Reference

Heinz Kozur, Helfried Mostler, John E. Repetski (1996): "Modern" siliceous sponges from the lowermost Ordovician (early Ibexian - early Tremadocian) Windfall Formation of the Antelope Range, Eureka County, Nevada, U.S.A. – Geologisch-Paläontologische Mitteilungen Innsbruck – 021: 201 - 221.