A probable cephalopod eggs as epibionts on Mastigograptus
Clistrocystis graptolithofilius, known from
Ordovician glacial boulders from Poland, was
described by
R. Kozłowski (1959) as an
enigmatic organic fossil. These distinctive
forms were epibionts on
R. Kozłowski (1965) reinterpreted
Clistrocystis as probable cephalopod egg
capsules, laid down on graptolite stipes.

A. Ordovician Clistrocystis graptolithofilius
Mastigograptus stipe.

B. Egg capsules of Recent Sepia officinalis
on the seagrass
Based on:

Kozłowski, R. 1959. Un microfossile enigmatique. -
Acta Palaeontologica Polonica 4, 273-277.
Kozłowski, R. 1965. Oeufs fossiles des Cephalopodes? -
Acta Palaeontologica Polonica 10, 3-9.