Therizinosauridae ("scythe lizards") is a subfamily of derived (advanced) therizinosauroid dinosaurs whose fossil remains have been dated to the Mid-to-Late Cretaceous period (100 to 70 mya). Even though representative fossils have only been found throughout China, Mongolia, and the United States, the range of Therizinosauridae is believed to have spanned much of the supercontinent of Laurasia at its height.