Barinophytes †
Obscure heterosporous lycophytes
Barinophytes, named after Barinophyton, are a group with ambiguous affinities. They possess a strobilar structure that is reminiscent of the zosterophylls as well as G-type tracheids. Most of these taxa are heterosporous with both megaspores and microspores within the same sporangium.
Ecology & Form
Wide geographic distribution
Probably were aquatic or semi-aquatic
Stems
G-type water-conducting cells for support
Due to cell type, plants were probably not very tall
Reproductive
Mostly known only from their strobili (clusters of sporangia or spore-producing organs);
Presumed individual microphylls have also been found in some strobili
The strobili have two rows of sporangia which are arranged both laterally and terminally in Barinophyton and terminally in Protobarinophyton
Pectinophyton, which has only a single sporangial row, may also be a barinophyte
Heterosporous sporangia
Both microspores and megaspores are found in the same sporangium (unique in the plant world)
Classification
└?Barinophytales †
Geologic Age
late Early Devonian into the Early Carboniferous
Diversity
Adoketophyton †
Early Devonian (Pragian) of Wenshan district, Yunnan, China
Distal aerial parts of the plant with smooth dichotomously branching axes and terminal strobili composed of compound lateral fertile units
Each unit comprises a bract-like flattened appendage and single adaxially inserted sporangium with two valves and distal dehiscence around convex margin
This group is probably a barinophyte
A. subverticillatum † (Li & Edwards 1992)
Originally named Zosterophyllum subverticillatum
A. parvulum † (Zhu et al. 2011)
Axes naked. Isotomously or pseudomonopodially branching, with vegetative ultimate tips circinately coiled.
Fertile axes naked, dichotomously branching at angles of 25°–55°.
Strobili parallel-sided, comprising four rows of oppositely and decussately inserted fertile units; the longest strobilus with more than 60 fertile units; each fertile unit consisting of a sporophyll and an adaxial sporangium.
Sporophyll fan-shaped, with a short pedicel, and the laminar region partly enclosing the sporangium.
Sporangia elliptical, attached to the adaxial base of the sporophyllous lamina by a short stalk, with distal dehiscence along convex margin.
Height of sporophyll lamina and associated sporangium almost equal, 0.8–1.4 mm.
Anatomy unknown.
A. pingyipuensis (Edwards & Li 2018)
Vegetative parts unknown
Parallel-side strobili with sporangial complexes inserted on all sides of the strobili
Sporangial complex above junction with stalks
Stalks parallel sided, adxially curved such that complexes are held upright or slightly reflexed
Ovoid sporangia lacking stalks attached near the base of a fan-shaped bract that partially curves around sporangium and extends beyond it
Above: Adoketophyton parvulum reconstruction (Fig 2, Zhu et al. 2011)
Barinophyton †
White 1905, Brauer 1980
B. citrulliforme † (Brauer 1980)
B. obscurum † (Brauer 1981)
Upper Devonian Catskill Formation of northern Pennsylvania
The fertile system consists of a main axis that bears alternate strobili that have a distinctive two-ranked appearance
The main axis is about 3 mm in width and bears strobili at 7-mm intervals; up to seven strobili per fertile segment.
The strobili are up to 5.5 cm in length and are probably at least 4.5 cm long when mature. They range from 0.7 to 1.0 cm in width.
The strobili appear to be borne in one plane, but this may be the result of compression. They may actually be spiral on the main axis.
B. sibericum †
Above: Barinophyton obscurum
Krithodeophyton croftii †
Edwards 1968
Naked, pseudomonopodial axes with some isotomous branching
Centrarch protostele
Sporangia in terminal spikes with straight or curved bracts (enations?)
Sporangia oval and sessile, born in 2 rows on either side of the axis
Homosporous
? Omniastrobus dawsonii †
Originally called Barinophyton dawsonii (Krausel and Weyland 1941)
Strobili in Omniastrobus are similar to those of the enigmatic order Barinophytales and consist of two rows of lateral sporangia.
Unlike in other Barinophytales, however, sporangia within the strobili show a continuous gradient in average spore size, from those producing smaller spores (∼70–150 mm) to those producing larger spores (1200 mm), as well as some with a bimodal mix of sizes.
Strobili up to at least 4.4 cm in length and 5.4–9.6 mm wide.
Strobili bear two lateral rows of closely packed ellipsoidal to elongate sporangia
Spores triangular to elliptical, unornamented, with thin walls and small, slightly raised trilete marks.
Individual sporangia within strobili produced spores of different average sizes, from those with primarily smaller spores (∼70–150 mm in diameter) to those with primarily large spores (∼200–280 mm) and those with intermediate spore sizes. Sporangia in strobili show a spore size gradient, with smaller spores borne proximally.
Above: Omniastrobus dawsonii from Fig 1 of Bonacorsi et al. 2021
Pectinophyton †
Hoeg, 1935
Protobarinophyton pennsylvanicum †
Ananiev 1955, Brauer 1981
Late Devonian of New York and Pennsylvanian
Plant bearing terminal strobili on elongate axes.
Strobili bearing two rows of alternate sporangiferous appendages
Appendages curving downward and back toward the strobilar axis, bearing along their concave surfaces large sporangia, one per appendage.
Above: Protobarinophyton