Stonebergia facts for kids

Stonebergia is an extinct plant genus that was part of the rose family, Rosaceae. It only has one known species, called Stonebergia columbiana. Scientists discovered this plant from fossil leaves found in shale rock. These fossils came from a place in southern British Columbia, Canada, and date back to the early Eocene epoch.

Discovering an Ancient Plant

Scientists learned about Stonebergia from fossils found at a special spot called the "One mile Creek" exposure. This place is part of the Allenby Formation near Princeton, British Columbia. The rocks in the Allenby Formation are very old, from the Early Eocene time period. Scientists figured out their age using a method called potassium–argon dating. This method measures how certain elements in rocks have changed over time.

Where Stonebergia Lived

The area where Stonebergia fossils were found used to be a mix of river lakes and wetlands. It was surrounded by mountains. This tells us that Stonebergia likely grew in a wet, marshy environment with a mountainous backdrop.

Naming Stonebergia

The first description of Stonebergia came from a special fossil leaf, known as the holotype specimen UWBM 54110 A,B. There were also eight other important fossils, called paratypes, that helped scientists study the plant. Most of these fossils are kept at the Burke Museum of Natural History and Culture in Seattle, Washington. Other pieces are at the Princeton Museum and District Archives and the University of Alberta.

Two paleobotanists, Jack A. Wolfe and Wesley C. Wehr, studied these fossils. They published their findings in 1988 in a science journal called Aliso. They named the plant Stonebergia to honor Margaret Stoneberg. She worked at the Princeton District Museum and greatly helped Wolfe and Wehr with their research. The second part of the name, columbiana, refers to British Columbia, where the fossils were found.

What Stonebergia Leaves Looked Like

The leaves of Stonebergia were simple, meaning they weren't divided into smaller leaflets. They had veins that branched out from a main central vein, a pattern called pinnately veined. These leaves were about 1.7 to 2.2 centimeters (0.7 to 0.9 inches) long and 1.0 to 3.0 centimeters (0.4 to 1.2 inches) wide.

Leaf Shape and Details

The leaf blade, or lamina, was deeply cut, almost looking like a compound leaf in some parts. This is called pinnatifid. Each leaf had between four and nine pairs of side veins branching off the main vein. These side veins came off at wide angles near the base of the leaf, becoming narrower closer to the tip. Each side of these veins had up to seven lobes, and each lobe had up to eight small teeth along its edge.

The leaf stalk, called the petiole, was about 0.8 to 1.0 centimeter (0.3 to 0.4 inches) long and was very hairy. At the base of the petiole, there was a small leaf-like part called a stipule. This stipule was about half the length of the petiole and also had many straight hairs, plus some special glandular hairs.