Dendrogramma is a monotypic genus of siphonophore
… identified in 2014 from a collection of specimens gathered in 1986. Although specimens were at first identified as two species, D. enigmatica and D. discoides, these were later shown to represent varieties of a single species.
When Dendrogramma was first discovered, it was speculated that the genus could not be classified into any existing phylum. However, examination of RNA material identified it as a siphonophore in 2016. The specimens are presumed to represent parts (bracts) of a larger organism whose entire morphology is unknown.
Photograph: Jean Just, Reinhardt Møbjerg Kristensen, and Jørgen Olesen