Big trees, little cones
Diane Erwin, Howard Schorn and Eric Seiple spent a week in July collecting from the five million year-old Washoe Lands Plant site near Carson City, NV, joined by Connie Millar, Wally Wolfenden, and John King from the USDA Forest Service, Pacific Southwest Research Station. Diane recalls It was great fun. I think this was their first time collecting fossils. Boy, it sure didnt take them long to get the hang of splitting rock. Seemed like every time I looked up, everyone was busy whacking away on a large block they had wrestled out of the hillside. We tripled the size of the Washoe collection that day, pulling out numerous leaves of live oak, willow, poplar, Oregon grape, birch, pine, fir, and Big Tree (Sequoiadendron giganteum). We found several complete specimens of Sequoiadendron branches and Connie collected the only cone to be recovered so far. This site is particularly significant as it represents the last megafossil occurrence of Big Trees in Nevada. Today, most Big Trees grow in a few isolated groves scattered throughout the central Sierra Nevada of California. The Washoe cone is smaller (only 1.5 cm long) than typical modern Big Tree cones (49 cm long), and the smaller size may suggest the trees were under stress. The Big Trees growing at nearly sea level here on campus and surrounded by asphalt pavement also produce really small cones (<2.0 cm). By comparing the fossil remains and associated dicotyledonous plants to modern analogs we can reconstruct the Washoe Big Tree and the environment in which these plants lived.
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At top (from left), Wally Wolfenden, Connie Millar, and John King scour the fossil-bearing diatomite of the Washoe Lands Plant locality. Below, Branch and cone of Washoe Big Tree for comparison to modern Big Tree Sequoiadendron giganteum. Large cone at top typical (4 cm long), smaller cone collected from tree growing on UCB campus. (photos by Diane Erwin)
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