Tuesday 30 December 2014

HAIDA GWAII: ISLANDS OF MIST

Steeped in mist and mythology, the islands of the Queen Charlottes abound in local lore that surrounds their beginnings.

Today, the Hecate Strait is a tempestuous 40-mile wide channel that separates the mist-shrouded archipelago of Haida Gwaii from the BC mainland. Haida oral tradition tells of a time when the strait was mostly dry, dotted here and there with lakes. 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 contain wood, pollen, and other terrestrial plant materials that tell of a tundra-like environment.

The court is still out on whether or not the strait was ever completely dry during these times, but it certainly contained a series of stepping-stone islands and bridges that remained free of ice.

An ancient Haida tale, recorded in the late 1800s by a Hudson’s Bay Company trader, records the island's glacial history. Scannah-gan-nuncus, a boy who lived in the village now called Skidegate, had canoed up the Hunnah, a once roaring tributary to Skidegate Channel that is now a rocky creek, seldom deep enough to navigate.

The Haida the legend accurately records that it used to be several times deeper. Tired from paddling upstream, Scannah-gan-nuncus landed to take a nap. “In those days at the place where he went ashore were large boulders in the bed of the stream, while on both sides of the river were many trees. While resting by the river, he heard a dreadful noise upstream. Looking to see what it was, he was surprised to behold all the stones in the river coming toward him. … all the trees were cracking and groaning … he went to see what was crushing the stones and breaking the trees. On reaching them, he found that a large body of ice was coming down, pushing everything before it.”

Scannah-gan-nuncus’ experience with the glacier would have been familiar to the inhabitants of the Queen Charlottes. In recent years, 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 the Queen Charlottes ice-sheet, a thick mass of flowing ice that ran tandem with the Cordilleran sheet in the Hecate Lowlands.

Strolling around you can see where the glaciers left their mark on the Islands’ U-shape valleys, once a steep V-shape, now scoured smooth by glaciers that also deposited the erratic boulders can been seen sitting like sentinels on the beach.

CRETACEOUS NANAIMO GROUP

The strata near Nanaimo and much of eastern Vancouver Island is underlain by sedimentary rocks of the Cretaceous Nanaimo Group. These mudstones, sandstones and conglomerates were deposited in deltas, rivers and marine environments between 95 and 65 million years ago. While there is a mix, almost all of the great fossil exposures are marine.

Monday 29 December 2014

CAMBRIAN TRILOBITES


The Cambrian was a time of expansion for the Earth's complex animal forms. Molluscs and arthropods and their friends with hard shells and exoskeletons dominated the seas. The specimen you see here is of a Wanneria dunnae trilobite from the Eager Formation, Rifle Range site near Cranbrook, British Columbia.

Thursday 25 December 2014

Friday 19 December 2014

JELLYFISH: DANCERS OF THE DEEP

This lovely ocean dancer with her long delicate tentacles or lappets and thicker rouched oral arms is a jellyfish. 

Her brethren are playing in the waters of the deep all over the world, from surface waters to our deepest seas — and they are old. They are some of the oldest animals in the fossil record.

Jellyfish and sea jellies are the informal common names given to the medusa-phase or adult phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria — more closely related to anemones and corals.

Jellyfish are not fish at all. They evolved millions of years before true fish. The oldest conulariid scyphozoans appeared between 635 and 577 million years ago in the Neoproterozoic of the Lantian Formation, a 150-meter-thick sequence of rocks deposited in southern China. 

Others are found in the youngest Ediacaran rocks of the Tamengo Formation of Brazil, c. 505 mya, through to the Triassic. Cubozoans and hydrozoans appeared in the Cambrian of the Marjum Formation in Utah, USA, c. 540 million years ago.

I have seen all sorts of their brethren growing up on the west coast of Canada. I have seen them in tide pools, washed up on the beach and swam amongst thousands of Moon Jellyfish while scuba diving in the Salish Sea. Their movement in the water is marvellous.  

In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, jellyfish are known as ǥaǥisama.

The watercolour ǥaǥisama you see here in dreamy pink and white is but one colour variation. They come in blue, purple, orange, yellow and clear — and are often luminescent. They produce light by the oxidation of a substrate molecule, luciferin, in a reaction catalyzed by a protein, luciferase.

Wednesday 17 December 2014

Monday 17 November 2014

Thursday 30 October 2014

KOALA: BABY JOEY

Koala, Phasscolarctos cinereus, are truly adorable marsupials native to Australia. These cuddly "teddy bears" are not bears at all. Koalas belong to a group of mammals known as marsupials. 

Fossil remains of Koala-like animals have been found dating back 25 million years. Some of the relatives of modern koalas were much larger, including the Giant Koala, Phascolarctos stirtoni

It should likely have been named the Robust Koala, instead of Giant, but this big boy was larger than modern koalas by about a third. Phascolarctos yorkensis, from the Miocene, was twice the size of the modern koalas we know today. Both our modern koalas and their larger relatives co-existed during the Pleistocene, sharing trees and enjoying the tasty vegetation surrounding them.

Tuesday 23 September 2014

TRACKING THEROPODS

Toe to Toe with a Theropod — In the outcrops around Clarens, South Africa.

We get a bird's eye view (or Theropod's eye view) of life back in the Late Triassic and Early Jurassic. Both here and at Elliott we see dinosaur remains tracks and dino eggs!

Thursday 18 September 2014

PETRIFIED WOOD

Petrified wood is amazing to behold in person. The original tree or branch is sometimes subjected to such a high degree of replacement that it is impossible to tell from the original at first glance. But fossilized it is. All of the original cells are replaced one by one with minerals, often a silicate such as quartz, leaving the original cell structure intact.



And while there is often amazing preservation of the big woody bits, the telltale leaves that help us identify that wood to species are often lost. If this is the case, we add our best guess at the genus and add xlon. So, Palmoxylon is the indeterminate wood of a palm, though we may never know which palm. If you have an interest in botany and fossils, you may want to consider making a career of it. The study of fossil wood is called palaeoxylology. And a palaeoxylologist is someone who studies fossil wood.

Thursday 21 August 2014

Tuesday 29 July 2014

Sunday 27 July 2014

Tuesday 22 July 2014

AMMONITES & MARINE REPTILES FROM THE MYSTERIOUS CREEK FORMATION

The Cretaceous-Jurassic exposures near Harrison Lake, British Columbia are an easy two hour drive from Vancouver and another hour or so to our final destination, the unyielding siltstone of the Callovian, 166 million year old, Mysterious Creek Formation.

A few hours of collecting yield multiple bivalves, ammonites, including what looks to be two new species. 

Amongst the best specimens of the day are several small, fairly well preserved Cadoceras (Paracadoceras) tonniense, a few Cadoceras (Pseudocadoceras) grewingki and two relatively complete specimens of the larger, smooth Cadoceras comma. Further up the road, we photograph blocks of buchia and large boulders encrusted with perfectly preserved belemnites from ancient squid.

Interestingly, the ammonites from here are quite similar to the ones found within the lower part of the Chinitna Formation, Alaska and Jurassic Point, Kyuquot, on the west coast of Vancouver Island. The siltstone here at Harrison has also offered up a small section of vertebra from a poorly preserved marine reptile, a find I'm rather keen to make one day. So, after much hammer swinging, I've enjoyed a splendid day, collected beautiful specimens and feel a wee bit closer to the big find. 

Sunday 13 July 2014

TYLOSTOMA TUMIDUM

This lovely big fellow is Tylostoma tumidum, an epifaunal grazing Lower Cretaceous Gastropod from white, micritic, coarsely nodular limestone deposits of the Goodland Formation at White Settlement west of Fort Worth, Texas, USA. (171.6 to 58.7 Ma). The bedding here is massive with some thin clay beds. The macro fossil found here include the ammonite, Oxytropidoceras acutocarinatum, pelecypods such as Protocardia, Pinna and Lima wacoensis along with heart-shaped urchins in abundance and lovely gastropods such as this beauty, Tylostoma tumidum.

Tylostoma have thick, smooth shells with a moderately elevated spire. Their aperture is ovato-lunate with the lips meeting above at a sharp angle. The outer lip is furnished internally, running the whole length and ending with a thickened edge. This specimen shows the wear and tear of erosion common at the site.

Saturday 5 July 2014

LIVING FOSSIL: COMB JELLY

Living Fossil / Comb Jelly / Ctenophore
This lovely invertebrate is a Comb Jelly, a living fossil. Coined by Charles Darwin, the term “living fossils” is used to describe organisms that have remained largely unchanged for millions of years. While simple in design, the Comb Jellies have stood the test of time. The color you see here is light refracting on rows of Mertensia ovum.

Saturday 14 June 2014

FIERCE WARRIORS: CRABS

Look how epic this little guy is! 

He is a crab — and if you asked him, the fiercest warrior that ever lived. While that may not be strictly true, crabs do have the heart of a warrior and will raise their claws, sometimes only millimetres into the air, to assert dominance over their world. 

Crabs are decapod crustaceans of the Phylum Arthropoda. 

In the Kwak'wala language of the Kwakwaka'wakw of the Pacific Northwest, this brave fellow is ḵ̓u'mis — both a tasty snack and familiar to the supernatural deity Tuxw'id, a female warrior spirit. Given their natural armour and clear bravery, it is a fitting role.

They inhabit all the world's oceans, sandy beaches, many of our freshwater lakes and streams. Some few prefer to live in forests.

Crabs build their shells from highly mineralized chitin — and chitin gets around. It is the main structural component of the exoskeletons of many of our crustacean and insect friends. Shrimp, crab, and lobster all use it to build their exoskeletons.

Chitin is a polysaccharide — a large molecule made of many smaller monosaccharides or simple sugars, like glucose. 

It is handy stuff, forming crystalline nanofibrils or whiskers. Chitin is actually the second most abundant polysaccharide after cellulose. It is interesting as we usually think of these molecules in the context of their sugary context but they build many other very useful things in nature — not the least of these are the hard shells or exoskeletons of our crustacean friends.

Crabs in the Fossil Record

The earliest unambiguous crab fossils date from the Early Jurassic, with the oldest being Eocarcinus from the early Pliensbachian of Britain, which likely represents a stem-group lineage, as it lacks several key morphological features that define modern crabs. 

Most Jurassic crabs are only known from dorsal — or top half of the body — carapaces, making it difficult to determine their relationships. Crabs radiated in the Late Jurassic, corresponding with an increase in reef habitats, though they would decline at the end of the Jurassic as the result of the decline of reef ecosystems. Crabs increased in diversity through the Cretaceous and represented the dominant group of decapods by the end.

We find wonderful fossil crab specimens on Vancouver Island. The first I ever collected was at Shelter Point, then again on Hornby Island, down on the Olympic Peninsula and along Vancouver Island's west coast near Nootka Sound. They are, of course, found globally and are one of the most pleasing fossils to find and aggravating to prep of all the specimens you will ever have in your collection. Bless them.