The Andes mountains, spanning a length of 4,500 miles, are recognised as the world's longest continental mountain range. They traverse seven South American countries, namely Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile, and Argentina, from north to south. Scholars have debated the origin of the term "Andes", with some proposing that it is derived from ‘anti’ Quechuan for east while others suggest it comes from anta, meaning "copper". The Andean mountain system was formed as a consequence of plate-tectonic activities during the Cenozoic Era (roughly the past 65 million years). The Andes host a diverse range of wildlife, including over 600 mammal species, 1,700 bird species, and 600 reptile species, of which 75% are endemic. Some of the remarkable animals that thrive here include the llama, alpaca, mountain tapir, and Andean condor.