Friday, 24 March 2023
CORAL: CLIMATE CHANGE INDICATORS
Annual growth bands in some corals, such as the deep-sea bamboo coral, Isididae, may be among the first signs of the effects of ocean acidification on marine life. The growth rings allow geologists to construct year-by-year chronologies, a form of incremental dating, which underlies high-resolution records of past climatic and environmental changes using geochemical techniques.
Certain species form communities called microatolls, which are colonies whose top is dead and mostly above the waterline, but whose perimeter is mostly submerged and alive. The average tide level limits their height. By analyzing the various growth morphologies, microatolls offer a low-resolution record of sea-level change and help us to reconstruct Holocene sea levels. Fossilized microatolls can also be dated using Radiocarbon dating, a method of discovering how old something is by measuring the decay of the radioactive isotope Carbon-14.
Increasing sea temperatures in tropical regions, ~1 degree C, over the last century have caused major coral bleaching, death, and collapsing of coral populations although they are able to adapt and acclimate. It is uncertain if this evolutionary process will happen quickly enough to prevent a major reduction in their numbers.
Though coral has large sexually-reproducing populations, their evolution can be slowed by abundant asexual reproduction. Gene flow is variable among our coral friends. According to the biogeography of coral species gene flow cannot be counted on as a dependable source of adaptation as they are very stationary organisms. Also, coral longevity might factor into their adaptivity.
However, adaptation to climate change has been demonstrated in many cases. These are usually due to a shift in coral and zooxanthellae genotypes. These shifts in allele frequency have progressed toward more tolerant types of zooxanthellae. Scientists found that a certain scleractinian zooxanthella is becoming more common where sea temperature is high. Symbionts able to tolerate warmer water seem to photosynthesize more slowly, implying an evolutionary trade-off.
In the Gulf of Mexico, where sea temperatures are rising, cold-sensitive staghorn and elkhorn coral have shifted in location. Not only have the symbionts and specific species been shown to shift, but there seems to be a certain growth rate favourable to selection. Slower-growing but more heat-tolerant corals have become more common. The changes in temperature and acclimation are complex. Some reefs in current shadows represent a refugium location that will help them adjust to the disparity in the environment even if eventually the temperatures may rise more quickly there than in other locations. This separation of populations by climatic barriers causes a realized niche to shrink greatly in comparison to the old fundamental niche.
Thursday, 23 March 2023
MIGHTY EAGLE: KWIKW
Bald Eagle / Kwikw / Haliaeetus leucocephalus |
Wednesday, 22 March 2023
FRAGILE BEAUTY: FOSSILIZED SCLERACTINIAN CORAL
Scleractinian Fossil Coral, Florida |
Corals first appeared in the Cambrian about 535 million years ago. Fossils are extremely rare until the Ordovician period, 100 million years later, when rugose and tabulate corals became widespread.
Palaeozoic corals seem to make friends wherever they live and often contain numerous endobiotic symbionts.
Tabulate corals occur in limestones and calcareous shales of the Ordovician and Silurian periods, and often form low cushions or branching masses of calcite alongside rugose corals.
Their numbers began to decline during the middle of the Silurian period, and they became extinct at the end of the Permian period, 250 million years ago.
Rugose or horn corals became dominant by the middle of the Silurian and became extinct early in the Triassic period. The rugose corals existed in solitary and colonial forms and were also composed of calcite.
The famous Great Barrier Reef is thought to have been laid down about two million years ago. If you have had the pleasure of scuba diving near it to take in its modern wonders, perhaps you will be interested to learn how it was formed. Over long expanses of time, the corals here have broken up, fragmented and died. Sand and rubble accumulate between the corals, and the shells of clams and other molluscs decay to form a gradually evolving calcium carbonate structure to what you view today.
Coral reefs are extremely diverse marine ecosystems hosting over 4,000 species of fish, massive numbers of cnidarians, molluscs, crustaceans, and many other animals.
Tuesday, 21 March 2023
BLADDER-BEARERS: HOODED SEALS
Hooded seals, Cystophora cristata, are large phocid seals in the family Phocidae, who live in some of the chilliest places on Earth, from 47° to 80° N in latitude.
These skilled divers are mainly concentrated around Bear Island, Norway, Iceland, and northeast Greenland.
In rare cases, we find them in the icy waters in Siberia. They usually dive depths of 600 m (1,968 ft) in search of fishy treats but can go as deep as 1000 m (3,280 ft) when needed. That is deep into the cold, dark depths of our oceans. Sunlight entering the sea may travel as deep as 1,000 m (3,280 ft) under the right conditions, but there is rarely any significant light beyond 200 meters (656 ft). This is the dark zone and the place we find our bioluminescent friends.
Hooded seals have a sparse fossil record. One of the first fossils found was a Pliocene specimen from Anvers, Belgium discovered in 1876. In 1983 a paper was published claiming there were some fossils found in North America thought to be from Cystophora cristata. Of the three accounts, the most creditable discovery was from a sewer excavation in Maine, the northeasternmost U.S. state, known for its rocky coastline, maritime history and nature areas like the granite and spruce islands of Acadia National Park. A scapula and humeri were found among other bones and thought to date to the post-Pleistocene.
Of two other accounts, one was later reassigned to another species and the other left unsolved. (Folkow, et al., 2008; Kovacs and Lavigne, 1986; Ray, 1983)
The seals are typically silver-grey or white in colour, with black spots that vary in size covering most of the body.Hooded seal pups are known as, Blue-backs as their coats are blue-grey on the back with whitish bellies, though this coat is shed after 14 months of age when the pups moult.
FIRST NATION, INUIT, METIS, MI'KMAQ L'NU
In the Kwak̓wala language of the Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, seal are known as migwat — and fur seals are known as x̱a'wa.
Hooded seals live primarily on drifting pack ice and in deep water in the Arctic Ocean and North Atlantic. Although some drift away to warmer regions during the year their best survival rate is in colder climates. They can be found on four distinct areas with pack ice: near Jan Mayen Island, northeast of Iceland; off Labrador and northeastern Newfoundland; the Gulf of St. Lawrence; and the Davis Strait, off midwestern Greenland.
The province of Newfoundland and Labrador is home to the Inuit, the Innu, the Mi'kmaq L'nu and the Southern Inuit of NunatuKavut, formerly the Labrador Inuit-Metis. The Hooded Seals that visit their traditional territory were a welcome source of food and clothing. In Mi'kmaw, the language spoken in Mi'kma'ki, the territory of the Mi'kmaq L'nu, the word for seal is waspu.
HOODED SEAL HABITAT
Males are localized around areas of complex seabeds, such as Baffin Bay, Davis Strait, and the Flemish Cap. Females concentrate their habitat efforts primarily on shelf areas, such as the Labrador Shelf.
Females reach the age of sexual maturity between two and nine years old and it is estimated that most females give birth to their first young at around five years of age. Males reach sexual maturity a little later around four to six years old but often do not mate until much later. Females give birth to one young at a time through March and April. The gestation period is 240 to 250 days.
Blue-back, Hooded Seal Pup |
These young are precocious and at birth are able to move about and swim with ease. They are independent and left to fend for themselves immediately after they have been weaned.
Hooded seals are known to be a highly migratory species that often wander long distances, as far west as Alaska and as far south as the Canary Islands and Guadeloupe.
Prior to the mid-1990s, hooded seal sightings in Maine and the east Atlantic were rare but began increasing in the mid-1990s. From January 1997 to December 1999, a total of 84 recorded sightings of hooded seals occurred in the Gulf of Maine, one in France and one in Portugal.
From 1996 to 2006, five strandings and sightings were noted near the Spanish coasts in the Mediterranean Sea. There is no scientific explanation for the increase in sightings and range of the hooded seal.
Cystophora means "bladder-bearer" in Greek and pays homage to this species' inflatable bladder septum on the heads of adult males. The bladder hangs between the eyes and down over the upper lip in a deflated state.
The hooded seal can inflate a large balloon-like sac from one of its nostrils. This is done by shutting one nostril valve and inflating a membrane, which then protrudes from the other nostril.
I was thinking of Hooded seals when contemplating the nasal bladders of Prosaurolophus maximum, large-headed duckbill dinosaurs, or hadrosaurid, in the ornithischian family Hadrosauridae. Perhaps both species used these bladders in a similar manner — to warn predators and attract mates.
Hooded seals are known for their uniquely elastic nasal cavity located at the top of their head, also known as the hood. Only males possess this display-worthy nasal sac, which they begin to develop around the age of four. The hood begins to inflate as the seal makes its initial breath prior to going underwater. It then begins to repetitively deflate and inflate as the seal is swimming.
The purpose of this is acoustic signaling. It occurs when the seal feels threatened and attempt to ward off hostile species when competing for resources such as food and shelter. It also serves to communicate their health and superior status to both other males and females they are attempting to attract.
In sexually mature males, a pinkish balloon-like nasal membrane comes out of the left nostril to further aid it in attracting a mate. This membrane, when shaken, is able to produce various sounds and calls depending on whether the seal is underwater or on land. Most of these acoustic signals are used in an acoustic situation (about 79%), while about 12% of the signals are used for sexual purposes.
References: Ray, C. 1983. Hooded Seal, Cystophora cristata: Supposed Fossil Records in North America. American Society of Mammalogists, Vol. 64 No. 3: 509-512; Cystophora cristata, Hooded Seal", 2007; "Seal Conservation Society", 2001; Kovacs and Lavigne, 1986.
Mi'kmaq Online Dictionary: https://www.mikmaqonline.org/servlet/dictionaryFrameSet.html?method=showCategory&arg0=animal
Monday, 20 March 2023
OYSTER: T'LOXT'LOX
While rare today, these are British Columbia’s only native oyster.
Had you been dining on their brethren in the 1800s or earlier, it would have been this species you were consuming. Middens from Port Hardy to California are built from Ostrea lurida.
These wonderful invertebrates bare their souls with every bite. Have they lived in cold water, deep beneath the sea, protected from the sun's rays and heat? Are they the rough and tumble beach denizens whose thick shells tell us of a life spent withstanding the relentless pounding of the sea? Is the oyster in your mouth thin and slimy having just done the nasty—spurred by the warming waters of Spring?
Is this oyster a local or was it shipped to your current local and, if asked, would greet you with "Kon'nichiwa?" Not if the beauty on your plate is indeed Ostrea lurida.
Oyster in Kwak'wala is t̕łox̱t̕łox̱ |
The area is home to the Nuu-chah-nulth First Nations who have consumed this species boiled or steamed for thousands of years. Here these ancient oysters not only survive but thrive — building reefs and providing habitat for crab, anemones and small marine animals.
Oysters are in the family Ostreidae — the true oysters. Their lineage evolved in the Early Triassic — 251 - 247 million years ago.
In the Kwak̓wala language of the Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest and my family, an oyster is known as t̕łox̱t̕łox̱.
I am curious to learn if any of the Nuu-chah-nulth have a different word for an oyster. If you happen to know, I would be grateful to learn.
Sunday, 19 March 2023
ANCIENT BEAUTIES: FOSSIL PEARLS
A simple search will show you a vast array of pearls being used for their ornamental value in cultures from all over the world. I suppose the best answer to why they are appealing is just that they are.
If you make your way to Paris, France and happen to visit the Louvre's Persian Gallery, do take a boo at one of the oldest pearl necklaces in existence — the Susa necklace. It hails from a 2,400-year-old tomb of long lost Syrian Queen. It is a showy piece with three rows of 72 pearls per strand strung upon a bronze wire.
A queen who truly knew how to accessorize.
I imagine her putting the final touches of her outfit together, donning the pearls and making an entrance to wow the elite of ancient Damascus. The workmanship is superb, intermixing pure gold to offset the lustre of the pearls. It is precious and ancient, crafted one to two hundred years before Christ. Perhaps a gift from an Egyptian Pharaoh or from one of the Sumerians, Eblaites, Akkadians, Assyrians, Hittites, Hurrians, Mitanni, Amorites or Babylonian dignitaries who sued for peace but brought war instead.
Questions, good questions, but questions without answers. So, what can we say of pearls? We do know what they are and it is not glamorous. Pearls form in shelled molluscs when a wee bit of sand or some other irritant gets trapped inside the shell, injuring the flesh. As a defensive and self-healing tactic, the mollusc wraps it in layer upon layer of mother-of-pearl — that glorious shiny nacre that forms pearls.
They come in all shapes and sizes from minute to a massive 32 kilograms or 70 pounds. While a wide variety of our mollusc friends respond to injury or irritation by coating the offending intruder with nacre, there are only a few who make the truly gem-y pearls.These are the marine pearl oysters, Pteriidae and a few freshwater mussels. Aside from Pteriidae and freshwater mussels, we sometimes find less gem-y pearls inside conchs, scallops, clams, abalone, giant clams and large marine gastropods.
Pearls are made up mostly of the carbonate mineral aragonite, a polymorphous mineral — the same chemical formula but different crystal structure — to calcite and vaterite, sometimes called mu-calcium carbonate. These polymorphous carbonates are a bit like Mexican food where it is the same ingredients mixed in different ways. Visually, they are easy to tell apart — vaterite has a hexagonal crystal system, calcite is trigonal and aragonite is orthorhombic.
As pearls fossilize, the aragonite usually gets replaced by calcite, though sometimes by vaterite or another mineral. When we are very lucky, that aragonite is preserved with its nacreous lustre — that shimmery mother-of-pearl we know and love.
Molluscs have likely been making pearls since they first evolved 530 million years ago. The oldest known fossil pearls found to date, however, are 230-210 million years old.
This was the time when our world's landmass was concentrated into the C-shaped supercontinent of Pangaea and the first dinosaurs were calling it home. In the giant ancient ocean of Panthalassa, ecosystems were recovering from the high carbon dioxide levels that fueled the Permian extinction. Death begets life. With 95% of marine life wiped out, new species evolved to fill each niche.
While this is where we found the oldest pearl on record, I suspect we will one day find one much older and hopefully with its lovely great-great grandmother-of-pearl intact.
Saturday, 18 March 2023
LOVE THE WILD: KU'MIS
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.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.
Friday, 17 March 2023
EXPLORING THE EAST KOOTENAY REGION
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 |
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 |
Cretaceous Plant Material, Fernie, BC |
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.
Thursday, 16 March 2023
LOVE LESSONS FROM THE NORTH
Nunatsiarmiut Mother and Child, Baffin Island, Nunavut |
As part of the Qikiqtaaluk Region of Nunavut, Baffin Island is home to a constellation of remote Inuit communities each with a deep cultural connection to the land—Iqaluit, Pond Inlet, Pangnirtung, Clyde River, Arctic Bay, Kimmirut and Nanisivik.
The ratio of Inuit to non-Inuit here is roughly three to one and perhaps the reason why the Inuktitut language has remained intact and serves as the mother tongue for more than 36,000 residents. Inuktitut has several subdialects—these, along with a myriad of other languages—are spoken across the north.
If you look at the helpful visual below you begin to get a feel for the diversity of these many tongues. The languages vary by region. There is the Iñupiaq of the Inupiatun/Inupiat; Inuvialuktun of the Inuinnaqtun, Natsilingmiutut, Kivallirmiutut, Aivilingmiutut, Qikiqtaaluk Uannanganii and Siglitun. Kalaallisut is spoken by many Greenlandic peoples though, in northwest Greenland, Inuktun is the language of the Inughuit.
We use the word Inuktitut when referring to a specific dialect and inuktut when referring to all the dialects of Inuktitut and Inuinnaqtun.
Northern Language Map (Click to Enlarge) |
The word for hello or welcome in Inuktitut is Atelihai—pronounced ahh-tee-lee-hi. And thank you is nakurmiik, pronounced na-kur-MIIK.
Perhaps my favourite Inuktitut expression is Naglingniq qaikautigijunnaqtuq maannakautigi, pronounced NAG-ling-niq QAI-kau-ti-gi-jun-naqtuq MAAN-na-KAU-ti-gi. This tongue-twister is well worth the linguistic challenge as it translates to love can travel anywhere in an instant. Indeed it can.
So much of our Indigenous culture is passed through stories, so language takes on special meaning in that context. It is true for all societies but especially true for the Inuit. Stories help connect the past to the present and future. They teach how to behave in society, engage with the world and how to survive in the environment. They also help to create a sense of belonging.
You have likely seen or heard the word Eskimo used in older books to refer to the Inuit, Iñupiat, Kalaallit or Yupik. This misnomer is a colonial term derived from the Montagnais or Innu word ayas̆kimew—netter of snowshoes. It is a bit like meeting a whole new group of people who happen to wear shoes and referring to them all as cobblers—not as a nickname, but as a legal term to describe populations from diverse communities disregarding the way each self-refer.
Inukshuk / Inuksuk Marker Cairn |
The Inuit of Greenland self-refer as Kalaallit or Greenlanders when speaking Kalaallisut. The Inupiat of Alaska, or real people, use Yupik as the singular for real person and yuk to simply mean person.
When taken all together, Inuit is used to mean all the peoples in reference to the Inuit, Iñupiat, Kalaallit and Yupik. Inuit is the plural of inuk or person.
You likely recognize this word from inuksuk or inukshuk, pronounced ih-nook-suuk — the human-shaped stone cairns built by the Inuit, Iñupiat, Kalaallit, Yupik, and other peoples of the Arctic regions of northern Canada, Greenland, and Alaska—helpful reference markers for hunters and navigation. The word inuksuk means that which acts in the capacity of a human, combining inuk or person and suk, to substitute.
A World of Confusion
You may be disappointed to learn that our northern friends do not live in igloos. I remember answering the phone as a child and the fellow calling was hoping to speak to my parents about some wonderful new invention perfect for use in an igloo.He was disappointed to hear that I was standing in a wooden house with the standard four walls to a room and a handy roof topping it off. "Well, what about your neighbours? Surely, a few of them live in igloos..."
It seems that some atlases in circulation at the time, and certainly the one he was looking at, simply blanketed everything north of the 49th parallel in a snowy white. His clearly showed an igloo sitting proudly in the centre of the province.
My cousin Shawn brought one such simplified book back from his elementary school in California. British Columbia had a nice image of a grizzly bear and a wee bit further up, a polar bear grinned smugly. British Columbia's beaver population would be sad to know that they did not inhabit the province though there were two chipper beavers with big bright smiles—one in Ontario and another gracing the province of Quebec. Further north, where folk do build igloos, their icy domes were curiously lacking.
Igloos are used for winter hunting trips much the same way we use tents for camping. The Inuit do not have fifty words for snow—you can thank the ethnographer Franz Boas for that wee fabrication—but within the collective languages of the frozen north there are more than fifty words to describe it. And kisses are not nose-to-nose. To give a tender kiss or kunik to a loved one, you press your nose and upper lip to their forehead or cheek and rub gently.
Fancy trying a wee bit of Inuktitut yourself? This link will bring you to a great place to start: https://inhabitmedia.com/inuitnipingit/
Inuit Language Map: By Noahedits - Own work, CC BY-SA 4.0. If you want to the image full size, head to this link: https://commons.wikimedia.org/w/index.php?curid=85587388
Wednesday, 15 March 2023
GULLS ON THE FORESHORE: T'SIK'WI
A gull cries in protest at not getting his share of a meal |
Tuesday, 14 March 2023
WEYLA OF THE SUNRISE FORMATION
Weyla (Nielsen, 1963) New York Canyon, Nevada |
The end-Triassic mass extinction was global, severe, and accompanied by worldwide disturbance to carbonate ramp and platform sedimentation. We see the effects played out in the Ferguson Hill Member of the Sunrise Formation. These outcrops are the result of the earliest known Jurassic carbonate ramp produced in the back-arc basin along NE Panthalassa following the extinction event to determine the biotic constituents and timing of local ecological recovery.
The Ferguson Hill Member (Hettangian and Sinemurian) of the Sunrise Formation in the New York Canyon area of west-central Nevada, USA has a lovely counterpart in the Rockies of British Columbia, Canada, explored over three field seasons in the early 2000s before being closed off as a provincial park.
In the Hettangian, post-extinction biosiliceous sedimentation extended to the inner ramp, where an ooid and grapestone shoal marked the outermost extent of a narrow belt of carbonate sedimentation. An early recovery phase in the late Hettangian is characterized by widespread, laterally homogeneous, demosponge-dominated level-bottom sedimentation across the mid- to inner-ramp, in addition to limited trophic tiering (sessile epifaunal suspension-feeding and mobile infaunal deposit-feeding), substantial ramp aggradation, and poor settling conditions for competitive benthic colonizers (e.g., corals, crinoids, infaunal bivalves).
Within 1.6–2 Myr after the extinction (in the early Sinemurian), a late recovery phase is recognized by the appearance of epifaunal grazers (gastropods, echinoids) and suspension feeders (crinoids, solitary scleractinian corals), phototrophic microbialites (oncoids, and possibly photosymbionts within corals), and infaunal deposit or suspension feeders (bivalves).
Although the late recovery faunas included more trophic levels than pre-extinction carbonate ramp habitats, development and progradation of the first Jurassic carbonate ramp still relied heavily on sponge, microbialite, and abiotic mineralization.
Monday, 13 March 2023
AMMONOIDS AND ICHTHYOSAURS: NEVADA PALAEONTOLOGY
Time Slows at Berlin-Ichthyosaur State Park |
High on the hillside up a long entry road sits the entrance to Berlin-Ichthyosaur State Park in central Nevada. It is a short 2-hour drive from our lodgings through orange-hued grasslands and low sloping hills.
A worn American flag and sun-bleached outbuildings greet you on your way to the outcrops. Away from the hustle and bustle that defines the rest of Nevada this place feels remarkably serene. Your eyes squint against the sun as you search for ammonoids and other marine fossil fauna while your nose tends to the assault from the bracing smell of sagebrush.
This site holds many stories. The interpretive centre displays wonderful marine reptiles, ichthyosaurs in situ, as you might expect from the name of the park — but it also showcases years of history lovingly tended. This stretch of dry golden low hills dappled with the yellow of creosote and desert grasses is an important locality for our understanding of the Carnian-Norian boundary (CNB) in North America.
The area is known worldwide as one of the most important ichthyosaur Fossil-Lagerstätte because of the sheer volume of remarkably well-preserved, fully articulated (all the sweet bones laid out all in a row...) specimens of Shonisaurus popularis.
Rich ammonoid faunas outcrop in the barren hills of the Upper Triassic (Early Norian, Kerri zone), Luning Formation, West Union Canyon, Nevada. They were studied by N. J. Silberling (1959) and provide support for the definition of the Schucherti and Macrolobatus zones of the latest Carnian — which are here overlain by well-preserved faunas of the earliest Norian Kerri Zone.
The genus Gonionotites, very common in the Tethys and British Columbia, is for the moment, unknown in Nevada. The Upper Carnian faunas are dominated by Tropitidae, while Juvavitidae are conspicuously lacking.
Middle Triassic Ammonoids |
October is an ideal time to do fieldwork in this area. There are a few good weeks between screaming hot and frigid cold. It is also tarantula breeding season so keep your eyes peeled. Those sweet little burrows you see are not from rodents but rather largish arachnids.
The eastern side of the canyon provides the best record of the Macrolobatus Zone, which is represented by several beds yielding ammonoids of the Tropites group, together with Anatropites div. sp.Conodont faunas from both these and higher beds are dominated by ornate metapolygnthids that would formerly have been collectively referred to Metapolygnathus primitius, a species long known to straddle the CNB. Within this lower part of the section, they resemble forms that have been separated as Metapolygnathus mersinensis. Slightly higher, forms close to Epigondolella' orchardi and a single Orchardella n. sp. occur. This association can be correlated with the latest Carnian in British Columbia.
Higher in the section, the ammonoid fauna shows a sudden change and is dominated by Tropithisbites. Few tens of metres above, but slightly below the first occurrence of Norian ammonoids Guembelites jandianus and Stikinoceras, two new species of conodonts (Gen et sp. nov. A and B) appear that also occur close to the favoured Carnian/Norian boundary at Black Bear Ridge, British Columbia. Stratigraphically higher collections continue to be dominated by forms close to M. mersinensis and E. orchardi after BC's own Mike Orchard.
The best exposure of the Kerri Zone is on the western side of the West Union Canyon. Ammonoids, dominated by Guembelites and Stikinoceras div. sp., have been collected from several fossil-bearing levels. Conodont faunas replicate those of the east section. The collected ammonoids fit perfectly well with the faunas described by Silberling in 1959, but they differ somewhat from coeval faunas of the Tethys and Canada.
The ammonoid fauna paints a compelling picture of Tethyan influence with a series of smoking guns. We see an abundance of Tropitidae in the Carnian, a lack of Pterosirenites in the Norian, copious Guembelites, the Tethyan species G. philostrati, the stratigraphic position of G. clavatus and the rare occurrence of Gonionotites. Their hallelujah moment was likely finding an undescribed species of the thin-shelled bivalve Halobia similar to Halobia beyrichi — the clincher that perhaps seals this deal on Tethyan influence.
I'll take a boo to see what Christopher McRoberts published on the find. A jolly good idea to have him on this expedition as it would have been easy to overlook if the focus remained solely on the conodonts and ammonoids. McRoberts has published on the much-studied Pardonet Formation up in the Willison Lake Area of Northeastern, British Columbia. He knows a thing or two about Upper Triassic Bivalvia and the correlation to coeval faunas elsewhere in the North American Cordillera, and to the Boreal, Panthalassan and Tethyan faunal realms.
If you fancy a read, they published a paper: "Towards the definition of the Carnian/Norian Boundary: New data on Ammonoids and Conodonts from central Nevada," which you can find in the proceedings of the 21st Canadian Paleontology Conference; by Haggart, J W (ed.); Smith, P L (ed.); Canadian Paleontology Conference Proceedings no. 9, 2011 p. 9-10.
Fig. 1. Location map of Berlin-Ichthyosaur State Park |
Marco Balini, James Jenks, Riccardo Martin, Christopher McRoberts, along with Mike Orchard and Norman Siberling, did a bed by bed sampling in 2013 and published on The Carnian/Norian boundary succession at Berlin-Ichthyosaur State Park (Upper Triassic, central Nevada, USA) and published in January 2014 in Paläontologische Zeitschrift 89:399–433. That work is available for download from ResearchGate. The original is in German, but there is a translation available.
After years of reading about the correlation between British Columbia and Nevada, I had the very great pleasure of walking through these same sections in October 2019 with members of the Vancouver Paleontological Society and Vancouver Island Palaeontological Society. It was with that same crew that I'd originally explored fossil sites in the Canadian Rockies in the early 2000s. Those early trips led to paper after paper and the exciting revelations that inspired our Nevada adventure.
If you plan your own adventure, you'll want to keep an eye out for some of the other modern fauna — mountain lions, snakes, lizards, scorpions, wolves, coyotes, foxes, ground squirrels, rabbits, falcons, hawks, eagles, bobcats, sheep, deer and pronghorns.
Figure One: Location map of Berlin-Ichthyosaur State Park. A detailed road log with access information for this locality is provided in Lucas et al. (2007).
Sunday, 12 March 2023
HERMIT CRAB: REAL ESTATE TYCOONS
His body is a soft, squishy spiral that he eases into the perfect size shell time and time again as he grows.
His first choice is always the empty shell of a marine snail but will get inventive in a pinch — nuts, wood, serpulid worm tubes, aluminium cans or wee plastic caps.
They are inventive, polite and patient.
You see, a hermit crabs' desire for the perfect bit of real estate will have them queueing beside larger shells — shells too large for them — to wait upon a big hermit crab to come along, discard the perfect home and slip into their new curved abode. This is all done in an orderly fashion with the hermit crabs all lined up, biggest to smallest to see who best fits the newly available shell.
There are over 800 species of hermit crab — decapod crustaceans of the superfamily Paguroidea. Their lineage dates back to the Jurassic, 200 million years ago. Their soft squishy, weakly calcified bodies do not fossilize all that often but when they do the specimens are spectacular. Think of all the species of molluscs these lovelies have had a chance to try on — including ammonites — and all the shells that were never buried in sediment to become fossils because they were harvested as homes.
On the shores of British Columbia, Canada, the hermit crab I come across most often is the Grainyhand hermit crab, Pagurus granosimanus.These wee fellows have tell-tale orange-brown antennae and olive green legs speckled with blue or white dots.
In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, a shell is known as x̱ala̱'is and gugwis means house on the beach.
I do not know the Kwak’wala word for a hermit crab, so I will think of these cuties as x̱ala̱'is gugwis — envisioning them finding the perfect sized shell on the surf worn shores of Tsax̱is, Fort Rupert, Vancouver Island.
MEET ACICULOLENUS ASKEWI AFTER DON ASKEW
The Dream Team at Fossil Site #15, East Kootenays |
Chris New, pleased as punch atop Upper Cambrian Exposures |
Saturday, 11 March 2023
OLENELLUS OF THE EAGER: CRANBROOK, BRITISH COLUMBIA
Near Cranbrook, the Eager Formation outcrops at several locations just outside of town. This particular lovely is from the Rifle Range locality and is in my collection at 98-CR-EF042 — meaning it was collected in 1998 and the 42nd find of the day. This is a prolific site and with diligent collecting, you can find many wonderful specimens of scientific and aesthetic value in the course of a day.
The Rifle Range locality sits on the Silhouette Rifle Range — which is literally on a rifle range where folks go to shoot at things.
The fossils we find here are just a shade older than those found at the Burgess Shale. Burgess is Middle Cambrian and the species match the Eager fauna one for one but the Eager fauna are much less varied.
Olenellus is an extinct genus of redlichiid trilobites, early arthropods, that litter this glorious Cambrian site. Olenellus is the only genus currently recognised in the subfamily Olenellinae. The sister group called the Mesonacinae consists of the genera Mesonacis and Mesolenellus.
Olenellus range in size but are about 5 centimetres or 2.0 inches long on average. They lived during the Botomian and Toyonian stages, Olenellus-zone, 522 to 510 million years ago, in what is currently North America in what was part of the paleocontinent of Laurentia.
Olenellus are both common in and restricted to Early Cambrian rocks — 542 million to 521 million years old — and thus a useful Index Fossil for the Early Cambrian.
Olenellus had a well-developed head, large and crescentic eyes, and a poorly developed, small tail. The fellow you see had a bit of his tail crushed as he turned to stone.
Trilobites were amongst the earliest fossils with hard skeletons. While they are extinct today, they were the dominant life form at the beginning of the Cambrian and it is what we find as the primary fossil in the fauna of the Eager Formation.
A slightly crushed lingulida brachiopod |
The specimens of Wanneria from here are impressively large. Some are up to thirteen centimetres long and ten centimetres wide. You find a mixture of complete specimens and head impressions from years of perfectly preserved moults.
From July 21 to 31, 2015, the Royal Ontario Museum (ROM), under the direction of Dr. Jean-Bernard Caron carried out a palaeontological dig at an exposure of the Eager Formation that outcrops between Cranbrook and Fort Steele in the East Kootenay Region of British Columbia.
The team included David George (APS), Dr. Bob Gaines (Pomona College), Dr. Jean-Bernard Caron (ROM), Dr. Gabriela Mangano (University of Saskatchewan), Maryam Akrami (ROM), Darrell Nordby (APS), Joe Moysiuk (University of Toronto), and local, Guy Santucci (APS and project field co-ordinator), and Dr. Mark Webster (University of Chicago).
Dr. Caron was interested in the fauna of the Eager Formation as there is an overlap with the Burgess Shale species — the Eager is a window into time 513 million years ago — 8 million years earlier than the Burgess.
Lower Cambrian Brachiopod |
Their excavation of the site was thorough — reducing all of the potentially fossil-bearing strata to pieces the size or smaller than a dinner plate. The 2015 team used a backhoe to take off the weathered top layer and get down to the bedrock below.
It has been six years since their visit and we will hopefully see some worthy publications from their efforts. There had been talk of multiple publications stemming from the spectrum of species, a comparison to the Burgess fauna and papers on the trace fossils. I checked in with Joe Moysuik from the University of Toronto who had been on the dig in 2015. To his knowledge, no new papers have yet to be published — though, Caron has been a busy bee on a sexy new nektobenthic suspension feeder from the Burgess material. I am rather hoping their team sorts out the naming of some of the species and gets them to publication so we can finally put them to bed.
Days after my correspondence with Moysuik, Chris Jenkins, a Cranbrook local and huge contributor to our knowledge of Upper Cambrian trilobites, shared an exciting find.The two had met some 10 years previous when Don, an avid outdoorsman and Jenkins' neighbour, had wandered over to see what all the rocks were about in Jenkins' yard.
Tales of trilobites and a lifelong friendship ensued. It was also the beginnings of shared fieldwork. This time, it was to outcrops of the Eager Formation just outside of Cranbrook. Together, the two unearthed a three-foot-wide band of Eager Formation bedrock. Not unusual in and of itself — but instead of the usual trilobites — this rock revealed several varieties of Lower Cambrian brachiopods.
Jenkins shared photos of at least three different types of brachiopods — potentially new fauna for the Eager. Although they superficially resemble the molluscs that make modern seashells, they are not related. Brachiopods were the most abundant and diverse fossil invertebrates of the Paleozoic — over 4500 genera known; the number of species is far greater. So, naturally, we had expected to find brachiopods in the Eager Formation as they were abundant in Lower Cambrian seas — but so far they had eluded us.
And, interestingly, the rock containing the brachiopods is devoid of any trilobite specimens — not a one. Have they found a wee slip of the Eager Formation that records a nearshore environment or have they stumbled across a segment that records another time period altogether?
The brachiopods you see in the photos above are roughly 1/4 inch to 3/4 inches. Should Caron and team return to the site, these new brachiopods will be of great interest as they look to rewrite the geology and palaeontology of the site and region.