Continental slope facies in eastern New York have the most diverse small shelly faunas known in Laurentian late Early Cambrian strata. Diversity of a lower Elliptocephala asaphoides assemblage, the oldest body fauna in the Taconic allochthon, reflects turbidity current exhumation, transport, and deposition of phosphatized fossil hash in a proximal facies of the Browns Pond Formation. Phosphatization is linked to the first of two Olenellus Chron intervals with a thickened dysaerobic water mass on the slope. This interval of increased rate of sea-level rise corresponds to development of extensive carbonate belts and onlap of dark shales (e.g., Forteau and lower Kinzers formations) on the east Laurentian shelf.
The assemblage includes two trilobites, archaeocyathan fragments, echinoderm debris, the first edrioasteriod from east Laurentia, and 26 small shelly fossil species. New taxa are Asperconella new genus and Stenotheca taconica new species (helcionellids); Mackinnonia obliqua new species (pararostroconch); Conotheca laurentiensis new species, Insolitotheca new genus, and Petasotheca minuta new genus and species (hyoliths); and Plinthokonion? psamminon new species (agglutinated problematicum).