FOSSIL SEA LILLIES: CRINOIDS

Uintacrinus socialis from Utah, USA

Crinoids are one of my favourite echinoderms. It is magical when all the elements come together to preserve a particularly lovely specimen in such glorious detail. 

If you look closely at the detail here you can see a stunning example of Upper Cretaceous, Santonian age, Uintacrinus socialis — named by O.C. Marsh for the Uinta Mountains of Utah nearly 150 years ago.  

These lovelies are best known from the Smoky Hills Niobrara Formation of central Kansas.

Crinoids are unusually beautiful and graceful members of the phylum Echinodermata. They resemble an underwater flower swaying in an ocean current. 

But make no mistake they are marine animals. Picture a flower with a mouth on the top surface that is surrounded by feeding arms. Awkwardly, add an anus right beside that mouth. 

Crinoids with root-like anchors are called sea lilies. They have graceful stalks that grip the ocean floor. Those in deeper water have longish stalks up to 3.3 ft or a meter in length. Then there are other varieties that are free-swimming with only vestigial stalks. They make up the majority of this group and are commonly known as feather stars or comatulids. 

Unlike the sea lilies, the feather stars can move about on tiny hook-like structures called cirri. It is these same cirri that allow crinoids to latch to surfaces on the seafloor. Like other echinoderms, crinoids have pentaradial symmetry. The aboral surface of the body is studded with plates of calcium carbonate, forming an endoskeleton similar to that in starfish and sea urchins.

These make the calyx somewhat cup-shaped, and there are few, if any, ossicles in the oral (upper) surface, an area we call the tegmen. It is divided into five ambulacral areas, including a deep groove from which the tube feet project, and five interambulacral areas between them. 

Crinoids are alive and well today. They are also some of the oldest fossils on the planet. We have lovely fossil specimens dating back to the Ordovician — if one ignores the enigmatic Echmatocrinus of the Burgess Shale. And they can be quite plentiful. Crinoid fossils, and in particular disarticulated crinoid columnals, can be so abundant that they at times serve as the primary supporting clasts in sedimentary rocks.

SLOTHS & BLUE GREEN ALGAE

Ever wonder why the slow moving sloth has a slightly greenish hue? Ever consider the sloth at all? Well, perhaps not. Location, location, location, is the mantra for many of us in our macro world, but it is also true for the small world of algae.

Blue green algae is a term used to describe any of a large, heterogeneous group of prokaryotic, principally photosynthetic organisms.

These little oxygenic (oxygen-producing) fellows appeared about 2,000,000,000 to 3,000,000,000 years ago and are given credit for greatly increasing the oxygen content of the atmosphere, making possible the development of aerobic (oxygen-using) organisms and some very special relationships with some of the slowest moving mammals on the planet, the sloths or Folivora.

The tribes of South America who live close to these insect and leaf-eaters, call these arboreal browsers "Ritto, Rit or Ridette, which roughly translates to variations on sleep, sleepy, munching and filthy. Not all that far off when you consider ths sloth and their lifestyle.

The sloth's body and shaggy coat, or pelage, provides a comfy habitat to two types of wee blue-green algae along with various other invertebrates. The hairs that make up the sloth's coat have grooves that help foster algal growth.

And, while Kermit the Frog says, "it's not easy being green," it couldn't be further from the truth for this slow-moving tree dweller. The blue-green algae gives the sloth a natural greenish camouflage, an arrangement that is certainly win-win.

DESTINATION BC: EAST KOOTENAY REGION

The East Kootenay region on the south-eastern edge of British Columbia is a land of colossal mountains against a clear blue sky. 

That is not strictly true, of course, as this area does see its fair share of rain and temperature extremes — but visiting in Autumn every view is a postcard of mountainous terrain.

Rocks from deep within the Earth's crust underlie the entire East Kootenay region and are commonly exposed in the areas majestic mountain peaks, craggy rocky cliffs, glaciated river canyons, and rock cuts along the highways. Younger Ice Age sediments blanket much of the underlying rock.

I've been heading to the Cranbrook and Fernie area since the early 1990s. My interest is the local geology and fossil history that these rocks have to tell. I'm also drawn to the warm and welcoming locals who share a love for the land and palaeontological treasures that open a window to our ancient past.  

Cranbrook is the largest community in the region and is steeped in mining history and the opening of the west by the railway. It is also a stone's throw away from Fort Steele and the Lower Cambrian exposures of the Eager Formation. These fossil beds rival the slightly younger Burgess Shale fauna and while less varied, produce wonderful examples of olenellid trilobites and weird and wonderful arthropods half a billion years old. 

Labiostria westriopi, McKay Group

The Lower Cambrian Eager Formation outcrops at a few localities close to Fort Steele, many known since the early 1920s, and up near Mount Grainger near the highway. 

Further east, the Upper Cambrian McKay Group near Tanglefoot Mountain is a palaeontological delight with fifteen known outcrops that have produced some of the best-preserved and varied trilobites in the province — many of them new species. 

The McKay Formation also includes Ordovician outcrops sprinkled in for good measure.

Other cities in the area and the routes to and from them produce other fossil fauna from Kimberley to Fernie and the district municipality of Invermere and Sparwood. This is an arid country with native grasslands and forests of semi-open fir and pine. Throughout there are a host of fossiliferous exposures from Lower Cretaceous plants to brachiopods. 

The area around Whiteswan Lake has wonderful large and showy Ordovician graptolites including Cardiograptus morsus and Pseudoclimacograptus angustifolius elongates — some of our oldest relatives. A drive down to Flathead will bring you to ammonite outcrops and you can even find Eocene fresh-water snails in the region. 

The drive from Cranbrook to Fernie is about an hour and change through the Cambrian into the Devonian which flip-flops and folds over revealing Jurassic exposures. 

Fernie Ichthyosaur Excavation, 1916

The Crowsnest Highway into Fernie follows Mutz Creek. From the highway, you can see the Fernie Group and the site along the Elk River where an ichthyosaur was excavated in 1916. 

The Fernie Formation is Jurassic. It is present in the western part of the Western Canada Sedimentary Basin in western Alberta and northeastern British Columbia. 

It takes its name from the town of Fernie, British Columbia, and was first defined by W.W. Leach in 1914. The town of Fernie is rimmed by rugged mountains tipped with Devonian marine outcrops. In essence, all these mountains are upside down with the oldest layers flipped to the top and a good 180 million years older than those they sit upon. 

Before they were mountains, these sedimentary rocks were formed as sediment collected in a shallow sea or inland basin. About 360 million years ago, the rocks that you see in Fernie today were down near the equator. They road tectonic plates, pushing northeast smashing into the coastline of what would become British Columbia. A little push here, shove there — compression and thrust faulting — and the rock was rolled over on its head — repeatedly. But that is how mountains are often formed, though not usually pushed so hard that they flip over. But still, it is a slow, relentless business. 

Cretaceous Plant Material, Fernie, BC

Within Fernie, there are small exposures of Triassic and Jurassic marine outcrops. East of the town there are Cretaceous plant sites, and of course, the Jurassic 1.4-metre Titanites occidentalis ammonite up on Coal Mountain.

The regional district's dominant landform is the Rocky Mountain Trench, which is flanked by the Purcell Mountains and the Rocky Mountains on the east and west, and includes the Columbia Valley region. The southern half of which is in the regional district — its northern half is in the Columbia-Shuswap Regional District. 

The regional district of Elk Valley in the southern Rockies is the entryway to the Crowsnest Pass and an important coal-mining area. 

Other than the Columbia and Kootenay Rivers, whose valleys shape the bottomlands of the Rocky Mountain Trench, the regional districts form the northernmost parts of the basins of the Flathead, Moyie and Yahk Rivers. 

The Moyie and Yahk are tributaries of the Kootenay, entering it in the United States, and the Flathead is a tributary of the Clark Fork into Montana.

Photo One: Tyaughton Mountain, Mckay Group; Photo Two: Labiostria westriopi, Upper Cambrian McKay Group, Site ML (1998); John Fam Collection; Photo Three: Ichthyosaur Excavation, Fernie, British Columbia, 1916; Photo Four: Cretaceous Plant Fossils, east of Fernie towards Coal Mountain. The deeply awesome Guy Santucci as hand-model for scale. 

SEA ANEMONES: CNIDARIA

These colourful beauties are sea anemones. They are familiar inhabitants of rocky shores and coral reefs around the world — with some of their brethren found at very low depths in our oceans. They are one of the wonderful examples of the diversity that radiated out of the Cambrian Explosion.

In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, sea anemones are known as 'mis'ma̱t̕sa. 

These beautiful predatory animals are a common site in tide pools all along the Pacific Coast. They form a large part of many special memories of exploring the tide pools along Storey's Beach on the east side of Vancouver Island as a child. 

Touching their soft tentacles is hypnotic and highly entertaining but our human skin is coated in oils and bacteria that may damage these delicate organisms. 

We sometimes see them turn up in First Nation's art — particularly in association with Kumugwe' or the Copper-Maker, Chief of the undersea world and the one to thank for the rising and ebbing of the tides.

At first glance, they look like beautiful and delicate marine flowers. If you have discovered them in tidepools, you will know that they retract or pull into themselves with the lightest touch. These would-be flowers are predatory marine animals of the order Actiniaria that have graced our oceans for over half a billion years. 

They are named after anemones — Anemonastrum, a genus of flowering plants in the family Ranunculaceae — because of their colourful flower-like appearance. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia. 

As cnidarians, sea anemones are related to corals, jellyfish, tube-dwelling anemones, and Hydra. Jellyfish have a complex life cycle that includes both sexual and asexual phases, with the medusa being the sexual stage in most instances. 

A typical sea anemone is a single polyp attached to a hard surface by its base, but some species live in soft sediment and a few float near the surface of the water. The polyp has a columnar trunk topped by an oral disc with a ring of sticky tentacles that fold in towards its central mouth. If they have stung and paralyzed a tasty snack, it is pulled towards the gaping mouth to be consumed. 

The tentacles can be retracted or pulled back inside the body cavity or stretched out and expanded to catch passing prey. They are armed with cnidocytes or stinging cells. In many species, nourishment comes from a symbiotic relationship with single-celled dinoflagellates — zooxanthellae or with green algae, zoochlorellae, that live within the cells. Some species of sea anemone live in association with hermit crabs, small fish or other animals to their mutual benefit.

Most actinarians are sessile — that is, they live attached to rocks or other substrates and do not move, or move only very slowly by contractions of the pedal disk. 

A number of anemones burrow into sand, and a few can even swim short distances, by bending the column back and forth or by "flapping" their tentacles. In all, there are about 1000 species of sea anemone in the world's oceans — including those who live amongst the mythic sea lions that form the posts and beams of Kumugwe''s undersea home.

Sea anemones breed by releasing sperm and eggs through their mouth into the surrounding ocean. The fertilized eggs develop into wee planula larvae that live as tiny planktonic bits floating in the sea. Eventually, they settle on the seafloor and develop directly into juvenile polyps. Sea anemones can also breed asexually. They do this by breaking in half or into smaller pieces that regenerate into polyps.

We sometimes see these beauties kept in saltwater aquariums. I can understand the appeal but it comes with a price. The global trade in marine ornamentals threatens our lovely sea anemone populations. 

Most Actiniaria do not form hard parts that can be recognized as fossils, but a few fossils of sea anemones have been found. The bag-like — almost sea cucumber-like — Mackenzia, from the Middle Cambrian, Stephen Formation in the Canadian Rockies of British Columbia and Alberta, is the oldest fossil identified as a sea anemone. These ancient sea anemones attached themselves to hard surfaces, such as brachiopod shells in a similar fashion to their modern sessile cousins. 

Mackenzia costalis, Walcott 1911

Fourteen specimens of Mackenzia costalis are known from the Greater Phyllopod bed, where they make up less than <0.1% of the fossil community. Mackenzia was originally described by Charles Walcott in 1911 — but as a holothurian echinoderm, which was a reasonable assumption at the time. Once additional specimens had been found and studied, Mackenzia costalis was reclassified as a cnidarian and the great grandparent of our modern sea anemones.

Some fossil sea anemones have also been found from the Lower Cambrian of China. The new find lends support to genetic data that suggests anthozoans — anemones, corals, octocorals and their kin — were one the first Cnidarian groups to diversify. We will likely find more of these rare fossils over time and perhaps get a better view of their long lineage.

Photo: Charles Doolittle Walcott - Charles D. Walcott: Middle Cambrian Holothurians and Medusae. Smithsonian Miscellaneous Collections Volume 57, Number 3 (Publication 2011). City of Washington. Published by the Smithsonian Institution. June 13, 1911. 

References:  

Caron, Jean-Bernard; Jackson, Donald A. (October 2006). "Taphonomy of the Greater Phyllopod Bed community, Burgess Shale". PALAIOS. 21 (5): 451–65. doi:10.2110/palo.2003.P05-070R. JSTOR 20173022.

 Durham, J. W. (1974). "Systematic Position of Eldonia ludwigi Walcott". Journal of Paleontology. 48 (4): 750–755. JSTOR 1303225.

Conway Morris, S. (1993). "Ediacaran-like fossils in Cambrian Burgess Shale–type faunas of North America". Palaeontology. 36 (31–0239): 593–635.

OPABINIA REGALIS

Opabinia regalis is an extinct stem-group arthropod found in the Greater Phyllopod Bed, Middle Cambrian Burgess Shale Lagerstätte of British Columbia, Canada. 

These marine arthropods flourished from 505 million years ago to 487 million years ago.

Charles Doolittle Walcott found nine partially complete fossils of Opabinia regalis and a few of what he classified as Opabinia media, that he published in 1912. 

The bizarre arthropod's name is derived from the Opabin pass between Mount Hungabee and Mount Biddle, southeast of Lake O'Hara, British Columbia, Canada. 

In 1966–1967, Harry B. Whittington found a rather good specimen which he published in 1975. He provided a detailed description based on a very thorough dissection of some specimens and photographs of these specimens lit from a variety of angles. Harry was a very thorough fellow.

But he was still ridiculed. Opabinia looked so strange that the audience at the first presentation of Whittington's analysis laughed.

Earth's ancient seas teemed with new life 541 - 485 Million Years Ago. The Cambrian Explosion had arrived. Weird and wonderful life forms like Hallucigenia and Anomalocaris are found in the fossil record giving us a peek at ancient life half a billion years ago.

CAMBRIAN MYSTERIES OF THE CANADIAN ROCKIES

Mount Stephen, Canadian Rockies

High up on the mountain tops of the Canadian Rockies of southeastern British Columbia — on the western edge of Western Canada's Sedimentary Basin — there are mysteries more than half a billion years old. 

Here, for more than a century, palaeontologists have been exploring over a dozen geologic outcrops that speak of a world when arthropods ruled the seas. 

The rocks we walk across are made of shale, thin-bedded limestone, and siltstone deposited during the Middle Cambrian — 513 to 497 million years ago. And these are no ordinary rocks for what they contain — exceptionally preserved soft-bodied fossils of the Burgess Shale biota. 

Charles Doolittle Walcott will be forever remembered for his extraordinary 1909 discovery of the Middle Cambrian Burgess Shale of Yoho National Park in southern British Columbia — delivering to the world one of the most important biota of soft-bodied organisms in the fossil record. Here we find a fairly complete look at an ancient ecosystem with algae, grazers and filter feeders, scavengers and active predators. Remarkably, soft-bodied organisms make up 98% of individuals and 85% of the genera. These animals lived and died in the deep waters at the base of what would later become the Cathedral Escarpment.

In 1908, Walcott wrote, "Nearly every fragment of shale found on the slopes from 2000 to 2600 feet above Field has fossils upon it; not only fragments but usually entire specimens of trilobites.” It was for this reason he returned the following year to collect and the rest, as they say, is history.

The sheer volume and level of preservation were unknown at the time. Walcott's material came from a single section on the west side of the ridge between Mount Wapta and Mount Field and was collected from the main quarry in the Phyllopod bed and the smaller Raymond quarry some 23 m above. 

The Burgess Shale section occurs in the lower two-thirds of the Stephen Formation where the basinal shales abut against the steep face of the adjacent dolomite reef of the Cathedral Formation. The conditions necessary for the preservation of the soft parts of the organisms appear to have been controlled by the proximity of this reef front. Away from the reef front, exceptional preservation is less common.

A view to Mount Stephen, Canadian Rockies

The Burgess Shale was long considered to be a unique occurrence. Then in 1977, Canadian geologist, Ian McIlreath, found that the Cathedral Escarpment or reef front, could be traced for about 20 km southeast of Walcott's quarry and that the contact between the reef and basinal shales cropped out again on Mount Field, Mount Stephen, Mount Odaray, Park Mountain and Curtis Peak. 

Des Collins speculated that more localities of soft-bodied fossils might be found in the basinal shales near these contacts, and, indeed, a few indications were later reported by Aitken and McIlreath (1981) along the line of the Escarpment. 

In 1981 and 1982, we expanded our knowledge of the region. Des Collins and others organized fieldwork that led to the discovery of about a dozen new localities, which Collins et al. published in 1983.

The most promising of the new localities occurred in a large in situ block of pale grey-blue siliceous shale about 1500 m southwest of the outcrop of the Cathedral Escarpment on the north shoulder of Mount Stephen. 

This is about 5 km almost directly south of the Burgess Shale quarries. The site was excavated by a Royal Ontario Museum party in the summer of 1983. Further fieldwork in 1986 led to the discovery of the arthropod Sanctacaris was first described by Briggs and Collins in 1988. 

Sanctacaris uncata, Mount Stephen Fossil Beds

The stratigraphic level where the block occurred is characterized by the trilobite, Glossopleura, which is the local zone fossil for the basal part of the basinal Stephen Formation (Fritz, 1971). 

In the Stephen Formation section of about 1000 m to the north on Mount Stephen measured by Fritz, the top of the Glossopleura Zone is 40 m below the level equivalent to the main Burgess Shale quarry. 

The block excavated was at least 40 m below the top of the Glossopleura Zone. This puts it 80 m or more stratigraphically below the level of the Burgess Shale Phyllopod bed.

The faunal assemblage from the block is dominated by the arthropods, Alalcomenaeua and Branchiocaris, which are very rare in the Burgess Shale. Many other Burgess Shale animals were found (Collins et al. 1983) but surprisingly not the most common — Marrella. They did find many new forms and published their finds in 1986 (Collins, 1986). By all accounts, this fauna is distinct from those in the Burgess Shale — and a shade older. 

But as we learn and gain insight, we also realize how much we have yet to learn. These outcrops help us to gain an understanding of the biology, ecology, diversity and evolution of Cambrian animals in a way that other Cambrian sites cannot. Without this insight, we would have a very limited view of the Cambrian Explosion and see only the shelly fossil assemblages. The unique conditions in the Burgess Shale record species that under typical circumstances, would never have fossilized and would be lost to us forever.

There has been no end of mysteries and riddles to be solved in the designating and correlating units within the Stephen Formation, Burgess Shale Formation, and the Cathedral Formation. Much of the controversy stems from the extensive faulting in the area and especially from environmental (facies) differences between the stratigraphic units. 

There are shelf platform sequences that include shallow water inner detrital belt, middle carbonate belt, and carbonate shelf edge facies, as well as deeper water (basinal) outer detrital belt facies. These have all have posed problems in correlation and descriptions of the formations in the area.

What used to be known as the Stephen Formation is now restricted to what was known as the "thin" Stephen Formation. The Stephen Formation now includes the Narao and Wapituk Members. What was formerly the "thick" Stephen Formation (basinal Stephen) is now called the Burgess Shale Formation. 

Pirania sp., extinct sea sponges, Burgess Shale

This formation comprises units that include the classic Burgess Shale localities (Walcott Quarry (including the "phyllopod bed"), Raymond Quarry), the Mt. Stephen Trilobite Beds, as well as most of the soft-bodied faunas (Collins Quarry, S7, Ehmaniella Zone faunas, etc.).

The Burgess Shale is a UNESCO World Heritage site. The Burgess Shale and Stephen Formations outcrop mainly in Banff and Yoho National Parks in the Alberta-British Columbia border area. All known outcrops are in Canada's Rocky Mountain Parks, so collecting is strictly forbidden. 

While you cannot collect in the parks, you can join in on a guided tour to hike, explore, capturing the beautiful scenery and fossils with your camera and through rubbings. If you fancy a hike to these exalted cliffs, follow the link below.

If an armchair visit is more your thing, pick up a copy of, A Geoscience Guide To The Burgess Shale. This illustrated guide immerses the reader in the history, geology, environment and, most importantly, fossils of the Burgess Shale in an easy-to-read, concise summary of life as it was over 500 million years ago. Excellent colour images of 3D interpretations of the organisms and photos of the fossils make this resource a must-have for anyone interested in the Burgess Shale. 

Burgess Shale Hikes: https://www.burgess-shale.bc.ca/burgess-shale-hikes/  / Toll free: 1 (800) 343-3006; Tel: 1 (250) 343-6006; Email: info@burgess-shale.bc.ca

A Burgess Shale Primer: History, Geology and Research Highlights; Jean-Bernard Caron & Dave Rudkin: https://www.rom.on.ca/sites/default/files/imce/burgess_shale_primer.pdf

References: Palaeontology, Vol 31, Part 3. 1988, pp 779-798, pls 71-73) was discovered by Collins (1986),http://palaeontology.palass-pubs.org/pdf/Vol 31/Pages 779-798.pdf

Image: Reconstruction of Sanctacaris uncata, a Cambrian Habeliidan arthropod (stem-Chelicerata: Habeliida). by Junnn11 @ni075; Pirania sp. & photos: @Fossil Huntress