Saur-ing spirits

A mosasaur -- a huge, extinct reptile that swam in the sea that flowed through the middle of North American some 80 million years ago and discovered last summer by Canadian Fossil Discovery Centre scientists, is being called one of the most significant fossil finds ever unearthed in Manitoba.

"It's the biggest discovery in terms of a scientific perspective in recent years," said Joseph Hatcher, a paleontologist with the centre in Morden, 130 kilometres southwest of Winnipeg, who calls mosasaurs the "T-Rex of the Cretaceous sea."

"This is the front line of paleontology," Hatcher said.

"As a researcher, it's important not because of what it is, but because of where it is in the stratigraphy of the escarpment. This is providing us with new insight into that ancient period of time. It's a pretty big deal for the scientific community.

"It's exciting because we're producing live science."

He said the find, which has not yet been fully unearthed, has tremendous implications for mosasaur bio-geography (how an animal's evolution is charted around the world) and paleo-ecology (the environment in which a prehistoric animal lived and the relationship of that animal to other extinct creatures).

On a sunny Saturday this fall, wildlife biologist Robert Wrigley and avid amateur paleontologist Andrew Fallak set out on a fossil-finding hike along the Pembina River, which snakes its way through a picturesque Badlands-like valley.

"The river provides an environment for material to be collected, preserved and sorted by the water action," said Wrigley, a longtime fossil collector and former director at the Manitoba Museum.

With their heads down, they scoured the shoreline and gravel sandbars for remains of ancient bison and other long-gone species from modern and ancient eras.

As their hunt progressed back in paleontological time, Wrigley's experienced eye spotted a plesiosaur vertebra, a 460-million-year-old coral and a piece of petrified wood among a scattering of smooth pebbles.

Their collection mounted throughout the day and included parts of three bison skulls with attached horn cores, an enormous elk antler and many bison teeth, which Fallak estimated at between 500 to 12,000 years old.

They also picked up a projectile point and a reworked flake tool -- both destined for local museums -- which may date back thousands of years to the time of Paleo-Indians, the ancestors of modern First Nations people.

"The Pembina River is continually eroding the valley, and fossils are always being washed out of the banks and onto the gravel beds below," Wrigley said.

"What we see is a wonderful panorama of millions of life forms that have lived in Manitoba over several billion years -- a whole succession of plant and animal communities."

Other former ferocious giants of the deep have also been discovered in the region, including Xiphactinus, a six-metre-long, jut-toothed predatory fish, plump-bodied, long-necked plesiosaurs and several other types of Cretaceous-era marine creatures. The western shoreline of the Cretaceous western interior seaway, in western North Dakota and Montana, was the habitat of duck-billed dinosaurs, Triceratops and Tyrannosaurs.

The largest mosasaur in Canada, 13 metres long and nicknamed Bruce, was unearthed over a two-year period north of Thornhill, Man., in 1974. Bruce now hangs in a threatening, tail-twisting swimming pose from the ceiling of a special gallery at the fossil discovery centre.

With its hills, "mountains" and rock outcrops, the 675-kilometre Manitoba Escarpment may be the province's most distinctive geological feature. The materials exposed in the escarpment originated more than 65 million years ago during the Cretaceous period, long before glaciers invaded the Red River lowlands, Hatcher said.

But the modern configuration of the Manitoba Escarpment is due to pre-glacial river activity, the glaciations of the great Ice Age and more recent river erosion and lakeshore development, he explained.

When the glaciers began melting around 11,000 BC, the adjacent lowlands filled with the melt waters of the expanding glacial Lake Agassiz.

That enormous body of water lasted about 5,000 years and formed western shorelines along the escarpment. Today, those stony shores are filled with the bones and fossilized remains of many types of fauna, flora and other artifacts from the Cretaceous period and more recent ages, geologically speaking.