[2][3] Cimolichthys was a large-sized nektonic aulopiform fish, making it related to modern lancetfish and lizardfish.

Within the Aulopiformes, it is generally considered a member of the Enchodontoidei, a dominant group of predatory nektonic fish throughout much of the Cretaceous;[3][4] however, some other treatments instead place it outside the Enchodontoidei and in a basal position as sister to the waryfishes, a small family of extant deep-sea aulopiformes.

[6] The following species are known:[7] C. anceps, C. gladiolus, C. semianceps, C. contracta, C. merillii, and C. sulcatus, all described by Cope (1872), are now considered synonymous with C.

[3][12] Indeterminate remains are known from the Maastrichtian of Niger & Brazil, and the Turonian of the Czech Republic.

[14] Their barbed teeth are distinctive, and can identify the presence of this genus even in formations where articulated remains are not otherwise known.