''Annularia'' is a

form taxon Form classification is the classification of organisms based on their morphology (biology), morphology, which does not necessarily reflect their biological relationships. Form classification, generally restricted to palaeontology, reflects uncer ...

, 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 preserve ...

foliage belonging to extinct plants of the genus ''

Calamites ''Calamites'' is a genus of Extinction, extinct arborescent (tree-like) horsetails to which the modern horsetails (genus ''Equisetum'') are closely related. Unlike their Herbaceous plant, herbaceous modern cousins, these plants were medium-size ...

'' in the order

Equisetales Equisetales is an order of subclass Equisetidae with only one living family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relation ...

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) is the only living genus in Equisetaceae, a family of vascular plants that reproduce by spores rather than seeds. ''Equisetum'' is a "living fossil", the only living genus of the entire subclass Equisetidae, which ...

'', an extant genus of

horsetail ''Equisetum'' (; horsetail) is the only living genus in Equisetaceae, a family of vascular plants that reproduce by spores rather than seeds. ''Equisetum'' is a "living fossil", the only living genus of the entire subclass Equisetidae, which ...

s. ''Annularia'' leaves are arranged in whorls of between 8 and 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 .

Fossil records

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 preserve ...

s of this

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

have been discovered in the

Permian The Permian ( ) is a geologic period and System (stratigraphy), 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 251.902 Mya. It is the s ...

strata of

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 ...

and in the

Carboniferous The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the ...

(around ) strata of the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

and

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

.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 the naturalist Giuseppe de Cristoforis donated his collections to the city. Its first director was the taxono ...

Calamitaceae foliage.jpg, The

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

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