''Albumares brunsae'' 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 ...

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 name ''Albumares'' derives from the Latin ''Mare Album'' (

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 ...

). The specific name "brunsae" honors Elizabeth P. Bruns, an early 20th-century Russian geologist noted for her extensive and important research of the Upper Precambrian stratigraphy of

European Russia European Russia is the western and most populated part of the Russia, Russian Federation. It is geographically situated in Europe, as opposed to the country's sparsely populated and vastly larger eastern part, Siberia, which is situated in Asia ...

Occurrence

Fossils of ''Albumares brunsae'' are known from deposits in the Verkhovka Formation, Syuzma River in the Onega Peninsula of the White Sea, 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 ...

. There are reports of ''Albumares'' sp. from the Rawnslay Quartzite, Flinders Ranges in

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...

, but photographs or description of these fossils have not yet been published.

Description

''Albumares'' fossils are preserved as negative, low impressions on the bases of sandstone beds. The fossil exhibits circular,

trefoil A trefoil () is a graphic form composed of the outline of three overlapping rings, used in architecture, Pagan and Christian symbolism, among other areas. The term is also applied to other symbols with a threefold shape. A similar shape with f ...

-like (three-lobe) form, and is covered by three dendritic-branched furrows and three oval lobes that radiate from the center, which are twisted into weak spirals. The diameters of known specimens vary from .

Reconstruction and affinity

''Albumares'' was originally described by Mikhail Fedonkin as a free-swimming scyphozoan

jellyfish Jellyfish, also known as sea jellies or simply jellies, are the #Life cycle, medusa-phase of certain gelatinous members of the subphylum Medusozoa, which is a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animal ...

. The branched furrows on the fossil were interpreted as imprints of a system of internal radial canals and tentacles along the outer margin of the fossil, with the three oval lobes described as imprints of mouth lobes or gonades. Later, with the discovery of the closely related '' Anfesta'' and with their seeming affinities to ''

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 ...

'', Fedonkin appointed these animals to the

, an extinct group of tri-radially symmetrical coelenterate-like animals that only superficially resembled cnidarians. Originally, Trilobozoa was established as a class in the

phylum In biology, a phylum (; : phyla) is a level of classification, or taxonomic rank, that is below Kingdom (biology), kingdom and above Class (biology), class. Traditionally, in botany the term division (taxonomy), division has been used instead ...

Coelenterata, but since Coelenterata has been divided into two 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 ...

, Trilobozoa itself has been promoted to the rank of phylum. According to the latest research, ''Albumares'' 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's body, and often some elements of its internal structure can be discerned. The branched furrows on the fossil are imprints of radial grooves on the surface of the animal, while the three lobes in the central part of the fossil 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.

Notes

References