Thylacopteris is unique among the Polypodiaceae with clathrate scales in having an abscission line between the pinnae and the midrib, although this line is hardly ever seen to be functional. In most other characters the genus is rather similar to Goniophlebium, to which it is probably closely allied. The two species of Thylacopteris have sometimes been considered as conspecific, but their differences are clear and consistent.
Thylacopteris, Hist. Fil.: 87. 1875