Monophorasteridae, Lahille, 1896

Ziegler, Alexander, Lenihan, Jennifer, Zachos, Louis G., Faber, Cornelius & Mooi, Rich, 2016, Comparative morphology and phylogenetic significance of Gregory’s diverticulum in sand dollars (Echinoidea: Clypeasteroida), Organisms Diversity & Evolution (New York, N. Y.) 16 (1), pp. 141-166 : 159

Monophorasteridae

The single sample belonging to this fossil sand dollar family that was available for analysis was a specimen of the species Monophoraster darwini . No Gregory’ s diverticulum could be identified in this individual of 65 mm test length, but the condition of this specimen does not permit conclusions regarding the presence or absence of the organ in this species.