Answer:
As the information about the film is missing to provide an exact answer to this question, it is possible to say that there are two possible answers:
Relative Dating or
Absolute Dating
Explanation:
These techniques can be used to determine the age and paleoenvironment of a fossil specimen. The first one, Relative dating is normally used to compare the fosil with the new layers it can have above from older to younger and some other fossils or rocks which age is already known. In this one a correlation is established among the fossils found and some rocks or fossils previously found.
The second option, Absolute dating takes into account the exact age of the material found (fossils or rocks) through radiometric dating techniques. That is to say, in this way it is possible to know the age like a clock since radioactive minerals are used for this purpose.