Troodon is a dubious genus of small coelurosaurian dinosaurs. It has been found in both the Arctic and the rest of North America, although the ones found in areas like the Arctic, Canada, and Alaska were significantly larger than their cousins further south.
They are also one of the few dinosaurs who have been found with a nest of eggs, sometimes with the parents nesting over the eggs. It probably was among the smartest dinosaurs, as it had a large brain for its relatively small size. It probably ate small lizards, mammals, and invertebrates.