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Seashells and Fossils in Folly Beach, SC

Ocean Treasures

folly beach vacation homes

The coastal waters of South Carolina are teeming with seashells. In fact, more than 700 species live in these waters. Common local shells include whelks, angel wings, arks, pen shells, augers, cockles, slipper shells, jingles, coquina, and olive shells. Starfish, sea urchins, and sand dollars also can be found on Folly Beach and Morris Island.

Searching for fossils is another popular pastime. The most common fossils found on area beaches are sharks teeth, which are usually black or dark brown. Fossilized sharks teeth are millions of years old. Other fossils found in the area include fish vertebrae and fossilized shells.

The best times to look for shells and fossils are on an outgoing tide, during a new or full moon, and after a storm.

Sand Dollar or Keyhole Urchin (Mellita quinquiesperforata)
up to about 6 inches

The keyhole urchin, sometimes called the “keyhole sand dollar,” is a relative of the common sand dollar (Echinarachnius parma); the five keyhole-shaped slots are distinguishing features of the keyhole urchin.

The skeleton of this flat sea urchin is often found on the Folly Beach and Morris Island. When the tan keyhole urchin dies, the soft tissues inside the skeleton decompose, the spines fall off, and the skeleton is bleached white.

Keyhole urchins live on sandy bottoms in shallow water below the tide line where they borrow into the sand for protection. In the living urchin’s mouth, located in the center of the underside (only the mouth hole remains in the skeleton), is a structure known as “Aristotle’s lantern,” a set of five teeth, shaped something like the beak of a bird, that can be used for scraping algae off rocks. The rattle you hear when you shake the skeleton may be caused by the dried teeth inside.

A live keyhole urchin’s body is covered with skin, muscle tissue, and short, fine spines that are used for burrowing. Rows of tube feet extend through holes forming the five “petals” on the top side.


The Sand Dollar or Holy Ghost Shell is one of the most unusual specimens of marine life. The markings on the shell, to some, symbolize the Birth, Crucifixion and Resurrection of Christ. On top of the shell, an outline of the Easter Lily is clearly seen. At the center of the Lily is a five pointed Star representing the Guiding Star of Bethlehem that led the Wise Men. The five narrow openings are representative of the four nail holes and the spear wound made in the body of Christ during the Crucifixion. Reversing the shell you will recognize the outline of the Poinsettia, the Christmas flower, and also the Bell. When broken, inside the shell are five little birds called the Doves of Peace. Some say they are the Angels that sang to the Shepherds the First Christmas Morning.

South Carolina Official State Shell

Lettered Olive (Oliva sayana)

The Lettered Olive, Oliva sayana, was designated the official shell of the State by Act No. 360, 1984. Dr. Edmund Ravenel of Charleston, South Carolina, an early pioneer in conchology, found and named the Lettered Olive shell which is quite prolific along the South Carolina Coast.Shells of the family Olividae tend to be cylindrical, smooth and shiny, and variously patterned with numerous fine wrinkles. The lettered olive is an attractive cream or tan colored shell with 5 or 6 whorls and distinct suturing. The spire is fairly low; the aperture is long, smooth, and without teeth; and, the columella shows folds. Like many gastropods, these mollusks maintain a highly polished shell, by pulling their mantle flaps over the exposed surface. Many specimens have purple zigzag patterns and purple outer lips. Olives are approximately 66mm in length and 20mm wide.All members of the Olividae family are carnivorous sand-burrowers.

Starfish Facts

  • Starfish (also called Sea Stars or Sea Suns) are related to sea urchins.
  • They are not really fish.The Folly Beach starfish, known as the White Finger Starfish, is part of the class Asteroidea and the phylum Echinodermata.
  • Asteroideas are the true sea stars and sun stars.
  • They vary in size from under 1/2 inch to 10 inches.
  • They are often found alive in tide pools. Those that wash up onto the beach are either not alive or near death. Some people think throwing them back into the ocean will help them, but it actually does no good.
  • If you find a White Finger Starfish you would like to preserve, simply lay it outdoors in a sunny location. It will turn white and harden. Some people like to paint them different colors.
  • Starfish are not shaped like stars until they are adults.
  • If a starfish looses an arm, it grows back.
  • If a starfish is torn in half, both halves will re-grow resulting in two starfish.
  • Each sea star has hundreds of tiny feet on the bottom of each ray. These are tube feet, or podia. These tiny feet can be filled with sea water. The vascular system of the sea star is also filled with sea water. By moving water from the vascular system into the tiny feet, the sea star can make a foot move by expanding it. This is how sea stars move around. Muscles within the feet are used to retract them.
  • Each ray of a sea star has a light sensitive organ called an eyespot. Though it can not see nearly as well as we do, sea stars can detect light and its general direction. They have some idea of where they are going.
  • One way they eat is by extending their stomachs over their prey and digesting it externally. They hunt for food on the sandy bottom and on reefs and on rocks.
  • Sea stars eat many things. A sea star’s diet can include: barnacles, snails, sea urchins, clams, and mussels. Sea stars eat mussels and clams in an interesting way. They surround the shell and use the suckers on their feet to pull the two shells (or valves) apart. The sea star has enough force in its arms to actually bend the shell! This creates an opening between the two shells that is only .01 inches wide. Using this tiny gap, the sea star puts its stomach into the clam’s shell and eats its insides. When it is done, nothing is left but an empty shell.