NOVA SCOTIA'S Arisaig Provincial Park yields fossils from more than 400 million years ago. -- Anne-Marie Tobin, CP

"We've got all the good fossils," two young boys announce jubilantly as they ascend a path through the trees from the rocky beach at Arisaig Provincial Park.

As it turns out, determined rockhounds and collectors who descend the spruce-lined winding path to comb the beach can find plenty more fossils -- mind-boggling, hold-in-your-hand evidence of life on this planet more than 400 million years ago.

The red and grey cliffs above the crashing waves are shedding so many shards of rock that the beach is strewn with fossil-bearing bits and pieces of sedimentary rock.

Arisaig overlooks the waters of Northumberland Strait, and has provided a wealth of information to geologists for the past 150 years. Local universities run field schools here, and it's the training ground for many geologists in Nova Scotia.

Crumbly rocks

It's a little off the beaten track for tourists -- there are no concessions or restaurants in the vicinity -- but it's well worth it to pack a picnic lunch and spend an afternoon on the beach, sunbathing, splashing in the waves and, yes, sifting through the crumbly rocks.

"It's one of the only sites in the world that exposes a continuous section of Silurian age rocks. That's very significant in terms of worldwide geology," says Deborah Skilliter, curator of geology at the Nova Scotia Museum of Natural History in Halifax.

Signs at an open-air interpretive centre between the parking lot and the beach provide a commentary on some of the fossils in the area. Brachiopods, for instance, are fairly common here. Also waiting to be found: Fossils of trilobites, bryozoans and pelecypods -- two-shelled creatures that were anchored to the bottom and fed by filtering water.

Skilliter says crinoids, or sea-lilies, are among her favourite fossils in the area.

"They look like plants -- these very beautiful flower-like structures, but they're actually animals," she says.

"They have these long, wavy, flowy, feathery arms that are tentacles and reach out for food in the water."

In 1998, a researcher named John Beck who studied the cliffs at Arisaig completed his PhD thesis documenting some of the world's first evidence of land plants.

"Arisaig was basically a shallow warm tropical sea," Skilliter says. Millions of years ago, rivers deposited sediment into the sea at this location.

"Some of that contained fossilized pollen grains of the world's first land plants," she says. "So I find that, as a paleontologist, that's just wow."

"As a Nova Scotian, to think that we have rocks that represent that major event in terms of life on planet Earth is exciting."

Above and beyond the fossils, the rock formations are also important to geologists. This is sedimentary rock, made of siltstone, sandstone and coquina (broken shells), layered like pancakes and an example of "original horizontality," says Skilliter.

And the fact that the layers are tilted is testament to the forces within the Earth -- tectonic forces, of the sort that might produce an earthquake today.

Continental drift can also be explained through understanding that 400 million years ago, the Arisaig region was in the same general area as parts of Britain.

"At this particular time, Nova Scotia lay pretty much near the equator and close to Scotland and the Welsh Basin," Skilliter says.

"Essentially that's one of the ways that we can prove that different parts of the world were once connected, is through the fossils. And in the Welsh Basin, during this time period, we find very similar microscopic plant remains."

The park has signs aplenty -- everything from "Danger. Actively eroding cliff" and "Unsupervised waterfront. Swim at own risk" to "Wear hard hats if you must be near cliffs."

Property of Nova Scotia

In terms of collecting, though, the directive reads: "All fossils are the property of the province of Nova Scotia. Please collect only from beach rocks."

According to Skilliter, the tides mean that cliffs are subject to a great deal of erosion so fossils are constantly being exposed.

"People will frequently collect fossils that are loose on the beach, and so what we ask is that people bring them to us for identification or bring them to someone who's knowledgeable about paleontology," she says.

"And if it's something that's really very common, often we'll say it's yours to keep. But that being said, they're not allowed to sell them or transport them outside the country."

To have fossils assessed, take them to the Museum of Natural History in Halifax, 1747 Summer St., or call Skilliter at 902-424-6451. Or, take them to Fundy Geological Museum in Parrsboro, N.S., or someone at a Department of Natural Resources or a university.