Slipper Shells often attach to clam, mussel and oyster shells.

Stacking on the same shell of rock is very common with slipper shells.

Slipper Shells are often washed up in the wrack line along with seaweeds and other shells.

After overturning horseshoe crab shells on the beach at New York’s Sunken Meadow State Park located on the Long Island Sound, my granddaughters turned their attention to the shells that washed up in the wrack. Most of the shells were Atlantic slipper shells – marine snails. If you overturn the shell and look at the underside, it resembles a small slipper.

Slipper shells lead a sedentary life, attaching themselves to hard surfaces including rock and even the empty shells of other animals. It is not unusual to see clusters of slipper shells on the same shell.

Unlike other marine snails that actively feed on algae, this species is a filter feeder. They strain plankton – microscopic bacteria, algae and protozoa that float in the marine water.

The slipper shell animal is abundant and ubiquitous, but the acidification of our oceans due to all the carbon we are putting into our atmosphere may lead to an inability for the organism to form calcium carbonate – the substance shells are made of.

Will slipper shells disappear through a mass extinction like the abundant and ubiquitous trilobites of several hundred million years ago leaving behind petrified impressions in rocks. Will Homo sapiens even be around to see these fossils and document a great extinction where most of life today as we know it disappears? Only time will tell.