I think we need to place stickers in high school textbooks stating that current classifications of lophotrochozoans represent only one possible scientific theory, and that scientists are not in agreement on the evolutionary history of deuterostomes.
Oh yes, scientists have heated arguments about this. I like to imagine that fights break out in bars.
"Translation" of Panel 4: Vik thinks these 500 million-year-old fossils of early filtrer-feeders are a sort of snail that stayed in one place and evolved with few distinct organs. Drew thinks they're a type of armored sponge, because their outer shell is more like a hard sponge than a mollusk.
The above controversey is currently unresolved. Although I often portray Vic as having the crazy, unfounded ideas, he does have a valid argument here. (Except for Drew's mom being a Chancelloriid. That's highly unlikely)
Also, the argument that chancelloriids should be classified with sponges is a whole different controversey (as well as the argument over whether sponges should be split up into two phyla).