Middle Proterozoic (1.5 Ga) Horodyskia moniliformis Yochelson and Fedonkin, the oldest known tissue-grade colonial eucaryote - Fedonkin, M. A. (Mikhail Aleksandrovich); Yochelson, Ellis Leon, 1928- (Washington, D.C. : Smithsonian Institution Press, 2001)
Includes bibliographical references
Keywords: Horodyskia moniliformis -- Montana; Paleontology -- Proterozoic; Fossils -- Montana