DEVONIAN CONODONT APPARATUSES AND THEIR VICARIOUS SKELETAL ELEMENTS

Abstract

Recognition of four types of skeletal apparatuses of Devonian compound and platform conodonts, which conform in their basic plan to those already established in the Ordovician, Silurian, and Carboniferous, emphasizes the persistence of but a few structural types in the Paleozoic. The vicarious nature primarily of compound but also of platform elements in different multielement associations demonstrates mosaic evolution in Devonian apparatuses and has far-reaching taxonomic implications. Homologies of skeletal elements, for which a system of symbols is introduced, are evident in different apparatus types and show that the relationships of elements have been obscured by the older form taxonomy. Multielement analysis revises the taxonomic scope of the common Devonian genera, Icriodus, Polygnathus, and Ozarkodina. As a consequence of apparatus reconstruction, four new genera are proposed: Parapolygnathus, Cryptotaxis, Delotaxis, and Pedavis.