Kozlowskitubus Mierzejewski, 1978
Diagnosis: "The encrusting-dendroid colonies are attached to the
substrate with a discoidal thecorhiza comprising a bottle-shaped
sicula at the center. The system of stolons makes a spiral within
the thecorhiza, prolonged into the branches. The irregular
branches comprise both the thecal bunches arising from
thecorhiza and thecae formed at the branches themselves. The
autothecae lack any apartuaral apparatus."
(Mierzejewski 1978, p.

Occurence. - Poland: Ordovician and Silurian erratic boulders;
Sweden, Gotland: upper Wenlock.

Species assigned: Only the type species.
Type species: Dendrotubus erraticus Kozłowski, 1963

Kozłowski, R. 1963. Le development d'un graptolite tuboide. - Acta Palaeontologica Polonica 8, 2, 103-134.
Mierzejewski, P. 1978. Tuboid graptolites from erratic boulders of Poland. - Acta Palaeontologica Polonica 23, 4, 557-575.
Mierzejewski, P. 1988. Encrusting graptolites from the Mulde Beds of Gotland. - Acta Palaeontologica Polonica 33, 3, 261-266.
Urbanek, A. 1979. Ultrastructure of the sicula in the tuboid graptolite Kozlowskitubus erraticus (Kozlowski, 1963). - Acta
Palaeontologia Polonica 24, 4, 493-503.
Holotype; erratic boulder from Poland,
Ordovician. From Kozłowski.
To the left is a young rhabdosome composed of
a sicula, an autotheca and a bitheca from the
Wenlock of Gotland; heigth 0.39 mm.

To the right is a diagrammatic sketch of a sicula.
From Urbanek, modified.

: a- 1st autotheca; h- helical line;
m- metasicula; p- prosicula; po- porus of foramen
for the first blastozooid; s- prostolon.
Order Tuboidea
Portal of Graptolites and Pterobranchs sponsored by M.M. plus M. SZTANDARY