![Geological Survey of Canada Geological Survey of Canada](/web/20061103021411im_/http://www.gsc.nrcan.gc.ca/esst_images/gsc_e.jpeg) Natural Resources Canada > Earth Sciences Sector > Geological Survey of Canada > Past lives: Chronicles of Canadian Paleontology
Past lives: Chronicles of Canadian Paleontology Clearwater 'cockles and muscles'
The first observation that
fossils are preserved in rocks in Canada was not made in the settled
eastern areas by a scholar or educated naturalist. It was made in the remote
Athabasca country by an observant apprentice surveyor with a
rudimentary education
![Bedding plane surface of the Waterways Formation along the Athabasca River or northeastern Alberta covered by Peter Fidler's "cockles and muscles" -- that is, Late Devonian brachiopods Allanaria and Productella. Area shown about 6 cm across. University of Alberta Collections. (Photo by BDEC (c).) Bedding plane surface of the Waterways Formation along the Athabasca River or northeastern Alberta covered by Peter Fidler's "cockles and muscles" -- that is, Late Devonian brachiopods Allanaria and Productella. Area shown about 6 cm across. University of Alberta Collections. (Photo by BDEC (c).)](/web/20061103021411im_/http://www.gsc.nrcan.gc.ca/paleochron/images/waterways1.jpg) Bedding plane surface of the Waterways Formation along the Athabasca River or northeastern Alberta covered by Peter Fidler's "cockles and muscles" -- that is, Late Devonian brachiopods Allanaria and Productella. Area shown about 6 cm across. University of Alberta Collections.
(Photo by BDEC (c).) |
In 1791 the Hudson's Bay
Company sent their surveyor Philip Turnor inland from York
Factory to find a route into the fur-rich Athabasca country. He
was assisted by the 21 year old Peter Fidler who proved himself a
perceptive observer and recorder of natural history phenomena. At
the headwaters of the Churchill River drainage, the small party
struggled across the long difficult Methy Portage to reach
Clearwater River, part of the Athabasca drainage. This river
winds though a narrow outcrop belt of limestones and shales. As
they tracked their canoes around one of the numerous rapids,
Fidler spotted some peculiar petrified shells. His journal entry
reads, "Several curious kinds of shells, some in the middle
of solid stone and several in bare earth, the exact figure
remaining and some appeared as if they had been petrified to a
solid stone, such as cockles, muscles and other kinds of
shells". This brief note appears to be the first recorded
observation of fossils occurring in rocks anywhere in Canada.
The Molly Malone identification
of "cockles and muscles" can safely be taken to mean
generic shellfish -- and probably brachiopods, not clams. The
limestones and shales exposed along the Clearwater River are now
assigned to the Waterways Formation which contains some of the
best preserved and most diverse early Late Devonian (Frasnian)
fossil assemblages in North America. Brachiopods are particularly
common -- some thin and wafer-like, but most inflated with
characteristic ribs and nodes. Atrypids are the most common.
These are fat, walnut-sized brachiopods with fine, tube-like ribs
and lacking a discernable hinge line. Also common are stretched
spiriferids with broad radial ribs and a wide straight hingeline.
Domal stromatoporoids are present, as are solitary and colonial
rugose corals.
![Devonian rocks are exposed at the Methy Portage above the Clearwater River. (GSC photo by A.W. Norris (c)) Devonian rocks are exposed at the Methy Portage above the Clearwater River. (GSC photo by A.W. Norris (c))](/web/20061103021411im_/http://www.gsc.nrcan.gc.ca/paleochron/images/nahanni2.jpg) Devonian rocks are exposed at the Methy Portage above the Clearwater River.
(GSC photo by A.W. Norris (c)) |
Most of the marine organisms
found in the Waterways Formation belong to groups that perished
in a mass extinction near the middle of the Upper Devonian (375
Ma). This extinction was highly selective. With few exceptions,
the animals that perished all lived in shallow marine waters.
Reefs were wiped out, along with the reef-building stromatoporoids and rugose corals. Four major brachiopod groups
became extinct; including the atrypids which were extremely
common in earlier Devonian rocks.
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