''Drewria potomacensis'' is a
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
megafossil
Macrofossils, also known as megafossils, are preserved organic remains large enough to be visible without a microscope. The term ''macrofossil'' stands in opposition to the term microfossil. Microfossils, by contrast, require substantial magnific ...
member of the
Gnetales
Gnetophyta () is a division of plants (alternatively considered the subclass Gnetidae or order Gnetales), grouped within the gymnosperms (which also includes conifers, cycads, and ginkgos), that consists of some 70 species across the three reli ...
, from the Potomac Group, hence its name. It was possibly a shrub.
[Crane, Peter R., and Garland R. Upchurch Jr. "Drewria potomacensis gen. et sp. nov., an Early Cretaceous member of Gnetales from the Potomac Group of Virginia." American Journal of Botany (1987): 1722-1736.] It is the only known species in the genus ''Drewria''.
Description
Its stems were slender, with opposite and decussate leaves. The leaves were oblong and measured up to long. Its reproductive structures consisted of short, loose spikes arranged in dichasial groups of 3.
References
Further reading
*
Friis, Else Marie, Peter R. Crane, and Kaj Raunsgaard Pedersen. Early flowers and angiosperm evolution. Cambridge University Press, 2011.
*
*Wilson, Karen, and David Morrison, eds. Monocots: Systematics and Evolution: Systematics and Evolution. CSIRO PUBLISHING, 2000.
*Pearson, David. New organic architecture: the breaking wave. University of California Press, 2001.
*Hughes, Norman Francis. The enigma of angiosperm origins. Vol. 1. Cambridge University Press, 1994.
*Bell, Peter R., and Alan R. Hemsley. Green plants: their origin and diversity. Cambridge University Press, 2000.
Gnetophyta
Prehistoric gymnosperm genera
Prehistoric plants of North America
Cretaceous plants
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