| Cyclostome, a collective term for the living members of the superclass Agnatha, the lamprey and the hagfish. |
| It is important to note here a major difference in morphology affecting regeneration in cheilostomes and cyclostome Bryozoa, such as those described by Ostrovsky. |
| The cyclostome fishes have, so far, been discovered only in Scotland, in the tiny Palaeospondylus. |
| The cyclostome specimens are preserved as compressions showing soft-part preservation, within ironstone concretions, from the exceptionally well-preserved Mazon Creek fossil deposit in Illinois. |
| Tullimonstrum, however, is a far from typical cyclostome, not least in the bizarre handlebar arrangement of its eyes, mounted on the ends of a rigid traverse bar. |
