Trilobozoa
| Trilobozoa Temporal range: Ediacaran, around 558–550 Ma Ediacaran |
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| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Trilobozoa Fedonkin, 1985 [nom. transl. Runnegar, 1992 ex Class Trilobozoa Fedonkin, 1985] |
| Family and Genera | |
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See article |
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See article
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.
The various members of Trilobozoa are organized into (monotypic) genera, and some are grouped into families.
The following genera are triradially symmetric edicarans that have not yet been classified into either Albumaresidae or Tribrachididae, nor a new family.
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