other small dinosaurs like Stegoceras, Dromaeosaurus and Ornithomimus, and various fishes, amphibians, crocodiles and pterosaurs. Discovery In 1917, Canadian paleontologist Charles M. Sternberg of the Geological Survey of Canada discovered a complete skull and significant amount of the skeleton of an armoured dinosaur in the sandstone layers of Quarry 69 of the Belly River Group, above sea level. The specimen, designated by the Canadian Museum of Nature accession number CMN 2759, and excavated south of the mouth of the Little Sandhill tributary of the Red Deer River in Alberta, includes a nearly complete skull in articulation, most or all of the cervical vertebrae and the front dorsal vertebrae, and armour plates covering them, a majority of the disarticulated forelimb and three articulated fingers, a fragment of the pelvis and partial sacrum, a few bones of the foot, and multiple hundreds of osteoderms and dermal ossicles. This material was being described by Canadian paleontologist Lawrence M. Lambe of the Geological Society, who completed the description of the skull and osteoderms prior to his death in March of 1919. Lambe's work was published posthumously by the Royal Society of Canada, where he named the new material as Panoplosaurus mirus, and a supplemental description of the vertebrae and limb material, which Lambe had not yet gotten to, was published by Sternberg in 1921. The name Panoplosaurus derived from the hoplon of Greece, translating as "well -armoured lizard". While the beds of discovery of the holotype, CMN 2759, were originally described as the Belly River beds, they are now considered part of the upper level of the Dinosaur Park Formation, pertaining to the late middle Campanian, 75 to 76 million years ago. Many additional specimens have since been referred to the genus, including Royal Ontario Museum (ROM) 1215 and Royal Tyrrell Museum of Paleontology (RTMP) 83.25.2 from the Dinosaur Park Formation of Alberta, and an unnumbered Oklahoma Museum of Natural History (OMNH) scapulocoracoid from the Aguja Formation of Texas. A scapula from the Naashoibito member of the Kirtland Formation in New Mexico was referred to Panoplosaurus in 1981, but as it is from a different age and location from other specimens, may instead represent the ankylosaurid taxon Nodocephalosaurus, although this is uncertain due to lack of overlapping material. 18 other specimens in the ROM, CMN, American Museum of Natural History, and Princeton University were referred to the genus by Walter P. Coombs in 1978,