''Annularia'' is a

form taxon Form classification is the classification of organisms based on their morphology, which does not necessarily reflect their biological relationships. Form classification, generally restricted to palaeontology, reflects uncertainty; the goal of s ...

, applied to

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

foliage belonging to extinct plants of the genus ''

Calamites ''Calamites'' is a genus of extinct arborescent (tree-like) horsetails to which the modern horsetails (genus '' Equisetum'') are closely related. Unlike their herbaceous modern cousins, these plants were medium-sized trees, growing to heights o ...

'' in the order

Equisetales Equisetales is an order of subclass Equisetidae with only one living family, Equisetaceae, containing the genus '' Equisetum'' (horsetails). Classification In the molecular phylogenetic classification of Smith et al. in 2006, Equisetales, in i ...

Description

''Annularia'' is a

name given to leaves of ''

''. In that species, the leaves formed radiating leaf whorls at each stem node, in a similar way to the branches of ''

Equisetum ''Equisetum'' (; horsetail, snake grass, puzzlegrass) is the only living genus in Equisetaceae, a family of ferns, which reproduce by spores rather than seeds. ''Equisetum'' is a "living fossil", the only living genus of the entire subclass ...

'', an extant genus of

horsetail ''Equisetum'' (; horsetail, snake grass, puzzlegrass) is the only living genus in Equisetaceae, a family of ferns, which reproduce by spores rather than seeds. ''Equisetum'' is a "living fossil", the only living genus of the entire subclass ...

s. ''Annularia'' leaves are arranged in whorls of between 8-13 leaves. The leaf shape is quite variable, being oval in ''Annularia sphenophylloides'' and linear to lanceolate in ''Annularia radiata'', but they are always flat and of varying lengths.MSN
/ref> ''Calamites'' were arborescent and grew to a height of 32 feet (10 meters).

Fossil records

Fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

of this

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

have been discovered in the

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleo ...

strata of

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-ei ...

and in the

Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carboniferou ...

(around ) strata of the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by to ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...

and

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

.Paleobiology Database
/ref> Calamitaceae - Annularia stellata.JPG, Specimen of ''Annularia stellata'' from Italy on display at the

Museo Civico di Storia Naturale di Milano The Museo Civico di Storia Naturale di Milano (Milan Natural History Museum) is a museum in Milan, Italy. It was founded in 1838 when naturalist Giuseppe de Cristoforis donated his collections to the city. Its first director was Giorgio Jan. ...

Calamitaceae foliage.jpg, The

foliage A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ...

of ''Calamites'' Calamites reconstrucción.png, Calamites reconstruction

References

External links

Fossil Museum
{{Taxonbar, from=Q2065549 Horsetails Carboniferous plants Prehistoric plant genera Carboniferous first appearances Carboniferous extinctions Fossil taxa described in 1821 Fossils of Georgia (U.S. state) Paleozoic life of New Brunswick Paleozoic life of Nova Scotia Prehistoric plants of North America

Description

Fossil records

See also

References

External links