Saturday, 6 May 2023

MUSKOX: CAPRINAE

Look at this soulful fellow. He is a muskox who spends his days slowly meandering through these gorgeous fields eating his fill of nutritious plants on the open tundra. They are social animals, moving together in large herds. 

As a member of the subfamily Caprinae of the family Bovidae, the muskox is more closely related to sheep and goats than to oxen. It has been placed in its own genus, Ovibos — Latin for sheep-ox. It is one of the two largest extant members of Caprinae, along with the similarly sized takin.

While the takin and muskox were once considered possibly closely related, the takin lacks common ovibovine features, such as the muskox's specialized horn morphology, and genetic analysis shows that their lineages actually separated early in caprine evolution. 

Instead, the muskox's closest living relatives appear to be the gorals of the genus Naemorhedus, nowadays common in many countries of central and east Asia. The vague similarity between takin and muskox must therefore be considered an example of convergent evolution.

The modern muskox is the last member of a line of ovibovines that first evolved in temperate regions of Asia and adapted to a cold tundra environment late in its evolutionary history. They lived alongside our lovely Mammoths and would have competed for the same plant resources as those much larger beasts. 

Muskox ancestors with sheep-like high-positioned horns — horn cores being mostly over the plane of the frontal bones, rather than below them as in modern muskoxen — first left the temperate forests for the developing grasslands of Central Asia during the Pliocene, expanding into Siberia and the rest of northern Eurasia. 

Later migration waves of Asian ungulates, including the high-horned muskox, reached Europe and North America during the first half of the Pleistocene. The first well-known muskox, the "shrub-ox" Euceratherium, crossed to North America over an early version of the Bering Land Bridge two million years ago and prospered in the American southwest and Mexico. Euceratherium was larger yet more lightly built than modern muskoxen, resembling a giant sheep with massive horns, and preferred hilly grasslands.

A genus with intermediate horns, Soergelia, inhabited Eurasia in the early Pleistocene, from Spain to Siberia, and crossed to North America during the Irvingtonian (1.8 million years to 240,000 years ago), soon after Euceratherium. Unlike Euceratherium, which survived in America until the Pleistocene-Holocene extinction event, Soergelia was a lowland dweller that disappeared fairly early, displaced by more advanced ungulates, such as the "giant muskox" Praeovibos (literally "before Ovibos"). 

The low-horned Praeovibos was present in Europe and the Mediterranean 1.5 million years ago, colonized Alaska and the Yukon one million years ago and disappeared half a million years ago. Praeovibos was a highly adaptable animal that appears associated with cold tundra (reindeer) and temperate woodland (red deer) faunas alike. 

During the Mindel glaciation 500,000 years ago, Praeovibos was present in the Kolyma river area in eastern Siberia in association with many Ice Age megafauna that would later coexist with Ovibos, in the Kolyma itself and elsewhere, including wild horses, reindeer, woolly mammoth and stag-moose. 

It is debated, however, if Praeovibos was directly ancestral to Ovibos, or both genera descended from a common ancestor since the two occurred together during the middle Pleistocene. Defenders of ancestry from Praeovibos have proposed that Praeovibos evolved into Ovibos in one region during a period of isolation and expanded later, replacing the remaining populations of Praeovibos.

Two more Praeovibos-like genera were named in America in the 19th century, Bootherium and Symbos, which are now identified as the male and female forms of a single, sexually dimorphic species, the "woodland muskox", Bootherium bombifrons. Bootherium inhabited open woodland areas of North America during the Late Pleistocene, from Alaska to Texas and maybe even Mexico, but was most common in the Southern United States, while Ovibos replaced it in the tundra-steppe to the north, immediately south of the Laurentian ice sheet.

Modern Ovibos appeared in Germany almost one million years ago and were common in the region through the Pleistocene. Muskoxen had also reached the British Isles. Both Germany and Britain were just south of the Scandinavian ice sheet and covered in the tundra during cold periods, but Pleistocene muskoxen are also rarely recorded in more benign and wooded areas to the south like France and Green Spain, where they coexisted with temperate ungulates like red deer and aurochs. Likewise, the muskox is known to have survived in Britain during warm interglacial periods.

Today's muskoxen are descended from others believed to have migrated from Siberia to North America between 200,000 and 90,000 years ago, having previously occupied Alaska (at the time united to Siberia and isolated periodically from the rest of North America by the union of the Laurentide and Cordilleran Ice Sheets during colder periods) between 250,000 and 150,000 years ago. 

After migrating south during one of the warmer periods of the Illinoian glaciation, non-Alaskan American muskoxen would be isolated from the rest in the colder periods. The muskox was already present in its current stronghold of Banks Island 34,000 years ago, but the existence of other ice-free areas in the Canadian Arctic Archipelago at the time is disputed.

Along with the bison and the pronghorn, the muskox was one of a few species of Pleistocene megafauna in North America to survive the Pleistocene/Holocene extinction event and live to the present day. The muskox is thought to have been able to survive the last glacial period by finding ice-free areas (refugia) away from prehistoric peoples.

Fossil DNA evidence suggests that muskoxen were not only more geographically widespread during the Pleistocene, but also more genetically diverse. During that time, other populations of muskoxen lived across the Arctic, from the Ural Mountains to Greenland. By contrast, the current genetic makeup of the species is more homogenous. Climate fluctuation may have affected this shift in genetic diversity: research indicates colder periods in Earth's history are correlated with more diversity and warmer periods with more homogeneity.

Friday, 5 May 2023

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

Tuesday, 2 May 2023

SUNSETS AND SUPERNOVAE

Sunsets — pure visual poetry: peaceful, meditative, mesmerizing.

What is sunlight, actually? Yes, it's light from the Sun but so much more than that. Sunlight is both light and energy. Once it reaches Earth, we call this energy, "insolation," a fancy term for solar radiation. The amount of energy the Sun gives off changes over time in a never-ending cycle.

Solar flares (hotter) and sunspots (cooler) on the Sun's surface impact the amount of radiation headed to Earth. These periods of extra heat or extra cold (well, cold by Sun standards...) can last for weeks, sometimes months. The beams that reach us and warm our skin are electromagnetic waves that bring with them heat and radiation, by-products of the nuclear fusion happening as hydrogen nuclei fuse and shift violently to form helium, a process that fires every star in the sky.

Our bodies convert the ultraviolet rays to Vitamin D. Plants use the rays for photosynthesis, a process of converting carbon dioxide to sugar and using it to power their growth (and clean our atmosphere!) That process looks something like this: carbon dioxide + water + light energy — and glucose + oxygen = 6 CO2(g) + 6 H2O + photons → C6H12O6(aq) + 6 O2(g).

Photosynthetic organisms convert about 100–115 thousand million metric tonnes of carbon to biomass each year, about six times more power than used us mighty homo sapien sapiens. Our plants, forests and algae soak up this goodness and much later in time, we harvest this energy from fossil fuels.

We've yet to truly get a handle on the duality between light as waves and light as photons. The duality of the two-in-oneness of light; of their waves and alter-ego, particle photons is a physicists delight. Einstein formulated his special theory of relativity in part by thinking about what it would be like to ride around on these waves. What would space look and feel like? How would time occur? It bends the mind to consider. His wave-particle view helped us to understand that these seemingly different forms change when measured. To put this in plain English, they change when viewed, ie. you look them "in the eye" and they behave as you see them.

Light fills not just our wee bit of the Universe but the cosmos as well, bathing it in the form of cosmic background radiation that is the signature of the Big Bang and the many mini-big bangs of supernovae as they go through cycles of reincarnation and cataclysmic death — exploding outward and shining brighter than a billion stars.

In our solar system, once those electromagnetic waves leave the Sun headed for Earth, they reach us in a surprising eight minutes. We experience them as light mixed with the prism of beautiful colours. But what we see is actually a trick of the light. As rays of white sunlight travel through the atmosphere they collide with airborne particles and water droplets causing the rays to scatter.

We see mostly the yellow, orange and red hues (the longer wavelengths) as the blues and greens (the shorter wavelengths) scatter more easily and get bounced out of the game rather early.

Monday, 1 May 2023

PISTA DE BAILE JURÁSICA

This busy slate grey dinosaur trackway from the Iberian Peninsula looks more like a dance floor than the thoroughfare it is. 

The numerous theropod dinosaur tracks — with a few enormous sauropod tracks thrown in for good measure — cover the entire surface. 
The local soil has a bit of rusty iron ore in it that highlights each print nicely when the soil is blown into the depressions the tracks left. 

The dinosaurs crossed this muddy area en masse sometime back in the Jurassic.

The Iberian Peninsula is the westernmost of the three major southern European peninsulas — the Iberian, Italian, and Balkan. It is bordered on the southeast and east by the Mediterranean Sea, and on the north, west, and southwest by the Atlantic Ocean. The Pyrenees mountains are situated along the northeast edge of the peninsula, where it adjoins the rest of Europe. Its southern tip is very close to the northwest coast of Africa, separated from it by the Strait of Gibraltar and the Mediterranean Sea.

The Iberian Peninsula contains rocks of every geological period from the Ediacaran to the recent, and almost every kind of rock is represented. To date, there are 127 localities of theropod fossil finds ranging from the Callovian-Oxfordian — Middle-Upper Jurassic — to the Maastrichtian (Upper Cretaceous), with most of the localities concentrated in the Kimmeridgian-Tithonian interval and the Barremian and Campanian stages. The stratigraphic distribution is interesting and suggests the existence of ecological and/or taphonomic biases and palaeogeographical events that warrant additional time and attention.

As well as theropods, we also find their plant-eating brethren. This was the part of the world where the last of the hadrosaurs, the duck-billed dinosaurs, lived then disappeared in the Latest Cretaceous K/T extinction event 65.5 million years ago.

The core of the Iberian Peninsula is made up of a Hercynian cratonic block known as the Iberian Massif. On the northeast, this is bounded by the Pyrenean fold belt, and on the southeast, it is bounded by the Baetic System. These twofold chains are part of the Alpine belt. To the west, the peninsula is delimited by the continental boundary formed by the magma-poor opening of the Atlantic Ocean. The Hercynian Foldbelt is mostly buried by Mesozoic and Tertiary cover rocks to the east but nevertheless outcrops through the Sistema Ibérico and the Catalan Mediterranean System. The photo you see here is care of the awesome Pedro Marrecas from Lisbon, Portugal. Hola, Pista de baile jurásica!

Pereda-Suberbiola, Xabier; Canudo, José Ignacio; Company, Julio; Cruzado-Caballero, Penélope; Ruiz-Omenaca, José Ignacio. "Hadrosauroid dinosaurs from the latest Cretaceous of the Iberian Peninsula" Journal of Vertebrate Paleontology 29(3): 946-951, 12 de septiembre de 2009.

Pereda-Suberbiola, Xabier; Canudo, José Ignacio; Cruzado-Caballero, Penélope; Barco, José Luis; López-Martínez, Nieves; Oms, Oriol; Ruíz-Omenaca, José Ignacio. Comptes Rendus Palevol 8(6): 559-572 septiembre de 2009.

Sunday, 30 April 2023

ANCIENT SWAMPS AND SOLAR FLARES

If fossil fuels are made from fossils, are oil, gas and coal made from dead dinosaurs? Well, no, but they are made from fossils. We do not heat our homes or run our cars on dead hadrosaurs. Instead, we burn very old plants and algae. 

It sounds much less exciting, but the process by which algae and other plant life soak up the Sun's energy, store it for millions of years, then give it all up for us to burn as fuel is a pretty fantastic tale.

Fossil fuel is formed by a natural process — the anaerobic decomposition of buried dead organisms. These plants and algae lived and died many millions of years ago, but while they lived, they soaked up and stored energy from the sun through photosynthesis. Picture ancient trees, algae and peat soaking up the sun, then storing that energy for us to use millions of years later. These organisms and their resulting fossil fuels are millions of years old, sometimes more than 650 million years. That's way back in the day when Earth's inhabitants were mostly viruses, bacteria and some early multi-cellular jelly-like critters.

Fossil fuels consist mainly of dead plants – coal from trees, and natural gas and oil from algae, a diverse group of aquatic photosynthetic eukaryotic organisms I like to think of as pond scum. These deposits are called fossil fuels because, like fossils, they are the remains of plants and animals that lived long ago.

If we could go back far enough, we'd find that our oil, gas, and coal deposits are really remnants of algal pools, peat bogs and ancient muddy swamps. Dead plants and algae accumulate and over time, the pressure turns the mud mixed with dead plants into rock. Geologists call the once-living matter in the rock kerogen. If they haven't been cooked too badly, we call them fossils.

Kerogen is the solid, insoluble organic matter in sedimentary rocks and it is made from a mixture of ancient organic matter. A bit of this tree and that algae all mixed together to form a black, sticky, oily rock. The Earth’s internal heat cooks the kerogen. The hotter it gets, the faster it becomes oil, gas, or coal. If the heat continues after the oil is formed, all the oil turns to gas. The oil and gas then seep through cracks in the rocks. Much of it is lost. We find oil and gas today because some happened to become trapped in porous, sponge-like rock layers capped by non-porous rocks. We tap into these the way you might crack into a bottle of olive oil sealed with wax.

Fossil fuel experts call this arrangement a reservoir and places like Alberta, Iran and Qatar are full of them. A petroleum reservoir or oil and gas reservoir is a subsurface pool of hydrocarbons contained in porous or fractured rock formations. Petroleum reservoirs are broadly classified as conventional and unconventional reservoirs. In the case of conventional reservoirs, the naturally occurring hydrocarbons, such as crude oil or natural gas, are trapped by overlying rock formations with lower permeability. In unconventional reservoirs, the rocks have high porosity and low permeability which keeps the hydrocarbons trapped in place, so these unconventional reservoirs don't need a rock cap.

Coal is an important form of fossil fuel. Much of the early geologic mapping of Canada — and other countries — was done for the sole purpose of mapping the coal seams. You can use it to heat your home, run a coal engine or sell it for cold hard cash. It's a dirty fuel, but for a very long time, most of our industries used it as the sole means of energy. But what is so bad about burning coal and other fossil fuels? Well, many things...

Burning fossil fuels, like oil and coal, releases large amounts of carbon dioxide and other gases into the atmosphere. They get trapped as heat, which we call the greenhouse effect. This plays havoc with global weather patterns and our world does not do so well when that happens. 

The massive end-Permian extinction event, the worst natural disaster in Earth's history — when 90% of all life on Earth died —  was caused by massive volcanic eruptions that spewed gas and lava, covering the Earth in volcanic dust, then acid rain. Picture Mordor times ten. This wasn't a culling of the herd, this was full-on decimation. I'll spare you the details, but the whole thing ended poorly.

Dirty or no, coal is still pretty cool. It is wild to think that a lump of coal has the same number of atoms in it as the algae or material that formed it millions of years ago. Yep, all the same atoms, just heated and pressurized over time. When you burn a lump of coal, the same number of atoms are released when those atoms dissipate as particles of soot. You may wonder what makes a rock burn. It's not intuitive that it would be possible, and yet there it is. Coal is combustible, meaning it is able to catch fire and burn. Coal is made up mostly from carbon with some hydrogen, sulphur — which smells like rotting eggs — oxygen and nitrogen thrown in.

It is just that the long-ago rain forest was far less dense than the coal you hold in your hand today, and so is the soot into which it dissipates once burned. The energy was captured by the algal pool or rain forest by way of photosynthesis, then that same energy is released when the coal is burnt. So the energy captured in gravity and released billions of years later when the intrinsic gravity of the coal is dissipated by burning. It's enough to bend your brain.

The Sun loses mass all the time because of its process of fusion of atomic content and radiating that energy as light. Our ancient rain forests and algal pools on Earth captured some of it. So maybe our energy transformations between the Earth and the Sun could be seen more like ping-pong matches, with energy, as the ball, passing back and forth.

As mass sucks light in (hello, photosynthesis), it becomes denser, and as mass radiates light out (hello, heat from coal), it becomes less dense. Ying, yang and the beat goes on.

Saturday, 29 April 2023

HUNTING NEUTRINOS AND DARK MATTER

Deep inside the largest and deepest gold mine in North America scientists are looking for dark matter particles and neutrinos instead of precious metals. It may not seem exciting on the surface — but it was far below!

The Homestake Gold Mine in Lawrence County, South Dakota was a going concern from about 1876 to 2001.

The mine produced more than forty million troy ounces of gold in its one hundred and twenty-five-year history, dating back to the beginnings of the Black Hills Gold Rush.

To give its humble beginnings a bit of context, Homestake was started in the days of miners hauling loads of ore via horse and mule and the battles of the Great Sioux War. Folk moved about via horse-drawn buggies and Alexander Graham Bell had just made his first successful telephone call.

Wyatt Earp was working in Dodge City, Kansas — he had yet to get the heck outta Dodge — and Mark Twain was in the throes of publishing The Adventures of Tom Sawyer.  — And our dear Thomas Edison had just opened his first industrial research lab in Menlo Park. The mine is part of the Homestake Formation, an Early Proterozoic layer of iron carbonate and iron silicate that produces auriferous greenschist gold. What does all that geeky goodness mean? If you were a gold miner it would be music to your ears. They ground down that schist to get the glorious good stuff and made a tiny wee sum doing so. But then gold prices levelled off — from 1997 ($287.05) to 2001 ($276.50) — and rumblings from the owners started to grow. They bailed in 2001, ironically just before gold prices started up again.

But back to 2001, that levelling saw the owners look to a new source of revenue in an unusual place. One they had explored way back in the 1960s in a purpose-built underground laboratory that sounds more like something out of a science fiction book. The brainchild of chemist and astrophysicists, John Bahcall and Raymond Davis Jr. from the Brookhaven National Laboratory in Upton, New York, the laboratory was used to observe solar neutrinos, electron neutrinos produced by the Sun as a product of nuclear fusion.

Davis had the ingenious idea to use 100,000 gallons of dry-cleaning solvent, tetrachloroethylene, with the notion that neutrinos headed to Earth from the Sun would pass through most matter but on very rare occasions would hit a chlorine-37 atom head-on turning it to argon-37. His experiment was a general success, detecting electron neutrinos,  though his technique failed to sense two-thirds of the number predicted. In particle physics, neutrinos come in three types: electron, muon and tau. Think yellow, green, blue. What Davis had failed to initially predict was the neutrino oscillation en route to Earth that altered one form of neutrino into another. Blue becomes green, yellow becomes blue... He did eventually correct this wee error and was awarded the Nobel Prize in Physics in 2002 for his efforts.

Though Davis’ experiments were working, miners at Homestake continued to dig deep for ore in the belly of the Black Hills of western South Dakota for almost another forty years. As gold prices levelled out and ore quality dropped the idea began to float to re-purpose the mine as a potential site for a new Deep Underground Engineering Laboratory (DUSEL).

A pitch was made and the National Science Foundation awarded the contract to Homestake in 2007.  The mine is now home to the Deep Underground Neutrino Experiment (DUNE) using DUSEL and Large Underground Xenon to look at both neutrinos and dark particle matter. It is a wonderful re-purposing of the site and one that few could ever have predicted. Well done, Homestake. The future of the site is a gracious homage to the now deceased Davis. He would likely be delighted to know that his work continues at Homestake and our exploration of the Universe with it.

Thursday, 27 April 2023

IDENTIFYING FOSSIL BONE


If you are wondering if you have Fossil Bone, you’ll want to look for the telltale texture on the surface. 

Fossil bone is also heavier than regular bone and will have some heft in your hand. This is because the bone has absorbed the yummy minerals from the material in which it was buried.  

If you plan to have someone help you with identifying your find, it is best to take the specimen outside & photograph it in natural light. Take many photos from every angle. If you have the urge to take a video, move the lens very slowly so that all the wee details can be seen. With fossil bone, you will be able to see the different canals and webbed structure of the bone, sure signs that the object was of biological origin. 

As my good friend Mike Boyd notes, without going into the distinction between dermal bone and endochondral bone — which relates to how they form or ossify — it is worth noting that bones such as the one illustrated here will usually have a layer of smooth (or periosteal) bone on the outer surface and spongy (or trabecular) bone inside.

Dinosaur Bone, Jurassic, Colorado, USA

The distinction can be well seen here in both photographs. The partial weathering away of the smooth external bone has resulted in the exposure of the spongy bone interiors. Geographic context is important, so knowing where it was found is very helpful for an ID. 

Knowing the geologic context of your find can help you to figure out if you've perhaps found a terrestrial or marine fossil. Did you find any other fossils nearby? 

Can you see pieces of fossil shells or remnants of fossil leaves? Things get tricky with erratics. That's when something has deposited a rock or fossil far from the place it originated. We see this with glaciers. The ice can act like a plough, lifting up and pushing a rock to a new location, then melting away to leave something out of context. If you do think you have found fossil bone, it is likely that your local government would like you to report it. You may have found something very significant. I very much hope you have. 

Tuesday, 25 April 2023

HOPLOSCAPHITES NEBRASCENSIS


This sweet macroconch with her lovely oil-in-water colouring is a Hoploscaphites nebrascensis (Owen, 1852). This is the female form of the ammonite that has a larger shell than the male, or microconch.

Hoploscaphites nebrascensis is an upper Maastrichtian species and index fossil. It marks the top of ammonite zonation for the Western Interior. This species has been recorded from Fox Hills Formation in North and South Dakota as well as the Pierre Shale in southeastern South Dakota and northeastern Nebraska.

It is unknown from Montana, Wyoming, and Colorado due to the deposition of coeval terrestrial units. It has possibly been recorded in glacial deposits in Saskatchewan and northern North Dakota, but that is hearsay. 

Outside the Western Interior, this species has been found in Maryland and possibly Texas in the Discoscaphites Conrad zone. This lovely one is in the collection of the deeply awesome (and enviable) José Juárez Ruiz. A big thank you to Joshua DrSlattmaster J Slattery for his insights on this species.

Monday, 24 April 2023

RHACOLEPIS BUCCALIS

This concretion contains a partially exposed Rhacolepis Buccalis, an extinct genus of ray-finned fossil fish in carbonate concretion from the Lower Cretaceous, Santana Formation, Brazil.

These ancient fish swam our Cretaceous seas 122-109 million years ago. Interestingly, we've been able to recover complete fossilized hearts from this species using X-ray synchrotron microtomography.

Lara Maldanis and her team published a paper on this back in 2016. They were looking at the evolution of cardiac outflow tracts in vertebrates and had a breakthrough moment when an x-ray revealed enough detail to show that Rhacolepis hearts contain a conus arteriosus containing at least five-valve rows making them a transitional morphology between the primitive, multivalve, conal condition and the derived, monovalvar, bulbar state of the outflow tract in modern actinopterygians.

Le premier et unique géoparc mondial UNESCO est situé dans le Cariri du Ceará (géoparc Araripe), dans l'intérieur semi-aride de la région Nordeste, Brésil. Reference: Maldanis et al. (2016) Heart fossilization is possible and informs the evolution of cardiac outflow tract in vertebrates.

Sunday, 23 April 2023

14TH BC PALAEONTOLOGICAL SYMPOSIUM

You will be delighted to know that it is time for the next BCPA Symposium, June 9th - 12th, 2023. 

This is the 14th BC Palaeontological Symposium and it will be hosted by the Victoria Palaeontology Society along with the School of Earth and Ocean Sciences (SEOS), University of Victoria (UVic); Royal British Columbia Museum (RBCM); and, BC Fossil Management Office.

The 2023 BCPA conference is being held at the Bob Wright Centre, University of Victoria, Victoria, BC. I'll post a wee map here to make finding all this goodness a wee bit easier. The Bob Wright Centre (BWC) is just a short walk from Bento Sushi and SciCafé near UVic Parking Lot B.

Keynote Speakers: Dr. Jean-Bernard Caron & Dr. Charles Helm

The Burgess Shale Fossil Deposit of Marble Canyon in Kootenay National Park: Retrospective of the Last 10 Years of Research. In Southeastern BC, the Burgess Shale is the internationally renowned site that keeps on giving.  Symposium 2023 welcomes you on a journey through the past decade, featuring the field research and expertise of:

Dr. Jean-Bernard Caron, Richard M. Ivey Curator of Invertebrate Palaeontology at the Royal Ontario Museum, Toronto.

Dr. Caron leads regular fieldwork activities to the Canadian Rockies primarily to study how the Burgess Shale biota changed through space and time in response to ecological, evolutionary and environmental factors. Field-based research is an important aspect of his work and his research lab primarily focuses on fossilization processes, ecology, phylogeny, and diversity of Burgess Shale animals.

Tracking vertebrates from two eras on two continents—Northern BC is home to our second keynote speaker, Dr. Charles Helm, who is trekking two continents in search of tracks. 

Dr. Charles Helm, Research Associate at the Tumbler Ridge Museum and at the African Centre for Coastal Palaeoscience, Nelson Mandela University, South Africa is currently pursuing his PhD in paleontology in the Department of Geoscience, Nelson Mandela University, South Africa.

His paleontological research interests are in Pleistocene vertebrate tracks in South Africa (including hominin tracks and traces) and Cretaceous vertebrate tracks in northern British Columbia.  

Many of you will know Dr. Helm as founder of the Tumbler Ridge Museum Foundation in 2002. He developed the proposal that led to the creation of the Tumbler Ridge UNESCO Global Geopark in 2014, and was its first President.

BCPA Conference Link: https://vicpalaeo.org/.../14th-bc-palaeontological.../...
BCPA Website: www.bcfossils.ca

Here is a handy dandy map for easy reference:



Saturday, 22 April 2023

VOLTERRA ALABASTER

The beautiful walled city of Volterra, an ancient Etruscan town some 45 miles southwest of Florence, is famous for its well-preserved medieval ramparts, museums and archeological sites and atmospheric cobblestone streets.

Since ancient times, Volterra, a key trading center and one of the most important Etruscan towns has been known as the city of alabaster.

The Etruscans mined alabaster in the nearby hills and considered it the stone of the dead. The mineral was used for elaborate funerary urns and caskets that housed the ashes of the departed, prized for its durability, beautiful coloration, natural veining and translucence. When the Romans ascended, alabaster fell out of favour and marble became the preferred sculpting material.

To work alabaster requires an assortment of hand tools, an artistic eye, and a tolerance for vast clouds of dust. An alabastraio begins with a block or chunk of alabaster. If the final product is to be a vase or bowl, the stone is turned on a lathe similar to what is used to make pottery and then shaped with chiselling tools.

Although alabaster and marble may seem similar in appearance when polished, they are very different materials, particularly when it comes to their hardness and mineral content. Alabaster is a fine-grained form of gypsum, a sedimentary rock made from tiny crystals visible only under magnification. The ancient Egyptians preferred alabaster for making their sphinxes or creating burial objects such as cosmetic jars. The purest alabaster is white and a bit translucent; impurities such as iron oxide cause the spidery veins. I like a mix of both, preferably backlit to show the blending of colour.

Alabaster is more graceful in appearance than marble. Marble consists mostly of calcite, formed when limestone underground is changed through extreme pressure or heat. It’s not quite as delicate as alabaster and became the preferred material for master sculptors such as Michelangelo who relied on marble from Carrara for his most famous works.

I had the very great pleasure of travelling to Carrara with Guylaine Rondeau many years ago, making her stop at every single roadcut along the way.

Alabaster is the common name applied to a few types of rocks. Translucent and beautiful, alabaster generally includes some calcium in gypsum. Gypsum is a composite of calcium sulphate, a type of sedimentary rock formed millions of years ago in the depths of a shallow sea. Left by time and tide, it evaporated into the creamy (full of lovely chemical impurities) or fully transparent (pure gypsum) stone we see today.

This glorious stone is simply beautiful. In the right hands, it can be sculpted to evoke the most wondrous reflections of light and emotion. And it stands the test of time, becoming more beautiful with each passing year... rather like my friend Guylaine. I'm thinking of you as I write this my beautiful one. More adventures await us in this amazing world.

Friday, 21 April 2023

UPPER TRIASSIC LUNING FORMATION

Exposures of the Upper Triassic (Early Norian, Kerri zone), Luning formation, West Union Canyon, just outside Berlin-Ichthyosaur State Park, Nevada.

The Berlin-Ichthyosaur State Park in central Nevada is a very important locality for the understanding of the Carnian-Norian boundary (CNB) in North America.

Rich ammonoid faunas from this site within the Luning Formation were studied by Silberling (1959) and provided 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. Despite its importance, no further investigations have been done at this site during the last 50 years.

Jim Haggart, Mike Orchard and Paul Smith (all local Vancouverites) collaborated on a project that took them down to Nevada to look at the conodonts (Oh, Mike) and ammonoids (Jim's fav); the group then 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.

They conducted a bed-by-bed sampling of ammonoids and conodonts in West Union Canyon during October 2010. 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 genus Gonionotites, very common in the Tethys and British Columbia, is for the moment unknown in Nevada. More in general, the Upper Carnian faunas are dominated by Tropitidae, while Juvavitidae are lacking.

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.

Thursday, 20 April 2023

FOSSIL SALMON OF PUGET SOUND

This toothy specimen is an Oncorhynchus nerka, a Pleistocene Sockeye Salmon from outcrops along the South Fork Skokomish River, Olympic Peninsula, Washington State, USA.

The area is home to the Skokomish — one of nine tribes of the Twana, Coast Salish First Nations in the northern-mid Puget Sound area of western Washington state in the United States. 

Each of the Tribal Nations are known by their locations — Dabop, Quilcene or salt-water people, Dosewallips, Duckabush, Hoodsport, Skokomish or Skoko'bsh, Vance Creek, Tahuya, and Duhlelap or Tule'lalap. The name Skokomish means river people or people of the river in the language of the Twana, sqʷuqʷóbəš or sqWuqWu'b3sH.

Closer to my home farther north in the Pacific Northwest on northern Vancouver Island are the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala. Here, sockeye salmon are known as ma̱łik. You would likely recognize these fossils' modern counterparts from their distinctive red bodies and greenish heads. 

Their descendants had been absent from the Skokomish River for more than a decade up to 2014 when construction to augment the negative impact of the Cushman Reservoir was undertaken to restore their natural habitat.

The fossil specimens include individuals with enlarged breeding teeth and worn caudal fins. It is likely that these salmon acted very similar to their modern counterparts with males partaking in competitive and sneaky tactics to gain access to the sexiest (large and red) females who were ready to mate. These ancient salmon had migrated, dug their nests, spawned and defended their eggs prior to their death. For now, we're referring to the species found here as Oncorhynchus nerka, as they have many of the characteristics of sockeye salmon, but also several minor traits of the Pink Salmon, Oncorhynchus gorbuscha.

I had expected to learn that the locality contained a single or just a few partial specimens, but the fossils beds are abundant with large, 45–70 cm, four-year-old adult salmon concentrated in a beautiful sequence of death assemblages.

Oncorhynchus nerka, Pleistocene Sockeye Salmon
Gerald Smith, a retired University of Michigan professor was shown the specimens and recognized them as Pleistocene, a time when the northern part of North America was undergoing a series of glacial advances and retreats that carved their distinctive signature into the Pacific Northwest.

It looks as though this population diverged from the original species about one million years ago, possibly when the salmon were deposited at the head of a proglacial lake impounded by the Salmon Springs advancement of a great glacier known as the Puget lobe of the Cordilleran Ice Sheet. 

Around 17,000 years ago, this 3,000 foot-thick hunk of glacial ice had made its way down from Canada, sculpting a path south and pushing its way between the Cascade and Olympic Mountains. The ice touched down as far south as Olympia, stilled for a few hundred years, then began to melt.

After the ice began melting and retreating north, the landscape slowly changed —  both the land and sea levels rising — and great freshwater lakes forming in the lowlands filled with glacial waters from the melting ice. The sea levels rose quite considerably, about one and a half centimetres per year between 18,000 and 13,000 years ago. The isostatic rebound (rising) of the land rose even higher with an elevation gain of about ten centimetres per year from 16,000 to 12,500 years ago.

Around 14,900 years ago, sea levels had risen to a point where the salty waters of Puget Sound began to slowly fill the lowlands. Both the land and sea continued to rise and by 5,000 years ago, the sea level was about just over 3 meters lower than it is today. The years following were an interesting time in the geologic history of the Pacific Northwest. The geology of the South Fork Skokomish River continued to shift, undergoing a complicated series of glacial damming and river diversions after these salmon remains were deposited.

Today, we find their remains near the head of a former glacial lake at an elevation of 115 metres on land owned by the Green Diamond Company. The first fossil specimens were found back in 2001 by locals fishing for trout along the South Fork Skokomish River.

Upon seeing the fossil specimens, Smith teamed up with David Montgomery of the University of Washington, Seattle, along with N. Phil Peterson and Bruce Crowley, a Late Oligocene Mysticete specialist from the Burke Museum, to complete fieldwork and author a paper.

The fossil specimen you see here is housed in the Burke Museum collection. They opened the doors to their new building and exhibitions in the Fall of 2019. These photos are by the deeply awesome John Fam from a trip to see the newly opened exhibits this year. If you fancy a visit to the Burke Museum, check out their website here: https://www.burkemuseum.org/.

David B. Williams did up a nice piece on historylink.org on the Salmon of the Puget lowland. You can find his work here: https://www.historylink.org/File/20263

If you'd like to read more of the papers on the topic, check out:

  • Smith, G., Montgomery, D., Peterson, N., and Crowley, B. (2007). Spawning sockeye salmon fossils in Pleistocene lake beds of Skokomish Valley, Washington. Quaternary Research, 68(2), 227-238. doi:10.1016/j.yqres.2007.03.007.
  • Easterbrook, D.J., Briggs, N.D., Westgate, J.A., and Gorton, M.P. (1981). Age of the Salmon Springs Glaciation in Washington. Geology 9, 87–93.
  • Hikita, T. (1962). Ecological and morphological studies of the genus Oncorhynchus (Salmonidae) with particular consideration on phylogeny. Scientific Reports of the Hokkaido Salmon Hatchery 17, 1–97.

If you fancy a read of Crowley's work on Late Oligocene Mysticete from Washington State, you can check out:  Crowley, B., & Barnes, L. (1996). A New Late Oligocene Mysticete from Washington State. The Paleontological Society Special Publications, 8, 90-90. doi:10.1017/S2475262200000927

Wednesday, 19 April 2023

CLALLAM BAY MARINE FAUNA

Panopea abrupt (Conrad, 1894)
This lovely large fossil bivalve is Panopea abrupta (Conrad, 1849) an extinct species of marine mollusc in the family Hiatellidae, subclass Heterodonta.

This fossil specimen was collected from lower Miocene deposits in the Clallam Formation on the foreshore bordering the Strait of Juan de Fuca near Clallam Bay, Olympic Peninsula, northwestern Washington. The oldest recorded specimen of one of their modern relatives lived not too far from here in the Strait of Juan de Fuca. That lovely was an impressive 168 years old.

A geoduck sucks water containing plankton down through its long siphon, filters this for food and ejects its refuse out through a separate hole in the siphon. Adult geoducks have few natural predators, which may also contribute to their longevity.

In Alaska, sea otters and dogfish have proved capable of dislodging geoducks; starfish also attack and feed on the exposed geoduck siphon.

Clallam Bay is a sleepy little town on the northwestern edge of the Olympic Peninsula. It was founded back in the 1880s as a steamboat stop and later served as a Mill town. If you are planning to visit the fossil exposures, head to the edge of town where it meets the sea.

Once at the water's edge, head east along the shore until you can go no further. You'll find marine fossils in the sandstone on the shore and cliffs. Mind the tide as access to the fossil site is only possible at low or mid-tide. You'll have to swim for it if you time it poorly. Clallam Bay: 48°15′17″N 124°15′30″W.

Near this site, there are many additional fossil localities to explore. In Sequim Bay, you can find Pleistocene vertebrates as well as Miocene cetacean bones near Slip Point. Near the Twin Post Office, you can find Oligocene nautiloids and bivalves (2.5km west in the bluff); You can find crabs including, Branchioplax in the Eocene limestone concretions from Neah Bay.

References: Addicott, Warren. Molluscan paleontology of the lower Miocene Clallam Formation, northwestern Washington, Geological Survey Paper 976.

Tuesday, 18 April 2023

AMMONITES OF THE CAUCAUS MOUNTAINS

A very pleasing example of the Ammonite Acanthohoplites bigoureti (Seunes, 1887). Lower Cretaceous, Upper Aptian, from a riverbed concretion, Kurdzhips River, North Caucasus Mountains, Republic of Adygea, Russia. 

Geologically, the Caucasus Mountains belong to a system that extends from southeastern Europe into Asia and is considered a border between them. The Greater Caucasus Mountains are mainly composed of Cretaceous and Jurassic rocks with the Paleozoic and Precambrian rocks in the higher regions. 

Some volcanic formations are found throughout the range. On the other hand, the Lesser Caucasus Mountains are formed predominantly of the Paleogene rocks with a much smaller portion of the Jurassic and Cretaceous rocks. 

The evolution of the Caucasus began from the Late Triassic to the Late Jurassic during the Cimmerian orogeny at the active margin of the Tethys Ocean while the uplift of the Greater Caucasus is dated to the Miocene during the Alpine orogeny.

The Caucasus Mountains formed largely as the result of a tectonic plate collision between the Arabian plate moving northwards with respect to the Eurasian plate. As the Tethys Sea was closed and the Arabian Plate collided with the Iranian Plate and was pushed against it and with the clockwise movement of the Eurasian Plate towards the Iranian Plate and their final collision, the Iranian Plate was pressed against the Eurasian Plate. 

As this happened, the entire rocks that had been deposited in this basin from the Jurassic to the Miocene were folded to form the Greater Caucasus Mountains. This collision also caused the uplift and the Cenozoic volcanic activity in the Lesser Caucasus Mountains.

The preservation of this Russian specimen is outstanding. Acanthohoplites bigoureti are also found in Madagascar, Mozambique, in the Rhone-Alps of France and the Western High Atlas Mountains and near Marrakech in Morocco. This specimen measures 55mm and is in the collection of the deeply awesome Emil Black.

Monday, 17 April 2023

TRIASSIC OF NORTH AMERICA

In the early 1980s, Tim Tozer, Geological Survey of Canada, looked at the distribution of marine invertebrate fauna in the Triassic of North America.

Tozer's interest in our marine invert friends was their distribution and what those occurrences could tell us. 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.

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 Triadic faunas of these areas, as well as some that are today up to 63 ° North, have the characteristics of the lower paleo latitudes. As far as is known, Middle Triadic faunas in these zones do not provide any significant data. In the western Cordillera, the faunas of the lower paleo latitudes can be found up to 3000 km north of their counterparts on the American plate. This indicates a tectonic shift of this 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 fauna provinces can be distinguished from one another. The differences in fauna are obviously linked to the paleolatitude. They are called LPL, MPL, HPL (lower, middle, higher paleolatitude). Nevada provides the diagnostic features of the lower; northeastern British Columbia that of the middle and Sverdrup Basin that of the higher paleolatitude. A distinction between the provinces of the middle and the higher paleo-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.

Diatoms / Microalgae dominant components of phytoplankton
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.

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.

Sunday, 16 April 2023

HYPHANTOCERAS ORIENTALE

A stunning example of the heteromorph ammonite, Hyphantoceras orientale macroconch. This beauty corresponds to 'Morphotype C' from Aiba (2017). 

The specimen is a handful at 136 mm and was lovingly prepared by the hand holding it, that of the talented José Juárez Ruiz.

This an adult specimen (not the juvenile stage) from Upper Santonian outcrops near Ashibetsu, Hokkaido, Japan.

Aiba published on a possible phylogenetic relationship of two species of Hyphantoceras (Ammonoidea, Nostoceratidae) earlier this year, proposing that a phylogenetic relationship may exist based on newly found specimens with precise stratigraphic occurrences in the Kotanbetsu and Obira areas, northwestern Hokkaido.

Two closely related species, Hyphantoceras transitorium and H. orientale, were recognized in the examined specimens from the Kotanbetsu and Obira areas. Specimens of H. transitorium show wide intraspecific variation in the whorl shape. The stratigraphic occurrences of the two species indicate that they occur successively in the Santonian–lowermost Campanian, without stratigraphic overlapping. 

The similarity of their shell surface ornamentations and the stratigraphic relationships possibly suggest that H.orientale was derived from H. transitorium. The presumed lineage is likely indigenous to the northwestern Pacific realm in the Santonian–earliest Campanian. Hyphantoceras venustum and H. heteromorphum might stand outside a H. transitorium–H. orientale lineage, judging from differences of their shell surface ornamentation.

Aiba, Daisuke. (2019). A Possible Phylogenetic Relationship of Two Species of Hyphantoceras (Ammonoidea, Nostoceratidae) in the Cretaceous Yezo Group, Northern Japan. Paleontological Research. 23. 65-80. 10.2517/2018PR010.

Saturday, 15 April 2023

SOFT-BODIED PRESERVATION: THE MIGUASHA COLLECTION

An exquisite fossil specimen of an Eusthenopteron Fordi from the upper Devonian (Frasnian), Eescuminac Formation, Miguasha Park, Bay of Heat, Gaspé, Quebec, Canadian Museum of Natural History, Miguasha Collection.

If you look closely at this specimen, you can see the remarkable 3-D and soft-bodied preservation. This fish specimen reminds me of the ray-finned fossil fish you see in carbonate concretion from Lower Cretaceous deposits in the Santana Formation, Brazil.

Eusthenopteron would have shared our ancient seas with the first ammonites and primitive sharks, along with well-established fauna including the trilobites, brachiopods, coral reefs and a whole host of interesting arthropods.

Miguasha National Park / Parc National de Miguasha, is a protected area near Carleton-sur-Mer on the Gaspé Peninsula along the south side of the Saint Lawrence River to the east of the Matapedia Valley in Quebec, Canada. It was created in 1985 by the Government of Quebec and designated as a World Heritage Site in 1999 in honour of paleontological significance for Devonian fish, flower and spore fossils.

These fossils represent five of the six main fossil fish groups recorded from the Devonian (370 million years ago) including specimens of the lobe-finned fish and tetrapods. We see the placoderms, armoured prehistoric fish, in their heyday, dominating almost every known aquatic environment. The Devonian is known as the 'Age of Fishes,' but it could have equally been called the 'Age of Spores,' as this was a time of significant adaptive radiation of terrestrial biota and free-sporing vascular plants. Immense forests carpeted the continents and we see the first of the plant groups evolving leaves, true roots and seeds.

The site was discovered in 1842 by a local geologist and medical doctor, Abraham Gesner. He shared much of his collection with both the British Museum and Royal Scottish Museum for further study.  Other names for this site are the Miguasha Fossil Site, the Bay of Escuminac Fossil Site, the Upper Devonian Escuminac Formation, and the Hugh-Miller Cliffs. It is also sometimes referred to on fossil specimens as 'Scaumenac Bay' or 'Scaumenac Bay P.Q. Photo credit to the deeply awesome John Fam

Friday, 14 April 2023

OSTRACODERMS TO ANGLERFISH

The festive lassie you see here is an Anglerfish. They always look to be celebrating a birthday of some kind, albeit solo. This party is happening deep in our oceans and for those that join in, I hope they like it rough.

The wee candle you see on her forehead is a photophore, a tiny bit of luminous dorsal spine. Many of our sea dwellers have these candle-like bits illuminating the depths. You may have noticed them glowing around the eyes of many of our cephalopod friends. 

These light organs can be a simple grouping of photogenic cells or more complex with light reflectors, lenses, colour filters able to adjust the intensity or angular distribution of the light they produce. Some species have adapted their photophores to avoid being eaten, in others, it's an invitation to lunch.

In anglerfish' world, this swaying light is dead sexy. It's an adaptation used to attract prey and mates alike.

Deep in the murky depths of the Atlantic and Antarctic oceans, hopeful female anglerfish light up their sexy lures. When a male latches onto this tasty bit of flesh, he fuses himself totally. He might be one of several potential mates. She's not picky, just hungry. Lure. Feed. Mate. Repeat.

A friend asked if anglerfish mate for life. Well, yes.... yes, indeed they do.

Mating is a tough business down in the depths. Her body absorbs all the yummy nutrients of his body over time until all that's left are his testes. While unusual, it is only one of many weird and whacky ways our fishy friends communicate, entice, hunt and creatively survive and thrive. The deepest, darkest part of the ocean isn't empty — its hungry.

The evolution of fish began about 530 million years ago with the first fish lineages belonging to the Agnatha, a superclass of jawless fish. We still see them in our waters as cyclostomes but have lost the conodonts and ostracoderms to the annals of time. Like all vertebrates, fish have bilateral symmetry; when divided down the middle or central axis, each half is the same. Organisms with bilateral symmetry are generally more agile, making finding a mate, hunting or avoiding being hunted a whole lot easier.

When we envision fish, we generally picture large eyes, gills, a well-developed mouth. The earliest animals that we classify as fish appeared as soft-bodied chordates who lacked a true spine. While they were spineless, they did have notochords, a cartilaginous skeletal rod that gave them more dexterity than the cold-blooded invertebrates who shared those ancient seas and evolved without a backbone. 

Fish would continue to evolve throughout the Paleozoic, diversifying into a wide range of forms. Several forms of Paleozoic fish developed external armour that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many species, including sharks, became formidable marine predators rather than just the prey of arthropods.

Fish in general respire using gills, are most often covered with bony scales and propel themselves using fins. There are two main types of fins, median fins and paired fins. The median fins include the caudal fin or tail fin, the dorsal fin, and the anal fin. Now there may be more than one dorsal, and one anal fin in some fishes.

The paired fins include the pectoral fins and the pelvic fins. And these paired fins are connected to, and supported by, pectoral and pelvic girdles, at the shoulder and hip; in the same way, our arms and legs are connected to and supported by, pectoral and pelvic girdles. This arrangement is something we inherited from the ancestors we share with fish. They are homologous structures.

When we speak of early vertebrates, we are often talking about fish. Fish is a term we use a lot in our everyday lives but taxonomically it is not all that useful. When we say, fish we generally mean an ectothermic, aquatic vertebrate with gills and fins.

Fortunately, many of our fishy friends have ended up in the fossil record. We may see some of the soft bits from time to time, as in the lovely fossil fish found in concretion in Brazil, but we often see fish skeletons. Vertebrates with hard skeletons had a much better chance of being preserved. 

Eohiodon Fish, McAbee Fossil Beds
In British Columbia, we have lovely two-dimensional Eocene fossil fish well-represented from the Allenby of Princeton and the McAbee Fossil Beds. 

We have the Tiktaalik roseae, a large freshwater fish, from 375 million-year-old Devonian deposits on Ellesmere Island in Canada's Arctic. Tiktaalik is a wonderfully bizarre creature with a flat, almost reptilian head but also fins, scales and gills. We have other wonders from this time. 

Canada also boasts spectacular antiarch placoderms, Bothriolepsis, found in the Upper Devonian shales of Miguasha in Quebec.

There are fragments of bone-like tissues from as early as the Late Cambrian with the oldest fossils that are truly recognizable as fishes come from the Middle Ordovician from North America, South America and Australia. At the time, South America and Australia were part of a supercontinent called Gondwana. North America was part of another supercontinent called Laurentia and the two were separated by deep oceans.

These two supercontinents and others that were also present were partially covered by shallow equatorial seas and the continents themselves were barren and rocky. Land plants didn't evolve until later in the Silurian Period. In these shallow equatorial seas, a large diverse and widespread group of armoured, jawless fishes evolved: the Pteraspidomorphi. The first of our three groups of ostracoderms. The Pteraspidomorphi are divided into three major groups: the Astraspida, Arandaspida and the Heterostraci.

The oldest and most primitive pteraspidomorphs were the Astraspida and the Arandaspida. You'll notice that all three of these taxon names contain 'aspid', which means shield. This is because these early fishes — and many of the Pteraspidomorphi — possessed large plates of dermal bone at the anterior end of their bodies. This dermal armour was very common in early vertebrates, but it was lost in their descendants. 

Arandaspida is represented by two well-known genera: Sacabampaspis, from South America and Arandaspis from Australia. Arandaspis have large, simple, dorsal and ventral head shields. Their bodies were fusiform, which means they were shaped sort of like a spindle, fat in the middle and tapering at both ends. Picture a sausage that is a bit wider near the centre with a crisp outer shell.

If you're a keen bean to see an anglerfish that recently washed up on the shores of Newport Beach this past May, hit this link: https://www.theguardian.com/us-news/2021/may/11/deep-sea-anglerfish-california-beach-finding-nemo. Kudos for my colleague, Giovanni, bringing this gloriously horrific lovely to my attention. 

Thursday, 13 April 2023

ANCIENT SEAS: HOKKAIDO

A very beautiful Lower Campanian block from Haroto, Hokkaido, Japan. This specimen contains an ancient undersea world at a glance.

The beautiful block you see here was prepared, photographed and is in the collections of José Juárez Ruiz. In it, you can see a lovely Pseudoxybeloceras (Parasolenoceras) soyaense (143 mm), Polyptychoceras jimboi (134 mm), Polyptychoceras sp. (114 mm), Gaudryceras mite (48 and 45 mm), Gaudryceras tenuiliratum (Hirano, 1978) at (48 and 20 mm), and a wee fragment of wood (69 mm).

Matsumoto published on the ammonites from the Campanian (Upper Cretaceous) of northern Hokkaido back in 1984, in the Palaeontological Society of Japan Special Series Papers, Number #27.

This was my first look at the glorious fauna from northern Japan. The species and preservation are truly outstanding. Since then, many of the Japanese palaeontologists have made their way over to Vancouver Island, to look at ammonites, inoceramids and coleoid jaws from the Nanaimo Group and compare them to the Japanese species.

Rick Ross and Pat Trask, both of Courtenay on Vancouver Island, collaborated with Dr. Kazushige Tanabe and Yoshinori Hikida of Japan, to produce a wonderful paper in the Journal of Paleontology, 82 (2), 2008, pp 398-408, on Late Cretaceous Octobrachiate Coleoid Lower Jaws from the North Pacific Regions. They compared eight well-preserved cephalopod jaws from Upper Cretaceous (Santonian and Campanian) deposits of Vancouver Island, Canada, and Hokkaido, Japan. Seven of these were from Santonian to lower Campanian strata of the Nanaimo Group in the northeastern region of Vancouver Island. The eighth specimen was from Santonian strata of the Yezo Group in the Nakagawa area, northern Hokkaido, Japan. 

While they were collaborating on identifying coleoid jaws from the Comox Valley, Rick was visited twice by Dr. Kazushige Tanabe who was joined by his colleague Akinori Takahashi. Takahashi is an expert on temporal species-diversity changes in Japanese Cretaceous inoceramid bivalves.

They had the very great pleasure of visiting many fossil sites and seeing personal and museum collections. If you'd like to read Matsumoto's paper, here is the link: http://www.palaeo-soc-japan.jp/download/SP/SP27.pdf  I have a pdf copy of the Coleoid paper from Rick. It has very nice photos and illustrations, including a drawing of the holotypes of Paleocirroteuthis haggerti n. gen. and Paleocirroteuithis pacifica.

Here's a link to one of Takahashi's papers: https://bioone.org/journals/paleontological-research/volume-9/issue-3/prpsj.9.217/Diversity-changes-in-Cretaceous-inoceramid-bivalves-of-Japan/10.2517/prpsj.9.217.short