Ordovician conodontophorid distribution, paleogeography, paleoclimate, and global tectonics strongly support the existence of one biogeographic conodontophorid province, largely restricted to equatorial regions and characterized by raised salinity and temperature. This Midcontinent Province is recognized in North America, Australia, and Siberia. The same data indicate that in other areas the North Atlantic Province represents a normal‐marine, virtually cosmopolitan fauna. In both provinces, communities are recognized that show a lateral segregation, strongly indicating that the majority of Ordovician conodontophorids were benthic or nektobenthic. The only Ordovician pelagic forms we recognize are the simple cone genera that either lack, or have a simple, symmetry transition series. It appears possible to correlate certain evolutionary changes in the conodont apparatus with changes in preferred habitat.

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The family‐group classification of conodonts presented in the revised edition of the Treatise on Invertebrate Paleontology, Part W, Supplement 2, Conodonta, published in 1981, is shown to contain errors with regard to the International Code of Zoological Nomenclature. The classification lacks a concise philosophical and methodological foundation and exhibits very poor conceptualization of the taxa it recognizes. The classification is analyzed and discussed in terms of, among Linnkan taxonomists, generally accepted objectives and conventions with regard to the internal structure and phylogenetic message of a hierarchical natural classification. The obvious errors in terms of the ICZN are pointed out and corrected. As a demonstration of an alternative approach, a classification of the superfamilies Prioniodontacea, Hibbardellacea, and Icriodontacea is presented.