Up until roughly 8,000-10,000 years ago, many large land mammals roamed all over North America. To this day we are unsure as to exactly why these animals - sometimes called "Megafauna" - died out when they did. Species featured: AMERICAN LION (Panthera leo atrox) ANCIENT BISON (Bison antiquus) COLUMBIA MAMMOTH (Mammuthus columbi) DIRE WOLF (Canis Dirus) HAGERMAN HORSE (Equus simplicidens) JEFFERSON’S GROUND SLOTH (Megalonyx jeffersonii) MASTODON (Mammut americanum) SABER-TOOTH CAT (Smilodon californicus) SHORT-FACED BEAR (Arctodus simus) WESTERN CAMEL (Camelops sp) All images are scientifically accurate and expertly drawn by wildlife artist Roger Hall, who has been working in the field for over 20 years for such noted organizations as National Geographic, Scholastic Books, Sunset Magazine and World Wildlife Fund. The poster is printed on matte, museum-quality paper with Giclée printing quality: • Paper thickness: 10.3 mil • Paper weight: 5.6 oz/y² (192 g/m²) • Opacity: 94%