A new, early crown-group asteroid (Echinodermata) from the Norian (Triassic) of Northern Italy

Noriaster barberoi gen. et. sp. n. is based on a single specimen from the C alcare di Zorzino (Norian, Triassic) of northern Italy A member of the surv iving Poraniidae (Valvatida; Echinodermata), N. barberoi is the oldest-know n species assignable to a Jurassic and younger family and the first such sp ecies known from the Triassic. No Paleozoic species with close affinities w ith crown-group families has been recognized. Noriaster and the slightly ol der Triassic genus Trichasteropsis from the Muschelkalk of Germany together indicate that the diversification of crown-group asteroids was well underw ay at least by Middle and Late Triassic time. Phylogeny of crown-group asteroids is problematic because extant familial-l evel taxa are morphologically divergent, and they exhibit comparatively few uncontested characters that clearly indicate phylogenetic affinities and s equence. Familial assignment of Noriaster is supported by a new cladistic a nalysis. To the student of living asteroids, the appearance of a living Noriaster wo uld be remarkable only because it would seem so commonplace. To the extent that form correlates with function, Noriaster suggests that modern asteroid life modes emerged quite promptly during the Mesozoic asteroid diversifica tion.