Do you know what this mysterious object is? If you’re thinking pearls and pretty shells, well, we have some you are wrong. Try shark eggs. Yes, the egg cases of sharks, skates, and chimaeras (or chondrichthyes, if you’re fancy). What’s that, sharks don’t lay eggs?
The photo above is an egg case of a Port Jackson shark. These leathery, usually black or dark brown pouches can be found washed up on beaches the world over and, to the untrained eye, can look like weird, alien artifacts.
While these cases pictured above and below are egg cases of a skate. They’re commonly called “mermaids’ purses,” or, less optimistically, “devils’ purses.” They’re also very rarely referred to as “skakets.” They look a bit weird, but they’re just made of collagen protein, and they’re actually soft and leathery.
Of the approximately 400 species of sharks, about 40% lay eggs.