What is "hemipneustes"

Hemipneustes is an extinct genus of sea urchins belonging to the family Holasteridae.

These semi-infaunal detritivores lived during the Upper Cretaceous period, from 70.6 to 66.043 Ma. Fossils of this genus have been found in the sediments of Netherlands, Belgium, Bulgaria, India, Iran, the Netherlands, Oman and Spain.