Acer ferrignoi facts for kids

Acer ferrignoi is an extinct maple species. We know about it from fossil leaves that have been found. These fossils come from rocks formed during the Miocene epoch in Oregon, USA. This ancient maple belongs to a group of living maples called section Rubra.

Discovering Acer ferrignoi

The story of Acer ferrignoi began with a small group of fossils. These fossils were found at a site known as USGS 9737. This place is located near Lolo Pass in the northern Oregon Cascade mountains.

Paleobotanists are scientists who study ancient plants. Jack A. Wolfe from the United States Geological Survey and Toshimasa Tanai from Hokkaido University were the first to study these fossils. They realized the fossils belonged to a new type of maple.

In 1987, Wolfe and Tanai officially described A. ferrignoi. They published their findings in a science journal. The species was named ferrignoi to honor James P. Ferrigno. He helped find and provide access to many fossils. These fossils are now kept at the Smithsonian Institution's National Museum of Natural History.

The main fossil used to describe the species is called the holotype. Its number is NMNH 396125. Several other important fossils, called paratypes, were also part of the museum's collections.

How Acer ferrignoi is Related to Other Maples

Wolfe and Tanai thought that A. ferrignoi might be a descendant of another extinct maple. This earlier maple was called Acer chaneyi. A. chaneyi lived from the late Oligocene to the Middle Miocene.

A. chaneyi leaves often had five lobes. However, A. ferrignoi leaves usually had three lobes. Still, the two species had similar shapes in their side lobes. This similarity made the scientists think they were related.

At first, A. ferrignoi was placed in a group called Acer section Eriocarpa. This was based on a system created by Japanese botanist Ken Ogata. Later, scientists studied maple trees more closely. They decided that section Eriocarpa should be included in section Rubra.

What Acer ferrignoi Leaves Looked Like

The leaves of Acer ferrignoi were simple in their structure. They had veins that spread out like fingers from the base. This is called an actinodromus vein structure. The leaves were shaped like an oval or a wide oval.

The bottom part of each leaf was rounded. The leaf stalk, called a petiole, could be up to 0.5 centimeters (0.2 inches) long. Each leaf was divided into three main parts, called lobes. The two side lobes were about half to three-quarters as long as the middle lobe.

The middle lobe was usually shaped like a triangle. The two side lobes were narrow and triangular. There were three main veins running through the leaf. Between three and ten smaller veins branched off from the outer main veins. These smaller veins branched at angles of 40 to 70 degrees. They either went straight to the edge of the leaf or curved gently.