DEVELOPMENT OF A GLOBAL DATABASE OF PALM MACROFOSSIL OCCURRENCES: PROGRESS AND PRELIMINARY ANALYSES

Palms (Aracaceae/Palmae) are an important component of some modern and ancient forested terrestrial ecosystems. Dominantly tropical dwellers today, their fossil record extends back to the Cretaceous in time and into the sub-polar latitudinal belt in space. Much recent work has been done on the evolution, systematics, historical ecology, and biogeography of palms, but what remains unavailable is a centralized and searchable global database of literature-reported macrofossil taxonomic occurrence data for this group, one that assembles the known palm paleobotanical leaf, fruit, axis, and inflorescence record.

Here we present progress toward such a database to help sedimentary geologists, paleontologists, and botanists address issues and questions concerning fossil taxonomy, palm group evolutionary origins, as well as modern and past biogeographical hypotheses. For each taxon (genus, species, and/or form) occurrence we provide the formation, literature age, age constraint, preservation lithology, modern geographic coordinates, paleogeographic coordinates, and the original reporting literature reference. More than 400 macrofossil occurrences are presently in the database. No attempt has yet been made to address taxonomic revisions or affinities of the literature-reported taxon occurrences.

Preliminary analyses of the developing database have shown the greatest paleolatitudinal extent of the palm macrofossil record to be during early Paleogene time (spanning >100 degrees). This is in timing with the highest number of palm macrofossil occurrences in the database. We present these and other latitudinal and time series analyses of the overall palm macrofossil record and individual fossil taxa.

As concern over modern climate change increases, such a database and its analysis can provide insight into the meaning of the distribution of fossil palm occurrences. By comparing these data to independent paleoclimate, paleoecological, and paleoenvironmental proxies, the effort can shed light on the paleobiogeographic and paleoecological meaning of the palm fossil record in Earth’s warmer past.