Saturday 14 March 2009

VOLCANIC DEMISE: THE TRIASSIC-JURASSIC EXTINCTION

Located as they are in Canada’s most active earthquake zone, the Queen Charlotte Islands have had their share of shake-ups and scourings. Many of the Islands’ hillsides are scarred by slides. But the rock beneath speaks of an even more violent past. Very few people know that the rock in the Queen Charlottes holds the key to a catastrophic event from eons ago.We’ve heard tales and seen images of the cataclysmic damage caused by meteriorites smashing into the Earth’s surface.

Until recently, it was a meteorite impact that was blamed for the worldwide Triassic/Jurassic Mass Extinction. This wholesale dying out of species occurred some 200 million years ago. New evidence challenges the meteorite theory. Experts now believe that tectonic forces may have caused hundreds of volcanoes around the world to erupt simultaneously. The subsequent showers of volcanic ash would have altered the composition of the atmosphere dramatically and plunged the world into near total darkness for years until it settled from the sky.

The picture painted of the sun flickering fitfully through inky clouds, paling against the torrents of glowing lava, while everywhere life is smothered, poisoned, or starved, rivals the most apocalyptic imaginings of Hollywood or religion. We know from worldwide evidence that the extinction was dramatic and affected upwards of 70% of the world’s biota.

Perhaps counterintuitively, for one might think of water as a refuge from fire, smoke, and lava, it was marine lifeforms that suffered the most. This is particularly well documented in the rocks of the Queen Charlottes, especially at Kennecott Point and Kunga Island.

Radiolarian microfossils – tiny, siliceous, single-celled microrganisms – tell the tale. In the Upper Triassic rocks, which predate the extinction 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.

Radiolarian microfossils – tiny, siliceous, single-celled organisms – tell the tale. These wee timekeepers have been living in the world’s oceans for about 600 million years. Because they occur in continuous and well-dated sequences of rock in the Queen Charlottes, these exquisitely beautiful microfossils act like a yardstick, helping geologists accurately date rock from around the globe.

In the Upper Triassic rocks, which predate the extinction 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 Queen Charlottes are most noted for their fossil ammonites, the coiled cousins to modern day nautilus. These perfectly preserved specimens tell of a deep water environment and warm tropical seas. The younger Jurassic rock shows a rebound of radiolarian diversity (though of course, in different forms) - a diversity that continues to flourish and expand in today’s oceans.

Friday 13 March 2009

COASTAL WOLVES: GENETIC DIFFERENCES

Have you ever seen headless salmon littering the banks of rivers and streams during spawning season? Most who have generally blame our local bears for this selective dining. The real culprits are coastal wolves who gorge themselves on the nutrient-rich brains, leaving the rest to scavengers.

It seems this preference for fish and a redish tinge to their pelts set our local wolves apart. Coastal wolves, from Alaska and Vancouver Island, have not only adapted to their local environment but have evolved into something altogether new.

Think Darwin's finches.

Researchers from the Raincoast Conservation Foundation have published in this month's Journal of Biogeography, that our coastal wolves, "are like no other wolves." Well, we could have told them that, but no one listens until a paper gets published.

Grey wolves (Canis lupus), coastal wolves and our household pets (Canis lupus familiaris) share a common ancestry but at some point our coastal wolves have broken from the pack. With genetic differences that, "are striking and their ecology is very, very different."

So it seems everything old is new again.

Thursday 12 March 2009

CEDAR: LIFEBLOOD TO AN ISLAND

The arrival of cedar, called “Tsuuaay” by the Haida, had profound effects on the material culture of the Haida (Approx 4000 BC). Once they were able to build canoes to fish year round for local halibut, red snapper and ling cod and increased their access to sea mammals, they were granted a bit of freedom. They still enjoyed their relationship to the spawning cycle of the salmon but cedar gave them options. The cedar bent wood box, a genius idea in food conservation and storage, allowed them to store food for the winter. Often carved with exquisite detail, the cedar bent wood box became art, status and lifebood.

CARIBOO LIGHT

Wednesday 11 March 2009

Tuesday 10 March 2009

VICIOUS MEAT-EATING HUNTER TRACKED TO AFRICA


While evidence of 95-million year old therapods from Africa is quite scare making one think that each fragment would be treated like gold, this was not the case the first evidence of Carcharodontosaurus iguidensis, a newly described dinosaur from the Cenomanian of Nigeria and published in this months issue Journal of Vertebrate Paleontology.

This fellow almost had the misfortune of going extinct twice! Tooth fragments collected by Charles Depéret and J. Savornin in 1927 were misplaced before this meat-eater could ever be described and when additional material was collected in Egypt in the 1930’s it also came to an unfortunate end. Sent to German paleontologists in Munich to describe, the fossils were lost in the rubble as Allied Forces bombed the building in which they were housed during WW II.But the rocky history and luck of Carcharodontosaurus iguidensis improved when paleontologist in residence at National Geographic, Paul Sereno found cranial material on a Moroccan dig in 1996.


:: THE EVIDENCE MOUNTS...



That find combined with material collected the following year in Nigeria were studied by Sereno, along with Steve Brusatte, a paleobiologist at the University of Bristol in England, and Paul Sereno and determined to be a new species, not C. saharicus as originally thought. The massive skull, neck and bone fragments belonged to Carcharodontosaurus iguidensis, one of the largest dinosaurs ever found. Carcharodontosaurus differs from C. saharicus, his smaller Saharan coursin, both in the maxilla and braincase.

Carcharodontosaurus iguidensis walked upright and was a massive beast, weighing in at an impressive 3.2 tons. Extending upwards of 14 meters (44 ft), nearly as long as Tyrannosaurs, alive today they could easily peer through a second story window - a menacing thought as they were well-equipped hunters with sizable teeth.The climate was much warmer when Carcharodontosaurus iguidensis and C. saharicus roamed the Earth and the seas much higher. Beyond geographic distance, the raised sea level may have been what set these therapods apart.
:: SHALLOW SEAS...

Shallow seas separated what is now Morocco and Nigeria and this separation may have prompted the development of the unique characteristics define the two species.. Perhaps more abundant prey and favorable conditions allowed Carcharodontosaurus iguidensis to grow to their huge size while C. saharicus remained a smallish 1.6 meters (5.2 ft). While not a reptile, C. saharicus has been compared with modern Crocodylia, another group who first appeared in the Cretaceous, as they share similar inner ear anatomy and cerebrum size relative to total brain.
Like many therapods prior to the 1930’s, the African species were originally misgrouped into the genus Megalosaurus. Paleontologist Ernst Stromer von Reichenbach corrected this error. After taking a closer look at their anatomy, particularly their dentition, he renamed them Carcharodontosaurus in 1931 citeing their "mainly Carcharodon-like teeth", which were "not recurved, almost bilaterally symmetrical but with convex edges”

The Carcharodontosaurids were a group of gigantic carnivorous carcharodontosaurid dinosaurs that lived 98 to 93 million years ago. Carcharodontosaurus means 'shark lizard', after the shark genus Carcharodon, an apt handle as they were ominous killers with enormous jaws and long, serrated teeth, some as long as eight inches.

References:

Brusatte, S. and Sereno, P.C. (2005). "A new species of Carcharodontosaurus (Dinosauria: Theropoda) from the Cenomanian of Niger and its implications for allosauroid phylogeny." Journal of Vertebrate Paleontology, 25: 40A.

Brusatte, S.L. and Sereno, P.C. (2007). "A new species of Carcharodontosaurus (dinosauria: theropoda) from the Cenomanian of Niger and a revision of the genus." Journal of Vertebrate Paleontology, 27 (4).

Deparet, C. and Savornin, J. (1927). "Sur la decouverte d'une faune de vertebres albiens a Timimoun (Sahara occidental)." Comptes Rendus, Academie du Sciences, Paris, 181: 1108-1111.Larsson, H.C.E. (2001). "Endocranial anatomy of Carcharodontosaurus saharicus (Theropoda: Allosauroidea) and its implications for theropod brain evolution." Pp. 19-33 in D.H.

Tanke & K. Carpenter (eds.), Mesozoic Vertebrate Life. Indiana University Press, Bloomington.Stromer, E. (1931). "Wirbeltiere-Reste der Baharijestufe (unterestes Canoman). Ein Skelett-Rest von Carcharodontosaurus nov. gen." Abhandlungen der Bayerischen Akademie der Wissenschaften, Mathematisch-naturwissenschaftliche Abteilung, 9(Neue Folge): 1–23.

KAYAKING LAKE ISAAC

Monday 9 March 2009

GLOBAL WARMING: THE TROPICAL EOCENE

In 2004, a scientific crew braced the cold and the odds to extract a sediment core from 400m below the seabed of the Arctic Ocean. The core showed that Fifty-five million years ago, deep in the Eocene, the North Pole was ice-free and enjoying tropical temperatures. It also told us that the temperature of the ocean was 20C, instead of the coolish –1.5C we see today… a truth that is hard to imagine with all the hype around global warming.

The bottom end of that core helped explain the fossils found at Eocene sites around British Columbia, species commonly seen in more tropical environments today.

The warmer temperatures seen at McAbee and around the globe were recorded in the core sample and reveal evidence for a global event known at the Palaeocene-Eocene Thermal Maximum. Back in the Eocene, a gigantic emission of greenhouse gases was released into the atmosphere and the global temperature warmed by about 5C.

While the bookends of the geologic time scale slide back and forth a wee bit, the current experts in the geologic community set the limits to be 33.9 +_ 0.1 to 55.8 +_ 0.2 million years ago. The fossil record tells us that this part of British Columbia and much of the Earth was significantly warmer around that time, so warm in fact that we find temperate and tropical plant fossils in areas that now sport plants that prefer much colder climes, or as is the case in the Arctic, snow and ice.

The Okanagan Highlands is an area centred in the Interior of British Columbia, but the term is used in a slightly misleading fashion to describe an arc of Eocene lakebed sites that extend from Smithers in the north, down to the fossil site of Republic Washington. The grouping includes the fossil sites of Driftwood Canyon, Quilchena, Allenby, Tranquille, McAbee, Princeton and Republic. These fossil sites range in time from Early to Middle Eocene, and the fossil they contain give us a snapshot of what was happening in this part of the world because of the varied plant fossils they contain..

While the area around the Interior of British Columbia was affected. McAbee was not as warm as some of the other Middle Eocene sites, a fact inferred by what we see and what is conspicuously missing.

In looking at the plant species, it has been suggested that the area of McAbee had a more temperate climate, slightly cooler and wetter than other Eocene sites to the south at Princeton, British Columbia and Republic and Chuckanut, Washington. Missing are the tropical Sabal (palm), seen at Princeton and the impressive Ensete (banana) and Zamiaceae (cycad) found at Republic and Chuckanut, Washington.

While we are the likely culprits of much of the warming of the Arctic today, natural processes operating in the not too distant past have also resulted in significant temperature fluxuations on a world-wide scale.

Friday 6 March 2009

Wednesday 4 March 2009

Saturday 28 February 2009

BUCHARESTI

The past few years, I've had occasion to travel to Bucharest, Romania for work. Each time I'm there, of course, there is always a great adventure to be had. I usually make my way to the city centre to visit their exquisite paleo museum and take care of a few things at the consulate.

This photo is from their central park which lines the greenbelt in the consultate district. Many times, I've walked through history entering this deceptively peaceful park that divided the population in their final push to free themselves from communism in 1989. Timing is everthing it seems, as I was also there to see the exchange between the Americans and Russians when Kosovo separated. Beautiful, delicious, cold and dangerous. Bucharest (Bucharesti) is quite a city.

Wednesday 18 February 2009

HAIDA GWAII : ISLANDS OF THE MIST

The islands have gone by many names. To the people who call the islands home, Haida Gwaii means “island of the people,” it is a shortened version of an earlier name, Haadala Gwaii-ai, or “taken out of concealment.” Back at the time of Nangkilslas, it was called Didakwaa Gwaii, or “shoreward country.” 

By any name, the islands are a place of beauty and spirit and enjoy a special place in both the natural and supernatural world.

Haida oral history traces the lineage of their families back to the ocean’s origins. Spear points from Huxley Island confirm a date of between 12,500 - 13,500 years ago. Their stories bear witness to the last the ice age, great floods, changes in sea levels and the arrival of the first tree – each binding them closer to the land and sea and enriching our understanding of this special place.

The islands form part of Wrangellia, an exotic terrane that includes parts of western British Columbia, Vancouver Island and Alaska. Today, the mist-shrouded archipelago of Haida Gwaii is separated from the British Columbia mainland by Hecate Strait, a 40-mile wide channel of tempestuous water.

Haida oral tradition tells of a time when the strait was mostly dry, dotted here and there with lakes. And indeed, during the last ice age, glaciers locked up so much water that the sea level was hundreds of feet lower than it is today. Soil samples from the sea floor of Hecate Strait contain wood, pollen, and other terrestrial plant materials that tell of a tundra-like environment. Whether or not the strait was ever completely dry during these times, it seems that it did at least contain a series of stepping-stone islands and bridges that remained free of ice.

Today, the highest peaks are often bare of vegetation and snow-covered during most of the year, but back in the time of the glaciers, these same local mountains were the birthplace of advancing ice. Precipitation and a significant drop in temperature gave rise to an ice-sheet, a thick mass of flowing ice that ran tandem with the Cordilleran sheet in the Hecate Lowlands.

Looking around today, you can see where the glaciers left their mark. Many of the Islands’ valleys sport the tell-tale post-glaciation U-shape profile and picturesque erratic boulders can been seen sitting like sentinels on the beach, lone watchmen with an eye to the sea. While the glaciers on the Queen Charlottes were localized, to the east, what had once been and would again be the continental coast was pressed down beneath over a kilometer of ice — the Cordilleran ice sheet.

The melting of the glaciers, between 15,000 and 10,000 years ago, which coincides with the Siberian big-game hunters migrating inland on foot across the Bering Land Bridge, had two other significant effects on the level of sea and land. The first was the release of all the previously locked up water, causing a dramatic rise in sea levels. The second was the simultaneous rise of the continental edge and fall of the islands of Haida Gwaii.

This rise in sea levels transformed the westernmost highlands and mountains of ancient BC into the archipelago of Haida Gwaii and its inhabitants into the master seafarers of the West Coast.

The Hecate Strait served the Haida much as the English Channel served the British after the Norman Conquest: it was a formidable moat that discouraged attacks from the mother continent, but which they could cross at will to explore, trade, and pillage.

For many cultures, obtaining the stable food supply and permanent residences needed to develop advanced artisanship and specialized trades and crafts required becoming an agrarian society: clearing fields, planting crops, and/or raising livestock. But for the Haida, Mother Nature served as farmer, tending the tideland fields.

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. An ancient Haida saying is still often heard today, “When the tide is out, the table is set.” Archaeological evidence shows that by about five thousand years ago, gathering shellfish replaced hunting and fishing as their primary food source. The shellfish meat could be smoked, skewered on sticks, and stored for use in winter or for travel.

Over the centuries, the discarded shells accumulated in mounds many feet thick, called middens. The thickness of the middens and carbon dating the shells provide good timelines for human habitation. In addition, as described in the sidebar, chemicals leaching from the shells helped “embalm” bone and antler artefacts that would otherwise have decayed.

Freed from the need to chase game or till soil, the Haida, sometimes called the Vikings of the West Coast, developed their equivalent of the Norse Longship: the war canoe. Whereas any European wooden boat for more than a few people had to be pieced together from planks and ribs, the enormous red cedars of Haida Gwaii allowed carving one-piece dugout canoes up to seventy feet long.

Paddled by as many as thirty warriors – sails did not come into use until after contact with Europeans – these long, elegant craft ranged from Alaska to California, trading for or taking what they wanted. It’s interesting to note that equality in job opportunities is not such a recent notion. It was not unheard of for women to be part of Haida war parties, and they were apparently as much feared as their male shipmates. Naval battles on the ancient Northwest coast may not have rung with the echo of cannon or musket shots, but they would still have been fearsome and deadly. Rocks weighing up to fifty pounds, aptly named canoe breakers, were hurled at enemy boats in attempts to stave in their thin sidewalls. A rope running through a hole drilled in the canoe breaker allowed for its retrieval and reuse.

Presumably, rapidity in retrieval was called for to prevent the embarrassment of your enemy sinking you with your own rock. If canoe breakers were the analogue of cannon, the equivalent of the musket was the atlatl (pronouced"ott-lottle"). 

In any city park, you will see dog walkers using a long plastic device with a scoop to catapult balls for Rover’s retrieving pleasure. If you’ve used one of these, you’ve experienced how much faster and further you can hurl a ball with it than with your unaided arm. You might have thought of this as a cunning modern gadget, but in fact, it’s a variation on the ancient atlatl, or spear-thrower, in use for twenty-five thousand years. The spear or dart lay in a groove in the throwing stick as they were both held in one hand. As the user swung that hand overhead, he released the missile. The butt end of the spear lodged in a notch at the tip of the atlatl until it launched forward at fearsome speed.

In South America, the Spanish Conquistadors were unpleasantly surprised to find that atlatl darts could pierce their armoured breastplates. Indeed, it is the awesome effectiveness of such weapons that has led some scholars to suggest that the extinction in North America of many species of large animals – megafauna, in the scientific jargon – was caused by the encroachment of man.

Giant beavers, oversized ground sloths, and huge armadillo-like creatures all disappeared within a couple of thousand years — a mere heartbeat in geological terms. Other scholars hotly dispute that humans were solely responsible for these extinctions. Significantly however, the disagreement is based on arguments about what effects the changing environment had on these animals, about the timing of human arrival in America, the possible speed and methods of human immigration down the two continents, and whether and when viable ice-free corridors existed down the center of North America; no one appears to be arguing that ancient peoples were technologically incapable of killing such large beasts in enormous numbers.

We know that the islands housed grizzly bears some 13,600 years ago and while they no longer live in the region, we are still searching for clues as to their disappearance. We also find evidence in caves of deer bones dating back 12,600 years, suggesting a post-glacial arrival and a date well before the arrival of Europeans, who were originally credited with their arrival.

Why did some of the larger game on the lush islands thrive for a time and then vanish altogether? Rapid environmental and geographical changes combined with more efficient hunting methods form part of the answer.

We often think that exploiting a renewable food source to extinction, or at least to the point it can no longer feed us, is exclusively a problem of the modern age. Passenger pigeons across the continent, cod on the east coast, and the imperilled salmon on the west coast all come to mind. But the evidence suggests this may well have occurred many times in the past.

If, as the saying goes, “Those who forget the past are condemned to repeat it.” we would be wise to learn from the history of the early humans in North America. The Haida know the dangers of taking too much from any one place, leaving nothing for the next season. Logging has had a great impact on the salmon stock, particularly the Sockeye whose numbers have dwindled significantly.

The watershed that once protected the streams has been laid bare, allowing seasonal floods to run faster and higher, destroying spawning pools and clawing outside channels. Ain River, once bursting with salmon is now all but bare. A similar fate awaits the Copper River as most of the watershed surrounding it has been logged and the salmon feel the change – they are down to critically small numbers. They have a plan for the islands their lives and spirits are intertwined with. They know that their future and the fate of future generations run parallel with the health and lifeblood of the land beneath their feet and the oceans that crest their shores - Yah’guudang - respect for this place and for all living things.

They know that managing the wealth of logging with the health of their streams and river systems, especially the vital headwaters, is paramount to their future.

The arrival of cedar, called “Tsuuaay” by the Haida, had profound effects on the material culture of the Haida (Approx 4000 BC). Once they were able to build canoes to fish year-round (Halibut, Red Snapper, Ling Cod etc) and could access sea mammals, they no longer only depended on the salmon to return at certain times. The cedar bentwood box, a genius idea in food conservation and storage, allowed them to store food for the winter and reduced their dependence on hunting land mammals throughout the year wained.

The arrival of cedar marks a whole new stone tool tradition. The microblade is abandoned for larger ground tools, which are more appropriate for working with cedar.

Haida stories, songs, dances and crests are displayed through the ancient tradition of feasting and potlatching, where prestige is gained through the distribution of property. This generosity of spirit and sharing has carried on as they now share their lands with newcomers. Haida Gwaii, once the exclusive domain of the Haida people, is now home to many.

Homesteaders began to arrive in the…. Fishermen, others… Their stories have added another layer of richness to this moss-covered landscape.

Protective Shells: How Middens Preserve Bones:

Having food “packaging” accumulate in vast heaps around towns and villages is hardly a modern phenomenon. Many First Nations sites were inhabited continually for centuries. The discard shells and scraps of bone from their food formed enormous mounds called middens.

Left over time, these unwanted dinner scraps can transform through a quiet process of preservation. Time and pressure leach calcium carbonate from the seashells and help “embalm” bone and antler artifacts that would otherwise decay. Bone already contains calcium carbonate, as well as calcium phosphate, but it is also made of protein, cells and living tissue. Decaying bone acts as a sort of natural sponge that wicks in the calcium carbonate displaced from the shells. As protein decays inside the bone, it is replaced by the incoming calcium carbonate. This makes the bone harder and more durable, somewhat as plaster applied to the fabric of a cast makes the structure stiffer and more robust. In addition, the presence of shells can change corrosive acidic soil into more alkaline or neutral earth, which also helps to preserve the bone.


Rock n’ Roll: The Convoluted – And Disputed – Prehistory of Haida Gwaii


The Queen Charlotte Islands 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 lifestory 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.

The two rival theories each rely on a different type of evidence: biogeographic or paleomagnetic. Volumes have been written on this complex argument. We’ll follow a single thread of the debate to get a sense of the science being marshalled on both sides. Biogeographic evidence compares the types of fossils found in rock with the historic ranges of the living creatures they were formed from, and sometimes with the ranges of comparable contemporary life forms.

Paleomagnetic dating uses the history of the Earth’s magnetic fields. It can give a rough estimate of how far north or south of the equator rock was formed. Palomagnetic data from Triassic rock of Wrangellia suggest that it was laid down somewhere in a band about two thousand miles wide, centered on the equator. The biogeographic work of geologist Dr. Tim Tozer on the fossil faunas of Haida Gwaii concurs with this. The fossils found in the Triassic rock of Wrangellia are equatorial or low latitude life forms quite different from those found today on the Continent at the latitude of the island.

This suggests those rocks were in the equatorial region during the Late Triassic, just over 200 million years ago. Further supporting this, Dr. Jim Haggart, a geologist at the Geologic Survey of Canada, who has worked extensively with the fossils of Haida Gwaii, notes that Lower Jurassic ammonite faunas found on Haida Gwaii are very similar to those found in the Eastern Pacific around South America and in the Mediterranean. The presence of these ammonites seems to indicate that the rock was still at or very near the equator during the Lower Jurassic epoch, which ended roughly 175 million years ago.

To this point in prehistory, the paleomagnetic and biogeographic evidence is in reasonable harmony (at least about how far south Wrangellia was created. There’s much debate about just where along the equator is was, but we’ll ignore that for simplicity’s sake.).It is as we move up through the rock column to younger layers that the two lines of evidence start to conflict. Around the beginning of the Middle Jurassic, the fossils found on the Queen Charlotte Islands, Vancouver Island and in southern Alaska start to be dominated by forms found in high latitudes. This suggests that by the time of the Middle Jurassic, about 165 million years ago, Wrangellia had already completed much of its journey northward. Similar biogeographic evidence from Cretaceous rocks supports this idea as the Cretaceous ammonite, bivalve and radiolarian faunas all appear to be high latitude as well.

In contrast, the paleomagnetic data from Wrangellian Cretaceous rocks on Vancouver, Hornby and Texada Islands initially suggested that they were formed while Wrangellia was still at low latitudes, roughly around present-day southern Baja Mexico. More recently, however, paleomagnetists have conceded that Wrangellia may have gotten as far north as central California by the Early Cretaceous. 

The paleomagnetists now maintain that the islands of Haida Gwaii arrived at their present-day position by the Lake Cretaceous or even earlier, around 60 million years ago. This revised dating still means these two groups do not see eye to eye on just when the islands arrived at their current position. However, the paleomagnetists face some major stumbling blocks:

They can’t locate many of the fault lines necessary to buttress their case. For example, rocks on either side of the valley at Churn Creek north of Lytton originated 2000 miles apart according to paleomagnetic calculations, but no fault line has yet been found running between the supposedly separately created sides.

The paleomagnetists assert that it’s just a matter of time before the required faults are unearthed — mere formalities they are happy to leave to the geologists. Needless to say, many geologists are unimpressed with having these burdens thrust upon them by “paleomagicians” unable to back-up their case. Both sides are able to find many faults in the opposing theory, if not in the Wrangellian terrane.So, are scientists discouraged by such vast gaps in their knowledge of the early Earth? On the contrary, they’re excited.

Paleogeology would be a very dull field if all that was left to do was to cross a few trivial Ts and dot a few insignificant Is. As it is, there are vast opportunities to have your name go down in history by making major contributions to our knowledge of Earth’s prehistory.

Paleomagnetic Dating

You probably remember a demo from science class where a sheet of paper is laid over a bar magnet, and iron filings are scattered lightly onto it. The filings line up with the fields generated by the magnet, in patterns that look rather like bottom-to-bottom fireworks bursts. Something similar occurs when rock is formed, whether by heat or by sedimentation:

Microscopic iron particles in the rock line up with the Earth’s magnetic fields as they are oriented at that time. But unlike the iron filings on the paper, which shift if the paper or the magnet is moved, iron particles in solidified rock remain frozen in their alignment unless the rock is reheated to 600°C or more.

This means that even when the Earth’s magnetic poles flip end for end – something they have done several hundred times during Earth’s history – the iron stays aligned as it was when the rock was formed. By comparing the residual magnetism in the rock with the known historical changes in the Earth’s magnetic fields, an age and birthplace for the rock can be easily be estimated — in theory.

The principle behind paleomanetic dating is easy to summerize: the practise is much more complicated. The intervals between pole reversals fluctuate wildly, from as little as one hundred thousand years to tens of millions of years. The time taken for the shifts to complete once started also varies, from a thousand to eight thousand years. Imagine trying to time events with a grandfather clock that had a pendulum which swung at intervals that could vary from one minute to many hours, while the period of the pendulum swing itself ranged randomly from one second to eight seconds, and you’ll get a sense of the complexity of paleomagnetic dating. While far from a perfect science, paleomagnetic dating provides valuable pieces of the puzzle of Earth’s past.

The Triassic/Jurassic Extinction: A Killer From Outer Space Or Inner Earth?

Located as they are in Canada’s most active earthquake zone, the islands of Haida Gwaii have had their share of shake-ups and scourings. Many of the Islands’ hillsides are scarred by slides (any specific examples?). But the rock beneath speaks of an even more violent past. Very few people know that the rocks here hold the key to a catastrophic event from eons ago. We’ve heard tales and seen images of the cataclysmic damage caused by meteriorites smashing into the Earth’s surface.

Until recently, it was a meteorite impact that was blamed for the worldwide Triassic/Jurassic Mass Extinction. This wholesale dying out of species occurred some 200 million years ago. New evidence challenges the meteorite theory. Experts now believe that tectonic forces may have caused hundreds of volcanoes around the world to erupt simultaneously. The subsequent showers of volcanic ash would have altered the composition of the atmosphere dramatically and plunged the world into near total darkness for years until it settled from the sky.

The picture painted of the sun flickering fitfully through inky clouds, paling against the torrents of glowing lava, while everywhere life is smothered, poisoned, or starved, rivals the most apocalyptic imaginings of Hollywood or religion. We know from worldwide evidence that the extinction was dramatic and affected upwards of 70% of the world’s biota.

Perhaps counterintuitively, for one might think of water as a refuge from fire, smoke, and lava, it was marine lifeforms that suffered the most. This is particularly well documented in the rocks of the Queen Charlottes, especially at Kennecott Point and Kunga Island.

Radiolarian microfossils – tiny, siliceous, single-celled microrganisms – tell the tale. In the Upper Triassic rocks, which predate the extinction 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.

Queen Charlotte Radiolarians: Time Keepers of the World Wide Mesozoic:

Radiolarian microfossils – tiny, siliceous, single-celled organisms – tell the tale. These wee timekeepers have been living in the world’s oceans for about 600 million years. Because they occur in continuous and well-dated sequences of rock in the Queen Charlottes, these exquisitely beautiful microfossils act like a yardstick, helping geologists accurately date rock from around the globe.

In the Upper Triassic rocks, which predate the extinction 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 younger Jurassic rock shows a rebound of radiolarian diversity (though of course, in different forms) - a diversity that continues to flourish and expand in today’s oceans. Inset: The islands of Haida Gwaii are most noted for their fossil ammonites, the coiled cousins to modern day nautilus. These perfectly preserved specimens tell of a deep water environment and warm tropical seas.

Dr. Mclearn, a geologist who has worked on the geology of Haida Gwaii published on the strata exposed at Maple Island was stratigraphically higher than the majority of Albian localities in Skidegate inlet. His findings show that the macrofossil fauna belonged to the Upper part of the Sandstone Member of the Haida formation.

The western end of the island contains numerous well-preserved inoceramids (Birostrina concentrica) and a few rare ammonites (Desmoceras bearskinese). The eastern shores house unusual ammonite fauna in the finer grained sandstones.

Most were in extremely hard concretions while others were loose in the shale. Species include Anagaudryceras sacya and Tetragonites subtimotheanus. A large whorl section of the rare Ammonoceratites crenucostatus was found in 2003.

Sidebar: Hoploparia sp. Paper with Torrey Nyborg (Loma Linda University) on the Rogueus sp. (Raninid crab) from Northwest Bay.

Photos: The ammonites, Desmoceras; Brewericeras; Douvelliceras, from Lower Cretaceous, Middle Albian, Haida Formation deposits

Sidebar: Evidence of human activity dating from 12,500 - 13,500 years ago. Section Cove finds including spear points, salmon remains and bear bones preserved in limestone.

Sidebar: Earliest presence of grizzly bears, 13,600 years ago, work of Rebecca Wigen

Photo: Shell coquina, with abundant Spisula praecursor clams, Late Miocene (~ 10 million years old, Skonun Formation)

Monday 16 February 2009

BACTERIA: EARLIEST FORMS OF LIFE

Water was home to the earliest life forms, the prokaryotes, simple cells without nuclei.

"There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved."

Charles Darwin, Origin of Species, 1st Edition (1859)

Sunday 15 February 2009

Friday 13 February 2009

FRESH FISH CONNOISSEURS: THE AMMONITES


Ammonites looked like the still extant Nautilus, a coiled shellfish that lives off the southern coast of Asia. They were kissing cousins in the Class Cephalopoda, meaning "head-footed," closely related to modern squid, cuttlefish and octopus. Cephalopods have a complex eye structure and can swim rapidly. They use these to their advantage as successful marine predators, cruising through the sea expertly grabbing prey with their tentacles - kind of like a hungry fellow at a smorgasborg. Fresh fish anyone?

The ammonite in the image is from the British Columbia Paleontological Alliance calendar. Beautiful photo... even though the ammonite is upside down. The opening at the edge of the shell is where the creature would have lived. Visit www.bcfossils.ca to see the original image and order your calendar for next year.

Thursday 5 February 2009

SCIENCE GEEK VALENTINE: PALEOMAGNETIC DATING

While in no way sexy, paleomagnetic dating stands the test of time for being useful. You probably remember a demo from science class where a sheet of paper is laid over a bar magnet, and iron filings are scattered lightly onto it. The filings line up with the fields generated by the magnet, in patterns that look rather like bottom-to-bottom fireworks bursts. Something similar occurs when rock is formed, whether by heat or by sedimentation:

Microscopic iron particles in the rock line up with the Earth’s magnetic fields as they are oriented at that time. But unlike the iron filings on the paper, which shift if the paper or the magnet is moved, iron particles in solidified rock remain frozen in their alignment unless the rock is reheated to 600°C or more.

This means that even when the Earth’s magnetic poles flip end for end – something they have done several hundred times during Earth’s history – the iron stays aligned as it was when the rock was formed. By comparing the residual magnetism in the rock with the known historical changes in the Earth’s magnetic fields, an age and birthplace for the rock can be easily be estimated — in theory.

The principle behind paleomanetic dating is easy to summerize: the practise is much more complicated. The intervals between pole reversals fluctuate wildly, from as little as one hundred thousand years to tens of millions of years. The time taken for the shifts to complete once started also varies, from a thousand to eight thousand years.

Imagine trying to time events with a grandfather clock that had a pendulum which swung at intervals that could vary from one minute to many hours, while the period of the pendulum swing itself ranged randomly from one second to eight seconds, and you’ll get a sense of the complexity of paleomagnetic dating. While far from a perfect science, paleomagnetic dating provides valuable pieces of the puzzle of Earth’s past.

STAGGERING ABUNDANCE: FOSSILS OF MCABEE

Wednesday 4 February 2009

2009 EIGHTH BC PALEONTOLOGICAL SYMPOSIUM


Eighth British Columbia Paleontological Symposium

Presented by the Vancouver Paleontological Society,
University of British Columbia, Earth and Ocean Sciences, and
British Columbia Paleontological Alliance
MAY 15-18, 2009

Call for Posters & Abstracts

2009 BCPA CONFERENCE - The Vancouver Paleontological Society invites you the Eighth British Columbia Paleontological Symposium, to be held at the University of British Columbia, May 15-18, 2009.

KEYNOTE SPEAKER - This year’s keynote speaker will be Dr. Gregory Wilson, a specialist on the evolution and ecology of early mammals, University of California, Berkeley, Department of Integrative Biology. Continuing the format of past symposia, the meeting will bring together both the professional and avocational paleontological community.

As well as an engaging line-up of speakers, there will also be field trips, workshops, retail booth and the return of the popular Paleo Art Show with juried prizes. A Community Open House will be held on the Sunday for members of the general public.

FOSSIL MAMMALS - While the symposium will highlight fossil mammals, we invite talks, posters and displays showcasing all aspects of paleontology, with non-academics especially encouraged to contribute.

SYMPOSIUM ABSTRACT VOLUME - There will be a symposium abstract volume published and provided to all registrants. We request that speakers and poster presenters submit abstracts for the publication. Abstracts can be 1-4 pages (with 1 being standard) in length. Mailing and e-mail address of the author should be included for insertion in the volume.

DEADLINE FOR SUBMISSION of posters and abstracts for publication is April 10, 2009. Submission of an abstract is mandatory for speakers and poster displays. Paleontologists unable to make the meeting but interested in contributing to the abstract volume to share their research on fossil mammals are welcome to contribute.

REGISTRATION – FULL SYMPOSIUM PASS
Professional Paleontologists $100 | Non-BCPA attendees $100 | BCPA Members $80 | Students $60

SEND CHEQUE PAYABLE TO:
Vancouver Paleontological Society, Centrepoint P.O. Box 19653, Vancouver, BC, V5T 4E7

FOR MORE INFORMATION:
www.bcfossils.ca | http://www.vcn.bc.ca/vanps/ | fossilhuntress@hotmail.co.uk

Tuesday 3 February 2009

Monday 2 February 2009

TRIASSIC-JURASSIC EXTINCTION

Located as they are in Canada’s most active earthquake zone, the Queen Charlotte Islands have had their share of shake-ups and scourings. Many of the Islands’ hillsides are scarred by slides (any specific examples?). But the rock beneath speaks of an even more violent past. Very few people know that the rock in the Queen Charlottes holds the key to a catastrophic event from eons ago.We’ve heard tales and seen images of the cataclysmic damage caused by meteriorites smashing into the Earth’s surface.

Until recently, it was a meteorite impact that was blamed for the worldwide Triassic/Jurassic Mass Extinction. This wholesale dying out of species occurred some 200 million years ago. New evidence challenges the meteorite theory. Experts now believe that tectonic forces may have caused hundreds of volcanoes around the world to erupt simultaneously. The subsequent showers of volcanic ash would have altered the composition of the atmosphere dramatically and plunged the world into near total darkness for years until it settled from the sky.

The picture painted of the sun flickering fitfully through inky clouds, paling against the torrents of glowing lava, while everywhere life is smothered, poisoned, or starved, rivals the most apocalyptic imaginings of Hollywood or religion. We know from worldwide evidence that the extinction was dramatic and affected upwards of 70% of the world’s biota.


Perhaps counterintuitively, for one might think of water as a refuge from fire, smoke, and lava, it was marine lifeforms that suffered the most. This is particularly well documented in the rocks of the Queen Charlottes, especially at Kennecott Point and Kunga Island.

Radiolarian microfossils – tiny, siliceous, single-celled microrganisms – tell the tale. In the Upper Triassic rocks, which predate the extinction 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.

EIGHTH BC PALEONTOLOGICAL SYMPOSIUM


Eighth British Columbia Paleontological Symposium

Presented by the Vancouver Paleontological Society,
University of British Columbia, Earth and Ocean Sciences, and
British Columbia Paleontological Alliance

May 15-18, 2009

Call for Posters & Abstracts

The Vancouver Paleontological Society invites you to submit a poster or abstract for the Eighth British Columbia Paleontological Symposium, to be held at the University of British Columbia, May 15-18, 2009.

This year’s keynote speaker will be Dr. Gregory Wilson, a specialist on the evolution and ecology of early mammals, University of California, Berkeley, Department of Integrative Biology. Continuing the format of past symposia, the meeting will bring together both the professional and avocational paleontological community.

As well as an engaging line-up of speakers, there will also be field trips, workshops, retail booth and the return of the popular paleontological art show with juried prizes. While the symposium will highlight fossil mammals, we invite talks, posters and displays showcasing all aspects of paleontology, with non-academics especially encouraged to contribute.

Symposium Abstract Volume
There will be a symposium abstract volume published and provided to all registrants. We request that speakers and poster presenters submit abstracts for the publication to the editor (see below). Abstracts can be 1-4 pages (with 1 being standard) in length although exceptions will be made for specific requests.

Abstract contributors are encouraged to include photos and/or diagrams although it should be noted that the abstract volume would be printed in black and white. Documents will not be edited for content but may be reformatted to fit into the volume. Mailing and e-mail address of the author should be included for insertion in the volume.

Deadline for submission of posters and abstracts for publication is April 1st, 2009. Submission of an abstract is mandatory for speakers and poster displays.

About the Vancouver Paleontological Society
The Vancouver Paleontological Society is a non-profit society whose purpose is to promote the science of paleontology through study and education and make contributions to the science through discovery, collection, description, public education and preservation of material for study and posterity.

British Columbia Paleontological Alliance
The Vancouver Paleontological Society is a member of the British Columbia Paleontological Alliance, a union of professional and amateur paleontologists working to advance the science of paleontology. For more information: www.bcfossils.ca

Submitting a Poster - Helpful Hints

What is a poster? A poster is a visual medium to express current results of one's research work on a topic the presenter has chosen to study or to provide an overview of a researched topic. A poster is something that you pin up on a board. The dimension of a poster can vary from 2' x 3' to 4' x 8'. It contains text and figures relevant to one's work. It follows the same pattern as any scientific article that appears in a journal does. One typical format:

Title, Author(s), Affiliation
Summary
Introduction – Reasons behind the work
General information
Geographical location of where the fossils were found
Description and interpretation
Conclusions
References

Dedicate a box to each one of the above categories. Within the box, include the text and figures relevant to the category. Number the boxes in such a way that the reader can follow from one box to the other in a sequence the presenter wishes. The structure of the above framework changes from topic to topic.

Who should do a poster?
Anyone who has an interest in sharing their work and who likes feedback from the audience (or attendees) on their work should consider doing a poster.

What should be considered for a poster?
Any topic that ties in with palaeontology can be considered for a poster.

Why posters?
Written presentations are mechanisms to convey past and recent developments in a field of study essential to the investigator. An effective written presentation is a poster presentation.

How does one make a poster & how should it look?
Most posters are made using a computer, either in a word processing program or PowerPoint. However, you do not have or use a computer to make a poster. Whatever the size of your poster is should be easily ready from 3 to 4 feet away. The same is true for photos, graphs and figures. Ensure they are printed large enough to be clear from a distance. Posters can be full color or black and white.

Good Luck!

Eighth British Columbia Paleontological Symposium
Presented by the Vancouver Paleontological Society,
University of British Columbia, Earth and Ocean Sciences & British Columbia Paleontological Alliance

May 15-18, 2009
Vancouver, BC

PROGRAM:

Fri, May 15, 2009:

5:00 PM Registration Opens
Poster & Fossil Display Set-up

6:00 - 10:00 Walcott Icebreaker
Posters, Fossil Displays & Art Show


Sat, May 16, 2009:

8:30 Registration & Package Pick-Up

9:00 Welcome & Keynote Address

9:45 -4:00 Speaker Program
Posters, Fossil Displays & Art Show

6:00 PM W.R Danner Banquet


Sun, May 17, 2009:

8:30 Registration & Package Pick-Up

9:00 – 3:00 Speaker Program
Posters, Fossil Displays & Art Show

3:00 – 5:00 Community Open House
Junior Paleontologist Workshops & Fossil ID

4:00 – 6:00 Symposium Workshops


Mon, May 18, 2009

9:00 AM Field Trip Departures

Location: University of British Columbia

Deadline for submission of posters and abstracts for publication is April 1st, 2009. Submission of an abstract is mandatory for speakers and poster displays.

Further Information

Posters presentation | Abstract submissions | General Information |

E-mail: fossilhuntress@hotmail.co.uk

MEANDERING THROUGH THE EOCENE: CHUCKANUT DRIVE


by Heidi Henderson


Chuckanut Drive, in northwestern Washington provides a visual feast from sea to sky.

An amazing array of plants and animals call this coastline home. For the fossil enthusiast, it is a chance to slip back in time and have a bird’s eye view to a more tropical time with a visit to the Chuckanut Formation. Snug up against the Pacific Ocean, this 6000m thick exposure yields a vast number of tropical and flowering plants that you might see in Mexico today. Easily accessible by car, this rich natural playground makes for an enjoyable daytrip just one hour south of the US Border.

Shaping our World

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.

Intuition tells us that the earth’s crust is a permanent, 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.

Washington is Born

Two hundred million years ago, Washington was two large islands, bits of 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 Formation

The area we will be visiting along Chuckanut Drive is much younger than other parts of Washington. The fossils we will visit 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 the Chuckanut 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 & 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. If you are interesting in viewing a tropical paradise in your own backyard, look no further than the Chuckanut.

Images and tag lines: Glyptostrobus, the Chinese swamp cypress, is perhaps the most common plant found here. Also abundant are fossilized remains of the North American bald cypress, Taxodium; Metasequoia (dawn redwood), Lygodium (climbing fern), large Sabal (palm) and leaves from a variety of broad leaf angiosperm plants such as (witch hazel), Laurus (laurel), Ficus (fig) and Platanus (sycamore), and several other forms.

Inset: Mammal Fossils in Washington

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. The movement of these celebrity vertebrates was captured in the soft mud on the banks of a river, one of the only depositional environments favorable for track preservation.

Sidebar: Fossils Must be Dinosaurs…

We can thank Mr. Spielberg and popular culture for the fact that most people think of dinosaurs when they think of fossils. The bone record is actually far less abundant that the plant record. While calcium rich bones and teeth fossilize well, they often do not get laid down in a situation that makes this possible.

Look around at the site today and the abundance of plants and lack of visible animal life. They are far fewer animals than plants and consequently in a setting such as this far fewer animals in the fossil record. It is the reverse at some sites, i.e. the Gobi desert and Alberta, but in the Chuckanut, this is the way it plays out.

In Alberta, most of what we find are small bone fragments from vertebrates. This colors our notions of what the world must have looked like. It shows us only one small piece of the puzzle as to what life must have been like in an area when part of the fossil record is missing.

Tuesday 27 January 2009

In Search of Ancient BC - Volume I


In Search of Ancient BC - Volume I by Barbara Huck, Heidi Henderson & Philip Torrens

"Once, parts of British Columbia lay on the far side of the Pacific. Once, its ancient seacoasts were inhabited by creatures on the threshold of evolution. Once it was populated by some of Canada's first peoples.

Today, B.C. is one of the world's most geographically varied places. But clues to its ancient past are everywhere, in its mountains and arid valleys, along its lakeshores and seacoasts.


For the first time, the geological, paleontological and archaeological wonders of southern B.C. are gathered in one place. With hundreds of color photographs, maps and drawings, In Search of Ancient British Columbia presents an accessible, route-oriented approach for today's time travellers, creating an indispensable guide to the forces that have shaped the spirit of the land."


Heartland Books is a Winnipeg-based publisher of history, heritage, travel and non-fiction. I look forward to Volume II covering the northern regions. - review of In Search of Ancient BC

Wednesday 21 January 2009

KIBBEE LAKE

Paddling in the rain, I notice bits of mica in the water, playing in the light and the rock change here to greywacke, argillite, phyllite and schist. Past Lanezi, we continue onto Sandy Lake, where old growth cedars line the south-facing slopes to our left and grey limestone, shale and dolostone line the shore. Mottled in with the rock, we sneak up on very convincing stumps posing as large mammals. Picking up the Cariboo River again, we follow it as it flows into Babcock Lake, an area edged with Lower Cambrian limestone, shale and argillite. At the time these rocks were laid down, the Earth was seeing our earliest relatives, the first chordates entering the geologic scene.

Tuesday 13 January 2009

Friday 9 January 2009

Thursday 1 January 2009

ON YOUR KNEES - PTEROSAURS TOOK FLIGHT ON ALL FOURS


Pterosaurs took flight using all fours, a discovery that flies in the face of previous research on the ancient reptiles, a new study says.

Two of the giant creatures' "legs" were extremely strong wings, which when folded, created "knuckles" that allowed the animals to walk and jump (above left, the pterosaur known as Hatzegotpteryx in an artist's rendering).

The way a bird lifts off—using two legs—doesn't make sense for pterosaurs, which would have had to heave their 500 pounds (227 kilograms) airborne using only their hind legs, the study says.

Instead, the "remarkably strong" animals apparently made a leaping launch in less than a second from flat ground, with no aid from wind or ledges.

"Most people are familiar with images of pterosaurs as very skinny, almost emaciated-looking things—basically a hang glider with teeth," study author Michael B. Habib, of Johns Hopkins University School of Medicine, told National Geographic News. "They're actually built a lot more like Arnold Schwarzenegger than Urkel."

Habib compared bone strength in 20 species of modern birds and 3 species of pterosaurs to develop the new model, announced yesterday by the journal Zitteliana.

The finding is also consistent with the idea that bigger animals require more overall brawn to power their movement, Habib added.

"We put V8 engines in our biggest, heaviest cars, not V4s, like the one in my Camry."

— Story sourced from National Geographic, Christine Dell'Amore

Tuesday 30 December 2008

Tuesday 23 December 2008

Wednesday 17 December 2008

Thursday 20 November 2008

Sunday 16 November 2008

Saturday 15 November 2008

Sunday 26 October 2008

Tuesday 21 October 2008

Saturday 4 October 2008

GOLDEN PEEKS AT RHODESIAN

When my little golden retriever, Meadow, was just a pup, I took her to the dog part where she played the day away with a gorgeous rhodesian ridgeback. Later that year, I let her pick a rhodesian puppy out of a litter and that is how we came to have my beautiful boy Kane. I love this shot.

Sunday 28 September 2008

Tuesday 9 September 2008

DINOSAURS VS. CROCODILIAN UPSTARTS -- A BATTLE FOR SURVIVAL


Dinosaurs, long hailed as the rulers of the Triassic almost lost the title belt to a group of crocodilian upstarts, the crurotarsans. In a short lived battle for survival, geologically speaking, the two groups ran head to head for about thirty million years. The Crurotarsi or "cross-ankles" as they are affectionately known, are a group of archosaurs - formerly known as Pseudosuchians when paleontologist Paul Serono renamed them for their node-based clade in 1991

Friday 8 August 2008

Friday 11 July 2008