Nilssonia mirovanae sp. nov. is described from the Late Cretaceous Cenomanian of the Bohemian Cretaceous Basin. It comes from the best-exposed portion of the Peruc-Korycany Formation, in the Pecínov quarry, west of Prague, the Czech Republic.
Although preserved only as a fragment of a pinna, it clearly shows haplocheilic stomata. In this paper, we compare N. mirovanae with Pseudoctenis babinensis J.Kvaček from the same horizon.
These two cycads have similar adaptations for surviving water stress: thick cuticles and sunken stomata, characteristic features among gymnosperms indicating adaptation to drought.