UCMP’s summer adventures (cont.)

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The Nell Tree (above) is one of the largest petrified stumps in the George W. Lund Petrified Forest. Below, one of two large trees next to Highway 34 caged for protection, with Howard Schorn for scale. (photos by Diane Erwin) Caged petrified tree

In the mid 1950s, Nell Murbarger set about to find a very large fossilized redwood stump, which she had seen pictured in a paleobotany pamphlet. Nell and her traveling companion Dora not only found this tree, butmany others, which she wrote about in her Natural History Magazine article “Our Largest Petrified Tree.” The identification of these trees remained unresolved, some considering them to be Redwoods (Sequoia), while others thought the trees produced the fossil leaf species, Metasequoia langsdorfii, and therefore were Dawn Redwoods. Until now, no scientific study of the forest had ever been done.

Diane Erwin and Howard Schorn spent time this summer with Constance Millar, Robert Westfall, and John King (USDA Forest Service Pacific Southwest Research Station) investigating these trees of the George W. Lund Petrified Forest. Mapping revealed over 250 stumps buried in place by volcanic ash fifteen million years ago. The wood and large size of some stumps suggest Big Trees (Sequoiadendron) did grow in this ancient forest, their fossilized remains a sobering reminder of the profound impact climate change has on the success and distribution of organisms through time.

Focusing on Mammals
Tony Barnosky spent most of the summer in the Rocky Mountains of Montana, Idaho, and Wyoming trapping small mammals. The first field effort was led by Stanford University paleoecologist Liz Hadly and focused on obtaining genetic samples for her efforts to model population genetics through space and time in small mammal populations. Tony also joined graduate students, Samantha Hopkins and Edward Davis, during part of their field seasons.
Samantha spent much of her summer traveling to museums in Washington, Kansas, South Dakota, and Montana to study specimens associated with her thesis research, the paleoecology of Miocene mammals form the Rocky Mountains. After this time in the museums, however, Sam got out in