BUILDING A FOSSIL IDENTIFICATION DATABASE FOR THE LEAVES OF FLORISSANT FOSSIL BEDS NATIONAL MONUMENT

Florissant Fossil Beds National Monument, Colorado, preserves one of the most diverse fossil assemblages in the world, including more than 130 late Eocene fossil plant species represented by wood, leaves, fruits, flowers, and pollen. The bulk of the Monument’s collection is leaves preserved in shale, many of which have yet to be definitively identified. Using the most current taxonomic classifications and the standardized leaf morphological characters from the Manual of Leaf Architecture, a database was constructed using Microsoft Access that can be used to assign unidentified Florissant fossil leaf specimens to distinct morphotypes, the majority of which have been taxonomically named in previous literature. The database includes discrete morphological characters such as venation and tooth shape for every Florissant species described thus far and represented by fossil leaves. Descriptions and illustrations from a variety of sources were used to ensure inclusion of a wide range of species variability, increasing the likelihood of matching unknown fossils with similar morphotypes, even if the unknown has uncommon features. These included descriptions created by using fossils from the Monument’s collection and images from its online Museum Database, which documents all previously published specimens, and descriptions from previous workers at the Monument. MacGinitie’s 1953 monograph Fossil Plants of the Florissant Beds, Colorado and other published descriptions were also used. This required converting the original authors’ terminology to the standardized characters and character states used in the database. The database was evaluated by testing its ability to match specimens from Florissant’s collection with known morphotypes. To identify a fossil leaf, a researcher describes it to the greatest extent allowed by its preservation and puts this information into the database. Morphotypes that share features with the unknown fossil are singled out with the end result of one or very few candidate types, which can be quickly verified or narrowed further using Florissant’s online resources. Using this database, researchers can efficiently assign leaves from the Florissant Fossil Beds to morphotypes using standardized characters and without having to search through previous literature and descriptions.