Two new petrified gymnosperms with solenoid piths from the Pedra de Fogo Formation, Permian of Maranhão, Brazil

• Published in: Review of palaeobotany and palynology 2022-04, Vol.299, p.104622, Article 104622
• Main Authors: Conceição, Domingas Maria da, Esperança Júnior, Mário G.F., Iannuzzi, Roberto, Cisneros, Juan C.
• Format: Article
• Language: English
• Subjects: Parnaíba Basin; Permian; Petrified gymnosperm; Solenoid Zone; Wood taxonomy
• ISSN: 0034-6667; 1879-0615
• DOI: 10.1016/j.revpalbo.2022.104622

Solenoid piths are formed by systems of secretory ducts or canals, and they are relatively common in petrified gymnosperms from the Permian of Gondwana. We described herein two new taxa, Polycanaloxylon merlottii gen. et sp. nov. and Europoxylon garapensis sp. nov., from the Pedra de Fogo Formation (Cisuralian), northeastern Brazil. In both species the pith is non-septate and solenoid, primary xylem bundles have endarch maturation, rays are short and uniseriate, pits on the radial walls of tracheids are commonly uni to biseriate, cross-field pitting is cupressoid and wood is pycnoxylic. Whereas P. merlottii has a solenoid pith with a parenchyma sheath and sclerenchyma cells, E. garapensis is distinguished by a pith that only has secretory canals and parenchyma cells. In addition to expanding the distribution area of a typical Euramerican taxon into Parnaíba Basin, the report of Europoxylon reinforces a connection between these areas in the Late Pennsylvanian, thus enabling the dispersion of floristic elements. Solenoid forms are especially common in Kungurian sedimentary deposits of southern Brazil, and possibly India. However, since the occurrence of them seems to be linked to specific habitats, it should be proven that such environments are indeed contemporaneous in order to use these stems as a tool for relative dating in Gondwanan localities. •New taxa Europoxylon garapensis and Polycanaloxylon merlottii are described.•They have solenoid pith, which is a feature commonly reported in Gondwana.•The report of Europoxylon in Gondwana suggests a dispersal in the Pennsylvanian.•Plants with solenoid piths may not be restricted to the middle to late Kungurian.