaurins are called eucentrosaurans.

 References 

Category:Ceratopsia