Euarthropoda
Euarthropoda is a major clade within the phylum Arthropoda that comprises the crown group of living arthropods and their fossil relatives. It is defined as the group descended from the most recent common ancestor of all living arthropods, and it excludes the velvet worms (Onychophora), which lie outside Euarthropoda. In many classifications, Euarthropoda represents the true, or crown, arthropods.
Members of Euarthropoda share a segmented, bilaterally symmetric body plan with a hard, jointed exoskeleton made
Within Euarthropoda are the major living lineages including Chelicerata (spiders, scorpions, mites, horseshoe crabs), Myriapoda (millipedes
The fossil record of euarthropods extends from the Cambrian, with many early forms showing the characteristic