Fragmentary remains of a vascular sporophyte from the Rhynie Chert are described as a new genus and species, Trichopherophyton teuchansii. The plant, which is characterised by the possession of unicellular spinous hairs, exarch xylem and laterally attached, marginally dehiscent sporangia, is assigned to the Zosterophyllophytina, but lack of information on the arrangement of sporangia prevents its more precise positioning within the subdivision. Unusual features include the combination of circinate tips to axes with almost terete xylem strands, and the lack of a thick-walled outer cortical zone. Associated axes, lacking spinous hairs, but having papillate or rhizoid-like epidermal emergences, are interpreted as likely rhizomes of Trichopherophyton. Features, such as unicellular spinous hairs, rhizoid-like emergences, circinate tipsand parenchymatous cortex are considered in relation to the functioning and growth of aplant inhabiting an early Devonian wetland.
New material collected from the Rhynie Chert Bed (Siegenian age) has revealed new filamentous and unicellular algae. Two of the filamentous forms and one palmelloid form are described. Filamentous and unicellular algae are particularly common in a white kind of chert not previously reported and which is interpreted as having been formed by the in situ silicification of a silicate‐rich pond.
Some rhizoid‐nodes of Palaeonitella cranii (Kidston & Lang) Pia and a possible rhizoid‐borne pro‐embryo are also described and compared with similar structures in living Charophyta.
SynopsisIncomplete, but structurally preserved remains of an organism referable to the Nematophytales Lang, are described from the Rhynie Chert as a new genus and species. The fossil is composed of a plexus of non-septate tubular cells of two types—the smaller having uniformly smooth walls, the larger, walls with conspicuous spiral thickenings. Branching of both types is localized in areas referred to as branch-knots. Comparison is made with other members of the Nematophytales which have been shown to possess differentially thickened tubes.
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