Ecdysozoa

The Ecdysozoa (including Cycloneuralia) are a group of protostome animal phyla. This is a taxon above the level of phylum. It includes the Arthropoda (insects and crustaceans), Nematoda, and several smaller phyla.^[1]

Ecdysozoa Temporal range: Lower Cambrian – Recent
Centipede (Panarthropoda)
Scientific classification
Kingdom:	Animalia
(unranked):	Protostomia
Superphylum:	Ecdysozoa Aguinaldo et al., 1997
Phyla, classes, and clades
Cycloneuralia: Kinorhyncha Loricifera Priapulida Nematoda Nematomorpha Palaeoscolecida Panarthropoda: "Lobopodia" Onychophora Tardigrada Arthropoda Dinocaridida

They were first defined in 1997, based mainly on phylogenetic trees taken from 18S ribosomal RNA genes.^[2] A large study in 2008 strongly supported the Ecdysozoa as a clade, that is, a group consisting of a common ancestor and all its descendants.^[3]

The group is also supported by morphological characters, and includes all animals that shed their exoskeleton (see ecdysis).