Paleobotany

Paleobotany is the scientific study of ancient plants. Paleobotanists learn what plants were like long ago from fossils found in sedimentary rocks. These fossils can be impressions or compressions of the plants left on the rock’s surface, or “petrified” objects, such as wood, which preserve the original plant material in rocklike form. Still other specimens are found in calcified lumps called coal balls, so named because they are usually found in or near coal deposits.

The Museum’s Paleobotany collection is composed of about 30,000 fossil specimens spanning the time period from the Precambrian Period to the Pleistocene Epoch. Of these, about 3,000 are from the Mississippian to Tertiary ages and the rest are from the Pennsylvanian (Coal Age). They are stored in steel cabinets. All have been cataloged in a computerized database.

The Paleobotany Department also houses 994 coal balls, which are principally of Pennsylvanian (Upper Carboniferous) bituminous and anthracite coals. The processes leading to coal-ball formation are still poorly understood, and they are very fragile specimens.

Dr. Chitaley developed a technique for preserving coal balls that prevents their degradation and allows them to be sliced and studied. Cellulose acetate peels, taken before their preservation, reveal the plant parts preserved inside. A sizeable collection from the Devonian Period, upper and lower, has been amassed by Dr. Chitaley and volunteers from the Fossil Society (now the North Coast Fossil Club).

The best Upper Devonian specimens, about 360 million years old, are from the Cleveland Shale, a formation that underlies the city and other areas along the shore of Lake Erie. Many specimens were unearthed and collected by the museum when Interstate 71 highway was built in the 1960s. Dr. Chitaley has done extensive research on this collection, which is from the most important period in the evolution of early plant life.

In addition, the department has more than 6,000 microslides and an equal number of cellulose acetate peels. The numbers of both are steadily increasing with ongoing research activity. All have been cataloged.

Of the department’s 30,000 specimens, approximately 28,000 are part of the Hoskins Collection. This was a donation from the University of Cincinnati in 1980. Most of the specimens date from the Pennsylvanian period.

Why study fossilized plants?
There are many reasons. Among them are:

• All coal (a prime source of energy) is formed from plants.
• Fossilized plants are a major source of hydrocarbons in oil (another energy source).
• Fossils tell us about the history of life on our planet.