''Zamites'' is an extinct genus of plants in the family

Williamsoniaceae ''Williamsoniaceae'' is a family within the Bennettitales, an extinct group of seed plants. Members of this family are believed to have been around two meters tall and with widely serrate leaves along a central stem. Reproductive organs of the ...

that lived from the

Triassic The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...

to the

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

. This plant is reported in the

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

from

North North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating Direction (geometry), direction or geography. Etymology T ...

and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

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 ...

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

, and

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...

, and in the

Cenozoic The Cenozoic Era ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterized by the dominance of mammals, insects, birds and angiosperms (flowering plants). It is the latest of three g ...

only in

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

Naming

As explained by Zijlstra & van Konijnenburg-van Cittert (2020), the application of the genus name ''Zamites'' has over time drifted away from Brongniart's original concept to one where the species ''Z. gigas'' (Lindl. & Hutton) Morris has been treated as a ''de facto'' type, to the degree that none of Brongniart's four original species would now be assigned to it, instead being allocated to ''

Otozamites ''Otozamites'' is a genus of plants in the order Bennettitales and the family Williamsoniaceae. The leaves are usually ovate to slightly lanceolate and have branched veins. The genus is found on all continents, although it is more widespread in ...

'' and possibly elsewhere; this includes ''Z. bucklandii'', designated as the type of ''Zamites'' by Pfeiffer in a publication dating from 1871-1875, but now (as ''O. bucklandii'') the type of ''Otozamites''. Technically, unless otherwise addressed, this renders ''Otozamites'' a synonym of ''Zamites'' and would mean that ''Z. gigas'' plus all the species recognisably closer to it than to ''Z. bucklandii'' would require a new genus name. Zijlstra & van Konijnenburg-van Cittert chose to attempt to circumvent this situation by proposing that ''Zamites'' should be re-defined based on designating ''Z. gigas'' as a new type to replace ''Z. bucklandii'', a proposal that was recommended for acceptance by the Nomenclature Committee for Fossils in 2022.

Description

The leaf blade is lanceolate to linear-lanceolate, and its dimensions vary between 50 and 60 centimeters. The pinnules are symmetrically clustered at the base and are connected obliquely to the upper surface of the

rachis In biology, a rachis (from the [], "backbone, spine") is a main axis or "shaft". In zoology and microbiology In vertebrates, ''rachis'' can refer to the series of articulated vertebrae, which encase the spinal cord. In this case the ''rachi ...

by this base. The apex of the pinnule is obtuse (sharp). The veins emerge from the clustered part and are divergent from each other. They are dichotomized once or more times and cut the pinnule edge. The midribs can extend to the end of the

pinnule A leaflet (occasionally called foliole) in botany is a leaf-like part of a compound leaf. Though it resembles an entire leaf, a leaflet is not borne on a main plant stem or branch, as a leaf is, but rather on a petiole or a branch of the leaf. C ...

.0300164351 Riddle of the Feathered Dragons: Hidden Birds of China by Feduccia, Alan, p. 75, 2012 It is associated with the ovulate cone '' Williamsonia'' and male cone '' Weltrichia''. Zamites_persica

Taxonomy

It was erected as a form taxon for leaves that superficially resembled. Due to the presence of the reproductive structure of Williamsonia and Weltrichia, this genus is placed in the family

Species

This genus includes 32 confirmed species, some of which are listed below. * ''Z. alaskana'' * ''Z. apertus'' * ''Z. arcticus'' * ''Z. bayeri'' * ''Z. brevipennis'' * ''Z. buchianus'' * ''Z. californica'' * ''Z. carruthersii'' * ''Z. corderi'' * ''Z. dowellii'' * ''Z. manoniae'' * ''Z. mariposana'' * ''Z. montanensis'' * ''Z. nicolae'' * ''Z. notokenensis'' * ''Z. occidentalis'' * ''Z. ovalis'' * ''Z. pennsylvanicus'' * ''Z. persica'' * ''Z. powelli'' * ''Z. subfalcatus'' * ''Z. tatianae'' * ''Z. truncatus'' * ''Z. wendyellisae'' * ''Z. yorkensis'' * Z. feneonis Zamites_feneonis_6

Distribution

Fossils of ''Zamites'' have been found in:''Zamites''
at

Fossilworks Fossilworks was a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world. History Fossilworks was cr ...

.org ;Triassic (to Jurassic) Antarctica, Austria, China, France, Germany, Honduras, Hungary, Italy, Japan, Mexico, Romania, Iran, Tajikistan, Ukraine, and the United States (New Mexico, North Carolina, Utah, Virginia, Virginia/North Carolina). ;Jurassic (to Cretaceous) Antarctica, Argentina, Azerbaijan, Belarus, Chile, China, Colombia (

Valle Alto Formation The Valle Alto Formation (, Jva) is a geological formation of the Central Ranges of the Colombian Andes. The formation is composed of shales, sandstones and conglomerates and dates to the Late Jurassic period. Ammonites and fossil flora have been ...

, Caldas), Egypt, France, Georgia, Germany, Iran, Italy, Japan, Kazakhstan, Mexico, Mongolia, Portugal, Romania, the Russian Federation, Serbia and Montenegro, Switzerland, Tajikistan, Turkey, Ukraine, the United Kingdom, and the United States (Montana, Wyoming). ;Cretaceous Canada (Alberta, British Columbia), Ecuador, Japan, Mexico, South Africa, Spain, and the United States (Montana, Virginia, Wyoming). ;Eocene United States (California)

References

{{Taxonbar, from=Q4023766 Bennettitales Triassic first appearances Triassic plants Jurassic plants Early Cretaceous plants Late Cretaceous plants Paleocene plants Eocene plants Eocene genus extinctions Mesozoic trees Mesozoic Antarctica Mesozoic life of Asia Mesozoic life of Europe Mesozoic life of North America Cretaceous Canada Jurassic Mexico Cretaceous Mexico Jurassic United States Cretaceous United States Mesozoic life of South America Prehistoric plants of South America Jurassic Argentina Fossils of Argentina Jurassic Chile Fossils of Chile Jurassic Colombia Fossils of Colombia Cretaceous Ecuador Fossils of Ecuador Fossil taxa described in 1828 Fossils of Serbia