ABSTRACT One of the common features of any natural history museum is its fossil collection. A visitor's prior knowledge of and experience with these prehistoric objects is expected to greatly influence how visitors make sense of these iconic displays. For this study, over 150 visitors to two natural history museums in Southern California were interviewed to find out what they knew about fossils and the fossil record. Findings showed that visitors referenced a wide range or breadth of salient characteristics when defining fossils and that almost two-thirds mentioned some sort of process for the formation of fossils. When asked to interpret a diagram of geological strata and fossil placement within the strata, most visitors recognized that older fossils were found in lower layers (suggesting an understanding of the principle of superposition), although this was age-dependent. Also, many visitors explained fossil distribution in terms of some sort of change process—either related to the organism or the environment. In addition, several potential misconceptions related to fossils and superposition also emerged from the analysis. Implications for supporting visitor understanding are discussed.