Insects, which are a type of arthropod, are easily the most numerous group of multicellular organisms on the planet, with about a million species identified so far. The title of heaviest insect in the world has many rivals, the most frequently crowned of which is the larval stage of the goliath beetle, Goliathus goliatus, the top size of which is at least 115 g (4.1 oz) and 11.5 cm (4.5 in). The largest confirmed weight of an adult insect is 71 g (2.5 oz) for a giant weta, Deinacrida heteracantha, although it is likely one of the elephant beetles, Megasoma elephas and Megasoma actaeon, or goliath beetles, both of which can commonly exceed 50 g (1.8 oz) and 10 cm (3.9 in), can reach a higher weight.
The longest insects are the stick insects, see below.
Representatives of the extinct dragonfly-like order Meganisoptera such as the Carboniferous Meganeura monyi and the Permian Meganeuropsis permiana are the largest insect species ever known. These creatures had a wingspan of some 75 cm (30 in) and an estimated body weight of over 1 pound (450 g), making them about the size of a crow.