Leonova T.B. 2017. Evolution of Palaeozoic ammonoid sutures // Invertebrate Zoology. Vol.14. No.1: 27–31 [in English].
Borissiak Paleontological Institute of the Russian Academy of Sciences. 123, Profsoyuznaya str., Moscow, 117647, Russia. E-mail: email@example.com
ABSTRACT. The history of the appearance and evolution of the suture, one of the major structural elements of the shells of ammonoids (a subclass of Cephalopoda), is briefly discussed. Its morphology is considered in the Devonian Anarcestida, the first members of which are very similar to the ancestral Bactritoidea, in the Late Devonian Clymeniida, the Devonian–Permian Tornoceratida, the Carboniferous–Permian Prolecanitida and Goniatitida, and the Permian Ceratitida. Three major trends in the evolution of the suture are recognized in the order Goniatitida, which were instrumental in the subdivision of this order into suborders. Variations of elements of the sutures allow the recognition of the familial, generic, and specific ranks.
KEY WORDS. Ammonoids, Paleozoic, evolution, sutures, systematics.