Element Arrangement in Conodont Apparatuses of Hindeodella Type and in Similar Forms

The criteria used for logical and numerical reconstruction of conodont apparatuses are: (1) Similar stratigraphical and geographical occurrence. (2) Similar frequency variation. (3) Similar appearance of details in the conodont-elements. (4) Similar composition of the conodont apparatuses. The position of conodont-elements in some types of apparatuses, as reconstructed by Lange (1968), is supported by further evidence, and it is also possible to reconstruct the precise position of certain elements. It is probable that a great number of apparatuses with compound conodont elements consisted of homologous elements and that a reconstruction of the positions of the elements from cluster material can be generalized to include all these apparatuses. From the periphery inwards, a complete apparatus of this type consisted of ne, hi, hi, pl, and tr elements and, posterior to these, of pairs of oz and sp elements.