ONE HUNDRED YEARS OF RANGE CHARTS: EXTRACTING AND MANAGING TAXONOMIC PRESENCE-ABSENCE DATA

Geologists have been producing taxonomic range charts for individual sections for over a hundred years, with detailed presence/absence data available. Current efforts at understanding patterns of Ordovician graptolite biodiversity and biogeography require these types of data, beyond what is recorded in currently popular databases. Extracting this level of detailed information from range charts can be both time consuming and error prone, but many modern paleobiological methods require detailed presence/absence data to estimate fossil recovery rates independently of biodiversity changes. In addition to the challenges of data collection and entry, changing taxonomic practices mean that species identification may be a “moving target” over the course of a study, requiring a systematic approach to documenting the original author’s taxonomic identifications as well as the subsequent series of taxonomic changes. This presentation addresses new approaches to semi-automated range chart digitization that gathers data for entry into relational databases. We present new software tools that minimize and locate digitization and data entry errors, and that also provide a systematic approach to documenting taxonomic changes and corrections over time.