01783nas a2200193 4500008004100000245007500041210006900116300001400185520122800199653001601427653001301443653001801456653001101474653001301485653001701498100002101515700001601536856003701552 2014 eng d00aAffinities and Architecture of Devonian Trunks of Prototaxites loganii0 aAffinities and Architecture of Devonian Trunks of Prototaxites l a1143-11583 a

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 (δ13CPDB) 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.

10aChlorophyta10aDevonian10aGlomeromycota10alichen10aNew York10aPrototaxites1 aRetallack, G., J1 aLanding, E. uhttp://dx.doi.org/10.3852/13-390