Backyard and Beyond

I am entering observations of animals on iNaturalist with dispatch and alacrity. That includes the structures made by animals, like the shells on this page. All the ones on this post were found last weekend on the shores of Red Hook, Brooklyn. I’m still waiting an ID on the mollusk who made the lovely shell above. Possibly Threeline Mudsnails (Tritia trivittata). That’s a centimeter scale at the top.
These, too, remain a mystery.
The most common find at this tiny sweep of rocky beach are the former homes of the Eastern Mudsnail, Tritia obsoleta. The species has had quite a taxonomic career, with six synonyms listed on its Wikipedia page. The binomial Ilyanassa obsoleta (Say) is used in a book published just last year.
This is, of course, a Blue Mussel (Mytilus edulis). A rather young one. When I say “of course,” I mean I grew up with and know them like the back of my hand. I don’t think most New Yorkers know they live in the waters of our archipelago.