The reliability of any survey of biodiversity through geologic time depends on the rigor and consistency by which taxa are recognized and samples are identified. The main goal of the Neogene Marine Biota of Tropical America (‘NMITA’) project is to create an online biotic database (http://nmita.geology.uiowa.edu) containing images and synoptic taxonomic information that are essential to collecting and disseminating high-quality taxic data. The database consists of an inventory of taxa collected as part of several large multi-taxa fossil sampling programs designed to assess marine biodiversity in tropical America over the past 25 m.y. In the first phase of the project, data for ~1,300 taxa and ~3,800 images are currently being entered into a relational database management system on an IBM RS6000 at the University of Iowa. Eleven taxonomic groups are represented: bivalves, gastropods (muricids, marginellids, strombinids), bryozoans (cheilostome, cyclostome), corals (azooxanthellate, zooxanthellate), benthic foraminifers, ostracodes, fish. The lowest taxonomic rank is species (genera/subgenera in mollusks) and the highest is family. Data that are collected and displayed on taxon pages include: (1) taxonomic authorship, synonyms, type specimens, and diagnostic morphologic characters; (2) images of representative specimens and associated museum catalog and measurement data; (3) distributional information including geologic ages, stratigraphic units, and spatial locations; and (4) higher level classification (genera and families) and bibliographic information. Illustrated glossaries of morphologic terms, character matrices, and identification tools are being developed for corals and mollusks. Interactive geographic maps and stratigraphic columns have been designed to provide information about taxa collected at different locations.