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).

Latest Early Cambrian continental slope deposition of the early Hatch Hill dysaerobic interval (new name, latest Early Cambrian—earliest Ordovician) is recorded by dark grey shales and turbidite limestones in the Bacchus slice at Ville Guay, Québec. Platform-derived microfaunas of the Bicella bicensis trilobite assemblage were transported into a dysoxic environment of the upper “Anse Maranda Formation,” and many organisms were buried alive. Phosphatization preserved a diverse skeletal fossil assemblage that includes four agnostid trilobites, echinoderm debris, and twenty small shelly fossil taxa. The latter include five helcionellids; Pelagiella Matthew, 1895b, classified herein as a gastropod; a bivalve (Fordilla Barrande, 1881); the brachiopod Linnarssonia taconica Walcott, 1887; two conodontomorphs; four hyoliths; and such phosphatic and calcareous problematica as Coleoloides Walcott, 1889, emend. Most small shelly fossil taxa, including Discinella micans Billings, 1872, range through much of the Olenellus Zone and Elliptocephala asaphoides assemblage interval. Trilobites allow a more resolved correlation into the uppermost Olenellus Zone. A comparable stratigraphy occurs in Cambrian—Ordovician slope facies of the Bacchus slice and the Giddings Brook slice in eastern New York. The “Anse Maranda Formation” correlates with the West Granville—Browns Pond—lower Hatch Hill formations in eastern New York and brackets two dysaerobic intervals (Browns Pond and early Hatch Hill). Sea-level change associated with the Hawke Bay regression between the Browns Pond and Hatch Hill onlap/dysaerobic intervals led to the longest period of oxygenated green shale and sandstone deposition on the east Laurentian slope in the late Early Cambrian-earliest Ordovician.

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