What is "trilobozoa"

Trilobozoa ("three-lobed animals") is an extinct taxon of organisms which displayed tri-radial symmetry. Fossils of trilobozoans are restricted to marine strata of the Late Ediacaran period — prior to the Cambrian explosion of modern life forms.

The taxonomic affinities of this groups are open to debate. Ivantsov and Fedonkin (2002) place them among the cnidarians. They reasoned that since the conulate Vendoconularia exhibited six-fold symmetry, the conularids — then regarded as a sister group to the scyphozoan cnidarians — must be nested within the trilobozoa, making the trilobozoan group part of the cnidarian phylum.

Most trilobozoans were disk-shaped, typified by Tribrachidium. Through comparisons with the other discoidal trilobozoans, it appears the different "arm" patterns on each genus/species occurred due to growth arresting or progressing at different stages of developmental growth.