"Nematothallus" was first described by Lang in 1937, who envisioned it being an early thallose land plant with tubular features and sporophytes, 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. Even so, it was picked up by Jonker (1973), who proposed that "Nematothallus" represented leaves of "Prototaxites", which he interpreted as a red alga.