"We were talking, a day or so ago, about "new" phyla. This is the sort of thing I was thinking about. (Whether this is a good example or not, I haven't a clue.) It could be happening, or be on the verge of happening, almost all the time. It's difficult to know except after millions of years of hindsight."
As a bugologist, IMHO, these are more likely an old group, just newly discovered, especially since the authors said they were related to the oldest branch of the forams.
Seems likely. I was just using this as an example. A new body type could pop up. In a crowded world it would have a tough time, and it would take forever for it -- and its ever-varying progeny -- to be recognized as a new phylum. The whole conjecture was in response to a question about "why don't we see new phyla"?