Acerentomata Eosentomata Sinentomata The Protura, or proturans, and sometimes nicknamed coneheads,[2][3] are very small (0.6–1.5mm long), soil-dwelling animals, so inconspicuous they were not noticed until the 20th century.

[7] Uniquely among hexapods, proturans show anamorphic development, whereby body segments are added during moults.

[10][14][15] Proturans live chiefly in soil, mosses, and leaf litter[8] of moist temperate forests[12] that are not too acidic.

[17] Although they are sometimes regarded as uncommon,[12] proturans are most likely overlooked because of their small size,[11] as densities of over 90,000 individuals per square metre have been recorded.

[11][12] The styliform mouthparts suggest the Protura may be fluid feeders, based on evidence that some species suck out the liquid contents of fungal hyphae.

[16] Proturan species which spend their lives near the soil surface generally produce one new generation of offspring each year; they also possess longer legs.

[10] Proturans were first discovered in the early 20th century, when Filippo Silvestri and Antonio Berlese independently described the animals.