Story and photos by William Smith
Above: Ken Tibbits of Hannibal, Mo., holds up a complete crinoid fossil inside the Des Moines County Heritage Museum that he donated to the museum in April. Below: Tibbits holds a handful of blastoid fossils.
In his younger years, Ken Tibbits was known as a “powder monkey.”
Tibbits, who makes his home in Hannibal, Mo., started working for the Atlas Cement Quarry, which is three miles south of Hannibal, in 1965. It was his job to blow away rock by drilling holes and filling them with explosives.
Tibbits never imagined the curiosities that lay under the rock would make him one of the largest contributors to the Des Moines County Heritage Museum. Fossils of 300-million-year-old marine animals, which he later discovered to be crinoids and blastoids, were seemingly endless within the quarry.
“All of my life I have been in cement quarries,” he said, “I started looking around, and that’s where I found most of my crinoids and blastoids.”
Crinoids, which could best be described as a deconstructed starfish on a stick, exist as both a current marine animal and an extinct one. There are about 270 species of crinoids living today, and another 6,000 extinct species that lived alongside the dinosaurs.
Blastoids, which are the extinct cousins of crinoids, are little round echinoderms that look like pale acorn shells.
“I thought they were little hickory nuts, so I started checking into them. We got boxes of them,” Tibbits said.
From Burlington
to Hannibal
Hannibal is about a two-hour drive from Burlington, but the limestone that runs beneath the two doesn’t adhere to state lines. It’s the largest source of crinoid and blastoid fossils in the world, usually referred to as “the Burlington Limestone.”
“These rocks are in southeast Iowa and Missouri and Illinois and suggest to us that there used to be a tremendous ocean in this particular area,” said Forest Gahn, Burlington native and crinoid expert.
That’s how Burlington became known as “the Crinoid Capital of the World.” The city even had its own crinoid museum at 111 Marietta St. from the late 1800s until 1911.
Gahn, who is now a geology professor at Brigham Young University-Idaho, started searching for crinoid and blastoid fossils when he was in high school. He cites former Burlington High School teacher Sherman Lundy as his inspiration.
Gahn never stopped searching for crinoids, and that’s how he formed a friendship with Tibbits decades ago. They spent a lot of time in the Atlas Cement Quarry together.
“Burlington doesn’t really have very good exposures of Burlington limestone anymore,” Gahn said. “You have to find other places, and some of the best places are active quarries like the quarries in Hannibal, Monmouth, Morning Sun, Columbia, Mo. There are good quarries scattered all over in the same rock. But Hannibal was always one of the best.”
A new exhibit
During his years of collecting, Tibbits amassed over 3,000 crinoids and blastoids (including 150 complete crinoid fossils). The crinoid collection is the third-largest public collection of that type of fossil in the world. The Smithsonian Institute has the largest collection, but most of it isn’t available for public viewing.
“They’ve been around for about 480 million years, they’ve survived all the major mass extinction events, and they’re still alive today. So, we can study them and how they’ve changed over time,” Gahn said.
That’s why Tibbits took a trip to Burlington last month. He donated his entire collection to the Des Moines County Heritage Museum. The collection will be on display in a large exhibit at the museum in 2024 or 2025. A smaller, more temporary exhibit featuring a few of the fossils is already up in the museum.
“These are going to be accessible to the public. They’re not going to be hidden away in drawers. We’re going to be able to see them and enjoy them,” Gahn said.
Loosely constructed marine animal
There is a rarity to the fossils that have been dictated by a unique combination of geology, time, and the loose genetic makeup of the creature itself. Much like a starfish, crinoids can endlessly replicate and create new limbs.
“Crinoids often take that single-arm, and they will divide it numerous times, in multiples of five. It might have 10 arms or 15 arms or 20 arms. All of those arms gather plankton out of the oceans, and then that food travels to a central mouth,” Gahn said.
And when they die, they tend to crumble apart into thousands of pieces. Finding the pieces isn’t that difficult. If you’ve ever found something like a thumb-sized spring coil that looks like it came from a machine, it’s more likely a piece of a crinoid. The partial specimens are buried all over Des Moines County.
“A single crinoid can have over 100,000 individual pieces that make up its body. And if they aren’t buried pretty quickly by a storm or hurricane or something like that, they completely fall apart into little, tiny pieces,” Gahn said.
Some of the best sources for crinoids are rock quarries and areas of mountains that have been tunneled out with explosives to make room for roads. That put Tibbits in a unique position, among a group of co-workers who didn’t understand why he insisted on collecting the fossils. He would use a can of spray paint to circle the specimens he wanted to keep, then would come back after work to collect them.
“(My coworkers) didn’t care for me too well,” Tibbits said with a laugh. “A couple of them turned me in, saying ‘Kenny isn’t doing his job.’ The plant manager called me into his office one time and said, ‘I don’t care what you’re doing or when you’re doing it, as long as the rock tanks are full.’ ”
Julie Martineau, Des Moines County Heritage Center collections coordinator, is ecstatic over the collection and is already in the planning stages for what eventually will be called “The Hall of Crinoids.”
She still can’t believe how many crinoids are in the museum now.
“Holy crow,” she said, her eyes sparkling with excitement.