UNIVERSITY PARK, Pa. — High on the craggy cliffs of Oman’s rocky desert landscape, Sarah Ivory squeezed into narrow, dark caves in search of a different kind of goldmine. Shaded away from the desert sun, Ivory tapped a dusty, gray rock with her hammer and heard the dull, hollow sound she’d been waiting for.
An assistant professor of geosciences at Penn State, Ivory had found a special kind of fossil that, when cut open, would reveal smooth golden-brown layers that can help scientists see deep into the past.
This was a fossil of a midden, a communal toilet used by generation after generation of a small, desert-dwelling animal. The same middens are sometimes used for tens of thousands of years.
Ivory journeyed to Oman, on the tip of the Arabian Peninsula, to find middens tucked in these caves, dig them out and ship them back to her laboratory at Penn State for analyses.
It’s a dirty job — but in one of the driest places in the world, middens may be the best evidence to understand how the climate changed in the past, and how plants, animals and even humans, responded, said Ivory.
“These unusual fossils are one of the only ways we can look back into the past and see how arid areas changed over time," explained Ivory. “That can help us answer important questions about how they will change in the future. These regions are very sensitive to changes in rainfall and are very at-risk.”