Acer taurocursum facts for kids

Acer taurocursum was an ancient type of maple tree. It's now extinct, meaning it no longer exists. Scientists know about it from a single fossil seed found in Nevada, USA. This special maple lived during the Eocene epoch, which was a very long time ago! It belongs to the same group as some maple trees we see today, called the Rubra section.

Discovering an Ancient Maple

Imagine finding a fossil of a plant that lived millions of years ago! That's how we know about Acer taurocursum. Scientists found just one fossil seed from this maple in the northeastern part of Nevada. This fossil was found in old lakebed sediments.

Two important scientists, Jack A. Wolfe and Toshimasa Tanai, studied this fossil. They described it in 1987. The fossil came from a place called the "Bull Run" flora. A "flora" is a collection of plant fossils from a specific area.

The rocks where the fossil was found were formed between 43 and 38 million years ago. Scientists used a method called Radiometric dating to figure out the age of the volcanic ash layers around the fossils. This showed the fossils were about 41 million years old.

Acer taurocursum was one of six maple species that Wolfe and Tanai described from the "Bull Run" flora. Other species they found included A. elkoanum and A. eonegundo. Some of these ancient maples are known from their leaves, some from their seeds, and some from both!

Scientists learned that A. taurocursum is the oldest known record of a maple group called Acer section Eriocarpa. This group is now considered part of the Acer section Rubra, which includes some modern maple trees.

The original fossil specimen of Acer taurocursum is kept at the University of California Museum of Paleontology in Berkeley, California. The name taurocursum comes from the "Bull Run" area in Nevada where the fossil was found.

What Did It Look Like?

Scientists can tell a lot about an ancient plant just from its fossilized seed. The seed of Acer taurocursum was a type of fruit called a samara. Maple seeds often have a "wing" that helps them spin and fly away from the tree.

The main part of the seed, called the nutlet, was narrow and oval-shaped. It was about 0.8 millimeters (0.03 inches) wide and 2.5 millimeters (0.1 inches) long. The whole samara, including its wing, was about 4.8 centimeters (1.9 inches) long. The wing itself was about 1.5 centimeters (0.6 inches) wide.

The wing was mostly behind the nutlet. When two of these seeds grew together, they formed a "V" shape with a 20-degree angle between them. The wing had about twenty veins, which are like tiny tubes that carried nutrients when the seed was alive. These veins joined together along the top edge of the wing.

By studying the shape of the nutlet, Wolfe and Tanai figured out that this ancient maple belonged to the Acer section Eriocarpa.