| Zamites | |
|---|---|
.JPG) | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Order: | †Bennettitales |
| Family: | †Williamsoniaceae |
| Genus: | †Zamites Brongniart, 1828 |
| Species | |
See text | |
Zamites is an extinct genus of plants in the familyWilliamsoniaceae that lived from theTriassic to theEocene. This plant is reported in theMesozoic fromNorth andSouth America,Europe,Asia,Africa, andAntarctica, and in theCenozoic only inNorth America.[1][2][3][4]
As explained by Zijlstra & van Konijnenburg-van Cittert (2020), the application of the genus nameZamites has over time drifted away from Brongniart's original concept to one where the speciesZ. gigas (Lindl. & Hutton) Morris has been treated as ade facto type, to the degree that none of Brongniart's four original species would now be assigned to it, instead being allocated toOtozamites and possibly elsewhere; this includesZ. bucklandii, designated as the type ofZamites by Pfeiffer in a publication dating from 1871-1875, but now (asO. bucklandii) the type ofOtozamites.[4] Technically, unless otherwise addressed, this rendersOtozamites a synonym ofZamites and would mean thatZ. gigas plus all the species recognisably closer to it than toZ. bucklandii would require a new genus name. Zijlstra & van Konijnenburg-van Cittert chose to attempt to circumvent this situation by proposing thatZamites should be re-defined based on designatingZ. gigas as a new type to replaceZ. bucklandii, a proposal that was recommended for acceptance by the Nomenclature Committee for Fossils in 2022.[2]
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 therachis 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 thepinnule.[5][6][7] It is associated with the ovulate coneWilliamsonia and male coneWeltrichia.[3]
It was erected as a form taxon for leaves that superficially resembled. Due to the presence of the reproductive structure ofWilliamsonia andWeltrichia, this genus is placed in the familyWilliamsoniaceae.[1][2][4]
This genus includes 32 confirmed species, some of which are listed below.[1]
Fossils ofZamites have been found in:[8]
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).
Antarctica, Argentina, Azerbaijan, Belarus, Chile, China, Colombia (Valle Alto Formation,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).
Canada (Alberta, British Columbia), Ecuador, Japan, Mexico, South Africa, Spain, and the United States (Montana, Virginia, Wyoming).
United States (California)