Saw these cute crustose coralline recruits the other day and thought of you! Tegula for scale; they were all 2 cm diameter or less, and relatively high up compared to everything else. (San Mateo county, CA)
ahhhh omg!! so pretty i ADORE how swirly they are. ok so im not especially familiar with exactly what's in california but i'm reasonably confident that this is a Corallina sp., most likely Corallina vancouveriensis!
you can see a few tinyyyy little baby uprights (only a couple of intergenicula long each) in a few places, but especially in the crusts at the very bottom right. the shape of the intergenicula makes me think corallina. that and the general crust morphology - i feel like the basal crusts of corallinas often kind of look like very thin crusticorallinas, they're like mostly quite flat but with a lot of texture and a white outer margin
the fact that it was decently high in the intertidal makes me think it's cor van, which, at least around here and im pretty sure also just generally across its range, tends to be one of the highest growing corallines
absolutely gorgeous, thank you for sharing!!













