Scolosaurus is an extinct genus of ankylosaurid dinosaurs within the subfamily Ankylosaurinae. It is known from the lower levels of the Dinosaur Park Formation and upper levels of the Oldman Formation in the Late Cretaceous (latest middle Campanian stage, about 76.5 Ma ago) of Alberta, Canada. It contains two species, S. cutleri and S. thronus. The type species, S. cutleri, measured up to in length and in body mass. Discovery Scolosaurus was named by Franz Nopcsa von Felső-Szilvás in 1928, based on holotype NHMUK R.5161, a nearly complete specimen that preserves the entire skeleton except for the distal end of the tail, the right forelimb, the right hindlimb, and the skull. The rare preservation of osteoderms and skin impression are also present. The fossil skeleton was discovered by William Edmund Cutler, an independent fossil collector in 1914 at Quarry 80 of the Deadlodge Canyon locality. It was collected from the bottom of the Dinosaur Park Formation in fine-grained sandstone and fine-grained claystone sediments that were deposited during the Campanian stage of the Late Cretaceous period, approximately 76.5 million years ago. The holotype specimen is housed in the collection of the Natural History Museum in London, England. In 2013, Arbour and Currie reassigned specimen MOR 433, upon which the genus Oohkotokia was based, to Scolosaurus. This specimen consists of a partial skull, both humeri, a caudal vertebra and several osteoderms and was recovered in the Upper Member of the Two Medicine Formation, in Montana, which has been dated at approximately 74 million years. The remains were collected in 1986-1987 in grey siltstone that was deposited during the Campanian stage of the Cretaceous period. The specimen is housed in the collection of the Museum of the Rockies in Bozeman, Montana. The generic name Scolosaurus means "pointed stake lizard" and is derived from the Greek words skolos (σκῶλος) meaning "pointed stake", and saûros (σαύρα) meaning "lizard". The specific name, cutleri, honours its discoverer and the collector of the holotype, W. E. Cutler, who was seriously injured when the specimen fell on him as he was excavating it. Classification In 1928, Nopcsa assigned the specimen to the family Ankylosauridae, and drew morphological comparisons with the fossil material known from Dyoplosaurus. In 1971, Walter Coombs concluded that there was only one species of ankylosaurid during the Campanian age of the Late Cretaceous of North America. He synonymized the species Anodontosaurus lambei, Dyoplosaurus acutosquameus, and Scolosaurus