Megafauna

In zoology, megafauna (from Greek μέγας megas "large" and Neo-Latin fauna "animal life") are large animals. The most common thresholds to be a megafauna are weighing over 45 kg (99 lb) or weighing over 1,000 kg (2,200 lb). The first occurrence of the term was in 1876. After the Cretaceous–Paleogene extinction event wiped out all non-avian dinosaurs, mammals and other vertebrates experienced an expansion in size. Millions of years of evolution led to gigantism on every major land mass. During the Quaternary extinction event, many species of megafauna went extinct as part of a slowly progressing extinction wave that affected ecosystems worldwide.

In practice, the most common usage encountered in academic and popular writing describes land mammals roughly larger than a human that are not (solely) domesticated. The term is especially associated with the Pleistocene megafauna – the land animals that are considered archetypical of the last ice age, such as mammoths, the majority of which in northern Eurasia, Australia-New Guinea and the Americas became extinct within the last forty thousand years.