PRELIMINARY PLANT FOSSIL DATA FROM THE DINOSAUR FOOTPRINT RESERVATION, MA: IMPLICATIONS FOR THE PALEOLAKE

The Dinosaur Footprint Reservation in Holyoke, MA is known for its abundance of Jurassic aged Eubrontes, Anomepus and small theropod footprints. The site also contains oscillation ripple marks and the casts of woody plant material. Over the past few years, the footprints and ripple marks have been mapped and studied, however little attention has been paid to the plant fossils.

This study serves to assess the potential of incorporating plant fossil information into the established data set for the site. Twenty-nine in situ plant fossils were digitally photographed with a compass to provide orientation and scale. The photographs were loaded into a GIS where the plant morphologies were traced and measured.

Graphical representations of the plant strike orientations shows dominant orientations in the NW-SE direction. The plants are shown to be oriented approximately perpendicular to the shore of the paleolake as represented by ripple marks oriented in a NE-SW direction. Some of the plant fossils have both a narrow end and a squared end. We know from invertebrate fossils, that in many instances, the narrow end becomes oriented up current. Measuring the orientations of the narrow ends of the of the plant fossils shows a dominant orientation between 300-310^o. This suggests the waves were coming out of the NW.

Preliminary analysis of the plant fossils shows promising contributions to the paleoecological story of the site; however previous researchers have illustrated the difficulty in using wood as paleocurrent indicators when working with small datasets. Further work should be done to map the plant traces in order to expand the dataset. This larger dataset should help reinforce the hypothesis presented here. Mapping the plant fossils over a large horizontal area has the potential to be used to chart the shore of the paleolake. Previous work with woody plants as current indicators have focused mainly on debris flows and fluvial settings, with little to no attention paid to lakes. This opens an additional area where research is needed.