Continent continent. From this perspective, the edge of the continental shelf is the true edge of the continent, as shorelines vary with changes in sea level. In this sense the islands of Great Britain and Ireland are part of Europe, while Australia and the island of New Guinea together form a continent. As a cultural construct, the concept of a continent may go beyond the continental shelf to include oceanic islands and continental fragments. In this way, Iceland is considered part of Europe and Madagascar part of Africa. Extrapolating the concept to its extreme, some geographers group the Australian continental plate
Smallest organisms that lives between sand grains on the coast of India. Its maximum length is only 4 mm. The smallest sea urchin, "Echinocyamus scaber", has a test only 6 mm across. "Patiriella parvivipara" is the smallest starfish, at only 5 mm across. The smallest vertebrates (and smallest amphibians) known are "Paedophryne amauensis" frogs from Papua New Guinea, which range in length from , and average . Previously, the title of smallest vertebrate was held by members of the fish genus "Paedocypris" of Indonesia. The one of world's smallest fish based on the minimum size at maturity is "Paedocypris progenetica" from Indonesia,