[1] However two epitypes described by Jobbins et al., (2024) that preserve more material shows that what Kulczycki, (1957) interpreted as "spines" are in fact fragmentary inferognathals.

[2] The epitypes, PIMUZ A/I 5239 and MCD 201, both comprise "a nearly complete articulated skull with all gnathal elements."

[1] Originally, Kulczycki, (1957) described Alienacanthus as a putative placoderm, noting that the traits the holotype possessed did not belong in either Selachii or Acanthodii.

The analysis resulted in Alienacanthus being recovered in Selenosteidae in a polytomy with Amazichthys, and a polytomic clade comprising Melanosteus, Enseosteus, Walterosteus, and Draconichthys.

Protitanichthys Plourdosteus Panxiosteus Janiosteus Driscollaspis Selenosteus Rhinosteus Gymnotrachelus Pachyosteus Gorgonichthys Heintzichthys Stenosteus Amazichthys Alienacanthus Melanosteus Enseosteus Walterosteus Draconichthys