Dentist Discovers Human-Like Jawbone and Teeth in a Floor Tile at His Parents' Home. Scientists are planning to study the specimen, embedded in travertine from western Turkey, in hopes of dating and identifying it. He found the jawbone in a tile made of travertine, a type of limestone that typically forms near hot springs. This specific tile came from a quarry in the Denizli Basin of western Turkey. The travertine excavated there formed between 0.7 million and 1.8 million years ago, which suggests the mandible did not come from a person who died recently.