Original paper

An astropectinid sea star from the early Maastrichtian Pierre Shale in Southern Colorado, USA, and the extinction of inoceramid bivalves

Berry, Keith; Lucas, Spencer G.

Abstract

Only two sea stars have been collected from Upper Cretaceous strata in southern Colorado (USA), and perhaps only four or five sea stars have been collected from these strata in all of western North America. We add to this record a sea star collected from the top of the Pierre Shale in southern Colorado, which demonstrates the potential for finding relatively complete (articulated) sea stars in these strata. The general morphology of this sea star indicates that it belongs in the family Astropecti- nidae Gray, 1840 and that it should probably be included in the genus Coulonia de Loriol, 1874. This specimen represents the only known record of an astropectinid sea star from the southern Western Interior Seaway (WIS) and indicates that voracious predators of bivalves occupied shallow-water settings of the WIS at or near the time inoceramids were extirpated from the WIS.

Keywords

astropectinidae"lophidiaster"western interior seawaytrinidad sandstoneinoceramid extinctioncouloniamid-maastrichtianpierre shale