The family Osmundaceae is significant among ferns due to its extensive fossil record with more than 200 species. Among them, over 80 species are recognized based on permineralized rhizome specimens. Compared to fossil foliages, the permineralized materials are crucial for studying the classification, phylogeny and evolution of the Osmundaceae because they bear more anatomical and phylogenetic information. However, the anatomical diversity and phytogeographic history of the fossil Osmundaceae are not well understood. A new fossil species, Ashicaulis plumites has been recognized from the Middle Jurassic in western Liaoning, NE China by Professor WANG Yongdong from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and his research team. This result has been published in a recent issue of Springer journal Journal of Plant Research.

This new species is characterized by a specialized petiolar structure yielding a sclerenchyma mass with a distinctive outward protuberance in the petiolar vascular bundle concavity, which distinguishes the present new species from other Ashicaulis species. Such a protuberance has been only observed in Osmunda pluma Miller from the Palaeocene of North America, and represents a distinct type for sclerenchymatous tissue in the osmundaceous vascular bundle concavity. The specialized structure of this new fossil species enriches anatomical diversity of permineralized osmundaceous ferns, indicating that the family Osmundaceae might have experienced a remarkable diversification during the Middle Jurassic in NE China.

Detailed information: Tian, N., Wang, Y.D.*, Philippe, M., Zhang, W., Jiang, Z.K., Li L.Q., 2014. A specialized new species of Ashicaulis (Osmundaceae, Filicales) from the Jurassic of Liaoning, NE China. Journal of Plant Research, 127: 209-219 (* corresponding author). 

The anatomical characteristics of Ashicaulis plumites (sp. nov.)

The specialized petiolar structure of Ashicaulis plumites (sp. nov.)

Variation of sclerenchyma mass of Ashicaulis plumites (sp. nov.)