title: A fossil grass (gramineae: chloridoideae) from the miocene with kranz anatomy.
abstract: A fossil leaf fragment collected from the Ogallala Formation of northwestern Kansas exhibits features found in taxa of the modern grass subfamily Chloridoideae. These include bullet-shaped, bicellular microhairs, dumbbell-shaped silica bodies, cross-shaped suberin cells, papillae, stomata with low dome- to triangular-shaped subsidiary cells, and Kranz leaf anatomy. The leaf fragment extends the fossil record of plants that show both anatomical and external micromorphological features indicating C(4) photo-synthesis back to the Miocene. On the basis of associated mammals, the leaf fragment is assigned a Hemphillian age (7 to 5 million years ago).
authors.forename: J R
authors.initials: JR
authors.lastname: Thomasson
authors.forename: M E
authors.initials: ME
authors.lastname: Nelson
authors.forename: R J
authors.initials: RJ
authors.lastname: Zakrzewski