Bilateria (unranked)
ZoologyBilateria is the clade with bilateral symmetry: they have a left and right side. It is the biggest group of animals and the most evolved including, crustacea, insects, reptiles, fish birds and mammals.
From some point of view it is more logical to look at the different clades in bilateria.
Deuterostomia Chordata Hemichordata Echinodermata XenoturbellidaProtostomia Ecdysozoa Arthropoda Platyzoa Lophotrochozoa