ABSTRACT
The advent of computers has allowed the use of new analytical methods while the nature and methods of original data acquisition have seen fewer changes. Most analytical methods rely on landmark data that can be easily recorded from teeth. The choice of landmarks, however, may limit the scope of a study as decisions on data collection have to be made prior to recording the landmarks. Here we present a method to record and analyze tooth crown morphology of small teeth with almost no loss of shape information. Epoxy resin casts with eosin dye are optically sectioned with 25-100 µm intervals using a laser confocal microscope with fluorescence detection. Alternatively, original specimens of Recent teeth can often be optically sectioned in reflective light mode. High-resolution digital elevation models (DEMs) of tooth crowns are produced from the image stacks using the 3Dview version of the NIH-Image software (MacOS). Digital elevation models can be transferred to Geographic Information System (GIS) software as well as interpreted by surface rendering computer programs. All traditional morphometrical measurements can be obtained from DEMs. However, the total shape data (i.e., DEMs) can be explored with GIS prior to the selection of appropriate measurements. Furthermore, as the DEMs can be stored as a museum database of tooth morphologies, the three-dimensional morphology can be accessed remotely via the Web, reducing the need to visit museum collections or borrow specimens. This confocal scanning method is well-suited for large samples of small teeth and other small fossils.
Jukka Jernvall, Institute of Biotechnology, P.O. Box 56, FIN-00014, University of Helsinki, Finland.
Lena Selänne, Department of Geology, Division of Geology and Palaeontology, P.O. Box 11, FIN-00014 University of Helsinki, Finland.
KEY WORDS: tooth, morphology, GIS, confocal microscopy, digital elevation models
Copyright:
Palaeontological Association, 15 March 1999
Submission: 25 January 1999, Acceptance: 3 March 1999