Cephalozoa Explained
Cephalozoa[1] are an extinct class of primitive segmented marine organisms within the Phylum Proarticulata from the Ediacaran period. They possessed bilateral symmetry and were characterized by a thin, rounded body.
Description
Unlike the other classes of proarticulates, the segmentation of the body is not complete and shows a "head" with fine distribution channels. Some species of the Yorgiidae family also show some asymmetry.[2] [3] [4]
They were discovered in Russia near the White Sea in the Arkhangelsk region, where they lived during the Ediacaran, approximately 635 to 540 Ma (millions of years ago).
Taxonomy
Cephalozoa includes the families Yorgiidae and Sprigginidae:
Yorgiidae
Sprigginidae
The genus Andiva sometimes includes Cephalozoa:
Recent studies indicate that the family Yorgiidae could be included or closely related to the class Vendiamorpha.
See also
Notes and References
- Ivantsov, A. Y. . 2001 . en . Vendia and Other Precambrian "Arthropods" . Paleontological Journal . 35 . 4 . 335–343 .
- Ivantsov, A. Yu . 2004 . en . New Proarticulata from the Vendian of the Arkhangel'sk Region . Paleontological Journal . 38 . 3 . 247–253.
- Ivantsov, A. Y. . Malakhovskaya, Y. E. . Serezhnikova, E. A. . 2004 . en . Some Problematic Fossils from the Vendian of the Southeastern White Sea Region . Paleontological Journal . 38 . 1 . 1–9 . 2021-08-11 . 2007-07-04 . https://web.archive.org/web/20070704183946/http://www.vend.paleo.ru/pub/Ivantsov_et_al_2004_eng.pdf . dead .
- Ivantsov . A. Y. . 2004 . Vendian Animals in the Phylum Proarticulata . The Rise and Fall of the Vendian Biota. IGSP Project 493. Abstracts. . Prato, Italy . 52.
- en. Ivantsov. Andrey Yu. Small Vendian transversely Articulated fossils. Paleontological Journal. 41. 2. 10.1134/S0031030107020013. 2007. 113–122. 2007PalJ...41..113I .