The Nematophyta or nematophytes are a paraphyletic group of land organisms, probably including some plants as well as algae known only from the

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

record, from the Silurian period until the early Devonian

Rhynie chert The Rhynie chert is a Lower Devonian sedimentary deposit exhibiting extraordinary fossil detail or completeness (a Lagerstätte). It is exposed near the village of Rhynie, Aberdeenshire, Scotland; a second unit, the Windyfield chert, is located ...

. The type genus ''

Nematothallus ''Nematothallus'' is a form genus comprising cuticle-like fossils. Some of its constituents likely represent red algae, whereas others resemble lichens. History of research ''Nematothallus'' was first described by Lang in 1937, who envision ...

'', which typifies the group, was first described by

Lang Lang may refer to: *Lang (surname), a surname of independent Germanic or Chinese origin Places * Lang Island (Antarctica), East Antarctica * Lang Nunatak, Antarctica * Lang Sound, Antarctica * Lang Park, a stadium in Brisbane, Australia * Lang, ...

in 1937, who envisioned it being a

thallose Thallus (plural: thalli), from Latinized Greek (), meaning "a green shoot" or "twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. Many of these organisms were ...

plant with tubular features and

sporophyte A sporophyte () is the diploid multicellular stage in the life cycle of a plant or alga which produces asexual spores. This stage alternates with a multicellular haploid gametophyte phase. Life cycle The sporophyte develops from the zygote pr ...

s, covered by a cuticle which preserved impressions of the underlying cells. He had found abundant disaggregated remains of all three features, none of which were connected to another, leaving his reconstruction of the phytodebris as parts of a single organism highly conjectural. No reproductive or vegetative structures common to the land plants are known, and certain members of the nematophyte plexus (including ''

Nemataplexus ''Nematoplexus rhyniensis'' is a fossil known from the Rhynie chert assigned to the nematophytes. It comprises a loose mass of coily aseptate tubes. Tubes which may have originated from a ''Nematoplexus''-like plant are known from earlier Silur ...

'', axial conjugations of banded and branching tubes) seem to belong to the fungi. The lack of a clear definition of the nematophytes has led to it being used as a

wastebasket taxon Wastebasket taxon (also called a wastebin taxon, dustbin taxon or catch-all taxon) is a term used by some taxonomists to refer to a taxon that has the sole purpose of classifying organisms that do not fit anywhere else. They are typically defined ...

, with all manner of tubes and cell-patterned cuticles from around the Silurian being dubbed "nematophytic" more as a statement of ignorance than as a scientifically meaningful statement. Nematophytes, including cuticle and banded tubes, have been found in

coprolite A coprolite (also known as a coprolith) is fossilized feces. Coprolites are classified as trace fossils as opposed to body fossils, as they give evidence for the animal's behaviour (in this case, diet) rather than morphology. The name is de ...

s that were apparently produced by millipedes.

References

} * McGregor and Narbonne (1978): "Upper Silurian trilete spores and other microfossils from the Read Bay Formation, Cornwallis Island, Canadian Arctic" {{Taxonbar, from=Q256478 Silurian plants Early Devonian plants