Trilobozoa
Trilobozoa ("three-lobed animals") is a taxon of extinct 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 more modern life forms.
Trilobozoa | |
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Scientific classification | |
Kingdom: | Animalia |
Subkingdom: | Eumetazoa |
Phylum: | †Trilobozoa Fedonkin, 1985 [nom. transl. Runnegar, 1992 ex Class Trilobozoa Fedonkin, 1985] |
Families and Genera | |
See text |
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.
Classification
- Phylum Trilobozoa †
- Family Albumaresidae †
- Family Tribrachididae †
- Genus Tribrachidium †
- Family Anabaritidae †
- Genus Aculeochrea †
- Genus Anabarites †
- Genus Cambrotubulus †
- Genus Mariochrea †
- Genus Selindeochrea †
- Family incertae saedis
- Genus Gastreochrea †
- Genus Hallidaya †
- Genus Kotuites †
- Genus Lobiochrea †
- Genus Longiocrea †
- Genus Paragloborilus †
- Genus Rugoconites †
- Genus Tinsitheca †
- Genus Triforillonia†
See also
References
- Ivantsov, Andrei Yu.; Fedonkin, Mikhail A. (2002). "Conulariid-like fossil from the Vendian of Russia: A metazoan clade across the Proterozoic/Palaeozoic boundary". Palaeontology. 45 (6): 1219–1229. doi:10.1111/1475-4983.00283.
- Fedonkin, Mikhail A. (2007). The Rise of Animals: Evolution and Diversification of the Kingdom Animalia. JHU Press. ISBN 9780801886799.
- McMenamin, M.A.S (1998). The Garden of Ediacara. New York: Columbia University Press. ISBN 0-231-10559-2.
- Dzik, Jerzy (2003). "Anatomical Information Content in the Ediacaran Fossils and Their Possible Zoological Affinities". Integrative and Comparative Biology. 43 (1): 114–126. doi:10.1093/icb/43.1.114. PMID 21680416.
External links
- Ediacara Assemblage University of Bristol