The sediment is boiled in solvent to remove the asphalt. The cleaned material is a mixture of sand, small pebbles, small pieces of large fossils, and microfossils, such as seeds. In the laboratory the fossils are cleaned, repaired, sorted, identified, and labeled. Technicians clean the large specimens by hand, using dental tools and a solvent to remove the asphalt. Small or fragile specimens are cleaned in ultrasonic tanks, where high-frequency sound waves help the solvent remove the asphalt and sand.
Technicians use lighted magnifiers to see the tiny fossil remains more easily.
The fossils are separated from the sediment and then identified and catalogued. Scientists identify the fossils by comparing them with other identified specimens from the research collection or with the hard parts such as seeds and bones from living plants and animals. Each fossil is given a protective coating and an individual number. This number is entered into a master catalog with the fossil's identification and location information. The fossils are then added to the research collection, where they are available for further study.