Southeastern Section - 62nd Annual Meeting (20-21 March 2013)

Paper No. 7
Presentation Time: 8:00 AM-5:30 PM

PALEOENVIRONMENTAL INTERPRETATION THROUGH OXYGEN ISOTOPES IN PHOSPHATE FROM BAROSAURUS INDICATE INCREASING ARIDITY AT THE AARON SCOTT QUARRY (MORRISON FORMATION, JURASSIC PERIOD)


SAMANTHA, Caldwell, Physics and Geology, Northern Kentucky University, Nunn Dr, Northern Kentucky University, Highland Heights, KY 41099, BERTOG, Janet L., Physics, Geology and Engineering Technology, Northern Kentucky University, SC 204, Nunn Dr, Highland Heights, KY 41099, KIM, Sora, Geology and Geophysics, University of Wyoming, 1000 University Ave. #3006, Laramie, WY 82071 and CLEMENTZ, Mark T., Geology and Geophysics, University of Wyoming, 1000 University Ave. University of Wyoming, Dept. 3006, Laramie, WY 82071, caldwells3@nku.edu

Taphonomic research, stratigraphy, and oxygen isotopes were used to determine the diet and climate of a Barasaurus from the Morrison Formation to determine if a change in the animal’s diet was evident during the animal’s life time. Data suggests that there was an increase in temperature and aridity over the animal’s lifetime. Oxygen isotopes of phosphate from the femur of the Barosaurus range from 13 to 16 per mil dO18 from the inner-most part of the bone to the outside edge. Millimeter-scale fluctuations in the dO18 of 1-2 per mil may be evidence of yearly fluctuations. The overall trend is an increase in dO18. This is consistent with a diet of increasingly drought tolerant plants including seed ferns and ginkos as opposed to conifers.