780mya we had a common ancestry with Placozoans

The Placozoa are a basal form of invertebrate. They are the simplest in structure of all non-parasitic multicellular animals (Metazoa). They are generally classified as a single species, the tiny (2 millimetre long) Trichoplax adhaerens, although there is enough genetic diversity that it is likely that there are multiple, morphologically similar species.  Although they were first discovered in 1883, a common name does not yet exist for the taxon; the scientific name literally means "flat animals".  Here we find an organization of the choanoflagellates into mats that recognize up and down and use gravity to adhere to substrates and their flagella to move around on it. They have no symmetry or purposeful directional movement.  They are not currently under any threat from human activities.

For more information see:

https://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/placozoans