Scientific Fact of the Day 596: Scientists have discovered a new species of dinosaur called "Thanatotheristes degrootorum" in Canada. Thanatotheristes, which means "reaper of death" in Greek, is the oldest known tyrannosaurid species in North America. It lived approximately 79.5 million years ago during the Late Cretaceous period. This discovery provides valuable insights into the early evolution of tyrannosaurids and helps expand our understanding of the diversity and distribution of these fascinating prehistoric creatures.