Symbion
Symbion is a genus of peculiar
animals, with a single species,
S. pandora. It was discovered in
1995 by Kristensen on the mouthparts of the Norwegian lobster
Nephrops.
Symbion does not appear to have any especially close relatives, and so was given its own phylum, called Cycliophora. It may be related to the
Ectoprocta and
Entoprocta.