would you know why a book about ice mummies at my library was classified 599 i feel like thats usually for animals. is the strong as fuck ice mummy a species
599 is about mammals. Human beings would be under 599.9, so maybe the book was about one of the subcategories; genetics, sex, age, anthropometry, environmental effects on physique, or ethnic groups. Was the ice mummy in question an earlier hominid? In that case it would make more sense to put it under 569.9 with Homo erectus and Neanderthals.
Looking up other books about ice mummies specifically, some are indeed classified in 599.9 for human remains, but most are classified in the 900s for history and geography of the region they were found in. The 930s, history of the ancient world. A lot of them are about intentional/ritual mummification in Ancient Egypt rather than natural mummification in swamps or tundras, so I don't think ice mummies have their own number.