Tate Geological Museum at Casper College

10/09/2026

Back in September we looked at the torso of the hadrosaur found at Limonite Gulch in Niobrara County, Wyoming. On this we look at the only other bones of that specimen that were found: The bones of the arm.
Most of the bones in the photo are of the left arm. The exception is the ulna, which was missing. The right ulna, however, was present and it’s standing in for the missing left ulna in this display – fortunately, the left and right ulna of a hadrosaur look pretty similar.
The drawing shows the bones that are in the photo in light yellow. I’ve drawn the left ulna as if it’s translucent so that you can see the shape of the radius behind it. The third drawing is a reconstruction of the muscles of a hadrosaur arm. The relatively small deltopectoral crest and narrow scapula suggest that the hadrosaur’s deltoid muscles weren’t particularly large or powerful. The small olecranon shows that it didn’t have prize-winning triceps muscles either.
When I was a kid, dinosaur books generally showed a hadrosaur posed like a kangaroo, standing upright using the tail as a third leg, and dangling its arms in front of its chest like the forepaws of a puppy. But during the “Dinosaur Renaissance” of the seventies, paleontologists noticed some features that cast doubt on this interpretation. The tail was laterally flattened and stiffened by bundles of ossified tendons, so it was neither thick enough nor flexible enough to serve as a prop, like a kangaroo’s tail. And the downward curve of the thoracic vertebrae and the hoof-shaped claws on the hands suggested that the animal spent a lot of time in a quadrupedal position, probably grazing on low-growing vegetation. Additional support for this interpretation came when hadrosaur trackways were discovered which clearly showed the prints of the hands as well as of the hind feet, showing that, at least some of the time, the animal walked on all fours.
Nevertheless, I’m sure that a hadrosaur was capable of rearing up into a bipedal pose if it wanted to browse on low-hanging tree leaves or get a better look at the horizon. And I’m pretty sure that when it needed to run, it ran bipedally – the arms were quite a bit shorter than the hind legs, which would have made a four-legged run awkward, and they were too slender to support a full gallop.

posts are curated by Education Specialist Russell J. Hawley

10/08/2026

Meet Lee Rex, the only T. rex found in Wyoming that has stayed in Wyoming. You can learn more about him by joining us on Fossil Day at the Tate this Saturday from 10am - 2pm. The event is free and we have dinosaur coloring posters for children while they last.

10/05/2026

Weird Rock Roadshow! Do you have a rock or fossil that you can't identify? Arnold Woods, author of "The Dinosaurs of Wyoming," will be at the Fossil Day at the Tate this Saturday from 10am - 2pm to lend his expertise to your mystery. He'll also have signed copies of his book available for sale in the gift shop.

10/02/2026

Today we spotlight one of the most beautiful skeletons in the Tate Museum: The freshwater stingray Heliobatis radians.
Heliobatis comes from the famous Green River Formation, which was deposited at the bottom of a huge freshwater lake that covered southwestern Wyoming during the early Eocene epoch. It is one of only two cartilaginous fishes found there, the other is the fat-tailed stingray, Asterotrygon. There are freshwater stingrays in modern-day south America but, surprisingly, Heliobatis does not seem to be closely related to them – instead, it shows closer affinities to the whip-tail stingrays of the family Dasyatidae, most of which are marine. Asterotrygon is even more distantly related to modern freshwater stingrays, showing a closer kinship to the round stingrays, the urolophids – also marine. So what I’m thinking is that the ancestors of the Green River rays probably lived in the marine waters of the Western Interior Seaway, back in the late Cretaceous period. As the seaway retreated at the end of the Cretaceous it left behind salt lakes, trapped in basins cut off from the rest of the ocean. As the millennia went by, the rains fell and the rivers flowed, and the salt water was gradually flushed from these lakes, turning them fresh. Generation after generation, the rays would have adapted to a freshwater existence.
We’re probably looking at the underside of this ray. Near the front are the labial cartilages that reinforced the edges of the ray’s mouth. Behind that are the gill arches. On each side is a large, semicircular pectoral fin, supported by a fan of long, thin ceratotrichia, and on either side of the tail are the smaller pelvic fins. The lack of claspers on the pelvic fins indicates that this specimen was female. Heliobatis bore live young, like many rays do today. One specimen in the Green River was found surrounded by tiny newborn rays, each one about the diameter of a quarter.
All of these structures would have been made of cartilage – the only truly hard parts were the teeth, the dermal denticles and the barbed stinger on the tail. There doesn’t seem to be a stinger visible on this specimen, so it might still be buried in the rock, or else it’s behind the tail vertebrae. Stingrays periodically shed and regrow the stinger, so it’s also possible that this individual was waiting for a new one to grow in. Cartilage very rarely preserves as a fossil – specimens like these, with relatively soft tissues preserved in such detail, are a large part of what makes the Green River Formation an important fossil site.
The Helio- in Heliobatis is derived from the Greek Ηλιος , meaning “sun,” while -batis is a suffix commonly applied to generic names for stingrays. It’s probably a reference to the batlike shape of certain ray species. The species name radians means “ray of light” – altogether it’s a good name for this round ray, with its radiating array of spoke-like ceratotrichia.
For the second image I’ve drawn Heliobatis as it might have appeared in life, cruising along the bottom of Fossil Lake. Other fish in the picture include the large Phareodus, a baby Diplomystus and two herring-like Knightia, all of whom we have met on previous .
The Heliobatis fossil can be seen in the Green River display in the Walk Through Time exhibit on the western wall of the exhibit hall.

posts are curated by Education Specialist Russell J. Hawley

09/30/2026

It was a great day of GLAM presentations, and you can watch Russell's discussion of the Bone Wars here

Russell Hawley, Education Specialist for the Tate Geological Museum...

09/28/2026

We hope you can join us on Saturday, October 3rd, for Saturday Club. "Mammoths and Sabertooths - Fossil Mammals" will focus on the Ice Age, one of the most interesting times in geological history. In this Saturday Club we will learn about the wild and woolly mammals that lived during the ice age, and then construct our own “Prehistoric Zoo.” Pre-cut stand-up beasts will be available for younger students to decorate, while more advanced members can use templates to trace and cut out their own. There’s also the option of designing and folding your own custom-designed beast from scratch.
Saturday Club is free and open to children ages 7-14. The Tate Geological Museum is located at the southern end of the Casper College campus; look for the life-size T. rex bronze near the Tate.

09/28/2026

Wyoming Jade is the subject of Renee Stewart's presentation on Wednesday, September 30th, at 10:00 at the Casper College Visual Arts Center. As part of the GLAM Exhibit day of talks, Renee will discuss why there is a surging interest in Wyoming Jade, types and patterns of our jade, famous thefts & other fine stories, and finally how to find jade. Renee is a jeweler, the current president of the Natrona County Rockhounds Club, and a volunteer in the Casper College geology department.

Here is the complete schedule, we hop to see you there!
10:00 a.m. Renee Stewart “Wyoming Jade”
10:30 Clint Gilchrist “The Making of a Beaver Top Hat”
11:00 - 11:30 Russell Hawley “Fighting for Fossils: Cope, Marsh, and the Bone Wars”
11:30 small bites are served
12:15 Sydney Smith “Western History Center: A Case Study in Conservation”
12:35 Patrick Amelotte "Hemingway and the Big Read"
12:45 Luis Alza Leon “The Casper College Herbarium”
1:00 John McCoy "Beavers - Ecosystem Engineers: Their decline and what we're doing to bring them back"
1:30 Hanz Olson, “Guiding Internships in GLAM: Finding the West in the Past, Present and Future”

09/25/2026

The specimen featured this week was on display in the main exhibit several years ago, but since has been retired to storage – today’s is an opportunity for our more recent members to see it for the first time.
The fossil is a Cretaceous bone bed, a jumble of disarticulated bones that were all buried in the same spot, even though they belong to several different animals of different species. Such a collection is referred to as a death assemblage. The bones in a death assemblage may been transported far from the locality where the animals actually died. In a fossil life assemblage, by contrast, the bones are still in articulation, indicating that the animals died at, or close to, the spot where they were buried.
The fossil came from Limonite Gulch, a fossil locality found by Dr. Kent Sundell over 20 years ago. Limonite Gulch is in the Lance Formation, which dates from the very tail-end of the Cretaceous. Tate field crews collected over three hundred bones from Limonite gulch over the course of several summers. The fossils in this specimen were jacketed, removed from the quarry, and then prepared in the lab. After preparation, each bone was placed back in its original position in the jacket, so that visitors could see them as they were found. The two largest bones both come from a hadrosaur, one of the duckbilled dinosaurs. Bone number three is the lower end of the scapula, or shoulder blade, while the bone at the right-hand end of the jacket is the p***s, one of the bones that make up the pelvis, or hip complex. The paddle-shaped expansion extending to the lower right is the prepubic process, the origin site for the pubofemoralis muscle, which helped pull the leg forward during the walking cycle. The diagram shows the complete skeleton of a hadrosaur, with the bones from the specimen shaded brown.
Bone number 18 is a rib. The proximal portion of the shaft is roughly T-shaped in cross section, which suggests that it’s probably from one of the bipedal carnivorous dinosaurs, the theropods. It’s even possible that it came from that most famous of Lancian dinosaurs, Tyrannosaurus rex.
Two more bones of note are number eight and the bone just to the left of it – these are pieces of the frill of Triceratops. They are identified by their flat shape and the network of deep grooves that run across the surface of the bone.
The second photo is a close-up of a small chunk of bone from the lower end of the jacket. The distinctive pitted texture identifies this as crocodilian bone, and its shape shows which bone it is: the frontal bone, on the top of the crocodilian’s skull. It’s located between and a little behind the eye sockets. In the diagram, the skull of a crocodilian is shown in dorsal view, with the frontal bone shaded brown.
The third photo details two more tiny pieces of bone from this specimen. At lower left is a piece of turtle shell. Once again, the texture of the bone aids in our identification: this was a trionychid, a member of the family that includes the modern soft-shelled turtles. At upper right is the tooth of a Triceratops. It’s missing the roots which, at first, might suggest that this was the crown of a tooth that was shed naturally during the course of the animal’s life. But the shearing surface shows little, if any wear, so this tooth was more likely still embedded in the dinosaur’s jaw at the time of its death. As the jaw disintegrated, the tooth came loose and washed away to be deposited near the other bones in this bed. The roots must have broken off somewhere along the way.
When this specimen was in the exhibit hall it was accompanied by a numbered key identifying each bone. However, since the jacket was taken off display and transported to storage many of the labels and a few of the bones have shifted their positions, so not all of the numbers are still accurate. Also, many of the smaller bones are either behind or partially underneath other bones, and thus not visible at the angle from which this photo was taken.

posts are curated by Education Specialist Russell J. Hawley

09/24/2026

GLAM, a Gallery, Library, Archive and Museum collaboration presents “The West,” August 17- October 22, 2026 at the Casper College Tobin Visual Arts Center. Discover a unique collaboration that brings together treasures from diverse collections on campus. This combined exhibit highlights the wonders of natural history, regional heritage, literature, and the visual arts. Visitors are invited to explore the rich stories, artifacts, and creativity that connect science, culture, and art, offering a rare opportunity to experience these collections side by side.

We will have a day of presentations on Wednesday, September 30th from 10:00 a.m.- 2:00 p.m, we hope you can join us.
10:00 a.m. Renee Stewart “Wyoming Jade”
10:30 Clint Gilchrist “The Making of a Beaver Top Hat”
11:00 - 11:30 Russell Hawley “Fighting for Fossils: Cope, Marsh, and the Bone Wars”
11:30 small bites are served
12:15 Sydney Smith “Western History Center: A Case Study in Conservation”
12:35 Patrick Amelotte "Hemingway and the Big Read"
12:45 Luis Alza Leon “The Casper College Herbarium”
1:00 John McCoy "Beavers - Ecosystem Engineers: Their decline and what we're doing to bring them back"
1:30 Hanz Olson, “Guiding Internships in GLAM: Finding the West in the Past, Present and Future”

09/18/2026

Louis and Mary Leakey had several kids and early on they, too, caught the fossil bug. So, in the 1960’s there was actually a whole family of Leakeys scouring Olduvai Gorge for more fossils. It was one of those kids – Johnathan Leakey – who made the next big discovery: A lower jaw. Louis was delighted – it had small, thinly-enameled molars like those of a modern man, rather than the big, robust molars of the Olduvai Gorge australopithecine, Zinjanthropus. Here, at last, was the sort of hominid that could have made the stone tools that had been found at the locality. The specimen was nicknamed
“Johnny’s Child” in honor of its discoverer.
In addition to the jawbone, Johnny’s child was represented by a partial hand and the top of the braincase. Over the course of the next eight years more specimens of the new hominid turned up: Partial crania of three more individuals, nicknamed “Cindy,” “George” and “Twiggy” as well as a partial foot. In recognition of its tool-making capability, the new species was given the Latin name of Homo habilis – which loosely translates as “Handy Man.”
Of the four H. habilis skulls found at Olduvai, Twiggy’s was the closest to being complete – and that skull is the subject of this week’s . She got her nickname from Phillip Tobias, Leakey’s co-author on the paper describing Homo habilis. When Twiggy was first discovered, her skull was squashed flat by depositional processes. When Tobias saw the skull, he is reported to have said “Only Twiggy has been that flat!” in reference to a notoriously thin British fashion model of the time. Twiggy – the model, not the skull – can be seen in the movie “The Blues Brothers,” wherein she makes a date with Elwood but gets stood up.
Twiggy was freed from the matrix and her skull pieced together, but the reconstruction probably isn’t perfectly accurate. In particular, the slope of her forehead is probably too shallow, leading to estimates of her brain size that may be too low. However, by comparing the partial crania of all four Olduvai H. habilis specimens, Tobias was able to create a composite reconstruction of a H. habilis braincase and get an idea of the average brain size for this species. It turned out to be 642 cubic centimeters – almost exactly half-way between the size of the largest ape brain and the smallest modern human brain.
Like the other hominid skulls in the Tate, this is a cast replica, so we don’t mind if visitors handle it. Next time you visit, turn Twiggy’s skull over to see the underside – you’ll note that the foramen magnum, the large hole through which the brain stem exits the braincase, points straight down when the skull is in its normal life position. This means that Twiggy’s vertebral column was entering the skull vertically, from below – she was walking bipedally, with the spine erect, just as modern humans do. Twiggy dates from the early Pleistocene, about 1.8 million years ago.

posts are curated by Education Specialist Russell J. Hawley