He, X.-Y.; Wang, S.-J.; Wang, J.; Hilton, J. (2019). The anatomically preserved tripinnate frond Rothwellopteris pecopteroides gen. et sp. nov. from the latest Permian of South China: timing the stem to crown group transition in Marattiales. International Journal of Plant Sciences. 180(8): 869-881.
The anatomically preserved tripinnate frond Rothwellopteris pecopteroides gen. et sp. nov. from the latest Permian of South China: timing the stem to crown group transition in Marattiales