Home / Everyday Users / There be monsters

There be monsters

Joe Terrell

Joe Terrell will never forget the day his Estwing rock pick helped him capture a monster.

“I like to take my daughters fossil hunting, and we always take our Estwings. One of the spots we go to is the Mazon Creek Lagerstätten in Illinois. It’s a world-famous fossil site, unique for its occurrence of preserved soft-bodied animals, most commonly worms and jellyfish,” he said. “But the holy grail of Mazon Creek finds is the Tully Monster, Illinois’ state fossil.”

Tullimonstrum (aka the Tully Monster) was discovered in the 1950s by Francis Tully and is only found in the area around Mazon Creek fossil beds. It has a long trunk with a claw at the end and an eye bar on its chest with an eye at each end. Not only is it rare, but the Tully Monster is a bit of an enigma. Scientists have debated for decades whether it is a vertebrate or an invertebrate.


“My daughter and I looked at it, and, lo and behold, we got a Tully! Then we proceeded to do the Holy Grail find dance.”


“In 2017, while fossil hunting with friends on private property, I found a concretion that was a typical shape for a Tully Monster,” Joe said. “While removing the shale layers with my Burpee geological pick, I showed it to my friends and said, ‘Here’s my Tully, guys,’ half joking and half praying.”

On his return home, Joe began the freeze-thaw cycle to open the concretion and see what was inside. After several cycles and an unfortunate break in the wrong spot, it finally split on the fossil plane.

“My daughter and I looked at it, and, lo and behold, we got a Tully! Then we proceeded to do the Holy Grail find dance. It was definitely the best day of my fossil hunting hobby and one I will never forget,” Joe said.

It turns out, the specimen is exceptionally well preserved and in near perfect condition, except for a missing proboscis (trunk) and claw, which is very common.

Along with his trusty Burpee pick, Joe’s Estwing tool collection includes a camp axe, two rock picks (leather and rubber-handled) and a daily use hammer. “There are three reasons I’m an Estwing fan,” Joe said. “First off, made in the USA is a huge selling point for me. I know that the craftsmanship will be unparalleled and that I’m supporting U.S. jobs. Second, a lot of people I look up to in the fossil/geology space use Estwings, so naturally I had to have one. Third, companies don’t stay in business for 100 years unless they make an exceptional product.”

Want to learn more about the Tully Monster? Joe recommends this video from the Field Museum Chicago.