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Phylum Hemichordata, Class Graptolithoidea (Graptolithina + Pterobranchia), Order Rhabdopleuroidea, Family
Rhabdopleuridae

Eorhabdopleura Koz?owski, 1970
- junior synonym of   Kystodendron Koz?owski, 1959

Koz?owski (1970) proposed the genus Eorhabdopleura Koz?owski with
a single species E. urbaneki Koz?owski on the basis of a single fragment
of zooidal tube with part of its creeping part. He claimed that these were
the only fragments of coenecium found but the analysis of
accompanying fossils showed the presence of cyst bearing stolons of
Kystodendron longicarpus (Eisenack) sensu Koz?owski. The holotype
(i.e. the only known specimen of Eorhabdopleura urbaneki) has been
lost  but an almost identical specimen, representing creeping part as well
as fragment of erect zooidal tube, was found among microfossils
extracted from the erratic boulder 0.166. This specimen was also
accompaniod by stolons and cysts of K. longicarpus (Eisenack) sensu
Koz?owski.

 The zooidal tube of Eorhandopleura urbaneki Koz?owski does not
display any features which would be of diagnostic value for a species.
Therefore, both the generic name Eorhabdopleura Koz?owski and the
specific name Eorhabdopleura urbaneki may be treated as nomina
dubia. In turn, tha fact that the holotype of the nominal taxon has been
accomnied by remains of K. longicarpus (Eisenack) suggest that the
taxa are conspecific.

 A strikingly similar specimen of a Rhabdopleura-like fossil was
described by Mierzejewski & Kulicki (2001) from the Arenig of Öland,
Sweden, as Kystodendron ex gr. longicarpus.

Holotype of
Eorhabdopleura urbaneki
(from Koz?owski)

References

Koz?owski, R. 1970. Nouvelles observations sur les Rhabdopleurides (Pterobranches) Ordoviciens. - Acta Palaeontologica Polonica 15, 3-17.
Mierzejewski, P. 1986. Ultrastructure, taxonomy, and affinities of some Ordovician and Silurian organic microfossils. - Palaeontologia Polonica 46, 129-220.
Mierzejewski, P. and Kulicki, C. 2001. Graptolite-like fibril pattern in the fusellar tissue of Palaeozoic rhabdopleurid pterobranchs. - Acta Palaeontologica
Polonica 46, 367-376.