Missouri has long been known for its rich diversity of fossils, ranging from Paleozoic animals such as trilobites, corals, and brachiopods, to Pleistocene Ice Age mammals including mastodons. Dozens of scientists have collected and documented this rich fossil heritage, including a 19th century paleontologist named William Gurley.
Scientists Describe Delocrinus missouriensis from Missouri
During the mid-to-late 1800s, Gurley collected thousands of fossils from not only Missouri, but also Indiana, Illinois and Iowa. During this time he became well-versed in the paleontology of the area, so when in about 1880 several individuals collected fossils from Pennsylvanian-aged sediments (about 300 million years old) known as the Upper Coal Measures near Kansas City, Missouri, it was natural for Gurley to learn about the finds and make his own collections.
After he gathered a suite of specimens, he collaborated with paleontologist Samuel Almond Miller on a paper describing some of the fossil echinoderms he found. Echinoderms are marine animals that include starfish, sea cucumbers, sea urchins, sand dollars, and crinoids - creatures superficially resembling plants.
In Miller and Gurley’s paper, they described several crinoids new to science, including one they named Delocrinus (meaning “manifest/clear lily”) missouriensis (“from Missouri”).
The Nature of Crinoids
Sometimes called sea lilies, crinoids date back in the fossil record to the Ordovician Period, roughly 450 million years ago. They were very common and diverse during the Mississippian Period (about 360-320 million years ago) and remain today as a relatively minor fauna in the world’s oceans.
Crinoid bodies generally consist of three main body parts, each of which are segmented. The calyx, a cup-like structure, contains the reproductive and digestive organs. Attached to the top of the calyx is an assemblage of arms, which are used to help feeding. The third body part, the stem, is not completely developed in all species. When it is, it’s attached to the calyx and anchors the animal to the ocean floor.
While complete crinoid fossils are sometimes found, more often than not the remains consist of disarticulated stem pieces. These often have holes in the middle and were used as beads in some ancient cultures, leading to their nickname Indian Beads. They have also been called rock cheerios, stone doughnuts and St. Cuthbert’s Beads
Delocrinus missouriensis is Named Missouri's State Fossil
In the late 1980s students in Lee’s Summit, Missouri, aware of the abundance of fossil crinoids in their state, began an effort to encourage legislators to designate the sea lilies as the state’s official fossil.
Lawmakers picked up on this initiative and on June 16, 1989 passed a state fossil law. Under Title II, Chapter 10 of the Missouri Code, 10.090 reads, “The fossilized remains of Crinoidea, scientifically designated as Delocrinus missouriensis, is declared to be the official state fossil of Missouri.”
Sources
Miller, S.A. & William F.E. Gurley. 1890-91. "Description of some new genera and species of Echinodermata from the coal measures and subcarboniferous rocks of Indiana, Missouri and Iowa". Journal of the Cincinnati Society of Natural History Volume XIII: 3-25.
Kevin Schindler - I have worked at scientific institutions for more than 20 years written more than 200 articles about science, history, and baseball.
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