The barinophytes are a group of extinct vascular plants (tracheophytes). Their relationship with other vascular plants is unclear. They have been treated as the separate class Barinophytopsida, the order Barinophytales of uncertain class and as a family or clade Barinophytaceae within the zosterophylls. They have also been considered to be possible lycopodiopsids.

Description

Barinophyton ''Barinophyton'' was a genus of early land plant with branching axes. It is placed in a group of early vascular plants (tracheophytes), the barinophytes, a group that has been given various ranks and scientific names. Known fossils are of Devoni ...

'' is the type genus of the group; ''

Protobarinophyton ''Protobarinophyton'' was a genus of Silu-Devonian land plant with branching axes. It is placed in a group of early vascular plants (tracheophytes), the barinophytes, a group that has been given various ranks and scientific names. Phylogeny Kenr ...

'' is similar. They were vascular plants with an

exarch An exarch (; from Ancient Greek ἔξαρχος ''exarchos'', meaning “leader”) was the holder of any of various historical offices, some of them being political or military and others being ecclesiastical. In the late Roman Empire and ea ...

protostele. Plants consisted of alternatively arranged branches, apparently without leaves or enations, with their sporangia arranged in two rows on one-sided spike-like structures that developed on side shoots. Each sporangium was born on a curved bract-like appendage (a "sporangiferous appendage") and contained several thousand microspores, about 30–40 µm in diameter and about 30 megaspores, 410–560 µm in diameter, so that the plants were heterosporous. A similar pattern of spore sizes and numbers has been found in the progymnosperm ''

Archaeopteris ''Archaeopteris'' is an extinct genus of progymnosperm tree with fern-like leaves. A useful index fossil, this tree is found in strata dating from the Upper Devonian to Lower Carboniferous (), the oldest fossils being 385 million years old, ...

''. '' Dibracophyton'' has been tentatively assigned to this group. It does have some outgrowths on the lower parts of the stems (axes), which raises the possibility that more fossil material might show that other barinophytes did not have naked stems.

Taxonomy

Phylogeny

Two very different cladograms have been produced showing the evolutionary relationships of taxa assigned to the barinophytes. Kenrick and Crane in 1997 placed two species of ''

'' and the genus ''

'' in the Barinophytaceae in their Sawdoniales, well nested within the zosterophylls. A summary cladogram produced by Crane et al. in 2004, shows ''Barinophyton'' and ''Protobarinophyton'' as 'core' zosterophylls. Taylor et al. in 2009 did not present a cladogram, but considered the barinophytes to be possible lycopsids rather than zosterophylls. By contrast, Hao and Xue in 2013 do not even place '' Dibracophyton'', which they consider to be a possible barinophyte, within the lycopodiopsids, instead putting it between this group and the euphyllophytes.

Genera

Genera that are placed, or tentatively placed, in the barinophytes (with the group treated at different ranks) include: *''

'' *''

Bracteophyton ''Bracteophyton'' is a genus of extinct vascular plants of the Early Devonian (around ) comprising a single species, ''Bracteophyton variatum''. Fossils were first found in the Xujiachong Formation of eastern Yunnan, China. The smooth stems (ax ...

'' *'' Dibracophyton'' *''

Krithodeophyton ''Krithodeophyton'' is a genus of lower Devonian plant with branching axes. It is considered to be a barinophyte. Phylogeny The phylogenetic position of the barinophytes remains disputed. Kenrick and Crane in 1997 called the group the Barinophy ...

'' *''

References

Bibliography

* {{Paleobotany-stub Prehistoric plant taxa Paleozoic plants