''Anfesta stankovskii'' is a tri-radially symmetrical fossil animal that lived on the late

Ediacaran The Ediacaran ( ) is a geological period of the Neoproterozoic geologic era, Era that spans 96 million years from the end of the Cryogenian Period at 635 Million years ago, Mya to the beginning of the Cambrian Period at 538.8 Mya. It is the last ...

(Vendian) seafloor. It is a member of the extinct group

Trilobozoa Trilobozoa, from Ancient Greek τρεῖς (''treîs''), meaning "three", λοβός (''lobós''), meaning "lobe", and ζῷον (''zôion''), meaning "animal", is a phylum of extinct, sessile animals that were originally classified into the Cnid ...

Etymology

The generic and specific names of ''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 The White Sea (; Karelian language, Karelian and ; ) is a southern inlet of the Barents Sea located on the northwest coast of Russia. It is surrounded by Karelia to the west, the Kola Peninsula to the north, and the Kanin Peninsula to the nort ...

, Arkhangelsk Region,

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

Description

''Anfesta'' represents a flattened, hemispherical form with three-fold symmetry. At the centre of the organism, 3 elongate and sausage-like lobes radiate from the centre and are spaced out from each other by 120 degrees, making the animal always divisible into 3 parts and the lobes becoming rounded at both edges. The same lobes bifurcate twice near both of their ends. In some specimens of ''A. stankovskii'', a large amount of furrows (originally interpreted as tentacles) appear, which are similar in appearance to ''

Albumares ''Albumares brunsae'' is a tri-radially symmetrical fossil animal that lived on the late Ediacaran seafloor. It is a member of the extinct group Trilobozoa. Etymology The generic name ''Albumares'' derives from the Latin ''Mare Album'' (White S ...

'' and '' Skinnera'' (Mostly ''Albumares''). The diameter of ''Anfesta'' is thought to be , with the length of the lobes reaching up to , and with the width of them being up to .

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 lobes as imprints of gonads. A year later, Fedonkin transferred such fossil animals as ''Anfesta'', ''

'' and ''

Tribrachidium ''Tribrachidium heraldicum'' is a tri-radially symmetric fossil animal that lived in the late Ediacaran (Vendian) seas. In life, it was hemispherical in form. ''T. heraldicum'' is the best known member of the extinct group Trilobozoa. Etymolo ...

'' to the separate group

, populated by three-lobed, radially symmetric, coelenterate-grade animals that only superficially resemble cnidarians. Originally, Trilobozoa was established as a class within the phylum Coelenterata, but since Coelenterata was divided into separate phyla -

Cnidaria Cnidaria ( ) is a phylum under kingdom Animalia containing over 11,000 species of aquatic invertebrates found both in fresh water, freshwater and marine environments (predominantly the latter), including jellyfish, hydroid (zoology), hydroids, ...

and

Ctenophora Ctenophora (; : ctenophore ) is a phylum of marine invertebrates, commonly known as comb jellies, that inhabit sea waters worldwide. They are notable for the groups of cilia they use for swimming (commonly referred to as "combs"), and they are ...

- the Trilobozoa have been transferred to rank of phylum. According to the latest research, ''Anfesta'' was a soft-bodied

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...

organism that temporarily attached (but did not adhere) to the substrate of its habitat ( microbial mats). Most, if not all, fossil specimens are of 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 lobes 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.

References

{{Taxonbar, from1=Q1953468, from2=Q21245969 Ediacaran life Trilobozoa White Sea fossils Fossil taxa described in 1984 Ediacaran

Etymology

Occurrence

Description

Reconstruction and affinity

See also

References