The Echinoid Directory

Stem group scutelliforms or laganiforms (and crown group neotenous derivatives)

Diagnosis	Scutellina with: internal buttressing of simple adradial bars basicoronal circlet with plates small and undifferentiated periproct supramarginal to submarginal, opening posterior to the first post-basicoronal interambulacral plates food grooves absent or rudimentary
Range	Early to Late Eocene; Europe (stem-group members only)

Diagnosis

internal buttressing of simple adradial bars
basicoronal circlet with plates small and undifferentiated
periproct supramarginal to submarginal, opening posterior to the first post-basicoronal interambulacral plates
food grooves absent or rudimentary

Range

Early to Late Eocene; Europe (stem-group members only)