Araucarioxylon arizonicum facts for kids

Quick facts for kids Araucarioxylon arizonicum Temporal range: Early Permian-Late Triassic 295–200Ma PreЄ Є O S D C P T J K Pg N
Petrified Araucarioxylon arizonicum
Agate House Pueblo, constructed with petrified wood
Scientific classification
Genus:	Araucarioxylon
Species:	arizonicum

Araucarioxylon arizonicum is an amazing type of ancient tree. It's so special that it's the official state fossil of Arizona. These trees lived a very long time ago, during the Triassic period. We know about them because their huge trunks turned into petrified wood.

You can find lots of these fossilized trees in places like the Petrified Forest National Park in Arizona. They are also found in nearby New Mexico and even in Chemnitz, Germany. In some areas, there are so many petrified trunks that people have used them to build things, like houses!

What is Rainbow Wood?

The petrified wood from A. arizonicum is often called "Rainbow wood." This is because the fossilized wood shows many different colors.

• Red and Yellow: These colors come from tiny bits of iron oxide. Yellow is usually from limonite, and red is from hematite.
• Purple: This color comes from very tiny balls of hematite spread throughout the quartz that makes up the petrified wood.

Life in the Triassic Period

During the Triassic period, about 200 to 250 million years ago, Arizona looked very different. It was a flat, warm, and wet area in the northwest part of the huge supercontinent called Pangaea.

Giant forests grew there. A. arizonicum trees were very tall, reaching up to 60 meters (about 200 feet) high. Their trunks could be more than 60 centimeters (about 2 feet) wide.

Scientists have found small holes in these fossilized trees. These holes were likely made by insect larvae, possibly from ancient beetles.

How Scientists Classify These Trees

Araucarioxylon arizonicum belongs to a plant family called Araucariaceae. This family includes modern trees like the monkey puzzle tree.

The first person to describe these ancient trees was an American paleobotanist (a scientist who studies ancient plants) named Frank Hall Knowlton. He described them in 1889.

However, some scientists now think that Araucarioxylon arizonicum might actually be made up of several different types of trees. A study in 2007 looked closely at the original fossils Knowlton used. It suggested that those fossils actually came from three different species. These new species were given names like Pullisilvaxylon arizonicum, Pullisilvaxylon daughertii, and Chinleoxylon knowltonii. This means that the name Araucarioxylon might not be used anymore, and the petrified logs in Petrified Forest National Park could be even more diverse than we first thought!

Images for kids

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  Petrified Araucarioxylon arizonicum.

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  Agate House Pueblo, constructed with petrified wood

See also

In Spanish: Araucarioxylon arizonicum para niños