Catalogue of Conodonts

"Knowledge of microscopic toothlike fossils named conodonts is summarized and indexed objectively, complete to 1949. A history of studies is given, together with an annotated bibliography and index to genera and species. Special sections are devoted to cross indexes, stratigraphy, key, anatomy, and glossary. Conodonts are found in Lower Ordovician (Tremadoc) to Middle Triassic rocks. They are considered parts of chordates because of calcium phosphate composition and bonelike basal attachment material, but their exact affinities are unknown. Assemblages suggest paired groups. Two distinct types of microstructure exist: lamellar and fibrous, suggesting perhaps that conodonts belong to animals of polyphyletic origin. About 100 valid genera and 1,000 valid species have been named, from 150 to 200 main pages."--Pg. 3.