To explain away the Cambrian explosion has been and remains a high priority for Darwinists.
Even though the differences appear superficially striking, they do not involve any novel body plans (i.e., no new proteins, new tissues, or new organs).
If identified as an animal, it would “predate the Cambrian explosion of bilaterian animal phyla as a kind of ‘advance guard.’”
Molecular clocks are a relatively simple concept.
It’s worth engaging him, since Swamidass is the relatively rare critic of ID who works at tackling arguments for design in a substantive fashion.