Geography of South America Great American Interchange. The Andes, likewise a comparatively young and seismically restless mountain range, runs down the western edge of the continent; the land to the east of the northern Andes is largely tropical rain forest, the vast Amazon River basin. The continent also contains drier regions such as eastern Patagonia and the extremely arid Atacama desert. The South American continent also includes various islands, most of which belong to countries on the continent. The Caribbean territories are grouped with North America. The South American nations that border the Caribbean Sea—including Colombia, Venezuela, Guyana, Suriname, and French Guiana—are also known
Smallest organisms smallest crocodilian is the Cuvier's dwarf caiman ("Paleosuchus palpebrosus") from northern and central South America. It reaches up to in length. One of the smallest snakes known is the recently discovered Barbados threadsnake ("Leptotyphlops carlae"). Adults average about long, which is only about twice as long as the hatchlings. The Common blind snake("Indotyphlops braminus") measures long, uncommonly to long. The smallest known dinosaur (excluding modern birds) is "Anchiornis", a genus of feathered dinosaur that lived in what is now China during the Late Jurassic Period 160 to 155 million years ago. Adult specimens range from long, and the weight has