This is one of my sea urchin embryos at about a day and a half old. Yes, it's not as complex as the starfish, but look at how much structure it's already got when it was a single cell just 36 hours ago! You're looking at it in cross section; it's roughly a flattened sphere with a hollow tube (the gut) growing up the middle of it. The gut is darker than the rest because I've hybridized the embryo with probe for the z54.1 zinc finger gene, and that's where it's expressed.
Once I casually mentioned to one of my new Catholic friends that I had to "go work on my embryos," and she suddenly looked concerned. "Human embryos?" she asked tentatively. "No, no, sea urchin!" Ethically safe, Church-approved. :)