It looks like some of the crinoids might've taken a different approach to feeding - instead of staying face-up suspension feeders, they went face-down.
Crinoids became the most abundant echinoderms of the Ordovician, and some were the ancestors of today's stalkless feather stars and stalked sea lilies.
And crinoids are still around, too, but their species number in the 600s, in contrast to the 6000 known species that've lived throughout Earth's history.
Sea levels were high, and the continents were surrounded by vast, shallow seas, full of exotic creatures like rugose corals, crinoids, and jawless fish.
Including the similar-looking and closely related group - the crinoids, also called sea lilies - which showed up and diversified into many species with different suspension-feeding body types.
But we still need more fossil evidence to help us figure out whether Cantabrigiaster really was a transitional animal between crinoids and sea stars or not.
But starfishes and their skinny-armed cousins called the brittle stars made it through, along with a few crinoids, sea cucumbers, and sea urchins – the groups we still see today.
So, as odd as the starfish body plan seems, something about it was successful -- from their ancient bilateral ancestors, to the radial crinoids with their upward-facing arms, to the predatory, downward-facing starfish.