[1] The Ommatidae are considered the extant beetle family that has most ancestral characteristics.

However, the geographical distribution was much wider during the Mesozoic spanning across Eurasia and Australia, suggesting that they were widespread on Pangea.

[5] The family is considered to be a subfamily of Cupedidae by some authors,[6] but have been found to be more closely related to Micromalthidae in molecular phylogenies.

[7] A close relationship with Micromalthidae is supported by several morphological characters, including those of the mandibles and male genitalia.

The extinct genus Fuscicupes Hong and Wang 1990 was included in the family by some authors, but was excluded by Kirejtshuk (2020).