Taxus masonii facts for kids

Taxus masonii was an extinct type of conifer, which is a tree that produces cones, like pine trees. It belonged to the yew family, called Taxaceae. We only know about this ancient plant from fossil seeds found in rocks from the Eocene period, about 45 to 43 million years ago. These special rocks were found in north-central Oregon. Scientists first learned about Taxus masonii from these fossil seeds, which were preserved in a type of rock called chert.

Discovering the Ancient Yew

Scientists found Taxus masonii in only one place: the John Day Fossil Beds National Monument in Oregon. This specific spot is called the Clarno nut beds, which is part of the Clarno Formation. It's about 3 kilometers (2 miles) east of a small community called Clarno, Oregon.

How Old Are These Fossils?

The rocks where the Taxus masonii fossils were found are from the middle Eocene period. Scientists figured out their age by using special methods like Fission track dating and Argon–argon dating. These methods measure tiny changes in minerals to tell how old they are. The results showed the rocks are about 45 to 43 million years old!

The area where the fossils were found was once a very active place. It might have been a delta where a river met a lake, or a place with floods and volcanic mudflows. There were even hot springs, which are like natural hot tubs, that helped preserve the plant fossils.

Studying the Fossils

The first fossil of Taxus masonii that scientists studied is called the holotype, named USNM355474. It's kept safe in the National Museum of Natural History in Washington, D.C.. Scientists also found fourteen other important fossils, called paratypes. Some of these are also in the National Museum, while others are at the University of Florida and the University of California Museum of Paleontology.

These fossils were collected over many years, from 1942 to 1989. Many people helped, including scientists like Thomas Bones and Steven R. Manchester, and even some high school students! They gathered about 20,000 fossils in total from this area.

Naming the Species

A scientist named Steven R. Manchester, who studies ancient plants (a paleobotanist) from the University of Florida, was the one who officially described Taxus masonii. He published his findings in 1994 in a science journal called Palaeontographica Americana. He named the species masonii to honor another botanist, Herbert L. Mason. Mason was known for his work studying ancient conifers in western North America.

What the Seeds Looked Like

The seeds of Taxus masonii were round and had a pointed tip. They were about 4.3 to 6.2 millimeters (about 0.17 to 0.24 inches) long and 4.5 to 5.6 millimeters (about 0.18 to 0.22 inches) wide.

Scientists could tell these seeds belonged to a Taxus (yew) species by looking at their outside shape and how their internal "veins" (vascular system) were arranged. The seeds were somewhat flat, like a lens, and had a flat bottom where a fleshy part called an aril would have been attached. They also had a ridge at the top and two small scars near the bottom where the veins entered the seed. These veins traveled along the top and bottom surfaces of the seed before going inside.