Anfesta
Anfesta stankovskii is a tri-radially symmetrical fossil animal that lived in the late Ediacaran (Vendian) seafloor. It is a member of the extinct group Trilobozoa.
| Anfesta stankovskii Temporal range: Ediacaran, around | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | †Trilobozoa |
| Family: | †Albumaresidae |
| Genus: | †Anfesta Fedonkin, 1984 |
| Species: | †A. stankovskii |
| Binomial name | |
| †Anfesta stankovskii Fedonkin, 1984 | |
Etymology
The generic and specific names of the Anfesta stankovskii honour the Arkhangel'sk geologist Anatoliy F. Stankovskii.
Occurrence
Fossils of Anfesta stankovskii are known from deposits of the Verkhovka and Yorga formations on the Karakhta River in Onega Peninsula and Zimnii Bereg (Winter Coast) of the White Sea, Arkhangelsk Region, Russia.[1][2]
Description
Anfesta represents a flattened, hemispherical form with three-fold symmetry.[3] At the centre of the organism, 3 elongate and sausage-like ridges radiate from the centre and are put away from each other by 120 degrees and make the animal always divisible into 3 parts and the ridges becoming rounded at both edges.[3] The same ridges bifurcate twice near both of their ends.[3] In some specimens of A. stankovskii, a large amount of furrows (originally interpreted as tentacles) appear and make Anfesta look similar in anatomy to Albumares and Skinnera (Mostly Albumares).[3] The diameter of Anfesta is thought to 18 cm (7.1 in), with the length of the ridges reaching up to 5 mm (0.20 in), and with the width of them being up to 1.3 mm (0.051 in).[3]
Reconstruction and affinity
Anfesta was originally described by Mikhail Fedonkin as a free-swimming scyphozoa-like medusa. The branched furrows on the fossil were interpreted as imprints of a system of internal radial canals, and the three oval ridges as imprints of gonads.[1][4]
A year later, Fedonkin transferred such fossil animals as Anfesta, Albumares and Tribrachidium to the separate group Trilobozoa, populated by three-lobed, radially symmetric, coelenterate-grade animals that only superficially resemble cnidarians.[4][5] Originally, Trilobozoa was established as a class within the phylum Coelenterata, but since Coelenterata was divided into separate phyla - Cnidaria and Ctenophora - the Trilobozoa have been transferred to rank of phylum.[6]
According to the latest research, Anfesta was a soft-bodied benthic organism that temporarily attached (but did not adhere) to the substrate of its habitat (microbial mats). This fossil is an imprint of the upper side of the animal body, with some elements of its external and internal anatomy visible to the naked eye. The branched furrows on the fossil are imprints of radial grooves on the animal's surface, while the three central ridges are imprints of cavities within the body. Presumably, this system of grooves and cavities could be related to the collection and digestion of food particles.[3]
See also
References
- Fedonkin, M. A. (1984). "Promorphology of the Vendian Radialia". In Sokolov, B. S.; Iwanowski, A. B. (eds.). Stratigraphy and Paleontology of the Earliest Phanerozoic (in Russian). Moscow: Nauka. pp. 30–58.
- Ivantsov, A. Yu. (2004). "New Proarticulata from the Vendian of the Arkhangel'sk Region" (PDF). Paleontological Journal. 38 (3): 247–253. Archived from the original (PDF) on 2007-09-27. Retrieved 2013-03-24.
- Fedonkin, Mikhail A.; Sciences), Mikhail A. (Head Fedonkin, Laboratory of Precambrian Organisms Russian Academy of; Gehling, James G.; Museum), James G. (Senior Curator Gehling, retired 6 27 2019 South Australian; Grey, Kathleen; Narbonne, Guy M.; Vickers-Rich, Patricia; University), Patricia (Director Vickers-Rich, Monash (Mar 16, 2007). The Rise of Animals: Evolution and Diversification of the Kingdom Animalia. JHU Press. ISBN 9780801886799. Retrieved July 1, 2022 – via Google Books.
{{cite book}}: CS1 maint: multiple names: authors list (link) - Fedonkin, M. A. (1985). "Systematic Description of Vendian Metazoa". In Sokolov, B. S.; Iwanowski, A. B. (eds.). Vendian System: Historical–Geological and Paleontological Foundation, Vol. 1: Paleontology (in Russian). Moscow: Nauka. pp. 70–106.
- Fedonkin, M. A. (1990). "Precambrian Metazoans". In Briggs D.; Crowther P. (eds.). Palaeobiology: A Synthesis (PDF). Blackwell. pp. 17–24. Archived from the original (PDF) on 2012-01-12. Retrieved 2013-03-24.
- Runnegar, B. N.; Fedonkin, M. A. (1992). "Proterozoic Metazoan Body Fossils". In Schopf, J. W.; Klein, C. (eds.). The Proterozoic Biosphere: A Multidisciplinary Study. Cambridge University Press. p. 373. ISBN 9780521366151.