Additional Occurrences and Extension of Stratigraphic Range of the Problematical Micro-Organism Nuia

Representatives of the problematical micro-organism Nuia siberica Maslov, 1954, have been found in three widely spaced areas of North America. These occurrences extend the stratigraphic range of Nuia from Late Cambrian? into Middle Ordovician (rocks of Porterfieldian age). Nuia siberica is found in the Day Point, Crown Point, and Valcour Limestones (Chazyan) of the Champlain Valley of northern New York and western Vermont, the Bromide Formation (Middle Ordovician) of southern Oklahoma, and the Black Rock Formation (Early Ordovician) of northeastern Arkansas. Significantly, Nuia is found in both biostromal layers and mound horizons and apparently is intimately associated with various algal forms, lithistid sponges, and spongelike organisms.