Locality
Cor. 60. Corwin Bluffs.
Remarks
Smiley informally assigned this specimen to Onychiopsis psilotoides, which in our view is indistinguishable from sterile foliage of Birisia alata (Prynada) Samylina. Several different 'species' of Birisia are known from late Albian - early Cenomanian deposits of N.E. Russia including B. onychioides (Vassilevskaya et Kara-Mursa), a name that underscores the gradation of form in these ferns. It is likely that such sterile ferns have been 'over split' regarding their taxonomy.