Loons are in the family Gaviidae, which in Latin means 'sea smew' (note: smews are small crested Old World ducks.) In Europe, they are called Divers because of their superior diving abilities. Loons are foot-propelled diving birds that are represented by four species in North Eurasia and North America. Loons were once thought to be related to Grebes, but have been found to have no relationship to any other living order of birds. The earliest fossil records of loon go back to the Paleocene age, over 65 million years ago!