Vaveliksia
Encyclopedia
Vaveliksia is a genus
of sponges or sponge-like organisms from the Ediacaran
. Their fossils are found in what is now the shores of the White Sea
, along the banks of the Dniester
River in Ukraine
, and in Australia
.
-like appearance, with one end attached to the substrate by a disk-like holdfast
. The body wall was very thin, and perforated. At the top was a hole, which may be an osculum
, if they were indeed true sponges. In V. velikanovi, found only in Precambrian strata of the Dneiper, the top has a crown of wrinkles which was originally interpreted as tentacles (the first fossils were originally thought to be of a polyp-like organism), and the holdfast is relatively flat and disk-like. V. vana, found at the White Sea shores and in Australia, is thinner in diameter, has an unwrinkled top, and the holdfast is much more convex or dome-like. Some specimens of V. vana also had arms.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of sponges or sponge-like organisms from the Ediacaran
Ediacaran
The Ediacaran Period , named after the Ediacara Hills of South Australia, is the last geological period of the Neoproterozoic Era and of the Proterozoic Eon, immediately preceding the Cambrian Period, the first period of the Paleozoic Era and of the Phanerozoic Eon...
. Their fossils are found in what is now the shores of the White Sea
White Sea
The White Sea 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 northeast. The whole of the White Sea is under Russian sovereignty and considered to be part of...
, along the banks of the Dniester
Dniester
The Dniester is a river in Eastern Europe. It runs through Ukraine and Moldova and separates most of Moldova's territory from the breakaway de facto state of Transnistria.-Names:...
River in Ukraine
Ukraine
Ukraine is a country in Eastern Europe. It has an area of 603,628 km², making it the second largest contiguous country on the European continent, after Russia...
, and in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
.
Morphology
The typical Vaveliksia had a frankfurterHot dog
A hot dog is a sausage served in a sliced bun. It is very often garnished with mustard, ketchup, onions, mayonnaise, relish and/or sauerkraut.-History:...
-like appearance, with one end attached to the substrate by a disk-like holdfast
Holdfast
A holdfast is a root-like structure that anchors aquatic sessile organisms, such as seaweed, other sessile algae, stalked crinoids, benthic cnidarians, and sponges, to the substrate. ...
. The body wall was very thin, and perforated. At the top was a hole, which may be an osculum
Osculum
The osculum is an excretory structure in the living sponge, a large opening to the outside through which the current of water exits after passing through the spongocoel. Wastes diffuse into the water and the water exits through the osculum at a velocity of nearly 8.4 cm/second, carrying away with...
, if they were indeed true sponges. In V. velikanovi, found only in Precambrian strata of the Dneiper, the top has a crown of wrinkles which was originally interpreted as tentacles (the first fossils were originally thought to be of a polyp-like organism), and the holdfast is relatively flat and disk-like. V. vana, found at the White Sea shores and in Australia, is thinner in diameter, has an unwrinkled top, and the holdfast is much more convex or dome-like. Some specimens of V. vana also had arms.