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CONIFER WOOD FROM THE UPPER JURASSIC OF UTAH PART I: XENOXYLON MORRISONENSE SP. NOV.
Author(s) -
Medlyn David A.,
Tidwell William D.
Publication year - 1975
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1975.tb14054.x
Subject(s) - podocarpaceae , tracheid , biology , botany , plateau (mathematics) , cupressaceae , xylem , pollen , mathematical analysis , mathematics
A new species of conifer wood, Xenoxylon morrisonense , is described from the Morrison Formation on the Colorado Plateau. It is compared with other species of Xenoxylon , with X. latiporosum being the closest. Xenoxylon morrisonense differs from X. latiporosum in its marked indentations, simple pits on the horizontal and tangential walls of ray cells, absence of crassulae, presence of wood parenchyma, and thin borders on podocarpoid type crossfield pits. The origin of the septa in the tracheids is summarized, and the possible affinity of Xenoxylon with the Podocarpaceae is considered.