title: Affinities and architecture of Devonian trunks of Prototaxites loganii.
abstract: Devonian fossil logs of Prototaxites loganii have been considered kelp-like aquatic algae, rolled up carpets of liverworts, enormous saprophytic fungal fruiting bodies or giant lichens. Algae and rolled liverwort models cannot explain the proportions and branching described here of a complete fossil of Prototaxites loganii from the Middle Devonian (386 Ma) Bellvale Sandstone on Schunnemunk Mountain, eastern New York. The "Schunnemunk tree" was 8.83 m long and had six branches, each about 1 m long and 9 cm diam, on the upper 1.2 m of the main axis. The coalified outermost layer of the Schunnemunk trunk and branches have isotopic compositions (δ(13)CPDB) of -25.03 ± 0.13‰ and -26.17 ± 0.69‰, respectively. The outermost part of the trunk has poorly preserved invaginations above cortical nests of coccoid cells embraced by much-branched tubular cells. This histology is unlike algae, liverworts or vascular plants and most like lichen with coccoid chlorophyte phycobionts. Prototaxites has been placed within Basidiomycota but lacks clear dikaryan features. Prototaxites and its extinct order Nematophytales may belong within Mucoromycotina or Glomeromycota.
authors.affiliation: Department of Geological Sciences, University of Oregon, Eugene, Oregon 97403 gregr@uoregon.edu.
authors.forename: G J
authors.initials: GJ
authors.lastname: Retallack
authors.affiliation: Department of Paleontology, New York State Museum, 222 Madison Avenue, Albany, New York 12230, and Department of Earth and Environmental Sciences, Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York 10964.
authors.forename: Ed
authors.initials: E
authors.lastname: Landing
mesh_terms: D001487:Basidiomycota / Q000145:classification / Q000648:ultrastructure; D000460:Chlorophyta / Q000145:classification* / Q000648:ultrastructure; D005580:Fossils / Q000648:ultrastructure; D005658:Fungi / Q000145:classification* / Q000648:ultrastructure; D055137:Glomeromycota / Q000145:classification / Q000648:ultrastructure; D035926:Hepatophyta / Q000145:classification* / Q000648:ultrastructure; D008011:Lichens / Q000145:classification / Q000648:ultrastructure*
keywords: Chlorophyta; Devonian; Glomeromycota; New York; Prototaxites; lichen