| 词条 | Annularia |
| 释义 |
| fossil_range = {{Geological range/linked|Carboniferous}} | name = Annularia | image = Annularia Stellata.jpg | image_width = 220px | image_caption = Annularia stellata | regnum = Plantae | divisio = Sphenophyta | classis = Equisetopsida | ordo = Equisetales | familia = Calamitaceae | genus = Annularia | genus_authority = Sternberg, 1821 }} Annularia is a plant fossil belonging to the order Equisetales. DescriptionAnnularia is a form taxon. It is the name given to Calamites leaves. In fact the stems and the radiating structures of the leaf whorls is similar in the Calamites, an extinct genus of horsetails. These horsetails, belonging to the class of Sphenopsida, were arborescent and grew to a height of 32 feet (10 meters) in a tree-like form.[1] Annularia leaves are arranged in whorls of between 8-13 leaves. Its shape is quite variable, being oval in Annularia sphenophylloides and between linear and lanceolate in Annularia radiata, but they are always flat and of varying lengths.[2]Fossil recordsFossils of this genus have been discovered in the Permian strata of Russia and in the Carboniferous (around {{period span/brief|Carboniferous|-1}}) strata of the United States, Canada, China and Europe.[2][3]See also
References1. ^Illinois State Museum - Annularia sp. Mazon Creek Fossils 2. ^1 [https://web.archive.org/web/20071222010031/http://es.encarta.msn.com/encyclopedia_961537580/Annularia.html MSN] 3. ^Paleobiology Database External links
10 : Equisetopsida|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 |
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