Nimbia
Encyclopedia
Nimbia occlusa is a form of Ediacaran
fossil shaped like a circular or oval disk, with a thick rim around the margin. Within the rim the fossil is usually flat, but may have a central nipple or dimple. These fossils were generally believed to be those of cnidaria
ns, but they have since been reinterpreted as structures made by microbial colonies (Grazhdankin, see Ediacaran biota for references and discussion.). They can reach up to 6 cm in diameter, with a centimeter-thick rim. Some fossils are distorted.
Nimbia occurs in numerous locations across a large range of time, which lends weight to theories that the fossil does not represent a single animal species. It occurs in the Twitya formation in the Mackenzie Mountains
in Canada
dated at 610 million years ago, near the end of the Marinoan glaciation, and in rocks in Kazakhstan. Aspidella
also appears in these areas. Morania
and Beltina carbonaceous film fossils in the Twitya formation are not considered to be animals. Nimbia-like fossils have also been found in the Cambrian
period.
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...
fossil shaped like a circular or oval disk, with a thick rim around the margin. Within the rim the fossil is usually flat, but may have a central nipple or dimple. These fossils were generally believed to be those of cnidaria
Cnidaria
Cnidaria is a phylum containing over 9,000 species of animals found exclusively in aquatic and mostly marine environments. Their distinguishing feature is cnidocytes, specialized cells that they use mainly for capturing prey. Their bodies consist of mesoglea, a non-living jelly-like substance,...
ns, but they have since been reinterpreted as structures made by microbial colonies (Grazhdankin, see Ediacaran biota for references and discussion.). They can reach up to 6 cm in diameter, with a centimeter-thick rim. Some fossils are distorted.
Nimbia occurs in numerous locations across a large range of time, which lends weight to theories that the fossil does not represent a single animal species. It occurs in the Twitya formation in the Mackenzie Mountains
Mackenzie Mountains
The Mackenzie Mountains are a mountain range forming part of the Yukon-Northwest Territories boundary between the Liard and Peel rivers. The range is named in honour of Canada's second Prime Minister Alexander Mackenzie. Nahanni National Park Reserve is in the Mackenzie Mountains.The Mackenzie...
in Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
dated at 610 million years ago, near the end of the Marinoan glaciation, and in rocks in Kazakhstan. Aspidella
Aspidella
Aspidella is an Ediacaran disk-shaped fossil.- Morphology :Aspidella consists of disk-shaped fossils, with concentric rings and/or centripetal rays. The diameter of circular Aspidella varies from 1 to 180 mm. Most individuals are between 4 and 10 mm, however; smaller animals would...
also appears in these areas. Morania
Morania
Morania is a genus of cyanobacterium preserved as carbonaceous films in the Middle Cambrian Burgess Shale. it is present throughout the shale; 2580 specimens of Morania are known from the Greater Phyllopod bed, where they comprise 4.90% of the community. It is filamentous, forms sheets, and...
and Beltina carbonaceous film fossils in the Twitya formation are not considered to be animals. Nimbia-like fossils have also been found in the Cambrian
Cambrian
The Cambrian is the first geological period of the Paleozoic Era, lasting from Mya ; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's...
period.