ESTONIOCAULIS OBUT ET ROTSK, 1958 AND RHADINOGRAPTUS OBUT, 1960
ARE NOT GRAPTOLITES
Acta Palaeontologica Polonica 1991, 36, 1,77-81.
Genera Estoniocaulis Obut et Rotsk, 1958 and Rhadinograptus Obut, 1960 were  erected
as inocaulid and dithecoid graptolites. The type material of these taxa was reexamined.
It was shown that all elements of their "rhabdosomes" are composed of a solid, granular
or homogenous material and do not show the slightest traces of fusellar structure,
presence of thecal cavities or stolons. Therefore, there are no doubts that both forms do
not represent graptolites.

The "rhabdosomes" of
E. jaervensis are composed only of solid, roller-like elements
resembling melanosclerites. Skeletal material of
Rh. jurgensonae consists of solid
segments and flat appendices.
 
The results support the author's earlier opinion that the orders
Dithecoidea and
Inocaulida should be interpreted as proposed on the basis of superficial similarities of
organic fossils representing distant systematic groups (
Mierzejewski 1986).
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