Panoramic view of ed leigth museum standing at main entrance looking in.

Ed Leith Cretaceous Menagerie

Welcome to The Ed Leith Cretaceous Menagerie!

Take a journey to the Cretaceous Period of 145 million to 65 million years ago, when the world was very different from that of today. The menagerie features complete skeletal replicas of four gigantic creatures from that fascinating time.

As you enter the menagerie, imagine that you're stepping into a Cretaceous landscape. An aggressive tyrannosaurid dinosaur comes at you! Look up and envision the sea, with three monsters swimming above you: the world's largest turtle, a vicious fish, and a formidable mosasaur (“sea lizard”). A stairway leads to the balcony, where you can join the sea creatures and get a bird's-eye view of the dinosaur.

On the wall under the stairway, there's a panel dedicated to Ed Leith. Other panels describe the Cretaceous Period and the Cretaceous rocks and fossils of Manitoba. In the “bone bed” display, see how real fossils of marine reptiles appear, as they're unearthed in southwestern Manitoba. On the wall in front of the stairway, there are panels about each of the four spectacular beasts in the menagerie.

Enjoy The Ed Leith Cretaceous Menagerie! There's ample space for individuals and groups to wander through the menagerie, to have a seat around the dinosaur, and to think about the past, present, and future of our evolving Earth.

Click for acknowledgements

Ed Leith

Professor Edward I. Leith
Ed Leith is remembered for his life-long love of teaching geology, and particularly for his dedication to introducing the wonders of paleontology, Earth history, and Earth processes to school children. Outreach was a mission close to his heart, and represents a legacy that the University of Manitoba, the Department of Geological Sciences, and Ed’s colleagues, alumni, friends, and family wish to perpetuate through The Ed Leith Cretaceous Menagerie.

Ed Leith was a member of the faculty of the Department of Geological Sciences from 1935 to 1971. He was appointed Professor Emeritus in 1972 and continued to be involved in departmental affairs until the year of his death.
The Ed Leith Cretaceous Menagerie was formally dedicated in a ceremony on the 19th of September 2003.

Ed Leith made many contributions throughout his career at the University of Manitoba, and received special recognition for his dedication to teaching and outreach. On a personal level, many of us remember his contagious life-long love of geology. This fascination and enthusiasm took the form of trips to schools where he introduced the wonders of paleontology, Earth history, and Earth processes to eager and inquiring young minds. His stories of meeting with school children conveyed his enormous delight in sharing his love of fossils. He took pride in the letters that he received from these young pupils, and kept them in a special file.

Ed Leith was an alumnus of the University of Manitoba, having graduated with a BSc in 1928 and an MSc in 1929. In 1935, he became a member of the University of Manitoba faculty, after postgraduate studies at Yale University. He retired in 1971, was appointed Professor Emeritus in 1972, and remained involved in departmental affairs until shortly before his death.

Cretaceous Period

Cretaceous Period

The Cretaceous Period began 145 million years ago and ended 65 million years ago. It was a time of global “greenhouse” conditions. The climate was much warmer and sea level was far higher than in the modern world.

The Western Interior Seaway extended over North America, sometimes covering Manitoba. Huge marine reptiles and fish swam in these waters. Dinosaurs roamed on coastal lowlands in places such as Alberta, while mountains were rising in the Cordillera.
At the end of Cretaceous time, an asteroid or comet struck the Earth. Global environmental change was severe. Dinosaurs and many other forms of life disappeared in a mass extinction.
The Cretaceous Period was a time of exceptionally rapid ocean-floor spreading and continental drift, accompanied by the release of carbon dioxide from the Earth's interior. This “greenhouse” gas promoted globally warm climatic conditions. Sea level was much higher than it is today, due to the uplift of oceanic spreading centres and the absence of polar ice sheets. Shallow seas flooded large areas of the continents.
In North America, seas advanced from the Gulf of Mexico and the Arctic Ocean, joining to form the Western Interior Seaway. West of the seaway, the Cordillera was a region of active mountain building, with occasional explosive volcanic eruptions. Sediment, eroded from the highlands and carried eastward by rivers, accumulated on a coastal plain and in the seaway.

Sixty-five million years ago, an extraterrestrial object struck the Yucatan Peninsula on the southern side of the Gulf of Mexico. This resulted in severe global environmental disruptions. The biosphere was devastated by a mass extinction. Marine life in the oceans and seas was greatly reduced. Dinosaurs, which had dominated the land for 130 million years, disappeared.

Cretaceous Rocks

Layer upon layer of sediment, which eventually hardened into sedimentary rock, was deposited over Manitoba during Cretaceous time. These layered deposits formed mainly at the bottom of the Western Interior Seaway. They have since been eroded away, except in the southwestern part of the province. Cretaceous rock can be seen mainly along the Manitoba Escarpment, where it isn't covered by younger rock and sediment.

The Cretaceous deposits preserved in southwestern Manitoba have a total thickness of up to 600 metres. Most of the layers originally accumulated at the bottom of the Western Interior Seaway, which covered this region for millions of years. These marine deposits are mainly composed of mud that hardened to become a type of rock known as shale. Interlayered with the shale are some bentonite beds, which represent volcanic ash that settled to the sea floor. The lowermost and uppermost Cretaceous layers in Manitoba formed on land before the sea arrived and after it withdrew. They contain sand, which hardened into sandstone.

Cretaceous Fossils


Certain layers of Cretaceous rock near Morden are famous for their abundance of fossilized marine animals. Giant reptiles, fish, and sea birds have been found.
Fossil bones:
Who marine reptiles
When 80 million years ago
Where near Morden, Manitoba

Many different kinds of fossils have been found in the Cretaceous deposits of Manitoba. They include the remains of land plants, but most represent organisms that lived in the sea. Among these marine forms are microscopic algae and protozoans, molluscs such as oysters and squids, and various vertebrates (animals with backbones). Certain layers of shale near Morden are noted for their abundance of vertebrates. Extinct species of huge marine reptiles, fish, and sea birds have been identified.

The menagerie’s “bone bed” display features fossils of mosasaurs (flipper, backbones, and jawbones) and a plesiosaur (spine with ribs). They were found near Morden, in a geologic unit known as the Pembina Member of the Pierre Shale


Gorgosaurus fossil at cretaceous menagerie.


GOR-go-SAWR-us, “fierce lizard”

Gorgosaurus was one of the tyrannosaurid dinosaurs. Tyrannosaurids were ferocious carnivores and occasional scavengers, with a preference for plant-eating “duck-billed” dinosaurs. They used their jaws to grip-and-rip large chunks of meat that were swallowed whole. Juveniles and adults may have lived and hunted together in packs.

Skeletal replica:
Who Gorgosaurus libratus
When 75 million years ago
Where southeastern Alberta

Dinosaurs, which lived on land, have not been found in Manitoba, where most sedimentary deposits formed in the sea.

Dinosaur head fossil at cretaceous museum.


With its long hind legs and slender body, Gorgosaurus might have reached speeds of 40 kilometres per hour. The large teeth, powerful jaws, and stocky neck suggest a violent grip-and-rip method of feeding. Flesh could also be nipped from bones using the smaller teeth at the front of the jaws.

The menagerie’s skeletal replica of Gorgosaurus libratus is 7½ metres long. It is based on a fossil that was found in the Red Deer River valley of southeastern Alberta, in a geologic unit known as the Dinosaur Park Formation.


AR-ke-LON, “ruling turtle”

Archelon was the biggest sea-turtle of all time, probably weighing over 2 tonnes when alive. Its large front limbs served as wings for underwater flight. The hooked beak was well suited for catching squid-like animals. Turtles are one of the few groups of reptiles that survived the end-Cretaceous mass extinction.

Skeletal replica:
Who Archelon ischyros
When 75 million years ago
Where southwestern South Dakota

Protostega (pro-TOS-te-ga, “first roof”), a smaller relative of Archelon, is found in southwestern Manitoba.

Archelon’s massive jaws were well suited for eating hard-shelled squid-like molluscs, which were common in the Western Interior Seaway. The trend toward gigantic size in Cretaceous sea-turtles involved a reduction in the amount of bone that formed the shell. These animals returned to shore only to lay their eggs.

The menagerie’s skeletal replica of Archelon ischyros is more than 5 metres across. It is based on a fossil that was found on the east side of the Black Hills in South Dakota, in a geologic unit known as the Pierre Shale.


zi-FAK-ti-nus, “sword ray”

Xiphactinus was the largest bony fish during Cretaceous time, and one of the biggest ever. It was a predator that approached victims slowly from below before striking swiftly. The long, cone-shaped teeth were perfect for seizing fish. Prey up to nearly half its own size were swallowed head first and whole.

Skeletal replica:
Who Xiphactinus audax
When 85 million years ago
Where northwestern Kansas

Xiphactinus is also found in southwestern Manitoba.

The overall shape of Xiphactinus, the position of its fins and eyes, and the orientation of its mouth were ideal for a predator that slowly closed in on its victims from below, and then attacked suddenly. Its skull was constructed to withstand the forces of struggling prey and to allow the mouth to open wide for big meals.

The menagerie’s skeletal replica of Xiphactinus audax is more than 5 metres long. It is based on a fossil that was found in Gove County, Kansas, in a geologic unit known as the Smoky Hill Member of the Niobrara Chalk.


PLAT-ee-KAR-pus, “oar wrist”

Platecarpus is a medium sized example of the mosasaurs, an extinct group of Cretaceous marine reptiles. Mosasaurs reached lengths of over 15 metres. Swimming was done by undulating the long body and tail from side to side, while steering with the flippers. Capable of sudden bursts of speed, mosasaurs were “ambush” hunters.

Skeletal replica:
Who Platecarpus species
When 80-85 million years ago
Where southwestern Arkansas

Platecarpus is also found in southwestern Manitoba.

The closest living relatives of mosasaurs are monitor lizards or perhaps snakes. Large teeth around the jaws of mosasaurs served to capture prey, and an additional set on the roof of the mouth forced food down the throat in one piece. Platecarpus was a fish-eater; larger mosasaurs ate whatever they wanted!

The menagerie’s skeletal replica of an unidentified species of Platecarpus is more than 6 metres long. It is based on a fossil that was found in the Upper Cretaceous deposits of southwestern Arkansas.

Visit Us

Dinosaurs and other extinct giants are an ideal attraction for young and old alike, capturing the imagination and sparking interest in science and education.  Visit us and take a self-guided tour of the Ed Leith Cretaceous Menagerie!  There's plenty of room for individuals and groups; parents and teachers with children are welcome.  Our displays are accompanied by wall mounted panels that provide explanations and diagrams.

You can prepare for your visit by previewing the “Panel” pages on this website; use the “learn more” feature for additional information. You can also explore the “Links” page. Drawings of the menagerie’s creatures, suitable for children’s activities, are available on the “Kids’ Corner” page.

When you visit The Ed Leith Cretaceous Menagerie, be sure to see the adjacent Geological Sciences Museum. It features numerous displays of fossils, minerals, and rocks, and has a seismograph that records earthquakes from around the world. In the hallway outside the menagerie, many choice specimens from the R.B. Ferguson Museum of Mineralogy are on exhibit.

The Ed Leith Cretaceous Menagerie, as well as the Geological Sciences Museum and displays from the R.B. Ferguson Museum of Mineralogy, are open to the public free of charge!

Location & Hours

University of Manitoba, Wallace Building
125 Dysart Road, Winnipeg, Manitoba, Canada R3T 2N2
(204) 474-9371

Monday to Friday, 8:30 a.m. to 4:30 p.m.
(except University holidays)