''Tortilicaulis'' is a

moss Mosses are small, non-vascular plant, non-vascular flowerless plants in the taxonomic phylum, division Bryophyta (, ) ''sensu stricto''. Bryophyta (''sensu lato'', Wilhelm Philippe Schimper, Schimp. 1879) may also refer to the parent group bryo ...

-like

plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...

known from

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 preserve ...

s recovered from southern Britain, spanning the Silurian-Devonian boundary (around ). Originally recovered from the Downtonian of the Welsh borderlands, ''Tortilicaulis'' has since been recovered in the famous Ludlow Lane locality. Whilst it is generally accepted that ''Tortilicaulis'' was moss-like, it has not yet been recovered in a sufficiently good state of preservation to allow the detailed study necessary to firmly assign it to a taxonomic group. Fossils consist of an elongate apical

sporangium A sporangium (from Late Latin, ; : sporangia) is an enclosure in which spores are formed. It can be composed of a unicellular organism, single cell or can be multicellular organism, multicellular. Virtually all plants, fungus, fungi, and many ot ...

(spore-forming organ), which may be branched, with spiralled walls attached to an undivided stalk that is also twisted. Unusually for plants of its time, spores of ''Tortilicaulis'' were covered all over with small granules. The initial suspicions of its describer,

Dianne Edwards Professor Dianne Edwards CBE, FRS, FRSE, FLS, FLSW (born 1942) is a palaeobotanist, who studies the colonisation of land by plants, and early land plant interactions. Early life Edwards was born in Swansea, South Wales, and spent much of he ...

, were that it was a

bryophyte Bryophytes () are a group of embryophyte, land plants (embryophytes), sometimes treated as a taxonomic Division (taxonomy), division referred to as Bryophyta ''Sensu#Common qualifiers, sensu lato'', that contains three groups of non-vascular pla ...

, and comparisons have been made with several groups. A potential association with the moss ''

Takakia ''Takakia'' is a genus of two species of mosses known from western North America and central and eastern Asia. The genus is placed as a separate family, order and class among the mosses. Discovery ''Takakia'' was discovered in the Himalayas and ...

'' is supported by features of the

sporangia A sporangium (from Late Latin, ; : sporangia) is an enclosure in which spores are formed. It can be composed of a unicellular organism, single cell or can be multicellular organism, multicellular. Virtually all plants, fungus, fungi, and many ot ...

, such as the elongate shape, unusual twisting, and terminal position of the

. As the sporangia of ''Tortilicaulis'' are branched, cladistic analysis suggests that the genus may instead belong to the

Horneophytopsida The Horneophytopsida, informally called horneophytes, are a class of extinct plants which consisted of branched stems without leaves, true roots or vascular tissue, found from the Late Silurian to the Early Devonian (around ). They are the simp ...

, a

class Class, Classes, or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used d ...

of the

polysporangiophyte Polysporangiophytes, also called polysporangiates or formally Polysporangiophyta, are plants in which the spore-bearing generation (sporophyte) has branching stems (axes) that bear sporangia. The name literally means 'many sporangia plant'. The cl ...

s, which unlike bryophytes, have branched stems bearing sporangia. Its precise nature and hence classification remains unclear., p. 165 For the cladogram, see the

article.

References

{{Taxonbar, from=Q7827290 Early Devonian plants Silurian plants Prehistoric plant genera Pridoli first appearances Early Devonian genus extinctions