permineralized wood; Miocene age; High Rock; Nevada
Permineralized wood of mid-late Mocene age occurs in local fluviolacustrine deposits of the Hight Rock volcanic sequence in northwestern Nevada. Stem, branch, and root fragments of at least one conifer and several dicot taxa, including Robinia and Quercus, are represented. Wall Canyon Creek lies several miles west and south of Virgin Valley, where material similar in age and preservation, including Picea wolfei Crabtree, and Vitoxylon opalinum Brown have been described. Tidwell has identified a new species of Yucca from a nearby localisty. One Wall Canyon speciment has vorings typical of those produced by larvae of modern longhorn beetles (Coleoptera: Cerambycidae). Other specimens are partially decomposed by fungi or contain branched, septate fungal hyphae. Preservation of fine cellular features of many specimens, as well as fungi, indicate relatively rapid incorporation into the volcanic sediments.