Eucycloidea Koken, 1897

Superfamily Eucycloidea Koken, 1897

Remarks – Recently two main opinions have evolved to classify this highly diversified, major Mesozoic gastropod group. One regards it as an early derived family of Seguenzioidea ( FERRARI et al. 2014), and this view has been adopted also in the new classification of Class Gastropoda by BOUCHET et al. (2017). The other opinion considers the origin of the Eucycloidea independent from the Seguenzioidea ( BANDEL 2009, 2010). Here, the latter suggestion is followed; for a more detailed discussion of this question, see SZABÓ et al. (in press). Three eucycloidean families are identified in the available material; however, presence of Eucyclidae is uncertain. The family interpretation follows mainly the suggestion by GRÜNDEL (2007) that has originally introduced this subdivision on the subfamily level.