The endemic echinoids Micraster (Micraster) maleckii MĄCZYŃSKA, 1979, from the Santonian deposits of Korzkiew near Cracow (southern Poland); their ecology, taphonomy and evolutionary position

Abstract

A relatively rich assemblage of the endemic echinoid species Micraster (Micraster) Maleckii MĄCZYŃSKA, 1979, from the Santonian glauconitic marly clays exposed at Korzkiew near Cracow allowed to study its variability, life strategy, and taphonomy. The specimens of this species were well adapted to live in cohesive deposits, as they penetrated the sediment to a moderate depth, and fed on suspended material. A morphologic analysis of the tests, and stratigraphic ranges of the species, indicate that Micraster (Micraster) maleckii MĄCZYŃSKA, 1979, is a direct successor after Micraster (Micraster) rogalae NOWAK, 1909, within a separate branch of the evolutionary lineage of the genus Micraster. This endemic branch was developing since the Turonian as late as the Santonian/Campanian boundary.