“Phytodebris” from Scottish Silurian and Lower Devonian continental deposits

Abstract

A palynological investigation of Scottish Silurian and Lower Devonian continental deposits revealed rich microfossil assemblages comprising dispersed sporomorphs and fragments (“phytodebris”). The fragments, which comprise filaments, tubular structures, associations of tubular structures and cuticles, are described and their affinities and palaeobotanical implications discussed. The filaments are interpreted as fungal in origin, and the majority of the tubular structures are believed to derive from nematophytes. Most of the cuticles are also believed to belong to the nematophytes, although some may represent cuticles derived from higher land plants. The assemblages of fragments from Scotland are similar to those described from contemporaneous strata from elsewhere indicating that the organisms from which they derive were geographically widespread. In addition to phytodebris, fragments of arthropod cuticle were also recovered and are described. Four species of tubular structure ( Laevitubulus frondifera Wellman, sp. nov., Porcatitubulus microspiralis Wellman, sp. nov., Porcatitubulus microannulatus Wellman, sp. nov. and Porcatitubulus strupus Wellman, sp. nov.) and one species of filament ( Ornatifilum lornensis Wellman, sp. nov.) are proposed as new.