Wood of Ginkgo in the Tertiary of Western North America

Abstract

Scott, R. A., E. S. Barghoorn, and U. Prakash. (U.S. Geol. Sur., Denver, Colo.) Wood of Ginkgo in the Tertiary of western North America. Amer. Jour. Bot. 49(10): 1095–1101. Illus. 1962. —Woods of Ginkgo and extinct related genera are very rare in the fossil record in contrast to the numerous ginkgoalean leaves. Ginkgo wood may be distinguished from other gymnosperms by a combination of anatomical features herein described. Ginkgo wood from beds of Miocene age at Vantage, Washington, first identified by Beck, is assigned to a new species, G. beckii. Ginkgo wood from the upper Eocene Clarno Formation, John Day Basin, Oregon, is described as G. bonesii sp. nov. Scarcity of fossil ginkgoalean woods may reflect unusual susceptibility to degradation of their cell walls in contrast to the greater chemical resistance to degradation which features many coniferous woods.

A physiologically explicit morphospace for tracheid-based water transport in modern and extinct seed plants

“…Callistophyton and Medullosa also have the longest tracheids, reaching 10 mm and more than 20 mm, respectively, and other seed plants have much shorter xylem cells, creating a gap within the seed plant morphospace (Figures 3, 4). Some tracheids from Ginkgo biloba can reach dimensions of Lyginopteris and Callistophyton, but their occurrence is rare (Scott et al 1962). …”

“…We measured xylem cell lengths and diameters from fossil stem material using light microscopy in tandem with the publically available image analysis software package ImageJ (found at: http://rsbweb.nih.gov/ij/), and also compiled values reported in the literature (Andrews 1940, Bailey and Tupper 1918, Bannan 1965, Chrysler 1926, Delevoryas 1955, Langdon 1920, Rothwell 1975, Ryberg et al 2007, Scott et al 1962, Terrazas 1991. Many of these compiled values are species averages for dozens or hundreds of tracheids (Bannan 1965, Chrysler 1926, Scott et al 1962).…”

“…Many of these compiled values are species averages for dozens or hundreds of tracheids (Bannan 1965, Chrysler 1926, Scott et al 1962). …”

“…For Cycadeoidea and Callistophyton, dimensions are averages of several specimens from literature reports (Rothwell 1975, Ryberg et al 2007). For Ginkgo beckii, dimensions are our measurements (n = 30) made from type material (Scott et al 1962). For Cordaites sp.…”

“…It is notable that Ginkgo biloba contains broad leaves in addition to a small number of large tracheids, while most conifers lack both (Scott et al 1962).…”