In a recent communication on carbon isotope chemostratigraphy of the uppermost Cambrian strata, it was claimed that the Top of Cambrian Excursion (TOCE) is (1) an undocumented negative δ13Ccarb excursion; (2) ambiguously defined; (3) deliberately fictitious or, in the authors’ words, a ‘nihilartikel’; and (4) not synonymous with the Hellnmaria–Red Tops Boundary (HERB) Event. As the authors who have been involved in much of the discussion surrounding the TOCE since its introduction and in subsequent clarification, we wish to emphasize that the recent communication overlooks the fact that the TOCE is in fact a well-documented and clearly defined negative δ13Ccarb excursion, and that the term ‘HERB Event’ was originally used informally, without definition or reference data, for a negative δ13Ccarb peak, a peak later shown to occur within the TOCE excursion. Nearly a decade after the TOCE was named, the concept of the HERB Event was modified from a negative δ13Ccarb peak to a negative δ13Ccarb excursion, making it conceptually synonymous with the TOCE excursion. The recently published commentary is misleading and replete with misconceptions, as we discuss here.

Chemostratigraphic units require consistent definitions and unambiguous names. So-called TOCE (Top of Cambrian Excursion) is used as an uppermost Cambrian δ13Ccarb negative excursion although it was proposed without documentation, is ambiguously defined, and variably correlated into four Laurentian trilobite zones. TOCE, a nihilartikel, is regularly substituted to the exclusion of the earlier named, precisely documented and geochronologically older HERB (Hellnmaria-Red Tops Boundary) Event. HERB allows late Cambrian global correlation; its onset is close to the lowest occurrence of the conodont Eoconodontus notchpeakensis at the base of a proposed replacement (Lawsonian Stage) of Cambrian Stage 10. TOCE must be retired from use and abandoned as a synonym of the HERB Event.