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 "Megaphragma caribea" from Guadeloupe, measuring 170 μm long, is another contender for smallest known insect in the world. Beetles of the tribe Nanosellini are all less than 1 mm long; the smallest confirmed specimen is of "Scydosella musawasensis" at 325 μm long; a few other nanosellines are reportedly smaller, in historical literature, but none of these records have been confirmed using accurate modern tools. These are among the tiniest non-parasitic insects. The western pygmy blue ("Brephidium exilis") is one of the smallest butterflies in the world. The smallest sea cucumber, and also the smallest echinoderm, is "Psammothuria ganapati", a synaptid