Petrobius brevistylis (a jumping bristletail, order Archaegnatha), is an elongated wingless insect resembling a household silverfish. It is up to 22 mm long, including the tail. Bristletails have a laterally compressed body, an arched body, and 3 tail-like posterior appendages. They can flex their bodies, using their tails to jump into the air. Bristletails are restricted to damp habitats. Petrobius marititmus inhabits upper intertidal and supratidal habitats, including natural rocky shores, and artificial seawalls and jetties. It is often found in the same kinds of habitats as the isopods of the genus (Ligia spp., Sea Roaches). Petrobius brevistylis is native to Europe, from Iceland and Norway to Brittany, France. They were first reported from Newfoundland in 1969, and first named as a new species, Petrobius canadensis, and then as the European congener P. maritimus, before being recognized as P. brevistylis. Petrobius brevistylis was probably introduced to North America in the 19th century with the dry ballast of sailing ships, and occurs form Newfoundland to Rhode Island.