''Tietea'' was a genus of Marattiales, marattialean tree ferns from the Late Carboniferous to the Permian. The genus has been placed in a number of families, including Psaroniaceae. The first described species was ''Tietea singularis'', which grew up to in height. It is estimated to represent close to 90% of some fossil assemblages in Brazil. ''Tietea derbyi'' was described in 1992, but its validity has been questioned as it could be a laterally flattened specimen of ''T. singularis''.

Description

''Tietea singularis'' stems usually are less than in diameter, bearing four orthostichies of leaves in a decussate arrangement. The stem is surrounded by a continuous ring of sclerenchyma that separates it from the root mantle. ''T. singularis'' stem transverse sections have the same basic structure as ''Psaronius'', but are composed of central vascular bundles having smaller, O- and C-shaped forms, or wavy segments having a short, rounded or fat configuration. Leaf traces are polymeristelic in Tietea, while they are monomeristelic in ''Psaronius''. The ''Tietea'' root mantle is composed of polyarch roots embedded in a parenchymatous tissue that is produced both by the stem and the roots.

Distribution

The preserved examples of ''Tietea singularis'' from Pedra do Fogo Formation, in the Maranhão River, Maranhão Basin (northeastern Brazil, near Araguaína) exhibit remarkable cell preservation and exquisite coloration. Much of the recovered wood material from this formation is of the tree ferns ''Psaronius'' and ''T. singularis'', with fewer examples of the fossilized stems being of ''Calamites''. Conifers such as ''Dadoxylon'' are also found. ''Tietea singularis'' is also seen abundantly in the Motuca Formation, Parnaíba River, Parnaíba Basin in Filadélfia, Tocantins, Filadélfia, Tocantins. In 2000, the area of the Motuca formation was transformed into a Natural monument (Brazil), Natural monument, the Monumento Natural das Árvores Fossilizadas-MONAF (Tocantins Fossil Trees Natural Monument).FAPESP Research Magazine
Edition 210 - August 2013
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References

Marattiidae Prehistoric plants of South America Carboniferous Brazil Permian Brazil Fossils of Brazil Paraná Basin {{fern-stub