________________________________________________________________________________________
GRAPTOLITE NET
is edited by
Piotr Mierzejewski, the Count of Calmont and Countess Maja A. Korwin-Kossakowska
since 2002
Radiographs of pyritized graptolites

from Merete Bjerreskov
To the right you can see radiographs of pyritized
graptolites
Rhaphidograptus toernquisti (Elles
&Wood, 1906),
Monograptus atavus Jones, 1909,
and
Pseudoclimacograptus undulatus (Kurck, 1882)
from the revolutus Zone, Bornholm, Denmark,
published by
Merete Bjerreskov (1978).

Explanations:

1.
Rh. toernquisti. Specimen with pyrite just outside
the thecal apertures.
2.
P. undulatus. Pyrite with ill defined shape
protruding out from the thecal apertures.
3.
Rh. toernquisti. Specimen with pyrite just outside
the thecal apertures.
4.
Rh. toernquisti. Pyrite precipitated outside thecal
apertures and along the thecal walls along the
periderm.
5.
Rh. tornquisti with pyrite protruding out from the
thecal apertures
, and M. atavus with pyritisations only
within the rhabdosome.

Bjerreskov, M. 1978. Discoveries on graptolites by X-ray
studies. - Acta Palaeontologica Polonica 23, 4, 462-471.