Waterston referred the new genus to the family "Woodwardopteridae" (now referred to as the Mycteroptidae), but no particular reasoning was given. Vernonopterus was assigned to Hibbertopterus by Cuban paleontolgost Erik N. Kjellesvig-Waering in 1966 as H. minutisculptus, but he noted that this classification was not certain. Similarities between the Vernonopterus specimen and specimens referred to Dunsopterus (today recognized as a junior synonym of Hibbertopterus) were noted by Waterston and Norwegian paleontologist Leif Størmer in 1968. Modern researchers classify the genus within the Hibbertopteridae instead, sometimes noting that its position is somewhat uncertain due to its fragmentary nature. Classification Vernonopterus is classified as part of the family Hibbertopteridae, a family of eurypterids within the superfamily Mycteropoidea, alongside the genera Hibbertopterus and Campylocephalus. The genus contains one species; V. minutisculptus from the Carboniferous of Lanarkshire, Scotland. The hibbertopterids are united as a group by being large mycteropoids with broad prosomas, a hastate (e.g. shaped like a gladius, a Roman sword) telson with paired keels on the ventral side, ornamentation consisting of scales or other similar structures on the exoskeleton, the fourth pair of appendages possessing spines, the more posterior tergites of the abdomen possessing tongue-shaped scales near their edges and there being lobes positioned posterolaterally (posteriorly on both sides) on the prosoma. The features of Campylocephalus and Vernonopterus makes it clear that both genera represent hibbertopterid eurypterids, but the incomplete nature of all fossil specimens referred to them make any further study of the precise phylogenetic relationships within the Hibbertopteridae difficult. Both genera could even represent synonyms of Hibbertopterus itself, though the highly incomplete nature of their remains again makes that hypothesis impossible to confirm. By comparing the ornamentation of various hibbertopterids in 2019, American geologist Emily Hughes could conclude that several genera were actually congeneric, subsuming some previously recognized hibbertopterids (such as Cyrtoctenus) into Hibbertopterus. She noted that the distinct ornamentation of Vernonopterus supported it as a distinct genus. Paleoecology Vernonopterus lived during the Westphalian age in modern-day Lanarkshire, Scotland. Though they probably would not have been prey items to Vernonopterus, a diverse contemporary fauna of actinopterygian fish are known from Lanarkshire as well, including species such as Rhadinichthys ornatocephalum, R. glabrolepis, R. plumosum, Pseudogonatodus aurulentum and Lanarkichthys gardineri. Out of this actinopterygian diversity, there are many haplolepid fishes, a small and basal group, known, including Blairolepis wallacei, Parahaplolepis poppaea, P. elenae, P. alexandrae, Braccohaplolepis fenestratum, Andrewsolepis lochlani, Protohaplolepis isabellae, P.