The Tate Geological Museum at Casper College is showcasing a first-of-its-kind fossil from Niobrara County. 

The 2-foot-long bladed structure belonged to one of Wyoming’s extremely elusive giant squids.

According to J.P. Cavigelli, the museum’s collections specialist, this “big chunk of calamari” has tentatively been identified as part of the internal shell of a Niobrarateuthis, a giant squid that lived in Wyoming’s last ocean around 80 million years ago.

“We found it last year,” he said. “If I told you any more, I’d have to kill you and all your readers.”

Cavigelli is very protective of this squid and the spot where it was found because it’s a rare and unique find for Wyoming. 

There could be more giant squid and other prehistoric monsters of the deep waiting to be found there.

“It’s the last time the ocean was here, according to traditional dogma,” he said.

Monster Of The Not Too Deep

The fossil recovered by the Tate is a partial gladius, the hard bone-like structure inside the otherwise soft bodies of squid. 

It’s the same as a cuttlebone in a cuttlefish, itself a modern relative of this prehistoric squid.

“We call it the squid pen,” Cavigelli said. “It’s not bone, but I guess you could call it a skeleton, of some sort.”

Cavigelli said this giant squid was found in the Sharon Springs member of the Pierre Shale, a rock layer from the Late Cretaceous Period. 

It preserves the inhabitants of the Western Interior Seaway, an inland sea that stretched from the Gulf of Mexico to the Arctic Ocean.

“It’s a black shale from the bottom of the ocean that split North America in half,” he said. “It wasn’t a very deep ocean but pretty expansive.”

The prehistoric squid pen is incomplete, but still over two feet long. That’s enough to quantify it as a truly giant squid.

“We saw (a squid pen) in a North Dakota museum that was five or six feet long and really thick, which would have been a really big animal,” Cavigelli said. “Ours is large, so still from a big animal, but not that huge.”

How big? It’s hard to say.

Paleontologists believe Niobrarateuthis and contemporaneous cephalopods could grow up to 10 feet long, and possibly much larger depending on the length of their tentacles.

“They could have been long or very short,” he said. “All we know is that it was much bigger than your average squid.”

Secretive Squids

Modern-day scientists are struggling to learn much about today’s giant squids. Paleontologists have an even harder time trying to understand prehistoric giant squids, especially given the rarity of their fossils.

Not much is known about North America’s prehistoric giant squids. 

Just like today’s squid and octopuses, most of their bodies were composed of soft tissue rather than hard parts, meaning they usually decomposed before they could be buried and fossilized.

Did Niobrarateuthis have long, terrifying tentacles like the modern-day colossal squid, or several smaller tentacles like today’s cuttlefish and Humboldt squid? 

According to Cavigelli, either is possible.

“We don’t know enough about it to give it long tentacles,” he said. “I’m sure it had tentacles, because all squids do, but we wouldn’t be able to say how long they were, because that’s quite variable in squids.”

A squid might not even be the best modern analogy for Niobrarateuthis. 

Although they outwardly resembled squids, paleontologists believe the Pierre Shale’s cephalopods are more closely related to modern-day octopuses.

The Tate’s fossilized gladius came from the back end of the giant squid. In life, the gladius was surrounded by a large, fleshy mass containing all the internal organs called the mantle.

A giant, squishy squid would have been appetizing dinner option for many of Wyoming’s sea monsters.

It’s What’s For Dinner

From what paleontologists can determine, Niobrarateuthis and the giant squids of the Western Interior Seaway would have had a healthy seafood diet of everything from plants and algae to crabs, fish, and each other. 

They would have processed this varied diet with an extremely strong beak, the only other hard part in modern and prehistoric cephalopods.

Meanwhile, even a fully-grown, 10-foot-long giant squid might not have been big enough to stay off the menu of the Western Interior Seaway’s biggest sea monsters.

Giant marine reptiles were at the top of the Pierre Shale’s food chain. One of the largest of these, the mosasaur Tylosaurus, might have grown over 50 feet long, with a 5.6-foot skull.

With such a big head, full of dozens of serrated teeth, a Niobrarateuthis would have made a soft, substantive meal for a fully-grown Tylosaurus. Fortunately, there’s fossilized evidence supporting this predator-prey interaction.

A large squid pen at the Museum of Natural History at the University of Colorado Boulder was found with a huge kink in the middle. 

It belonged to Tusoteuthis, another species of giant squid that lived in the Western Interior Seaway.

Multiple grooves found on this Tusoteuthis specimen matched the size and shape of mosasaur teeth. That suggests the giant squid might have survived a failed predation attempt by a large Tylosaurus.

Cephalopods of all sizes were extremely abundant in prehistoric seas. 

Smaller squid pens are among the most common fossils found in many marine deposits from the Mesozoic Era and often turn up in the stomachs of marine reptiles.

“I think mosasaurs would have had a great time with them,” Cavigelli said.

Searching for Sea Monsters

Niobrarateuthis and the other denizens of the Pierre Shale went extinct when the Western Interior Seaway disappeared.

The Tate’s Niobrarateuthis gladius was prepared by fossil preparator Bryan Aivazian. It’s currently on display in the museum’s lobby.

Cavigelli said giant squid fossils are an incredible find anywhere in Wyoming. 

In addition to their inherent rarity, there aren’t many spots in the state where the Sharon Springs member of the Pierre Shale is exposed and accessible.

“You can find fossils in it, but there aren’t many spots where you’d expect to find these things, and the preservation is typically pretty lousy,” he said.

Other rare specimens from Wyoming’s Pierre Shale exposures include the huge-eyed Unktaheela and the long-snouted Serpentisuchops. 

These are both polycotylid plesiosaurs, a family of marine reptiles that probably would have enjoyed feeding on Niobrarateuthis while the giant squid was young and bite-sized.

Notable specimens from the same formation include the 15-foot-long, three-ton sea turtle Archelon, the 34-foot-long plesiosaur Elasmosaurus, 20-foot-long cannibalistic fish, and the famous flying reptile Pteranodon.

The Tate’s squid pen was found during a field trip for participants of the museum’s annual paleontological conference in May 2025. 

That’s why Cavigelli will continue to be excited and secretive about the spot where this squid surfaced.

“We collected the squid and the first Cretaceous marine bird bones from Wyoming in about three hours on the same trip,” he said. “I’d say it was a pretty good field trip.”

Andrew Rossi can be reached at arossi@cowboystatedaily.com.

CASPER, Wyo. — Saturday is here once again, and with it comes a slew of events and activities happening all throughout town! It’s a busy day in Casper, with a variety of things happening for people of all ages. From Independent Bookstore Day to Boots and Bling, this is everything happening Saturday in the Oil City.

The Oil City Daily Event Guide is sponsored by Central Wyoming Fair & Rodeo.

Aerial Yoga Conditioning

Theraexpressions Meditation is hosting an aerial yoga conditioning class on Saturday from 11 a.m. to 12:15 p.m. The price is $25 per person.

“There is a version of you that rises on effort instead of hesitation,” the event page states. “That welcomes challenge and climbs towards strength. That turns strain into power. Our high-intensity Aerial Conditioning Yoga is not about looking graceful. It is about feeling empowered within your whole self. Having a fierce rhythm of breath as you lift, stabilize, invert, repeat. Muscles awakening. Mind sharpening. Limits expanding. You meet yourself beyond the edge you thought was final. Where endurance is physical and presence is practiced with every hold. As effort builds, you will feel: total-body strength, igniting endurance rising in waves, grip and shoulder stability, deepening coordination under challenge, mental resilience under load. Not because it’s easy but because you stayed. You kept showing up and trying again even when it got hard. You did this for YOU!! Aerial conditioning teaches a rare truth. You can hold yourself through intensity. You can stabilize inside effort. You can rise again while shaking, sweating, striving and discover you ARE stronger than your doubt. Between earth and air, discipline becomes freedom. Effort becomes empowerment. Resilience becomes identity. All levels of yogis welcomed. Come ready. Leave powerful. Return stronger.”

Happening at 11 a.m.

Wind City Books is celebrating Independent Bookstore Day on Saturday, and bibliophiles of all ages are welcome to participate. It’s happening at Wind City Books from 10 a.m. to 5 p.m., and it’s free and open to the public.

“Join us at Wind City Books Saturday, April 25 to celebrate Independent Bookstore Day 2026!” the event page states. “There will be all kinds of fun beginning as soon as doors open at 10 a.m. with the Libro.fm Golden Ticket Hunt (one lucky person will receive 12 free audio book credits), free book with purchase while supplies last, exclusive independent bookstore day merchandise available for purchase, giveaways, and a book signing featuring local authors India Hayford and Summer Smith Melin.”

Happening at 10 a.m.

The Good, the Bad and the Bugly: Insects and Gardens

The Natrona County Library is hosting a closer look at the tiny creatures that shape the health of the environment, with “The Good, the Bad, and the Bugly: Insects and Gardens” on Saturday from 10 to 11 a.m.

“Inspired by ‘Lab Girl’ and the NEA Big Read theme Our Nature, this program invites participants to examine the often-overlooked relationships between plants and insects,” the event page states. “Alex Hutchinson of Wyoming State Parks will guide participants through the difference between beneficial insects and common garden pests, and share practical tips for identifying who’s helping, who’s harming, and how to respond thoughtfully. From pollinators and soil-builders to leaf-chewers and larvae, we’ll explore how even the smallest organisms play a role in larger ecosystems. In ‘Lab Girl,’ Hope Jahren reminds us that understanding begins with observation. This program encourages gardeners and nature enthusiasts alike to look more closely at the life buzzing, crawling, and fluttering around them — and to see gardens not just as cultivated spaces, but as living communities. This event will take place in the Crawford Room and is open to adults. No registration is required.

Happening at 10 a.m.

The Wyoming Symphony Orchestra is hosting its latest concert, “United Through Music: Pursuit of Happiness,” on Saturday beginning at 3 p.m.

“Join us on April 25 for the final concert of our 2025–26 season!” the event page states. “The season finale features a celebration of American voices and symphonic grandeur. Valerie Coleman’s ‘Seven O’Clock Shout,’ written in honor of frontline workers during the pandemic, leads into Peter Boyer’s patriotic ‘Rhapsody in Red, White, and Blue,’ performed by guest pianist Jeffrey Biegel. Howard Hanson’s choral-orchestral ‘Song of Democracy’ and Respighi’s sweeping ‘Pines of Rome’ bring the season to a majestic close.”

Happening at 3 p.m.

The Barn by the Five Deuces is hosting Boots and Bling on Saturday beginning at 5:30 p.m., with proceeds benefitting the Wyoming Foundation for Cancer Care.

“Dust off your boots and bring a little shine,” the event page states. “Boots & Bling is Wyoming Foundation for Cancer Care’s signature spring fundraiser, and it’s shaping up to be a night you won’t want to miss. Tickets are limited so don’t wait to snag yours! Enjoy dinner by Heirloom and Native, drinks by Occasions by Cory, music, one-of-a-kind items for raffles, and a western-glam atmosphere built around community and connection. We’ll kick things up a notch with a quick, easy line dance lesson, then open up the dance floor for anyone ready to jump in or just cheer from the sidelines. Two left feet welcome… This is a judgment-free dance floor! Every ticket helps ease the burden for Wyoming cancer patients by covering everyday essentials like travel, lodging, groceries, housing, and utilities, giving them one less thing to worry about while they focus on healing.

Happening at 5:30 p.m.

Don’t see an event on the calendar? Add it! Click here, add your details and submit to let Casper know all about it.

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