Sunday, 23 June 2019

PREHISTORIC BOWFIN

Calamopleurus cylindricus (Agassiz, 1841) / Collection of David Murphy
This well-preserved fossil fish skull is from Calamopleurus (Agassiz, 1841), an extinct genus of bony fishes related to the heavily armored ray-finned gars.

They are fossil relics, the sole surviving species of the order Amiiformes. Although bowfins are highly evolved, they are often referred to as primitive fishes and living fossils as they retain many of the morphologic characteristics of their ancestors.

This specimen is from Calamopleurus cylindricus of the Family Amiidae. He was found in Lower Cretaceous outcrops of the Santana Formation in the Araripe Basin UNESCO Global Geopark of northeastern Brazil.

Friday, 21 June 2019

YELLOWSTONE NATIONAL PARK

Mammoth Hot Springs Yellowstone National Park
Yellowstone National Park in Wyoming, Montana and Idaho is a 3,500-sq.-mile wilderness recreation area atop a volcanic hot spot.

While the park is mostly in Wyoming, it spreads into parts of Montana and Idaho. Yellowstone features dramatic canyons, alpine rivers, lush forests, hot springs and gushing geysers. You'll maybe know it by its most famous geyser, Old Faithful. It's also home to hundreds of animal species, including Black bear, Canada lynx, Bobcats, Northwestern gray wolves, Bighorn sheep, American bison, elk and antelope.

Tuesday, 18 June 2019

ANCIENT SALMON OF THE SOUTHERN INTERIOR

Sockeye Salmon / Oncorhynchus nerka
In the southern Interior, ice built up first in the northern Selkirk Mountains, then slowly flowed down into the valleys. Once the valleys were filled, the depth of the ice increased until it began to climb to the highlands and finally covered most of the Interior of British Columbia.

Between ice advances, there were times when the Kamloops area was ice free and the climate warm and hospitable. Glacial ice was believed to have initiated its most recent retreat from the South Thompson area around 11,000 to 12,000 years ago, but salmon remains from 18,000 years ago suggest that it may have actually began its northwest decline much earlier and indicating a much warmer climate in the Interior than archaeologists or geologists had originally estimated.

Eighteen thousand year-old salmon also challenge the archaeological notion that aboriginal people of the Interior have had access to salmon as a significant protein source for only a few thousand years. In the popular view, people living in the Okanagan and Thompson Valleys were felt to have moved to settlements that were semi-permanent about 4,500 years ago.

By that time they would have had a seasonally regulated diet composed primarily of salmon and supplemented by local game - deer, elk, small mammals – and available shellfish, birds and plant foods. If salmon were present much earlier, it is possible that this pattern of food utilization may have arisen earlier than thought.

Monday, 17 June 2019

HAIDA GWAII BOUNTY

Seafood Bounty / Haida Gwaii, British Columbia
“When the tide is out, the table is set.” This wisdom from those who call Haida Gwaii home is still true today. The enormous difference between high and low tide in Haida Gwaii – up to twenty-three vertical feet – means that twice a day, vast swathes of shellfish are unveiled, free for the taking.

Archaeological evidence tells us that roughly five thousand years ago, gathering shellfish replaced hunting and fishing as a primary food source on the islands. The shellfish meat was skewered on sticks, smoked and stored for use in winter or for travel.

The islands of Haida Gwaii are at the western edge of the continental shelf and form part of Wrangellia, an exotic terrane of former island arcs, which also includes Vancouver Island, parts of western mainland British Columbia and southern Alaska.

While we’ll see that there are two competing schools of thought on Wrangellia’s more recent history, both sides agree that many of the rocks, and the fossils they contain, were laid down somewhere near the equator. They had a long, arduous journey, first being pushed by advancing plates, then being uplifted, intruded, folded, and finally thrust up again. It’s reminiscent of how pastry is balled up, kneaded over and over, finally rolled out, then the process is repeated again.

This violent life story applies to most of the rock that makes up the Insular Belt, the outermost edge of the Cordillera. Once in their present location, the rocks that make up the mountains and valleys of this island group were glaciated and eroded to their present form.

Despite this tumultuous past, the islands have arguably the best-preserved and most fossil-rich rocks in the Canadian Cordillera, dating from very recent to more than 200 million years old. On these details, there is a pretty broad consensus. On much else, including exactly where the Wrangellia terrane was born and how fast it moved to its present position, there is lively debate. But we all agree on their bounty and beauty.