The petrified fossil forests in the Specimen Creek area of Gallatin Petrified Forest contain spectacular petrified tree stumps, trunks and logs in horizontal and vertical positions. These fossils forests are embedded in early middle Eocene volcaniclastic rocks and piled in sequential layers.
One hundred and nineteen fossil wood samples were collected from three selected layers [unit 1, unit 5 and unit 9, (DeBord 1977)] of the sequentially entombed Fossil Forests in the above area, and identified as follows: 3 families, 9 genera, in Gymnosperms; 13 families, 15 genera in Angiosperms.
PINACEAE: Keteleeria*, Larix*, Pinus, Tsuga*
TAXODIACEAE: Glyptostrobus*, Sequoia, Taxodium*
BETULACEAE: Alunus, Betula*
MAGNOLIACEAE: Lirondendron*, Magnolia*
The identified wood stumps were compared with previous pollen analysis of the same layers. In a few cases correlation was observed between fossil stumps and fossil pollen of associated organic levels whereas in most cases no fossil pollen correlated with the adjacent stumps. Overall, correlation was lacking.
The identified woods were plotted on modern climatic ranges and each unit exhibits the following climatic range.
Unit 1. Subtropical to boreal, mostly warm temperate to cool temperate.
Unit 5. Tropical to boreal, mostly subtropical to cool temperate.
Unit 9. Warm temperate to boreal, mostly cool temperate and boreal.
As a result of this study 6 new families (*) and 16 new genera (*) based upon wood are added to the Eocene "Fossil Forest '' flora. In addition several features have emerged which suggest the "fossil forest" represents a unique assemblage of plant types. These are:
- The presence of an uncommon admixture of tree types
- The lack of correlation in many cases between the vertical fossil trees and the associated microfossils
- The indications of a strange admixture of climatic ranges within each tree level.
Arthur V. Chadwick
Raymond E. Ryckman
Earl W. Lathrop
Master of Arts (MA)
Year Degree Awarded
Date (Title Page)
Library of Congress/MESH Subject Headings
Trees; Fossil; Petrified forests
Loma Linda University Libraries
This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.
Yamamoto, Tetsuya, "Identification of Fossil Wood from the Specimen Creek Area of the Gallatin Petrified Forest, Yellowstone National Park, Montana" (1980). Loma Linda University Electronic Theses, Dissertations & Projects. 676.
Loma Linda University Electronic Theses and Dissertations
Loma Linda University. Del E. Webb Memorial Library. University Archives