Crinoid fossils are among the most abundant and beautiful prehistoric invertebrate specimens available, representing one of the most successful and long-lived animal groups in the history of life on Earth with living species still thriving in today’s oceans.
Quick Facts
| Common Name: Crinoid (Sea Lily) | Scientific Name: Various — Actinometra, Encrinus, Pentacrinites | Meaning: Lily-like |
| Period: Ordovician to present (485 million years ago to today) | Diet: Filter Feeder | Size: Small to Large |
| Length: A few cm to over 1 meter including stem | Weight: Under 1 lb | Named by: Miller, 1821 |
Overview
Crinoids, commonly known as sea lilies, are marine animals related to sea urchins and starfish that have existed largely unchanged since the Ordovician period over 485 million years ago. Despite their plant-like appearance they are animals, using feathery arms to filter food particles from the water. Crinoids were so abundant in the Paleozoic that entire limestone formations are composed almost entirely of their disintegrated skeletal plates. Complete crinoid fossils with the crown, arms and stem preserved are among the most spectacular invertebrate fossils available and have been found in exceptional Mississippian deposits in the American Midwest and Jurassic formations in Europe. Living crinoid species still inhabit the world’s deep oceans today making them one of the oldest continuously surviving animal groups on Earth.
What to Look For
Individual stem columnals are the most common crinoid fossils — look for the distinctive round disc-shaped segments often with a star-shaped central hole or canal. Complete crowns with arms preserved are exceptional and highly prized. Mississippian specimens from Indiana and Ohio are typically tan to buff in color. European specimens from Germany and England often show exceptional detail. Lyme Regis specimens are preserved in the distinctive Lower Jurassic limestone. The finest complete specimens with stems, calyx and arms all intact are rare and spectacular display fossils.
Fun Facts
Crinoid fossils are so abundant they form entire limestone formations — the building stone used in the US Capitol and many other famous buildings contains visible crinoid fossils. Crinoids are living fossils with species today virtually identical to those from 300 million years ago. The star-shaped cross sections of crinoid stem sections have been collected and used as beads and jewelry by Native American peoples for thousands of years. Crinoids are the official state fossil of Missouri. Some Jurassic crinoids from the Holzmaden Formation of Germany are preserved with stems over 12 meters long.
Museum Research Articles
Learn more about the Crinoid
- National Park Service: Crinoid Fossil — Grand Canyon
- National Park Service: Fossil Echinoderms: Crinoids
- National Park Service: Uncovering the Fossil Record of Buffalo National River
- Lyme Regis Museum: Fossils Collection
- Britannica: Crinoid
- Royal Tyrrell Museum: Palaeozoic Era Exhibit