Wednesday 31 May 2017

RADIOLARIAN TIMEKEEPERS

Anthocyrtium hispidum Haeckel
Radiolarian microfossils, tiny, siliceous, single-celled organisms, make for excellent timekeepers. Think of them as the world's smallest clocks. These wee fellows have been living in the world’s oceans for over 600 million years.

Radiolarians are unicellulars, wee little things with a diameter of 0.1–0.2 mm.

They produce intricate mineral skeletons, typically with a central capsule dividing the cell into the inner and outer portions of endoplasm and ectoplasm.Their beautifully elaborate mineral skeletons are usually made of silica. We find radiolaria as zooplankton throughout the ocean and their skeletal remains make up a large part of the cover of the ocean floor as siliceous ooze.

Due to their rapid turnover of species, they represent an important diagnostic fossil from the Cambrian onwards. Because they occur in continuous and well-dated sequences of rock, they act like a yardstick, helping geologists accurately date rock from around the globe.

In the Upper Triassic rocks, which predate the Triassic / Jurassic Mass Extinction event by about 10 million years, radiolarians are preserved in hundreds of forms. Just above them, in the early Jurassic rock layers laid down about the time of the great die-offs, only a fraction of the previous number of forms are represented. The more recent Jurassic rock shows a rebound of radiolarian diversity, though of course, in different forms, a diversity which continues to flourish and expand in today’s oceans.

Photo: Anthocyrtium hispidum Haeckel, magnification: 400x, bright field (negative image), stacked image Fundort / Site: Barbados Alter / Age: approx. 32-35 million years (late Eocene - early Oligocene) Präparation / Preparation: Andreas Drews

Tuesday 30 May 2017

CRETACEOUS DINOSAUR TRACKWAY

After an exciting hike in the dark through the woods and down a steep incline, we reached the river. 

The tracks in this photo are from a type of armored dinosaur that date from the very end of the Cretaceous, between 68-66 million years ago.

Imagine a meandering armored tank munching on ferns and low-growing vegetation.
This is a photograph of an ankylosaur trackway filled with water and lit by lamplight along Wolverine River, a research site of Lisa Buckley, one of two magnificent paleontologists working in the area.
Some of the prints contain skin impressions, which is lucky as many of the prints are so shallow that they can only be recognized by the skin impressions.

There are two types of footprints at the Wolverine River Tracksite, the meat-eating theropods (at least four different sizes) and the slow, lumbering plant-eating ankylosaurs. 

Filling the prints with water and using light in a clever way was a genius idea for viewing tracks that are all but invisible in bright sunlight by day.

Monday 29 May 2017

SUMAS SLIDE FOSSIL SITE

Heidi Henderson at Sumas Slide Eocene Fossil Site 

Sunday 28 May 2017

Monday 22 May 2017

Saturday 20 May 2017

AMMONITE BEAUTY: PALTECHIOCERA

This detail of the Jurassic ammonite, Paltechioceras sp. shot with an ultra-low f-stop, is from an all but inaccessible site in Sayward, Bonanza Group, Vancouver Island. By the time these ammonites were being buried in sediment, Wrangellia, the predominately volcanic terrane that now forms Vancouver Island and the Queen Charlotte Islands, had made its way to the northern mid-latitudes.

We did a fossil field trip up there a few years ago with the Courtenay & Qualicum beach crew. The drive up the mountain was thrilling as the road narrowed until it was barely the width of our wheel base -- thrilling to say the least. 

I’m headed back there this June for a wee look at what the Spring rains have revealed. This time, however, I believe I will hike up instead of driving as I’m not sure my heart could take going round-two on that road/trail via my jeep.

Tuesday 16 May 2017

Monday 15 May 2017

URSAVUS: CANADA'S GREAT BEARS

Hiking in BC, both grizzly and black bear sightings are common. These majestic beasts live up to 28 years and nearly half the world's population, some 25,000 grizzlies, roam the Canadian wilderness.

Both bear families descend from a common ancestor, Ursavus, a bear-dog the size of a raccoon who lived more than 20 million years ago. Seems an implausible lineage given the size of their very large descendants.

An average Grizzly weighs in around 800 lbs (363 kg), but a recent find in Alaska tops the charts at 1600 lbs (726 kg). This mighty beast stood 12' 6' high at the shoulder, 14' to the top of his head. It is one of the largest grizzly bears ever recorded. This past September, the King of the forest was seen once again in the Washington Cascades -- the first sighting in over 50 years.

Friday 12 May 2017

Thursday 11 May 2017

STAY AT HOME PENGUINS

 This touching scene

Tuesday 2 May 2017

WASHINGTON RISING

Over vast expanses of time, powerful tectonic forces have massaged the western edge of the continent, smashing together a seemingly endless number of islands to produce what we now know as North America and the Pacific Northwest.

In the time expanse in which we live our very short human lives, the Earth's crust appears permanent. A fixed outer shell – terra firma. Aside from the rare event of an earthquake or the eruption of Mount St. Helen’s, our world seems unchanging, the landscape constant. In fact, it has been on the move for billions of years and continues to shift each day.

As the earth’s core began cooling, some 4.5 billion years ago, plates, small bits of continental crust, have become larger and smaller as they are swept up in or swept under their neighboring plates. Large chunks of the ocean floor have been uplifted, shifted and now find themselves thousands of miles in the air, part of mountain chains far from the ocean today or carved by glacial ice into valleys and basins.

Two hundred million years ago, Washington was two large islands, bits of the continent on the move westward, eventually bumping up against the North American continent and calling it home.

Even with their new fixed address, the shifting continues; the more extreme movement has subsided laterally and continues vertically. The upthrusting of plates continues to move our mountain ranges skyward, the path of least resistance.

This dynamic movement has created the landscape we see today and helped form the fossil record that tells much of Washington’s relatively recent history – the past 50 million years. Chuckanut Drive is much younger than other parts of Washington. The fossils found there lived and died some 40-55 million years ago, very close to where they are now, but in a much warmer, swampy setting. The exposures of the Chuckanut Formation were once part of a vast river delta; imagine, if you will, the bayou country of the Lower Mississippi.

The siltstones, sandstones, mudstones and conglomerates of this formation were laid down about 40-54 million years ago during the Eocene epoch, a time of luxuriant plant growth in the subtropical flood plain that covered much of the Pacific Northwest.

This ancient wetland provided ideal conditions to preserve the many trees, shrubs, and plants that thrived here. Plants are important in the fossil record because they are more abundant and can give us a lot of information about climate, temperature, the water cycle, and humidity of the region. The Chuckanut flora is made up predominantly of plants whose modern relatives live in tropical areas such as Mexico and Central America.

While less abundant, evidence of the animals that called this ancient swamp home are also found here. Rare bird, reptile, and mammal tracks have been immortalized in the outcrops of the Chuckanut Formation.

Tracks of a type of archaic mammal of the Orders Pantodonta or Dinocerata (blunt foot herbivores), footprints from a small shorebird, and tracks from an early equid or webbed bird track give evidence to the vertebrates that inhabited the swamps, lakes and river ways of the Pacific Northwest 50 million years ago.

Fossil mammals from Washington do get most of the press. The movement of these celebrity vertebrates captured in the soft mud on the banks of a river, one of the depositional environments favorable for track preservation.

The bone record is actually far less abundant that the plant record, except near shell middens, given the preserving qualities of calcium and an alkaline environment. While calcium-rich bones and teeth fossilize well, they often do not get laid down in a situation that makes this possible. Hence the terrestrial paleontological record of Washington State at sites like Chuckanut is primarily made up of plant material.