Giving fossils a facelift
If you think about it, a fossil has not shown its best face in a long time, maybe ever. It has spent millions of years embedded in rock, ice, tar or amber. It is a fossil preparator's job to remove a fossil from the surrounding materials to reveal it for study and display. The difficulty of the preparation depends not only on what the fossilized organism is, but also how it has changed over time.
We think of fossils as animals or plants that have mineralized (changed to rock). But, that is only part of the story. Fossils are defined as any traces of life 10,000 years old or older. A fossil can be as subtle as a footprint. Or it can be as substantial as a skeleton. Whether it mineralizes or not depends on the conditions it experiences. And how long it experiences those conditions. Living material buried in ocean sediment might get totally replaced with minerals. Living material in a peat bog might survive for thousands of years nearly unchanged.
A fossil preparator's work often begins in the field. It starts with the extraction of a fossil from the landscape where it is discovered. Along with the fossil comes a lump of surrounding material. It is left on as protection for packaging and transport to a fossil preparation lab. There, a fossil preparator uses an array of specialized tools to remove the material around the fossil. Depending on the matrix, tools may range from soft brushes to metal dental picks. In addition, even air-powered, needle-tipped jackhammers are sometimes used.
But not all fossil organisms are created equal. Usually the hard parts of an organism, such as bones, shells or stems, have fossilized. The soft parts decay or are eaten away. A fossil preparator must piece together fossilized bits of the organism like a puzzle. The preparator restores missing parts using information from other sources about what they should look like. This makes a preparator part scientist, part detective, part artist and part engineer.
Preparator Michelle Pinsdorf prepares fossils for display and research. She works at the Smithsonian's National Museum of Natural History.
Learn more about her job, and how volunteers play a role, in this "Smithsonian Science How" webcast. During Inside the Smithsonian's Fossil Prep Lab, Michelle takes you on a tour of the Fossil Prep Lab while answering questions.
You can get teaching resources to use with the webcast.
CRITICAL THINKING QUESTION
Why does a fossil preparator’s work not end in the field?
Write your answers in the comments section below