A new microscope-based method is described that uses a beam of laser light to cause casts of teeth to fluoresce or give off light. By varying the distance from microscope lens to a cast in a controlled way, only fluorescence from a thin portion of the cast is detected. A series of cross-section pictures can be obtained that, when stacked together, create an accurate three-dimensional virtual model of the tooth's external surface. The method is illustrated by applying it to the study of the enamel tops, or crowns, of small mammal teeth. One use of the new method is to precisely locate features on the morphologically complicated surfaces of teeth so that their relative positions can be measured. By using such measurements paleontologists can identify different species and test a wide range of evolutionary and ecological hypotheses. In addition, the similarity between the new virtual morphological models and land-surface elevation maps suggests that the same computer software used to characterize landforms could be used to characterize the complex surfaces of teeth, as well as the shapes of other fossils. These methods have wide application throughout paleontology and organismal biology.