|There is only one genus of pedinoid alive today, and its species are found exclusively in deeper water settings (never less than about 100 m and often at more than 1000 m water depth). They are epifaunal, but little else is known of their biology. Mortensen (1940 A monograph of the Echinoidea Volume III.1, Aulodonta. C. A. Reitzel, Copenhagen) records their diet (based on gut contents) as bottom material with small organisms.
|Pedinoids first appear in the Late Triassic (Norian) of Peru and are a distinctive and often dominant element of the early Jurassic echinoid faunas of Europe. They continue to be represented in Middle and Late Jurassic shallow water echinoid faunas, though rarely in large numbers and are rare in the Early Cretaceous. There is then a large gap, with no true pedinoids being reported from the Late Cretaceous. Leiopedina appears in the Eocene in shelf basinal settings, but is rare. Apart from one Miocene record from Patagonia, the remaining forms are all Recent and deep-water.