(conifers); Class: Pinopsida; Order: Pinales; Family: Araucariaceae
Time: Late Triassic, Norian-Carnian Stage
mm long by 50 mm wide by 24 mm thick; weight 128 grams
Site: Winslow, Arizona
This is a specimen of highly-colored petrified wood from the
Chinle Formation (Norian-Carnian Stage, ~225 million year old)
deposits of Winslow, Arizona comes with a story. The rich green
color is the result of ~2% Chromium content. While the many
types of petrified wood come in a panoply of colors, only a
very few types are green; the only other is found in Africa.
This material comes from a small deposit near Winslow, and is
not known from any other location. Araucarioxylon arizonicum
is the state fossil of Arizona, and is the taxon comprising
some 90% of all specimens found in the Petrified Forest National
Monument. It was a coniferous tree standing some 150-200 feet
tall, and some 6-8 feet in diameter. Its closest relatives today
are the Monkey Puzzle Tree of South America and the Norfolk
Island Pine. The rich green color is quite evident in this piece
with flattened ends that would be suitable for polishing.
arizonicum is the state fossil of Arizona.