Black Beauty (specimen number RTMP 81.6.1) is a well preserved fossil of Tyrannosaurus rex. The nickname stems from the apparent shiny dark color of the fossil bones, which occurred during fossilisation by the presence of minerals in the surrounding rock. The specimen is housed in the Royal Tyrrell Museum in Drumheller, Alberta, Canada. Black Beauty is the 14th of the 20 most complete skeletons of Tyrannosaurus rex found so far, featuring 85 original bones (28% complete) and casts are on display in museums around the world, like the display at Naturhistoriska Riksmuseet in Stockholm, Sweden. In 2009, a paper by Jack Horner and colleagues illustrated the concept of parasitic infections in dinosaurs by analysing the lesions found on the cranial bones of Black Beauty. The specimen has been used to study comparative morphology between tyrannosaurids and Tyrannosaurus individuals, and some[who?] have suggested that Black Beauty should be classed as Dynamosaurus.