Showing posts with label fossils. Show all posts
Showing posts with label fossils. Show all posts

Sunday, 10 November 2024

HERMIT CRAB: REAL ESTATE TYCOONS OF THE FORESHORE

This little cutie is a hermit crab and he is wearing a temporary home borrowed from one of our mollusc friends. 

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. 

Wednesday, 6 November 2024

LIVING FOSSILS: MASTERS OF MASS EXTINCTION EVENTS

Horseshoe crabs are marine and brackish water arthropods of the order Xiphosura — a slowly evolving, conservative taxa.

Much like (slow) Water Striders (Aquarius remigis), (relatively sluggish) Coelacanth (Latimeria chalumnae) and (the current winner on really slow evolution) Elephant Sharks (Callorhinchus milii), these fellows have a long history in the fossil record with very few anatomical changes. 

But slow change provides loads of great information. It makes our new friend, Yunnanolimulus luoingensis, an especially interesting and excellent reference point for how this group evolved. 

We can examine their genome today and make comparisons all the way back to the Middle Triassic (with this new find) and other specimens from further back in the Ordovician — 445 million years ago. 

These living fossils have survived all five mass extinction events. They are generalists who can live in shallow or deep water and will eat pretty much anything they can find on the seafloor.

The oldest horseshoe crab fossil, Lunataspis aurora, is found in outcrops in Manitoba, Canada. Charmingly, the name means crescent moon shield of the dawn. It was palaeontologist Dave Rudkin and team who chose that romantic name. Finding them as fossils is quite remarkable as their shells are made of protein which does not mineralized like typical fossils.

Even so, the evolution of their exoskeleton is well-documented by fossils, but appendage and soft-tissue preservation are extremely rare. 

A new study analyzes details of the appendage and soft-tissue preservation in Yunnanolimulus luoingensis, a Middle Triassic (ca. 244 million years old) horseshoe crab from Yunnan Province, SW China. The remarkable anatomical preservation includes the chelicerae, five pairs of walking appendages, opisthosomal appendages with book gills, muscles, and fine setae permits comparison with extant horseshoe crabs.

The close anatomical similarity between the Middle Triassic horseshoe crabs and their recent analogues documents anatomical conservatism for over 240 million years, suggesting persistence of lifestyle.

The occurrence of Carcinoscorpius-type claspers on the first and second walking legs in male individuals of Y. luoingensis tells us that simple chelate claspers in males are plesiomorphic for horseshoe crabs, and the bulbous claspers in Tachypleus and Limulus are derived.

As an aside, if you hadn't seen an elephant shark before and were shown a photo, you would likely say, "that's no freaking shark." You would be wrong, of course, but it would be a very clever observation.

Callorhinchus milii look nothing like our Great White friends and they are not true sharks at all. Rather, they are ghost sharks that belong to the subclass Holocephali (chimaera), a group lovingly known as ratfish. They diverged from the shark lineage about 400 million years ago.

If you have a moment, do a search for Callorhinchus milii. The odd-looking fellow with the ironic name, kallos, which means beautiful in Greek, sports black blotches on a pale silver elongate body. And their special feature? It is the fishy equivalent of business in the front, party in the back, with a dangling trunk-like projection at the tip of their snout and well-developed rectal glands near the tail.

As another small point of interest with regards to horseshoe crabs, John McAllister collected several of these while working on his MSc to see if they had microstructures similar to trilobites (they do) and whether their cuticles were likewise calcified. He found no real calcification in their cuticles, in fact, he had a rather frustrating time getting anything measurable to dissolve in acid in his hunt for trace elements. 

Likewise, when looking at oxygen isotopes (16/18) to get a handle on water salinity and temperature, his contacts at the University of Waterloo had tons of fun getting anything at all to analyze. It made for some interesting findings. Sadly, for a number of reasons, he abandoned the work, but you can read his very interesting thesis here: https://dr.library.brocku.ca/handle/10464/1959

Ref: Hu, Shixue & Zhang, Qiyue & Feldmann, Rodney & Benton, Michael & Schweitzer, Carrie & Huang, Jinyuan & Wen, Wen & Zhou, Changyong & Xie, Tao & Lü, Tao & Hong, Shuigen. (2017). Exceptional appendage and soft-tissue preservation in a Middle Triassic horseshoe crab from SW China. Scientific Reports. 7. 10.1038/s41598-017-13319-x.

Tuesday, 5 November 2024

CTENOPHORES: COMB JELLIES

Cannibalistic Comb Jellies
This festive lantern looking lovely belongs to a group of invertebrates known as comb jellies.

Comb jellies are named for their unique plates of giant fused cilia, or combs, which run in eight rows up and down the length of their bodies. They are armed with sticky cells or colloblasts, that do not sting but display wonderful bioluminescent colouring as they move through the sea.

Ctenophores or comb jellies are one of the phylogenetically most important and controversial metazoan groups. They are not jellyfish and are not closely related, though they do share some characteristics with the gelatinous members of the subphylum Medusozoa. 

Comb jellies are not picky eaters. Their tastes range to what is at hand, including cannibalizing other comb jellies. They will feast on their kin along with tasty plankton, zooplankton, crustaceans and wee fish.

Interest in their fossil record has been catalysed by spectacularly preserved soft-bodied specimens from Cambrian Lagerstätten of the 518-million-years-old Chengjiang Biota, the 505-million-years-old Burgess Shale and other Burgess Shale-like deposits. 

We find them in the Late Devonian Escuminac Formation at Miguasha National Park, Quebec, Canada — a UNESCO world heritage site famous for its abundance of well-preserved vertebrate fossils including most major evolutionary groups of Devonian lower vertebrates from jawless fish to stem-tetrapods.

Based on morphological similarities of this Canadian fossil with stem-ctenophore fossils from the Cambrian Lagerstätte of the Chinese locality Chengjiang, they have been assessed for their affinity to stem-group ctenophores (dinomischids, Siphusauctum, scleroctenophorans) and early crown-group ctenophores. Modern ctenophores and many fossil forms lack mineralized hard parts, which renders the rare fossils that have been extracted from several Lagerstätten quite remarkable. 

Like the soft bodies of jellyfish and the polyps of hydrozoans and anthozoans, the probability for such soft bodies (or body regions) to become fossilized is extremely low. In spite of this low preservation potential, remains of stem-ctenophores have become known from several Cambrian and younger conservation deposits, and with even older candidate ctenophores in the Ediacaran. 

While Cambrian Lagerstätten have yielded several genera, ctenophore remains are much rarer in the Devonian; in particular, two studies, describing material from the German Hunsrück Slate. 

Bioluminescent Comb Jellies
This Early Devonian material, however, appears to belong to crown ctenophores morphologically similar to living forms such as Pleurobrachia, unlike the stem Cambrian taxa and the new Devonian stem taxon described here.

The most basal stem ctenophores are the dinomischids: sessile benthic petaloid invertebrates, many of which are equipped with a stalk. This group first was described from the Middle Cambrian Burgess Shale. Based on the genus Dinomischus, these early stalked forms were commonly called ‘dinomischids’. 

Zhao et al. shared that dinomischids "form a grade in the lower part of the ctenophore stem group” and include taxa such as Xianguangia, Daihua, and Dinomischus that have hexaradiate-based symmetry (e.g., sixfold, 18-fold). 

Some later, skeletonised stem-ctenophores were termed ‘Scleroctenophora’; ‘scleroctenophorans’ have a shorter stalk, lack the ‘petals’ and have no bracts and might be monophyletic. 

To date, all known dinomischids and scleroctenophorans are Cambrian. Remarkably, analysis of the material described here suggests it is a very late-surviving member of this part of the ctenophore tree, occurring in strata over a hundred million years younger with no intervening known record, thus making it a Lazarus taxon with an extensive ghost lineage. 

Palaeozoic sediments yield a growing number of fossil invertebrates with radial symmetries, some being quite enigmatic with body plans differing radically from those of extant organisms.

The morphological similarities to Cambrian forms and the mix of characters regarding overall shape and symmetries render this discovery important. The aims of this study are to describe the only known specimen of this Devonian ctenophore, discuss its phylogenetic and systematic position, and the impact of fossil data for ctenophore affinities, and assess its palaeoecological role.

Saturday, 2 November 2024

HAIDA GWAII: ISLANDS OF MIST

Misty shores, moss covered forests, a rich cultural history, dappled light, fossils and the smell of salt air—these are my memories of Haida Gwaii.

The Haida have lived, loved, raised families, planned wars, weddings and potlatches on the islands of Haida Gwaii since time immemorial. Our traditional territory encompasses parts of southern Alaska, the archipelago of Haida Gwaii and its surrounding waters. 

The remote archipelago of Haida Gwaii lays at the western edge of the continental shelf due west of the central coast of British Columbia.

They form part of Wrangellia, an exotic tectonostratigraphic terrane that includes Vancouver Island, parts western British Columbia and Alaska.

The Geological Survey of Canada sponsored many expeditions to these remote islands and has produced numerous reference papers on this magnificent terrain, exploring both the geology and palaeontology of the area.

Joseph Whiteaves, the GSC's chief palaeontologist in Ottawa, published a paper in 1876 describing the Jurassic and Cretaceous faunas of Skidegate Inlet, furthering his reputation globally as both a geologist, palaeontologist as well as a critical thinker in the area of science.

The praise was well-earned and foreshadowed his significant contributions to come. Sixteen years later, he wrote up and published his observations on a strange Mount Stephen fossil that resembled a kind of headless shrimp with poorly preserved appendages. 

Because of the unusual pointed shape of the supposed ventral appendages and the position of the spines near the posterior of the animal, Whiteaves named it Anomalocaris canadensis. The genus name "Anomalocaris" means "unlike other shrimp" and the species name "canadensis" refers to the country of origin.

Whiteaves work on the palaeontology of Haida Gwaii provided excellent reference tools, particularly his work on the Cretaceous exposures and fauna that can be found there.

One of our fossil field trips was to the ruggedly beautiful Cretaceous exposures of Lina Island. We had planned this expedition as part of our “trips of a lifetime.” 

Both John Fam, the Vice Chair of the Vancouver Paleontological Society and Dan Bowen, the Chair of both the British Columbia Paleontological Alliance and Vancouver Island Palaeontological Society, can be congratulated for their efforts in researching the area and ably coordinating a warm welcome by the First Nations community and organizing fossil field trips to some of the most amazing fossil localities in the Pacific Northwest.

With great sandstone beach exposures, the fossil-rich (Albian to Cenomanian) Haida formation provided ample specimens, some directly in the bedding planes and many in concretion. Many of the concretions contained multiple specimens of typical Haida Formation fauna, providing a window into this Cretaceous landscape.

It is always interesting to see who was making a living and co-existing in our ancient oceans at the time these fossils were laid down. We found multiple beautifully preserved specimens of the spiny ammonite, Douvelleiceras spiniferum along with Brewericeras hulenense, Cleoniceras perezianum and many cycads in concretion.
Douvelliceras spiniferum, Cretaceous Haida Formation

Missing from this trip log are tales of Rene Savenye, who passed away in the weeks just prior. While he wasn't there in body, he was with us in spirit. I thought of him often on the mist-shrouded days of collecting. 

Many of the folk on who joined me on those outcrops were friends of Rene's and would go on to receive the Rene Savenye Award for their contributions to palaeontology. There is a certain poetry in that. 

The genus Douvilleiceras range from Middle to Late Cretaceous and can be found in Asia, Africa, Europe and North and South America. 

We have beautiful examples in the early to mid-Albian from the archipelago of Haida Gwaii in British Columbia. Joseph F. Whiteaves was the first to recognize the genus from Haida Gwaii when he was looking over the early collections of James Richardson and George Dawson.

My collections from Haida Gwaii will all be lovingly prepped and donated to the Haida Gwaii Museum in Skidegate, British Columbia.

Friday, 1 November 2024

SHONISAURUS OF NEVADA

The beauties you see here are ichthyosaurs. The largest of their lineage is the genus Shonisaurus who ruled our ancient seas 217 million years ago.

At least 37 incomplete fossil specimens of the marine reptile have been found in hard limestone deposits of the Luning Formation, in far northwestern Nye County of Nevada. This formation dates to the late Carnian age of the late Triassic period when present-day Nevada and parts of the western United States were covered by an ancient ocean.

The first researcher to recognize the Nevada fossil specimens as ichthyosaurs was Siemon W. Muller of Stanford University. He had the work of Sir Richard Owen and others to build on. That being said, there are very few contenders for a species that boasts vertebrae over a foot wide and weighing in at almost 10 kg or 21 lbs. Muller contacted the University of California Museum of Paleontology at Berkeley. Surface collecting by locals continued at the site but no major excavation was planned.

Sir Richard Owen, the British biologist, comparative anatomist and paleontologist, coined the name ichthyopterygia, or "fish flippers," one hundred and fourteen years earlier, but that wee bit of scientific knowledge hadn't made its way west to the general population. The finds at Luning were still, "marine monsters."

Owen, too, was building on research going back to 1699, the very first recorded fossil fragments found of these beasties in Wales. Shortly thereafter, fossil vertebrae were published in 1708 from the Lower Jurassic.

The first complete skeleton was discovered in the early 19th century by Mary Anning and her brother Joseph along the Dorset Jurassic Coast. Mary's find was described by a British surgeon, Sir Everard Home, an elected Fellow of the Royal Society, in 1814. The specimen is now on display at the Natural History Museum in London bearing the name Temnodontosaurus platyodon, or “cutting-tooth lizard.”

In 1821, William Conybeare and Henry De La Beche, a friend of Mary's, published a paper describing three new species of unknown marine reptiles based on the Anning's finds. The Rev. William Buckland would go on to describe two small ichthyosaurs from the Lias of Lyme Regis, Ichthyosaurus communis and Ichthyosaurus intermedius. All of this early work was instrumental in aiding the researchers who would join the project at Luning.

Owen is considered to have been an outstanding naturalist with a remarkable gift for interpreting fossils. Contrary to common belief, advanced study does help with identifying fossils, but what is truly needed is a keen eye. The finds at Luning were blessed to be seen by an enthusiastic local with just that right kind of keen eye.

Almost a quarter of a century after Muller's initial reports, Dr. Charles L. Camp from UCMP received correspondence further detailing the finds from a lovely Mrs. Margaret Wheat of Fallon. She wrote to Camp in September of 1928 to say that she'd been giving the quarry section a bit of a sweep, as you do, and had uncovered a nice aligned section of vertebrae with her broom. The following year, Dr. Charles L. Camp went out to survey the finds and began working on the specimens, his first field season of many, in 1954.

Back in the 1950s, these large marine reptiles were rumoured to be "marine monsters," as the concept of an ichthyosaur was not well understood by the local townsfolk. Excitement soon hit West Union Canyon as the quarry began to reveal the sheer size of these mighty beasts. Four of the specimens were fully excavated. Most of the ichthyosaur bones were left in situ, partially because the work was tremendously difficult, and partially to allow others to see how the specimens were laid down over 200 million years ago.

Camp continued to work with Wheat at the site and brought on Sam Welles and a host of students to help with excavations. The team understood the need for protection at the site. They canvassed the Nevada Legislature to establish the Ichthyosaur Paleontological State Monument. You can see one of the Park Rangers above giving a tour within the lovely Fossil Hut building they built on the site to protect the fossils.

In 1957, the site was incorporated into the State Park System and Berlin-Ichthyosaur State Park was born. The park Twenty years later, in 1977, the population of Nevada weighed in and the Legislature designated Shonisaurus popularis as the State Fossil of Nevada. Visitors are welcome to collect fossils from the exposures of the Upper Triassic (Early Norian, Kerri Zone) of the Luning Formation, West Union Canyon, just outside Berlin-Ichthyosaur State Park.

Address: State route 844, Austin, NV 89310, United States. Area: 4.58 km². Open 24 hours;
Elevation: 6,975 ft (2,126 m); Tel: +1 775-964-2440; http://parks.nv.gov/parks/berlin-ichthyosaur

Wednesday, 30 October 2024

NOOTKA: FOSSILS AND FIRST NATIONS HISTORY

Nootka Fossil Field Trip. Photo: John Fam
The rugged west coast of Vancouver Island offers spectacular views of a wild British Columbia. Here the seas heave along the shores slowly eroding the magnificent deposits that often contain fossils. 

Just off the shores of Vancouver Island, east of Gold River and south of Tahsis is the picturesque and remote Nootka Island.

This is the land of the proud and thriving Nuu-chah-nulth First Nations who have lived here always

Always is a long time, but we know from oral history and archaeological evidence that the Mowachaht and Muchalaht peoples lived here, along with many others, for many thousands of years — a time span much like always

While we know this area as Nootka Sound and the land we explore for fossils as Nootka Island, these names stem from a wee misunderstanding. 

Just four years after the 1774 visit by Spanish explorer Juan Pérez — and only a year before the Spanish established a military and fur trading post on the site of Yuquot — the Nuu-chah-nulth met the Englishman, James Cook.  

Captain Cook sailed to the village of Yuquot just west of Vancouver Island to a very warm welcome. He and his crew stayed on for a month of storytelling, trading and ship repairs. Friendly, but not familiar with the local language, he misunderstood the name for both the people and land to be Nootka. In actual fact, Nootka means, go around, go around

Two hundred years later, in 1978, the Nuu-chah-nulth chose the collective term Nuu-chah-nulth — nuučaan̓uł, meaning all along the mountains and sea or along the outside (of Vancouver Island) — to describe themselves. 

It is a term now used to describe several First Nations people living along western Vancouver Island, British Columbia. 

It is similar in a way to the use of the United Kingdom to refer to the lands of England, Scotland and Wales — though using United Kingdom-ers would be odd. Bless the Nuu-chah-nulth for their grace in choosing this collective name.  

An older term for this group of peoples was Aht, which means people in their language and is a component in all the names of their subgroups, and of some locations — Yuquot, Mowachaht, Kyuquot, Opitsaht. While collectively, they are the Nuu-chah-nulth, be interested in their more regional name should you meet them. 

But why does it matter? If you have ever mistakenly referred to someone from New Zealand as an Aussie or someone from Scotland as English, you have likely been schooled by an immediate — sometimes forceful, sometimes gracious — correction of your ways. The best answer to why it matters is because it matters.

Each of the subgroups of the Nuu-chah-nulth viewed their lands and seasonal migration within them (though not outside of them) from a viewpoint of inside and outside. Kla'a or outside is the term for their coastal environment and hilstis for their inside or inland environment.

It is to their kla'a that I was most keen to explore. Here, the lovely Late Eocene and Early Miocene exposures offer up fossil crab, mostly the species Raninid, along with fossil gastropods, bivalves, pine cones and spectacularly — a singular seed pod. These wonderfully preserved specimens are found in concretion along the foreshore where time and tide erode them out each year.

Five years after Spanish explorer Juan Pérez's first visit, the Spanish built and maintained a military post at Yuquot where they tore down the local houses to build their own structures and set up what would become a significant fur trade port for the Northwest Coast — with the local Chief Maquinna's blessing and his warriors acting as middlemen to other First Nations. 

Following reports of Cook's exploration British traders began to use the harbour of Nootka (Friendly Cove) as a base for a promising trade with China in sea-otter pelts but became embroiled with the Spanish who claimed (albeit erroneously) sovereignty over the Pacific Ocean. 

Dan Bowen searching an outcrop. Photo: John Fam
The ensuing Nootka Incident of 1790 nearly led to war between Britain and Spain (over lands neither could actually claim) but talk of war settled and the dispute was settled diplomatically. 

George Vancouver on his subsequent exploration in 1792 circumnavigated the island and charted much of the coastline. His meeting with the Spanish captain Bodega y Quadra at Nootka was friendly but did not accomplish the expected formal ceding of land by the Spanish to the British. 

It resulted however in his vain naming the island "Vancouver and Quadra." The Spanish captain's name was later dropped and given to the island on the east side of Discovery Strait. Again, another vain and unearned title that persists to this day.

Early settlement of the island was carried out mainly under the sponsorship of the Hudson's Bay Company whose lease from the Crown amounted to 7 shillings per year — that's roughly equal to £100.00 or $174 CDN today. Victoria, the capital of British Columbia, was founded in 1843 as Fort Victoria on the southern end of Vancouver Island by the Hudson's Bay Company's Chief Factor, Sir James Douglas. 

With Douglas's help, the Hudson's Bay Company established Fort Rupert on the north end of Vancouver Island in 1849. Both became centres of fur trade and trade between First Nations and solidified the Hudson's Bay Company's trading monopoly in the Pacific Northwest.

The settlement of Fort Victoria on the southern tip of Vancouver Island — handily south of the 49th parallel — greatly aided British negotiators to retain all of the islands when a line was finally set to mark the northern boundary of the United States with the signing of the Oregon Boundary Treaty of 1846. Vancouver Island became a separate British colony in 1858. British Columbia, exclusive of the island, was made a colony in 1858 and in 1866 the two colonies were joined into one — becoming a province of Canada in 1871 with Victoria as the capital.

Dan Bowen, Chair of the Vancouver Island Palaeontological Society (VIPS) did a truly splendid talk on the Fossils of Nootka Sound. With his permission, I have uploaded the talk to the ARCHEA YouTube Channel for all to enjoy. Do take a boo, he is a great presenter. Dan also graciously provided the photos you see here. The last of the photos you see here is from the August 2021 Nootka Fossil Field Trip. Photo: John Fam, Vice-Chair, Vancouver Paleontological Society (VanPS).

Know Before You Go — Nootka Trail

The Nootka Trail passes through the traditional lands of the Mowachaht/Muchalat First Nations who have lived here since always. They share this area with humpback and Gray whales, orcas, seals, sea lions, black bears, wolves, cougars, eagles, ravens, sea birds, river otters, insects and the many colourful intertidal creatures that you'll want to photograph.

This is a remote West Coast wilderness experience. Getting to Nootka Island requires some planning as you'll need to take a seaplane or water taxi to reach the trailhead. The trail takes 4-8 days to cover the 37 km year-round hike. The peak season is July to September. Permits are not required for the hike. 

Access via: Air Nootka floatplane, water taxi, or MV Uchuck III

  • Dan Bowen, VIPS on the Fossils of Nootka: https://youtu.be/rsewBFztxSY
  • https://www.thecanadianencyclopedia.ca/en/article/sir-james-douglas
  • file:///C:/Users/tosca/Downloads/186162-Article%20Text-199217-1-10-20151106.pdf
  • Nootka Trip Planning: https://mbguiding.ca/nootka-trail-nootka-island/#overview


Sunday, 27 October 2024

BEARS OF THE PACIFIC NORTHWEST

A Grizzly Bear takes a rest on a fallen log in Alaska. While stumbling upon them may cause us surprise, they have heard us 
(and smelled us) coming for miles.

If you work or play in the woods of British Columbia, both grizzly and black bear sightings are common.

Nearly half the world's population, some 25,000 Grizzly Bears, roam the Canadian wilderness — of those, 14,000 or more call British Columbia home. These highly intelligent omnivores spend their days lumbering along our coastlines, mountains and forests.

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

An average Grizzly weighs in around 800 lbs (363 kg), but a recent find in Alaska tops the charts at 1600 lbs (726 kg). This mighty beast stood 12' 6' high at the shoulder, 14' to the top of his head and is one of the largest grizzlies ever recorded — a na̱ndzi.

Adult bears tend to live solo except during mating season. Those looking for love congregate from May to July in the hopes of finding a mate. Through adaptation to shifting seasons, the females' reproductive system delays the implantation of fertilized eggs — blastocysts —until November or December to ensure her healthy pups arrive during hibernation. If food resources were slim that year, the newly formed embryo will not catch or attach itself to her uterine wall and she'll try again next year. 

Females reach mating maturity at 4-5 years of age. They give birth to a single or up to four cubs (though usually just two) in January or February. The newborn cubs are cute little nuggets — tiny, hairless, and helpless — weighing in at 2-3 kilograms or 4-8 pounds. They feast on their mother’s nutrient-dense milk for the first two months of life. The cubs stay with their mamma for 18 months or more. Once fully grown, they can run 56 km an hour, are good at climbing trees and swimming and live 20-25 years in the wild. 

A Grizzly bear encounter inspires a humbling appreciation of just how remarkable these massive beasts are. Knowing their level of intelligence, keen memory and that they have a bite force of over 8,000,000 pascals — enough to crush a bowling ball — inspires awe and caution in equal measure. 

They have an indescribable presence. It is likely because of this that these majestic bears show up often in the superb carvings and work of First Nations artists. I have had close encounters with many bears growing up in the Pacific Northwest, meeting them up close and personal in the South Chilcotins and along our many shorelines. 

First Nation Lore and Language

In the Kwak'wala language of the Kwakiutl First Nations of the Pacific Northwest — or Kwakwaka'wakw, speakers of Kwak'wala — a Grizzly bear is known as na̱n

The ornamental carved Grizzly bear headdress was worn by the comic Dluwalakha Grizzly Bear Dancers, Once more from Heaven, in the Grizzly Bear Dance or Gaga̱lalał, is known as na̱ng̱a̱mł

The Dluwalakha dancers were given supernatural treasures or dloogwi which they passed down from generation to generation. 

In the Hamat'sa Grizzly bear dance, Nanes Bakbakwalanooksiwae, no mask was worn. Instead, the dancers painted their faces red and wore a costume of bearskin or t̓ła̱ntsa̱m and long wooden claws attached to their hands. You can imagine how impressive that sight is lit by the warm flickering flames of firelight during a Winter Dance ceremony.

Smoke of the World / Speaking of the Ancestors — Na̱wiła

Kwaguʼł Winter Dancers — Qagyuhl
Should you encounter a black bear and wish to greet them in Kwak'wala, you would call them t̕ła'yi. Kwakiutl First Nations, Smoke of the World, count Grizzly Bears as an ancestor — along with Seagull, Sun and Thunderbird. 

To tell stories of the ancestors is na̱wiła. Each of these ancestors took off their masks to become human and founded the many groups that are now bound together by language and culture as Kwakwaka’wakw. 

The four First Nations who collectively make up the Kwakiutl are the Kwakiutl (Kwágu7lh), K’umk’utis/Komkiutis, Kwixa/Kweeha (Komoyoi) and Walas Kwakiutl (Lakwilala) First Nations. 

There is likely blood of the Lawit’sis in there, too, as they inhabited the village site at Tsax̱is, Fort Rupert before the Kwakiutl made it a permanent home. 

Not all Kwakwaka'wakw dance the Gaga̱lalał, but their ancestors likely attended feasts where the great bear was celebrated. To speak or tell stories of the ancestors is na̱wiła — and Grizzly bear as an ancestor is na̱n helus.

Visiting British Columbia's Great Bears

If you are interested in viewing British Columbia's Great Bears, do check out Indigenous Tourism BC's wonderfully informative website and the culturally-rich wildlife experiences on offer. 

You will discover travel ideas and resources to plan your next soul-powered adventure. To learn more about British Columbia's Great Bears and the continuing legacy of First Nation stewardship, visit: 

Indigenous Tourism BC: https://www.indigenousbc.com

Great Bear Lodge has been offering tours to view the majestic animals of the Pacific Northwest. They keep both the guests and the animals' comfort and protection in mind. I highly recommend their hospitality and expertise. To see their offerings, visit: www.greatbeartours.com

Image: Group of Winter Dancers--Qagyuhl; Curtis, Edward S., 1868-1952, https://lccn.loc.gov/2003652753. 

Note: The Qagyuhl in the title of this photograph refers to the First Nation group, not the dancers themselves. I think our dear Edward was trying to spell Kwaguʼł and came as close as he was able. In Kwak'wala, the language of the Kwaguʼł or Kwakwakaʼwakw, speakers of Kwak'wala, the Head Winter Dancer is called t̕seḵa̱me' — and to call someone a really good dancer, you would use ya̱'winux̱w

Charmingly, when Edward S. Curtis was visiting Tsaxis/T'sakis, he was challenged to a wrestling competition with a Giant Pacific Octopus, Enteroctopus dofleini. George Hunt (1854-1933) had issued the challenge and laughed himself senseless when Edward got himself completely wrapped up in tentacles and was unable to move. Edward was soon untangled and went on to take many more photos of the First Nations of the Pacific Northwest. Things did not go as well for the octopus or ta̱ḵ̕wa. It was later served for dinner or dzaḵwax̱stala, as it seemed calamari was destined for that night's menu.  


Tuesday, 22 October 2024

TRACKING THROUGH THE TRIASSIC

Grambergia sp. Middle Triassic Ammonoid of  BC, Canada
In the early 1980s, Tim Tozer, Geological Survey of Canada was looking at the spread of marine invertebrate fauna in the Triassic of North America. 

In the western terranes of the Cordillera, marine faunas from southern Alaska and Yukon to Mexico are known from the parts that are obviously allochthonous with regard to the North American plates.

Lower and upper Triassic faunas of these areas, as well as some that are today up to 63 ° North, have the characteristics of the lower palaeo latitudes. 

In the western Cordillera, these faunas of the lower paleo latitudes can be found up to 3,000 km north of their counterparts on the American plate. This indicates a tectonic shift of significant magnitude. There are marine triads on the North American plate over 46 latitudes from California to Ellesmere Island. 

For some periods, two to three different faunal provinces can be distinguished. The differences in faunal species are linked, not surprisingly, to their palaeolatitude. They are called LPL, MPL, HPL (lower, middle, higher palaeolatitude).

Nevada provides the diagnostic features of the lower (LPL); northeastern British Columbia that of the middle (MPL) and Sverdrup Basin, the large igneous province on Axel Heiberg Island and Ellesmere Island, Nunavut, Canada near the rifted margin of the Arctic Ocean, that of the higher palaeolatitude (HPL).

A distinction between the provinces of the middle and the higher palaeo-situations can not be made for the lower Triassic and lower Middle Triassic (anise). However, all three provinces can be seen in the deposits of Ladin, Kam and Nor.

In the early 2000s, as part of a series of joint UBC, VIPS and VanPS fossil field trips (and then Chair of the VanPS), I explored much of the lower faunal outcrops of northeastern British Columbia. It was my first time seeing many of British Columbia's Triassic outcrops. 

Years later, and fueled by seeing paper after paper correlating the faunal assemblages of BC to those of Nevada, I had the very great pleasure of walking through the Nevada strata with John Fam (VanPS, Vice-Chair), Dan Bowen (VIPS, Chair) and Betty Franklin (VIPS, Goddess of Everything and BCPA, Treasurer) — and witnessing first-hand the correlation between the Nevada fauna and those from the Triassic of British Columbia, Canada.

Triassic ammonoids, West Humboldt Mountains, Nevada, USA
The Nevada faunal assemblages are a lovely match. The quality of preservation at localities like Fossil Hill in the Humboldt Mountains of Nevada, perhaps the most famous and important locality for the Middle Triassic (Anisian/Ladinian) of North America, is truly outstanding.

Aside from sheer beauty and spectacular preservation, the ammonoids and belemnites were tucked in cozily with very well preserved ichthyosaur remains.

Tozer's interest in our marine invert friends was their distribution. How and when did certain species migrate, cluster, evolve — and for those that were prolific, how could their occurrence — and therefore significance — aide in an assessment of plate and terrane movements that would help us to determine paleolatitudinal significance. 

I share a similar interest but not exclusive to our cephalopod fauna. The faunal collection of all of the invertebrates holds appeal.

Middle Triassic (Anisian/Ladinian) Fauna
This broader group held an interest for J.P. Smith who published on the marine fauna in the early 1900s based on his collecting in scree and outcrops of the West Humboldt Mountains, Nevada. He published his first monograph on North American Middle Triassic marine invertebrate fauna in 1914.

N. J. Siberling from the US Geological Survey published on these same Nevada outcrops in 1962. His work included nearly a dozen successive ammonite faunas, many of which were variants on previously described species. Both their works would inform what would become a lifelong piecing together of the Triassic puzzle for Tozer.

If one looks at the fauna and the type of sediment, the paleogeography of the Triassic can be interpreted as follows: a tectonically calm west coast of the North American plate that bordered on an open sea; in the area far from the coast, a series of volcanic archipelagos delivered sediment to the adjacent basins. 

Some were lined or temporarily covered with coral wadding and carbonate banks. Deeper pools were in between. The islands were probably within 30 degrees of the triadic equator. They moved away from the coast up to about 5000 km from the forerunner of the East Pacific Ridge. The geographical situation west of the back was probably similar.

Jurassic and later generations of the crust from near the back have brought some of the islands to the North American plate; some likely to South America; others have drifted west, to Asia. There are indications that New Guinea, New Caledonia and New Zealand were at a northern latitude of 30 ° or more during the Triassic period.

The terranes that now form the western Cordillera were probably welded together and reached the North American plate before the end of the Jurassic period.

Marine Triassic occurs on the North American Plate over a latitudinal spread of 46 degrees, from California to Ellesmere Island. At some intervals of time faunas on the Plate permit the discrimination of two or three provinces with distinctively different coeval faunas. 

The faunal differences are evidently related to paleolatitude and the provinces are designated LPL, MPL, HPL (low, mid, high paleolatitude). Nevada provides the diagnostic characters of the LPL province; northeastern British Columbia the MPL; the Sverdrup Basin the HPL. In the Lower Triassic and early Middle Triassic (Anisian), the distinction between the MPL and HPL provinces cannot be made. All three provinces are recognized in the Ladinian, Carnian and Norian deposits.

Juvavites sp. Geological Survey of Canada. Photo: John Fam
In the western tracts of the Cordillera, the part formed of suspect terranes, apparently allochthonous with respect to the North American Plate, marine faunas are known all the way from southern Alaska and Yukon to Mexico.

Lower and Upper Triassic faunas from these terranes, including some which today are at 63 degrees north, have the characters of the LPL province.

Middle Triassic faunas from the terranes, as presently known, do not contribute significant data. In the terranes of the Western Cordillera, LPL faunas were now up to 3,000 km north of their counterparts on the American Plate. Through the fossil fauna assemblages, we can see this level of tectonic displacement.

Taking into account the faunas and the nature of the rocks, the Triassic paleogeography is interpreted as a tectonically quiet west shore for the North American Plate, bordered by an open sea or ocean; then, well off-shore, a series of volcanic archipelagos shedding sediment into adjacent basins. Some were fringed or intermittently covered by coralline shoals and carbonate banks. Deeper basins were in between. The islands probably were within 30 degrees of the Triassic equator and extended offshore for about 5000 km, to the spreading ridge directly ancestral to the East Pacific Rise. The geography west of the spreading ridge was probably comparable.

Jurassic and later generation of crust at the ridge had driven some of the islands into the North American Plate; some probably to South America; others have gone west to Asia. Evidence is given that northern New Guinea, New Caledonia and New Zealand may have been at a north latitude of 30 degrees or more in the Triassic. The terranes now forming the Western Cordillera had probably amalgamated, and reached the North American Plate, before the end of the Jurassic.

At the end of the Rhaetian (part of the Triassic period), most of the ammonites had died out. These are the lovely coiled molluscs you often see in museums and gift shops that sell fossils. They are a particular favourite of mine and they are both beautiful and useful to tell us much about deep time. The Hettangian, a rather poorly understood 3 million year time interval followed the Triassic-Jurassic mass extinction event.

During the Hettangian, the new or  Neoammonites developed quite quickly. Within a million years, a fairly large, diverse selection of genera and species had risen to fill the void. The gap created by the Triassic-Jurassic extinction event was re-filled and our ability to "read the rocks' to understand their continued movement through tectonic plate shifting recommenced.

Alsatites proaries, Hettangian Ammonite
It is during the Hettangian that the smooth shelled ammonite genus Psiloceras first appears. They span the time between 201.3 ± 0.2 Ma and 199.3 ± 0.3 Ma (million years ago). For my European friends, the Hettangian is the time span in which the marine limestone, shales and clay Lias of western Europe were deposited.

This Hettangian ammonite, Alsatites proaries, is a lovely example of the cephalopods cruising our ancient oceans at that time. Alsatites is an extinct genus of cephalopod belonging to the Ammonite subclass. They lived during the Early Jurassic, Hettangian till the Sinemurian and are generally extremely evolute, many whorled with a broad keel. Or, as described by one of my very young friends, he looks like a coiled snake you make in pottery class.

The Hettangian is an interesting little period of our history. It spans the time between 201.3 ± 0.2 Ma and 199.3 ± 0.3 Ma (million years ago). For my European friends, the Hettangian is the time in which the marine limestone, shales and clay Lias of western Europe were deposited. In British Columbia, Canada, we see the most diverse middle and late Hettangian (Early Jurassic) ammonite assemblages in the Queen Charlotte Islands (Haida Gwaii), an archipelago about 50 km off British Columbia's northern Pacific coast. In total, 53 ammonite taxa are described of which Paradasyceras carteri, Franziceras kennecottense, Pleuroacanthites charlottensis, Ectocentrites pacificus and Curviceras haidae are new.

In general, North American Early Jurassic ammonites are of Tethyan affinity or endemic to the eastern Pacific. For this reason, a separate zonation for the Hettangian and Sinemurian of the Western Cordillera of North America was established. Taylor et al. (2001), wrote up and published on much of this early research though, at the time, very little Canadian information was included.

Longridge, L. M., et al. “Three New Species of the Hettangian (Early Jurassic) Ammonite Sunrisites from British Columbia, Canada.” Journal of Paleontology, vol. 82, no. 1, 2008, pp. 128–139. JSTOR, www.jstor.org/stable/20144175. Accessed 27 Jan. 2020.

Tozer, ET (Tim): Marine Triassic faunas of North America: Their significance for assessing plate and terrane movements. Geol Rundsch 71, 1077-1104 (1982). https://doi.org/10.1007/BF01821119

Danner, W. (Ted): Limestone resources of southwestern British Columbia. Montana Bur. Mines & Geol., Special publ. 74: 171-185, 1976.

Davis, G., Monger, JWH & Burchfiel, BC: Mesozoic construction of the Cordilleran “collage”, central British Columbia to central California. Pacific Coast Paleography symposium 2, Soc. Economic Paleontologists and Mineralogists, Los Angeles: 1-32, 1978.

Gibson, DW: Triassic rocks of the Rocky Mountain foothills and front ranges of northeastern British Columbia and west-central Alberta. Geol. Surv. Canada Bull. 247, 1975.

Photo of the large belemnite (Atractites sp?) and ammonites (Sunrisites & Badouxia) from the Lower Jurassic (Late Hettangian), Last Creek Formation (Castle Pass member), Taseko Lakes area, British Columbia, Canada in the collection of the deeply awesome John Fam.

Photo: A drawer of Juvavites sp. in the collections of the Geological Survey of Canada. These rarely seen Upper Triassic (Carnian to Norian) ammonoids were collected over many decades by geologists of the Geological Survey of Canada from Northeastern British Columbia. Photo care of the deeply awesome John Fam.

Photo: Grambergia sp. from the Early Anisian (Middle Triassic) ammonoid biostratigraphy of northeastern British Columbia, Canada. Collection of Fossil Huntress.

Photo: Alsatites proaries, Coll. Reiter, Neoammoniten, 30 July 2011, 19:26:10

Friday, 4 October 2024

FOSSILS, LIMESTONE AND SALT: HALLSTATT

Hallstatt Salt Mines, Austria / Permian Salt Diapir
The Hallstatt Limestone is the world's richest Triassic ammonite unit, yielding specimens of more than 500 ammonite species.

Along with diversified cephalopod fauna  — orthoceratids, nautiloids, ammonoids — we also see gastropods, bivalves, especially the late Triassic pteriid bivalve Halobia (the halobiids), brachiopods, crinoids and a few corals. We also see a lovely selection of microfauna represented. 

For microfauna, we see conodonts, foraminifera, sponge spicules, radiolaria, floating crinoids and holothurian sclerites —  polyp-like, soft-bodied invertebrate echinozoans often referred to as sea cucumbers because of their similarities in size, elongate shape, and tough skin over a soft interior. 

Franz von Hauer’s exhaustive 1846 tome describing Hallstatt ammonites inspired renowned Austrian geologist Eduard Suess’s detailed study of the area’s Mesozoic history. That work was instrumental in Suess being the first person to recognize the former existence of the Tethys Sea, which he named in 1893 after the sister of Oceanus, the Greek god of the ocean. As part of the Northern Limestone Alps, the Dachstein rock mass, or Hoher Dachstein, is one of the large karstic mountains of Austria and the second-highest mountain in the Northern Limestone Alps. It borders Upper Austria and Styria in central Austria and is the highest point in each of those states.

Parts of the massif also lie in the state of Salzburg, leading to the mountain being referred to as the Drei-Länder-Berg or three-state mountain. Seen from the north, the Dachstein massif is dominated by the glaciers with the rocky summits rising beyond them. By contrast, to the south, the mountain drops almost vertically to the valley floor. The karst limestones and dolomites were deposited in our Mesozoic seas. The geology of the Dachstein massif is dominated by the Dachstein-Kalk Formation — the Dachstein limestone — which dates back to the Triassic.

Hallstatt and the Hallstatt Sea, Austria
There were several phases of mountain building in this part of the world pushing the limestone deposits 3,000 metres above current sea level. The rock strata were originally deposited horizontally, then shifted, broken up and reshaped by the erosive forces of ice ages and erosion.

The Hallstatt mine exploits a Permian salt diapir that makes up some of this area’s oldest rock. 

The salt accumulated by evaporation in the newly opened, and hence shallow, Hallstatt-Meliata Ocean. This was one of several small ocean basins that formed in what is now Europe during the late Paleozoic and early Mesozoic when the world’s landmasses were welded together to form the supercontinent Pangea. 

Pangea was shaped like a crescent moon that cradled the famous Tethys Sea. Subduction of Tethyian oceanic crust caused several slivers of continental crust to separate from Pangea, forming new “back-arc basins” (small oceans formed by rifting that is associated with nearby subduction) between the supercontinent and the newly rifted ribbon continents.

The Hallstatt-Meliata Ocean was one such back-arc basin. As it continued to expand and deepen during the Triassic, evaporation ceased and reefs flourished; thick limestone deposits accumulated atop the salt. When the Hallstatt-Meliata Ocean closed in the Late Jurassic, the compression squeezed the low-density salt into a diapir that rose buoyantly, injecting itself into the Triassic limestones above.

The Hallstatt salt diapir and its overlying limestone cap came to rest in their present position in the northern Austrian Alps when they were shoved northward as nappes (thrust sheets) during two separate collision events, one in the Cretaceous and one in the Eocene, that created the modern Alps. It is from the Hallstatt salt diapir that Hallstatt, like so many cities and towns, gets its name.

Deposits of rock salt or halite, the mineral name of sodium chloride with the chemical formula of NaCl, are found and mined around the globe. These deposits mark the dried remains of ancient oceans and seas. Names of rivers, towns and cities in Europe — Salzburg, Halle, Hallstatt, Hallein, La Salle, Moselle — all pay homage to their connection to halite and salt production. The Greek word for salt is hals and the Latin is sal. The Turkish name for salt is Tuz, which we see in the naming of Tuzla, a salt-producing region of northeastern Bosnia-Herzegovina and in the names of towns that dot the coast of Turkey where it meets the Black Sea. Hallstatt with its salt diapir is no exception.

The salt-named town of Hallstatt sits on the shores of the idyllic Hallstätter Sea at the base of the Dachstein massif. Visiting it today, you experience a quaint traditional fishing village built in the typical upper Austrian style. Tourism drives the economy as much as salt as this area of the world is picture-perfect from every angle.

Space is at a minimum in the town. For centuries, every ten years the local cemetery exhumes the bones of those buried there and moves them to an ossuary to make room for new burials. The Hallstatt Ossuary is called Karner, Charnel House, or simply Beinhaus (Bone House). Karners are places of secondary burials. They were once common in the Eastern Alps, but that custom has largely disappeared.

Hallstatt Beinhaus Ossuary, Hallstatt, Austria
A collection of over 700 elaborately decorated skulls rest inside the ossuary. They are lined up on rows of wooden shelves that grace the walls of the chapel. Another 500 undecorated skulls, bare and without any kind of adornment, are stacked in the corners.

Each is inscribed and attached to a record with the deceased's name, profession and date of death. The Bone House is located in a chapel in the basement of the Church of Saint Michael. The church dates from the 12th century CE. 

Decorating the skulls was traditionally the job of the local gravedigger and an honour granted to very few. At the family's request, garlands of flowers were painted on the skulls of deceased as decorative crowns if they were female. The skulls of men and boys were painted wreaths of oak or ivy.

Every building in Hallstatt looks out over the Hallstätter Sea. This beautiful mountain lake considered one of the finest of Austria's Salzkammergut region. It lies at the northern foot of the Dachstein mountain range, sitting eight-and-a-half kilometres long and two kilometres wide. The shoreline is dotted by the villages of  Obertraun, Steeg, and Hallstatt.

The region is habitat to a variety of diverse flora and fauna, including many rare species such as native orchids, in the wetlands and moors in the south and north.

Linked by road to the cities of Salzburg and Graz, Hallstatt and its lake were declared one of the World Heritage sites in Austria in 1997 and included in the Hallstatt-Dachstein Salzkammergut Alpine UNESCO World Heritage Site. The little market village of Hallstatt takes its name from the local salt mine.

Hallstatt, Salzkammergut region, Austria
The town is a popular tourist destination with its quaint shops and terraced cafes. In the centre of town, the 19th-century Evangelical Church of Hallstatt with its tall, slender spire is a lakeside landmark. You can see it here in the photo on the left.

Above the town are the Hallstatt Salt mines located within the 1,030-meter-tall Salzburg Salt Mountain. They are accessible by cable car or a three-minute journey aboard the funicular railway. There is also a wonderful Subterranean Salt Lake.

In 1734, there was a corpse found here preserved in salt. The fellow became known as the Man in Salt. Though no archaeological analysis was performed at the time — the mummy was respectfully reburied in the Hallstatt cemetery — based on descriptions in the mine records, archaeologists suspect the miner lived during the Iron Age. This Old Father, Senos ph₂tḗr, 'ɸatīr 'father' may have been a local farmer, metal-worker, or both and chatted with his friends and family in Celtic or Proto-Celtic.

Salt mining in the area dates back to the Neolithic period, from the 8th to 5th Centuries BC. This is around the time that Roman legions were withdrawing from Britain and the Goths sacked Rome. In Austria, agricultural settlements were dotting the landscape and the alpine regions were being explored and settled for their easy access to valuable salt, chert and other raw materials.

The salt-rich mountains of Salzkammergut and the upland valley above Hallstatt were attractive for this reason. The area was once home to the Hallstatt culture, an archaeological group linked to Proto-Celtic and early Celtic people of the Early Iron Age in Europe, c.800–450 BC.
Bronze Age vessel with cow and calf

In the 19th century, a burial site was discovered with 2,000 individuals, many of them buried with Bronze Age artefacts of amber and ivory.

It was this find that helped lend the name Hallstatt to this epoch of human history. The Late Iron Age, between around 800 and 400 BC, became known as the Hallstatt Period.

For its rich history, natural beauty and breathtaking mountainous geology, Hallstatt is a truly irresistible corner of the world.

Salzbergstraße 1, 4830 Hallstatt.  https://www.salzwelten.at/en/home/

Photo: Bronze vessel with cow and calf, Hallstatt by Alice Schumacher - Naturhistorisches Museum Wien - A. Kern – K. Kowarik – A. W. Rausch – H. Reschreiter, Salz-Reich. 7000 Jahre Hallstatt, VPA 2 (Wien, 2008) Seite 133 Abbildung 6. Hallstatt Village & Ossuary Photos: P. McClure Photography ca. 2015.

Bernoulli D, Jenkyns HC (1974) Alpine, Mediterranean, and Central Atlantic Mesozoic facies in relation to the early evolution of the Tethys. Soc Econ Paleont Mineral Spec Publ 19:129–160

Bernoulli D, Jenkyns H (2009) Ancient oceans and continental margins of the Alpine-Mediterranean Tethys: deciphering clues from Mesozoic pelagic sediments and ophiolites. Sedimentology 56:149–190

Thursday, 3 October 2024

WASHINGTON STATE PALEONTOLOGY

North Cascades National Park, Washington State, USA
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.

Washington is home to a wide variety of fossils—from new species of fossil crabs to marine mollusks and the fossil palm fronds that symbolize the Chuckanut formation.

We also find fossil whales, bird trackways, fossil sockeye salmon, mammal footprints, mammoth bones & the trace fossil remains of ancient rhino. In the time expanse in which we live our very short human lives, the Earth's crust appears permanent.

A fixed outer shell – terra firma. Aside from the rare event of an earthquake or the eruption of Mount St. Helen’s in 1980, 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 neighbouring plates. Large chunks of the ocean floor have been uplifted, shifted and now find themselves thousands of miles in the air, part of mountain chains far from the ocean today or carved by glacial ice into valleys and basins.

Two hundred million years ago, Washington was two large islands, bits of the continent on the move westward, eventually bumping up against the North American continent and calling it home. Even with their new fixed address, the shifting continues; the more extreme movement has subsided laterally and continues vertically. The upthrusting of plates continue to move our mountain ranges skyward, the path of least resistance.

Fossil Palm Front, Washington State
This dynamic movement has created the landscape we see today and helped form the fossil record that tells much of Washington’s relatively recent history – the past 50 million years. Chuckanut Drive is much younger than other parts of Washington.

The fossils found there lived and died some 40-55 million years ago, very close to where they are now, but in a much warmer, swampy setting. The exposures of the Chuckanut Formation were once part of a vast river delta; imagine, if you will, the bayou country of the Lower Mississippi.

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

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

Shore Bird Trackway, Washington State
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 riverways of the Pacific Northwest 50 million years ago.

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

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

Monday, 23 September 2024

BOENY REGION OF MADAGASCAR

Aioloceras besairiei (Collingnon, 1949)
A stunning example of the internal suturing with calcite infill in this sliced Aioloceras besairiei (Collingnon, 1949) ammonite from the Upper Cretaceous (Lower Albian) Boeny region of Madagascar. 

This island country is 400 kilometres off the coast of East Africa in the Indian Ocean and a wonderful place to explore off the beaten track.

Madagascar has some of the most spectacular of all the fossil specimens I have ever seen. This beauty is no exception. The shell has a generally small umbilicus, arched to acute venter, and typically at some growth stage, falcoid ribs that spring in pairs from umbilical tubercles, usually disappearing on the outer whorls. I had originally had this specimen marked as a Cleoniceras besairiei, except Cleoniceras and Grycia are not present in Madagascar. 

This lovely, seen in cross-section, is now far from home and in the collection of a wonderful friend. It is an especially lovely example of the ammonite, Aioloceras besairiei, making it a beudanticeratinae. Cleoniceras and Grycia are the boreal genera. If you'd like to see (or argue) the rationale on the name, consider reading Riccardi and Medina's riveting work from back in 2002, or Collingnon from 1949.

The beauty you see here measures in at a whopping 22 cm, so quite a handful. This specimen is from the youngest or uppermost subdivision of the Lower Cretaceous. I'd originally thought this locality was older, but dating reveals it to be from the Lower Albian, so approximately 113.0 ± 1.0 Ma to 100.5 ± 0.9 Ma.

Aioloceras are found in the Cretaceous of Madagascar at geo coordinates 16.5° S, 45.9° E: paleo-coordinates 40.5° S, 29.3° E.; and in four localities in South Africa: at locality 36, near the Mzinene River at 28.0° S, 32.3° E: paleo-coordinates 48.6° S, 7.6° E. 

We find them near the Mziene River, at a second locality north of Hluhluwe where the Mzinene Formation overlies the Aptian-Albian Makatini Formation at 28.0° S, 32.3° E: paleo-coordinates 48.6° S, 7.6° E; and at Haughton Z18, on the Pongola River in the Albian III, Tegoceras mosense beds at 27.3° S, 32.2° E: paleo-coordinates 48.0° S, 7.8° E.

If you happen to be trekking to Madagascar, know that it's big. It’s 592,800 square kilometres (or  226,917 square miles), making it the fourth-largest island on the planet — bigger than Spain, Thailand, Sweden and Germany. The island has an interesting geologic history.

Although there has been a geological survey, which was active extending back well into French colonial times, in the non-French-speaking world our geological understanding of the island is still a bit of a mystery. 

Plate tectonic theory had its beginnings in 1915 when Alfred Wegener proposed his theory of "continental drift." 

Wegener proposed that the continents ploughed through the crust of ocean basins, which would explain why the outlines of many coastlines (like South America and Africa) look like they fit together like a puzzle. Half a century after Wegener there is still no agreement as to whether in continental reconstructions Madagascar should be placed adjacent to the Tanzanian coast to the north (e.g., McElhinny and Embleton,1976), against the Mozambique-Natal coast (Flores 1970), or basically left where it is (Kent 1974, Nairn 1978).

There have been few attempts apart from McKinley’s (1960) comparison of the Karoo succession of southwestern Tanzania with that of Madagascar to follow the famous geological precept of “going to sea.” One critical reason is that although there may be a bibliography of several thousand items dealing with Madagascan geology as Besairie (1971) claims, they are items not generally available to the general public. The vital information gained of the geology of the offshore area by post-World War II petroleum exploration has remained largely proprietary. 

Without this data to draw upon, our understanding remains incomplete. I don't actually mind a bit of a mystery here. It is interesting to speculate on how these geologic puzzle pieces fit together and wait for the big reveal. Still, we have good old Besairie from his 1971, Geologie de Madagascar, and a later précis (Besairie, 1973).

We do know that Madagascar was carved off from the African-South American landmass early on. The prehistoric breakup of the supercontinent Gondwana separated the Madagascar–Antarctica–India landmass from the Africa–South America landmass around 135 million years ago. Madagascar later split from India about 88 million years ago, during the Late Cretaceous, so the native plants and animals on the island evolved in relative isolation. 

It is a green and lush island country with more than its fair share of excellent fossil exposures. Along the length of the eastern coast runs a narrow and steep escarpment containing much of the island's remaining tropical lowland forest. If you could look beneath this lush canopy, you'd see rocks of the Precambrian age stretching from the east coast all the way to the centre of the island. The western edge is made up of sedimentary rock from the Carboniferous to the Quaternary.

Red-Tailed Lemurs, Waiwai & Hedgehog
Madagascar is a biodiversity hotspot. Just as Darwin's finches on the Galápagos were isolated, evolving into distinct species (hello, adaptive radiation), over 90% of the wildlife from Madagascar is found nowhere else. 

The island's diverse ecosystems, like so many on this planet, are threatened by Earth's most deadly species, homo sapien sapiens. 

We arrived back in 490 CE and have been chopping down trees and eating our way through the island's tastier populations ever since. Still, they have cuties like this Red-Tailed Lemur. Awe, right?

Today, beautiful outcrops of wonderfully preserved fossil marine fauna hold appeal for me. The material you see from Madagascar is distinctive — and prolific.

Culturally, you'll see a French influence permeating the language, architecture and legal process. There is a part of me that pictures these lovely Lemurs chatting away in French. "Ah, la vache! Regarde le beau fossile, Hérissonne!"

We see the French influence because good 'ol France invaded sleepy Madagascar back in 1883, during the first Franco-Hova War. Malagasy (the local Madagascarian residents) were enlisted as troops, fighting for France in World War I.  During the Second World War, the island was the site of the Battle of Madagascar between the Vichy government and the British. By then, the Malagasy had had quite enough of colonization and after many hiccuping attempts, reached full independence in 1960. Colonization had ended but the tourist barrage had just begun. You can't stop progress.

If you're interested in learning more about this species, check out the Treatise on Invertebrate Paleontology, Part L (Ammonoidea). R.C. Moore (ed). Geological Soc of America and Univ. Kansas Press (1957), p L394. Or head over to look at the 2002 paper from Riccardi and Medina. 2002. Riccardi, A., C. & Medina, F., A. The Beudanticeratinae and Cleoniceratinae (Ammonitina) from the Lower Albian of Patagonia in Revue de Paléobiologie - 21(1) - Muséum d’Histoire Naturelle de la ville de Genève, p 313-314 (=Aioloceras besairiei (COLLIGNON, 1949). You have Bertrand Matrion to thank for the naming correction. Good to have friends in geeky places!

Collignon, M., 1933, Fossiles cenomaniens d’Antmahavelona (Province d’ Analalave, Madagascar), Ann. Geol. Serv. Min. Madagascar, III, 1934 Les Cephalopods du Trias inferieur de Madagascar, Ann. Paleont. XXII 3 and 4, XXII 1.

Besairie, H., 1971, Geologie de Madagascar, 1. Les terrains sedimentaires, Ann. Geol. Madagascar, 35, p. 463.

J. Boast A. and E. M. Nairn collaborated on a chapter in An Outline of the Geology of Madagascar, that is very readable and cites most of the available geologic research papers. It is an excellent place to begin a paleo exploration of the island.

If you happen to parle français, check out: Madagascar ammonites: http://www.ammonites.fr/Geo/Madagascar.htm