 While it was initially separated from the closely related "Sinopterus" by several characters including its larger size and larger crest, later studies showed that it was in fact more closely related to "Sinopterus dongi" than to either of the other two species of "Huaxiapterus".Some researchers have considered "H. jii" to be a species of "Sinopterus" for this reason, though a more thorough analysis has suggested it is slightly more primitive than "Sinopterus".The second species, ""H."" "corollatus", is based on ZMNH M8131, another nearly complete skeleton from the same formation.