Very unlikely indeed. They are new species but have been classified into previously-known taxonomic groups. They're related to other, perfectly prosaic Earthly animals.

Please don't down mod comments when they aren't trolling.

The parent comment is at -2 points at the time of writing, which is very unfair. Just argue the comment and leave it at that.

The organelles they use for anaerobic respiration are found in other unicellular eukaryotes (single-celled organisms that aren't bacteria, like some fungal pathogens). The interesting thing here is that they're multicellular, not that their cellular biochemistry is unique.

given the similarities in the environments we and they evolved in, (ie Earth) I think it's likely that you have wildly more in common with these lifeforms than with any you'd find elsewhere.