| Ventogyrus Temporal range:
| |
|---|---|
| |
| A Ventogyrus fossil | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Superphylum: | †Vendobionta |
| Genus: | †Ventogyrus Ivantsov and Grazhdankin 1997 |
| Species | |
| |
Ventogyrus is an Ediacaran fossil found in the White Sea-Arkhangelsk region of Russia. It was first discovered in the Teska member of the Ust'-Pinega formation, in a thick lens of sandstone, originally sand dumped by storm waves that cut a deep channel through the shallow sea bottom where the organisms lived. Many individuals were preserved on top of each other, often torn or in distorted positions. As a result, it was originally thought to have had a "boat shaped" form and to have lived anchored in the sea floor. However, a nearby site discovered later by Mikhail Fedonkin yielded separate specimens which were beautifully preserved in an upright position and showed the internal anatomy.[1]
Ventogyrus is now believed to have lived on or above the sea floor, an egg-shaped organism made of three modules (like the sections of an orange), all connected to a central rod. This three-fold, or triradial, symmetry is not usually found in the living world today, but it is also seen in other Ediacarans. The whole organism was wrapped by an external membrane. Individual fossils are approximately 6 cm in diameter and 12 cm long.[2]
Fedonkin and Ivantsov suggested there was a stalk attached to the body of Ventogyrus. Specimens with an intact basal side show the presence of a triangular cross-section with a circular structure in the center. It is possible this is where a stalk may have attached. Such a structure could have tethered Ventogyrus to the sea floor, or hung down to stabilize its position in the water column.[3] Unidentifiable fossil fragments that could have been the remains of stalks were associated with the specimens.[1]
Ventogyrus is unique among Ediacaran fossils because so many have been preserved in three dimensions. The quality of its complex anatomical preservation is also unique among Ediacarans.[3] This preservation allows paleontologists to more accurately conceive of how it, and other species similar in morphology, lived in and interacted with its environment.
- ^ a b Fedonkin, Mikhail, James Gehling, Kathleen Grey, Guy Narbonne, and Patricia Vickers-Rich (2007). The Rise of Animals. Baltimore: Johns Hopkins University Press. pp. 143–145. ISBN 978-0-8018-8679-9.
{{cite book}}: CS1 maint: multiple names: authors list (link) - ^ Retallack, Gregory (15 November 2011). "Problematic megafossils in Cambrian palaeosols of South Australia". Palaeontology. 54 (6): 1223–1242. Bibcode:2011Palgy..54.1223R. doi:10.1111/j.1475-4983.2011.01099.x. S2CID 130692406.
- ^ a b Fedonkin, M. A.; Ivantsov, A. Y. (1 January 2007). "Ventogyrus, a possible siphonophore-like trilobozoan coelenterate from the Vendian Sequence (late Neoproterozoic), northern Russia". Geological Society, London, Special Publications. 286 (1): 187. Bibcode:2007GSLSP.286..187F. doi:10.1144/SP286.14. S2CID 128927444. Retrieved 4 June 2018.