Atrial fibrillation (AF or A-fib) is an abnormal heart rhythm characterized by rapid and irregular beating.
Emperor penguins owe their scientific name (Aptenodytes forsteri) to their discoverer, the first natural scientist to reach Antarctica, the German Johann Reinhold Forster. Forster came to Antarctica in 1770, on Captain James Cook's ship, and saved Cook's life during the voyage.
Index of Types of Penguins. There are typically 17 different species of penguin recognised as living in the world today. Each species belongs to a larger grouping of closely related species known as a genus. The living penguins comprise six genera (the plural of genus): Aptenodytes, Eudyptes, Eudyptula, Megadyptes, Pygoscelis, and Spheniscus (you can see which species belong to each genus by clicking on the link).