A review of the evolution, biostratigraphy, provincialism and diversity of M iddle and early L ate T riassic conodonts

The taxonomy, diversity, evolutionary lineages, and stratigraphical distributions of M iddle and early L ate T riassic conodonts are reviewed and re‐evaluated. Twenty‐five genera are recognized in the M iddle and early L ate T riassic, including a new genus cited in open nomenclature. Of these, 24 genera are assigned to two families and seven subfamilies. The family G ondolellidae consists of the subfamilies C ornudininae, E pigondolellinae, N eogondolellinae, N ovispathodinae, P aragondolellinae and P seudofurnishiinae. The family G ladigondolellidae is monotypic, consisting of the subfamily G ladigondolellinae. The genus N eostrachanognathus is not assigned to any family or subfamily as its origin is unclear. Conodont provincialism was low in the early A nisian, but from the late A nisian faunistic differences started to increase and became stronger during the early L adinian, reaching a peak around the mid‐ L adinian. Provincialism remained strong until the earliest C arnian and changed to an all‐ T riassic low in the early T uvalian. The provincialism between N orth A merica and T ethys rebounded on the specific level during the late T uvalian. Diversities on generic and specific levels have been established, and two major conodont diversity cycles are recognized: the first ranges from the B ithynian (early A nisian) to the J ulian (late early C arnian), and the second is restricted to the T uvalian (late C arnian).