Orthacanthus plicatus (Fritsch, 1879) Plicatodus is a prehistoric cartilaginous fish in the family Xenacanthidae that lived in Europe during the late Carboniferous and Early Permian Periods.

[2] Plicatodus fossils generally only consist of scattered, isolated teeth, with one exception: a partial skeleton that includes the head, dorsal spine, and pectoral girdle.

The type species for this genus, P. jordani was described in 1995 from Permian-aged material (the Asselian part of the Cisuralian to be specific) found in the upper Odernheim Formation of the Saar–Nahe Basin: a molasse of freshwater and shallow marine deposits from late Carboniferous to the early Permian Periods.

P. plicatus was originally described as a member of the genus Orthacanthus by Karl von Fritsch in 1879.

It came from the Kasimovian (Carboniferous) aged Slany Formation in the Rakovnik Basin of Bohemia.