The Ypresian Fur Formation in northwestern Denmark is one of the most famous and important sources of insect fossils from the early Eocene (ca. 55–54 Ma, Pedersen et al., 2012; Madsen pers. unpublished obs.) only six species have been formally described to date. Of these the most recently described species, Archerythrogonia furensis Dietrich & Perkovsky, 2023 belongs to the infraorder Cicadomorpha (Dietrich & Perkovsky, 2023). The remaining five species all belong to the infraorder Fulgoromorpha (Szwedo et al., 2004).
Simonsen et al. (Fri,) studied this question.