Ammonites
(AM MUN ITES)
Description : Marine Mollusk – Cephalopod
Specimen location: Northwestern Kansas
Name Means: “ Coiled horn”.
Like squid and octopus, ammonites belong to the class Cephalopoda, meaning "feet-onhead." The head and arms of the ammonites extended from their chambered and typically coiled shells. Ammonites first appeared nearly 225 million years ago; the last species died along with the dinosaur extinction approximately 65 million years ago .
Model/ Fossil Specimen
Baculites (5 feet)
(BAK ‘YU LIT EEZ)
Description : Marine Mollusk – Cephalopod
Specimen location: Northwestern Kansas
Ammonites were usually tightly coiled. A few species had loose coils and others were more irregular. A very few types such as Baculites , were straight except for the very end. When all of the external shell surface is removed, an intricate suture pattern can be seen. The ammonite occupied only the outermost chamber at any one time. Model
Bunker Tylosaurus Skull
(TIE low SOAR us) Description : Marine Lizard
Specimen Location : Pierre Shale of Northwestern Kansas
Name Means : "knob lizard” for its rounded nose
In 1911, a man named C.D. Bunker collected the largest mosasaur ever found in North
America measuring about 45 feet long .
By special agreement, the Bunker Tylosaurus was restored, molded, cast and is now a significant SAS specimen. Its skull is the largest ever found: almost six feet long, weighing 600 pounds and has 6 inch teeth. Like other mosasaurs, Tylosaurus could flex its lower jaw, allowing it to swallow large prey in one piece, much as snakes do today. Tylosaurus is known to have eaten a smaller mosasaur,
Clidastes. Cast
Clidastes (11 feet)
(KLIE DAS TEEZ)
Carcharodon Megalodon ( 8 feet)
(CAR CAR O DON MEG A LO DON)
Description: Marine Lizard
Specimen location: Niobrara Chalk of Northwestern Kansas
Name Means: "one who locks" for locking vertebrae that could restrict vertical bending.
Clidastes was the smallest mosasaur in the North American Inland Sea, with lengths ranging from 8 to 20 feet. Fossil records show that Clidastes is the only mosasaur known to have been eaten by another mosasaur ( Tylosaurus ).
Discoverers: Laverne Mauck, Michael Triebold Cast
Description: Fish (Shark )
Specimen location: Florida
Name Means: “Sharp pointed tooth”
This specimen represents the largest species of shark. The huge jaw came from the mouth of a 50 foot, 50 ton monster shark that lived about 20 million years ago and became extinct ~ 1.5 million years ago! Cast

Coelacanth (4.5 feet)
(SEE LA KANTH)
Elasmosaurus (42 feet)
(EE LAS MOH SOAR US)
Pachyrhizodus (6 feet)
(PAK EE RIZE OH DUS)
Placenticeras Ammonite (3 feet)
Platecarpus (15 feet)
(PLAT EE KAR pus)
Pteranodon (5 x 11 feet)
(TEH RAN UH DON)
Description: Lobed Finned Fish
Specimen location: Niobrara Chalk of Northwestern Kansas
The coelacanth specimen is one of the most complete Macropoma fossils found in
North America. Macropoma coelacanths lived through the end of the Cretaceous Period
(65 million years ago) to be ancestors of land dwelling animals. Since 1938 live coelacanths ( Latimeria ) have been discovered off Madagascar.
Discoverers: Michael & Pam Everhart Cast
Description: Marine Reptile
Specimen location: Pierre Shale of Northwestern Kansas
Name Means: "plate-boned lizard" for large plate bones of the shoulders & pelvis areas.
Elasmosaurus was a member of a group of marine reptiles called plesiosaurs. This animal was distinguished by its extremely long neck and tiny head. Elasmosaurus probably ate small fish, squid or ammonites since its small head and narrow neck would have limited the size of prey it could swallow.
Discoverer: Theophilus Turner Cast
Description: Ray-finned FISH
Specimen Location: Niobrara Chalk of Northwestern Kansas
Name Means: "thick enameled tooth"
While these fish were certainly predators, they were also prey to many larger prehistoric fish. In fact, the first specimen of a Xiphactinus audax with Pachyrhizodus caninus remains inside was found by a person from the Los Angeles County Museum of Natural
History. Cast
See Ammonites above
Description: Marine Lizard
Specimen location: Niobrara Chalk of Northwestern Kansas
Name Means: "flat-wristed" for the bone structure of its paddles.
Platecarpus was a member of the group of marine lizards called Mosasaurs (MOE SAH
SOARS). Scientists have found Platecarpus specimens with thick fossilized eardrums; this adaptation may have made it easier for the animal to dive in deep water.
Discoverer: Michael Triebold Cast
Description: Flying Reptile
Specimen Location: Niobrara Chalk of Northwestern Kansas
Name Means: "winged and toothless"
The wingspan of Pteranodon ranged from 6 to 26 feet and the skull could be nearly 6 feet long. Scientists debate whether Pteranodon used only its hind feet to walk on the land (bipedal) or all four feet (quadrupedal). Cast
Toxochelys (juvenile 1 feet)
(TOKS UH KEE LEEZ)
Description : Sea Turtle
Specimen Location: Pierre Shale of Northwestern Kansas
Toxochelys was probably the most abundant turtle in the North American inland seaway. It is a close relative of modern sea turtles. Toxochelys had numerous adaptations which allowed it to glide swiftly through the water: a lighter shell, flattened wrist and ankle bones, and front limbs built for flapping rather than walking. Cast
Xiphactinus (17 feet)
(ZIE FAK TIN US)
Description: Ray Finned Fish
Specimen Location : Niobrara Chalk of Northwestern Kansas.
Name Means: "sword ray" after the large pectoral fins.
The teeth of this fish, ideal for grasping and puncturing, tell us that Xiphactinus was a predator. Fossil specimens show these fish swallowed their prey whole, head first.
Scientists believe that fish were swallowed head first to keep the fins and tail of the prey from expanding and choking the predator. Cast

Dolichorynchops (15 feet)
(DOH LIK KOH RIN KOPS)
Description: Marine Reptile
Specimen location: Wyoming/South Dakota Border
Name Means: “Sharp pointed tooth”
Fast and agile, this short-necked plesiosaur was wider than long. The Dolichorynchops’ conical, interlocking teeth were perfect for capturing fish.
Cast
Protostega (15 feet)
(PRO TOH STEH GUH)
Description: Sea Turtle
Specimen location: Texas and Western Kansas
Name Means: "first roof"
First discovered in Kansas in the Niobrara Chalk and named by E.D. Cope, Protostega had a somewhat reduced shell for streamlining and weight reduction. The largest specimens show that this species is the second largest sea turtle species in history.
Discoverer: Theophilus Turner Cast
Archelon (17 feet)
(AR KEH LON)
Megacephalosaurus skull (5 feet, 7 inches)
(MEG UH SEF UH LOH SOR US)
Prionochelys (2 feet, 8 inches)
(PRE ON OH KEE LEEZ)
Ichthyodectes (5 x 11 feet)
(IK THEE OH DEK TEEZ)
Description: Sea Turtle
Specimen Location: South Dakota
Name Means: "ruling turtle"
Archelon is the largest known sea turtle to ever have lived. It lived during the latest
Cretaceous and fed on squid and jellyfish. When alive, it would have weight nearly
5000 lbs.
Cast
Description: Marine Reptile
Specimen location: Russell County Kansas
Name Means: “big-headed lizard”
Megacephalosaurus was a brachauchenine pliosaurid plesiosaur recently redescribed from the early Late Cretaceous Carlile Shale (middle Turonian stage) of Russell
County, Kansas. Before the advent of mosasaurs, Megacephalosaurus would have been the marine reptile with the most gape to its maw in the Western Interior Seaway allowing it to tackle the largest prey it cared to.
Cast
Description: Sea Turtle
Specimen location: Alabama
Name Means: "saw turtle" for the serrations on its carapace.
Prionochelys was a spiky sea turtle that lived during the Late Cretaceous in Alabama around eighty million years ago. With beautifully scalloped margins, this is one of the most appealing of all sea turtles of the Cretaceous.
Cast
Description: Ray Finned Fish
Specimen Location: Niobrara Chalk of Western Kansas
Name Means: "fish biter"
Nearly identical to Xiphactinus in body shape but less than half the length, the closelyrelated Ichthyodectes found itself as an occasional meal for the bigger contemporary predator. Not quite as large as its enormous cousin, Ichthyodectes was still a voracious predator and is aptly named as Ichthyodectes translates to “fish biter”.
Cast

Saurodon (8 feet)
(SAR OH DON)
Hesperornis (3 feet)
(HES PER OR NIS)
Description : Ray Finned Fish
Specimen Location: Niobrara Chalk of Western Kansas
Name Means: "lizard tooth"
The most unusual and rarest member of the Ichthyodectid fishes, Saurodon possesses an extremely elongated and narrow body with nearly 120 vertebrae. Saurodon has a very distinguished profile, unique from other fish of the Niobrara chalk provided by a long and pointed predentary bone, a possible adaptation for feeding at the water’s surface.
Cast
Description: Flightless Bird
Specimen Location : Niobrara Chalk of Northwestern Kansas.
Name Means: "Western Bird".
Hesperornis was the first known toothed bird. It was flightless and probably lived much like a penguin, diving after small fish. Its arms were greatly reduced to vestigial elements of the wings of their ancestors.
Cast