The Jurassic Period is important in the history of sea stars because the first occurrences of many extant
families are from rocks of this age. The range of the asteroid family Benthopectinidae is extended to the
Hettangian, the lowest stage of the Jurassic System, with the transfer of
Plesiaslropeclen hallovensis to the family. The presence of
Plesiaslropeclen in the Hettangian demonstrates that differentiation of modern sea stars had begun by very early in that period. In addition,
Xandarosaster hessi n.gen., n.sp. is described from the
Middle Jurassic (Bajocian). The new subfamily Paleobenthopectininae is recognized for the fossils and the
Benthopectininae is redefined for the remainder of the family.
Modern benthopectinids are inferred to be partial suspension feeders. Morphologies of the fossils suggest a mosaic pattern in the evolution of the family with certain changes linked to improved adaptation to a suspension feeding life mode.
