In terrestrial zoology, megafauna (Ancient Greek megas "large" + New Latin fauna "animal") are large or giant animals. The most common thresholds used are 45 kilograms (100 lb) or 100 kilograms (220 lb). This thus includes many species not popularly thought of as overly large, such as white-tailed deer, red kangaroo, and humans.In practice, the most common usage encountered in academic and popular writing describes land animals roughly larger than a human that are not (solely) domesticated.