Friday, 14 February 2025
SPIRRALING BEAUTY: TURRITELLA
Many are marine, but two-thirds of all living species live in freshwater or on land. Their entry into the fossil record goes all the way back to the Cambrian.
Slugs and snails, abalones, limpets, cowries, conches, top shells, whelks, and sea slugs are all gastropods. They are the second-largest class of animals with over 60,000–75,000 known living species. The two beauties you see here are Turritella, a genus of medium-sized sea snails with an operculum, marine gastropod mollusks in the family Turritellidae. They hail from the Paris Basin and have tightly coiled shells, whose overall shape is basically that of an elongated cone. The name Turritella comes from the Latin word turritus meaning "turreted" or "towered" and the diminutive suffix -ella.
Many years ago, I had the pleasure of collecting in the Paris Basin with a fellow named Michael. I had stalked the poor man from Sunday market to Sunday market, eventually meeting up with him in the town of Gordes. He graciously shared his knowledge of the local fossil localities from the hills south of Calais to Poitiers and from Caen to the Rhine Valley, east of Saarbrücken. I deeply regret losing my notebook from that trip but cherish the fossils and memories.
The Paris Basin has many fine specimens of gastropods. These molluscs were originally sea-floor predators, though they have evolved to live happily in many other habitats. Many lines living today evolved in the Mesozoic. The first gastropods were exclusively marine and appeared in the Upper Cambrian (Chippewaella, Strepsodiscus). By the Ordovician, gastropods were a varied group present in a variety of aquatic habitats. Commonly, fossil gastropods from the rocks of the early Palaeozoic era are too poorly preserved for accurate identification. Still, the Silurian genus Poleumita contains fifteen identified species.
Most of the gastropods of the Palaeozoic belong to primitive groups, a few of which still survive today. By the Carboniferous, many of the shapes we see in living gastropods can be matched in the fossil record, but despite these similarities in appearance the majority of these older forms are not directly related to living forms. It was during the Mesozoic era that the ancestors of many of the living gastropods evolved.
In rocks of the Mesozoic era, gastropods are more common as fossils and their shells often very well preserved. While not all gastropods have shells, the ones that do fossilize more easily and consequently, we know a lot more about them. We find them in fossil beds from both freshwater and marine environments, in ancient building materials and as modern guests of our gardens.
Thursday, 13 February 2025
AINOCERAS: A CUTE AS YOU PLEASE HETEROMORPH FROM VANCOUVER ISLAND
Within their shells, they had a number of chambers, called septa, filled with gas or fluid that were interconnected by a wee air tube.
By pushing air in or out, they were able to control their buoyancy in the water column. These little cuties were predators who hunted in Cretaceous seas.
They lived in the last chamber of their shells, continuously building new shell material as they grew. As each new chamber was added, the squid-like body of the ammonite would move down to occupy the final outside chamber.
Not all ammonites have this whacky corkscrew design. Most are coiled and some are even shaped like massive paperclips. This one is so remarkable, so joyously perfect my internal thesaurus can’t keep up.
I will be heading back to the area where these lovelies are found in late March this year to see if I can find other associated fossils and learn more about his paleo community
Sunday, 9 February 2025
DRIFTWOOD CANYON FOSSIL BEDS FOR JESSY
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| Puffbird similar to Fossil Birds found at Driftwood Canyon |
| Metasequoia, the Dawn Redwood |
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| A Tapir showing off his prehensile nose trunk |
Saturday, 8 February 2025
NANAIMO MOTOR CROSS PIT FOSSIL SITE
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| Steller's Jay, Cyanocitta stelleri |
The quarry is no longer active as such though there is a busy little gravel quarry a little way down the road closer to Ammonite falls near Benson Creek Falls.
Today it is an active motocross site and remains one of the classic localities of the Nanaimo Group.
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| Upper Cretaceous Haslam Formation Motocross Pit near Brannen Lake |
While he lived on Vancouver Island, he was an active member of the VanPS back when I was Chair. Several of the best joint VIPS/VanPS paleontological expeditions were planned with or instigated by his passion for fossils. I tip my hat to him for that drive to see so many of the hard to reach but incredibly beautiful and scientifically important sites—and shared love of all things paleo.
John grew up 15 minutes from the motocross locality and used to collect there a few times a week with his father. John has wonderful parents and since marrying his childhood sweetheart, the amazing Grace, those excellent genetics, curiosity and love of fossils are now being passed to a new generation. It's lovely to see John and Grace continuing tradition with two boys of their own.
I met John way back then and did an overnight at his parent's house the Friday before a weekend field trip to Jurassic Point. It was a joy to have him walk me through his collections and tell his stories from earlier years. After learning about the site from John, I headed up to the Motocross Pit with my Uncle Doug. He was a delightful man who grew up on the coast and had explored much of it but not the fossil site just 10-minutes from his home. It was wonderful to walk through time with him so many years ago and then again solo this past year with sadness in my belly that one of the best I've ever known has left this Earth.
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| Upper Cretaceous Haslam Formation Motocross Pit near Brannen Lake |
The rocks we find here were laid down south of the equator as small, tropical islands. They rode across the Pacific heading north and slightly east over the past 80 million years to where we find them today.
Jim Haggart and Peter Ward have done much to increase our understanding of the molluscan fauna of the Nanaimo Group. Personally, both personify the charming Indiana Jones school of rugged manly palaeontologists you picture in popular film. Professionally, their singular contributions and collaborative efforts have helped shape our understanding of the correlation of Nanaimo Group fauna to those we find in the Gulf Islands of British Columbia and down in the San Juan Islands of Washington State.
Their work builds on the work of Usher (1952), Matsumoto (1959a, 1959b) and Mallory (1977). A healthy nod goes out to the work of Muller and Jeletzky (1970) for untangling the lithostratigraphic and biostratigraphic foundation for our knowledge of the Nanaimo Group.
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| Candoceras yokoyama, Photo: John Fam, VanPS |
If you fancy some additional reading, check out a paper published in the Journal of Paleontology back in 1989 by Haggard and Ward on new Nanaimo Group Ammonites from British Columbia and Washington State.
In it, they look at the ammonite species Puzosia (Mesopuzosia) densicostata Matsumoto, Kitchinites (Neopuzosia) japonicus Spath, Anapachydiscus cf. A. nelchinensis Jones, Menuites cf. M. menu (Forbes), Submortoniceras chicoense (Trask), and Baculites cf. B. boulei Collignon are described from Santonian--Campanian strata of western Canada and northwestern United States.
Stratigraphic occurrences and ranges of the species are summarized and those taxa important for correlation with other areas in the north Pacific region and Late Cretaceous ammonite fauna of the Indo-Pacific region. Here's the link: https://www.jstor.org/stable/1305358?seq=1
Peter Ward is a prolific author, both of scientific papers and more popularized works. I highly recommend his book Gorgon: Paleontology, Obsession, and the Greatest Catastrophe in Earth's History. It is an engaging romp through a decade's research in South Africa's Karoo Desert. It looks like Peter will be at the 15th BCPA Symposium giving a talk and perhaps some paleo-battle with Jim Haggart as we tease through the pros and cons for the Baja California—Baja BC origin story for some of the strata we find further north today.
Photo: Candoceras yokoyamai from the Upper Cretaceous Haslam Formation (Lower Campanian) near Nanaimo, British Columbia. One of the earliest fossils collected by John Fam (1993) and a classic fossil found at the site. This lovely was prepared using only a cold chisel and hammer. Photo & collection of John Fam, VIPS.
Thursday, 6 February 2025
FOSSILS OF TURTLE ISLAND'S EASTERN SHORES
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| Pennsylvanian Coal Age Ecosystem, 300-Million-Years-Old |
References & further reading:
Joggins Fossil Cliffs: https://jogginsfossilcliffs.net/cliffs/history/
Image: Hylonomus lyelli, Una ricostruzione di ilonomo by Matteo De Stefano/MUSEThis file was uploaded by MUSE - Science Museum of Trento in cooperation with Wikimedia Italia., CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=48143186
Image: Arthropleura: Par Tim Bertelink — Travail personnel, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=48915156
Joggins Map: Joggins Fossil Cliffs: https://jogginsfossilcliffs.net/cliffs/history/
Thursday, 30 January 2025
TRACKING WHALES WITH BARNACLES
University of California Berkeley doctoral student Larry Taylor published some clever findings on how fossil barnacles hitched a ride on the backs of humpback and grey whales millions of years ago and used this data to reconstruct the migrations of ancient whale populations.
The barnacles record details about the whales’ yearly travels in the fossil record. By following this barnacle trail, Taylor et al. were able to reconstruct migration routes of whales from millions of years in the past.
Today, Humpback whales come from both the Southern Hemisphere (July to October with over 2,000 whales) and the Northern Hemisphere (December to March about 450 whales along with Central America) to Panama (and Costa Rica). They undertake annual migrations from polar summer feeding grounds to winter calving and nursery grounds in subtropical and tropical coastal waters.
One surprising find is that the coast of Panama has been a meeting ground for humpback whales going back at least 270,000 years. To see how the barnacles have travelled through the migration routes of ancient whales, the team used oxygen isotope ratios in barnacle shells and measured how they changed over time with ocean conditions.
Did the whale migrate to warmer breeding grounds or colder feeding grounds? Barnacles retain this information even after they fall off the whale, sink to the ocean bottom, and become fossils. As a result, the travels of fossilized barnacles can serve as a proxy for the journeys of whales in the distant past.
Barnacles can play an important role in estimating paleo-water depths. The degree of disarticulation of fossils suggests the distance they have been transported, and since many species have narrow ranges of water depths, it can be assumed that the animals lived in shallow water and broke up as they were washed down-slope.
Barnacles have few predators, with their one nemesis being whelks—a type of carnivorous sea snail in the family Muricidae. Whelks feasting on barnacles reads like a bit of a horror movie thriller. The whelks bore through the barnacle's shell and ingest digestive enzymes to make a slushy barnacle stew then such up all that barnacle goodness using their proboscis like a bit of a straw.
Not surprisingly then, the offer of catching a lifetime's ride on a passing whale has both evolutionary and survival appeal. Add to that the locals facilitation of feeding on plankton within arms reach—or cirri's reach in their case as they have these lovely feather-like appendages to sweep plankton out of the water—whelk-free. All in all a much more attractive choice than being cemented to a rock on the sea floor.
Monday, 20 January 2025
FOSSIL RHINO AND THE GREAT DEPRESSION
We have known about this gem for a long while now. The fossil was discovered by hikers back in 1935 and later cast by the University of California palaeontologists in 1948.
The Dirty Thirties & The Great Depression
These were the Dirty Thirties and those living in Washington state were experiencing the Great Depression along with the rest of the country and the world. Franklin D. Roosevelt was President of the United States, navigating the States away from laissez-faire economics.
Charmingly, Roosevelt would have his good name honoured by this same park in April of 1946, a few years before researchers at Berkeley would rekindle interest in the site.
Both hiking and fossil collecting was a fine answer to these hard economic times and came with all the delights of discovery with no cost for natural entertainment. And so it was that two fossil enthusiast couples were out looking for petrified wood just south of Dry Falls on Blue Lake in Washington State.
While searching the pillow basalt, the Frieles and Peabodys came across a large hole high up in a cave that had the distinctive shape of an upside-down rhinoceros.
This fossil is interesting in all sorts of ways. First, we so rarely see fossils in igneous rocks. As you might suspect, both magma and lava are very hot. Magma, or molten rock, glows a bright red/orange as it simmers at a toasty 700 °C to 1300 °C (or 1300 °F to 2400 °F) beneath the Earth's surface.
A Rhinoceros Frozen in Lava
During the late Miocene and early Pliocene, repeated basaltic lava floods engulfed about 63,000 square miles of the Pacific Northwest over a period of ten to fifteen million years. After these repeated bathings the residual lava accumulated to more than 6,000 feet.
As magma pushes up to the surface becoming lava, it cools to a nice deep black. In the case of our rhino friend, this is how this unlikely fellow became a fossil. Instead of vaporizing his remains, the lava cooled relatively quickly preserving his outline as a trace fossil and remarkably, a few of his teeth, jaw and bones. The lava was eventually buried then waters from the Spokane Floods eroded enough of the overburden to reveal the remains once more.
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| Diceratherium tridactylum (Marsh, 1875) |
While there are likely many more, we have found fossil remains of Diceratherium, an extinct genus of rhinoceros, in the Miocene of Canada in Saskatchewan, China, France, Portugal, Switzerland, and multiple sites in the United States.
He has also been found in the Oligocene of Canada in Saskatchewan, and twenty-five localities in the United States — in Arizona, Colorado, Florida, Nebraska, North Dakota, Oregon, South Dakota, Washington and Wyoming.
Diceratherium was a scansorial insectivore with two horns and a fair bit of girth. He was a chunky fellow, weighing in at about one tonne (or 2,200 lbs). That is about the size of a baby Humpback Whale or a walrus.
Back in the Day: Washington State 15 Million-Years Ago
He roamed a much cooler Washington state some 15 million years ago. Ice dams blocked large waterways in the northern half of the state, creating reservoirs. Floodwaters scoured the eastern side of the state, leaving scablands we still see today. In what would become Idaho, volcanic eruptions pushed through the Snake River, the lava cooling instantly as it burst to the surface in a cloud of steam.
By then, the Cascades had arrived and we had yet to see the volcanic eruptions that would entomb whole forests up near Vantage in the Takama Canyon of Washington state.
Know Before You Go
You are welcome to go see his final resting site beside the lake but it is difficult to reach and comes with its own risks. Head to the north end of Blue Lake in Washington. Take a boat and search for openings in the cliff face. You will know you are in the right place if you see a white "R" a couple hundred feet up inside the cliff. Inside the cave, look for a cache left by those who've explored here before you. Once you find the cache, look straight up. That hole above you is the outline of the rhino.
If you don't relish the thought of basalt caving, you can visit a cast of the rhino at the Burke Museum in Seattle, Washington. They have a great museum and are pretty sporting as they have built the cast sturdy enough for folk to climb inside.
The Burke Museum
The Burke Museum recently underwent a rather massive facelift and has re-opened its doors to the public. You can now explore their collections in the New Burke, a 113,000 sq. ft. building at 4300 15th Ave NE, Seattle, WA 98105, United States. Or visit them virtually, at https://www.burkemuseum.org/
Photo: Robert Bruce Horsfall - https://archive.org/details/ahistorylandmam00scotgoog, Public Domain, https://commons.wikimedia.org/w/index.php?curid=12805514
Reference: Prothero, Donald R. (2005). The Evolution of North American Rhinoceroses. Cambridge University Press. p. 228. ISBN 9780521832403.
Reference: O. C. Marsh. 1875. Notice of new Tertiary mammals, IV. American Journal of Science 9(51):239-250
Lincoln, Roosevelt and Recovery from The Great Depression
Rural Tennessee has electricity for the same reason Southeast Alaska has totem parks. In order to help the nation recover from The Great Depression, President Franklin D. Roosevelt, created a number of federal agencies to put people to work. From 1938-1942 more than 200 Tlingit and Haida men carved totem poles and cleared land for the Civilian Conservation Corps in an effort to create “totem parks” the federal government hoped would draw travelers to Alaska.
This odd intersection of federal relief, Alaska Native art and marketing is the subject of Emily L. Moore’s book “Proud Raven, Panting Wolf: Carving Alaska’s New Deal Totem Parks.”
This effort to bring poles out of abandoned villages includes the Lincoln Pole being moved to Saxman Totem Park by the Civilian Conservation Corps (CCC), who established the Saxman Totem Park in 1938.
The top carving on the Lincoln Pole bears a great likeness of Abraham Lincoln. According to the teachings of many Tlingit elders, this carving was meant to represent the first white man seen in Tlingit territory in the 18th century.
A century later, in the 1880s, one of my ancestors from the Gaanax.ádi Raven clan of the Tongass Tlingit commissioned the pole to commemorate our ancestor's pride to have seen this first white man—which has become a Gaanax.ádi crest—using a photograph of Abraham Lincoln as the model.
It is important not only for these various readings of the crests but also because it claims Gaanax.ádi clan territory before the first Europeans and budding Americans came to these shores—territory that Tlingit carvers who were re-carving the pole in the 1940s were trying to assert to the U.S. government as sovereign land.
Interestingly, another pole in that same park is the Dogfish Pole, carved for Chief Ebbits Andáa, Teikweidi, Valley House. The Chief Ebbits Memorial Pole—the Dogfish Kootéeyaa Pole—was raised in 1892 in Old Tongass Village in honour of a great man, Head Chief of the Tongass and my ancestor. It was then moved, re-carved and re-painted at Saxman Totem Park in 1938 as part of Roosevelt's program—and it due to be re-carved again this year.
It tells the story of his life and the curious way he became Ebbits as he was born Neokoots. He met and traded with some early American fur traders. One of those traders was a Mister Ebbits. The two became friends and sealed that friendship with the exchanging of names.
If you would like to read more about that pole and others, I recommend, The Wolf and the Raven, by anthropologist Viola Garfield and architect Linn Forrest (my talented cousin), published in 1961 and still in print as I ordered a copy for a friend just this year.
Sunday, 12 January 2025
GENAL SPINES A GO GO
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| Cibelella Coronata / Photo: Alexei Molchanov |
Saturday, 11 January 2025
OH MEDUSA
Jellyfish are found all over the world, from surface waters to our deepest seas — and they are old. They are some of the oldest animals in the fossil record.
Jellyfish are not fish at all. These gossamer wonders evolved millions of years before true fish.
Jellyfish and sea jellies are the informal common names given to the medusa-phase or adult phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria — more closely related to anemones and corals.
The oldest conulariid scyphozoans appeared between 635 and 577 mya in the Neoproterozoic of the Lantian Formation in China. Others are found in the youngest Ediacaran rocks of the Tamengo Formation of Brazil, c. 505 mya, through to the Triassic. Cubozoans and hydrozoans appeared in the Cambrian of the Marjum Formation in Utah, USA, c. 540 mya.
I have seen all sorts of their brethren growing up on the west coast of Canada in tide pools, washed up on the beach and swam amongst thousands of Moon Jellyfish while scuba diving in the Salish Sea. Their pulsating movements are marvellous.
In the Kwak̓wala language of the Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, jellyfish are known as ǥaǥisama.
The dreamy blue and purple ǥaǥisama you see here is but one of a large variety of colours and designs. Jellyfish come in bright yellow, orange, clear with pink spots and are often luminescent.
Tuesday, 31 December 2024
BIOLUMINESCENCE: CHEMICAL POETRY
In the inky blackness of the deep sea, more than 90% of the animals are luminescent. It is quite a startling number but makes good sense when you think of the edge bioluminescence provides.
The ability to generate light helps umpteen animals find mates, attract prey and avoid predation. Handy stuff, light.
What you know about light above the surface does not hold true for the light you see as bioluminescence. Its energy and luminosity come from a chemical reaction.
In a luminescent reaction, two types of chemicals — luciferin and luciferase — combine together. Together, they produce cold light — light that generates less than 20% thermal radiation or heat.
The light you see is produced by a compound called Luciferin. It is the shiny, showy bit in this chemical show. Luciferase acts as an enzyme, the substance that acts as a catalyst controlling the rate of chemical reactions, allowing the luciferin to release energy as it is oxidized. The colour of the light depends on the chemical structures of the chemicals. There are more than a dozen known chemical luminescent systems, meaning that bioluminescence evolved independently in different groups of organisms.
Coelenterazine is the type of luciferin we find in shrimp, fish and jellyfish. Dinoflagellates and krill share another class of unique luciferins, while ostracods or firefleas and some fish have a completely different luciferin.
The luciferase found in dinoflagellates is related to the green chemical chlorophyll found in plants. Bioluminescent dinoflagellates are a type of plankton — teensy marine organisms that make the seaways shimmer like the Milky Way as you swim through them.
Their twinkling lights are brief, each containing about 100 million photons that shine for a tenth of a second. While each individual flicker is here and gone in the wink of an eye, en masse they are awe-inspiring. I have spent many wondrous evenings scuba diving amongst these glittering denizens off our shores.
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| Cotylorhiza Tuberculata Jellyfish |
Bacteria and fireflies have unique luminescent chemistries. Fireflies light up when oxygen combines with calcium, adenosine triphosphate (ATP) and luciferin in the presence of luciferase.
For bacteria, the world stage of luminosity is quite small — and a bit gormless. Just how much light they emit and when is a free-for-all. Not so for the rest of our bioluminescent friends who have very precise control over when they shine and just how bright.
Bioluminescence comes in a variety of colours, from blue through red. The colour is based on the chemistry, which involves a substrate molecule called luciferin, the source of energy that goes into light, and an enzyme called luciferase or photoprotein.
In the ocean, bioluminescence is mostly blue-green or green. You would think that blues and green would not show up all that well in our seas but, surprisingly, they do. While sound travels better through saltwater than air, it is the reverse for light.
Various colours of light do not transmit equally through saltwater. Once we move deeper than the top layer of the ocean warmed by the sun and brimming with nutrients, the epipelagic zone, and move deeper through the mesopelagic, deeper and deeper still to the bathypelagic, frigid abyssalpelagic and finally the deep trenches of the icy pressure and all but inhospitable hadalpelagic, less and less light — until no light — gets through.
It is the twilight of the mesopelagic, 200 - 1000 metres below the surface, that is the sweet spot for most of our bioluminescent friends. Here, only very faint sunlight gets through. The water pressure is higher than at the surface but still lacks the crushing intensity of the lower zones. It is here that bioluminescence becomes a real advantage — good real estate and the showmanship of light pays gold.
We know that the deeper you go in our oceans, less and less sunlight gets through, so if the purpose of bioluminescence is to provide a signal that is noticed by prey, potential mates and predators alike, it is important that the light moves through the seawater, and not be absorbed or scattered — and this plays out in the colours evolved to be seen here.
If you have spent any time underwater, you will know that blue-green light transmits best through seawater. The deeper you go, the colours fade. Gone are the reds and yellows until everything looks brown or blue-green. Because of this, it is no surprise that blue-green is the most common colouring of bioluminescence in our oceans.
There are some exceptions to the blue-green/green colour rule — minuscule planktonic polychaete worms, Tomopteris helgolandica, emit yellow light, and deep-sea fish Malacosteus niger in the family Stomiidae, the barbeled dragonfishes, produce both red and blue.
Malacosteus niger's unique adaptation of producing red bioluminescence is only found in two other deep-sea dwelling creatures, Aristostomias and Pachystomias.
This rare form of bioluminescence can reach up to 700 nm in the deep-sea and cannot be perceived by green and blue bioluminescent organisms — granting M. niger a considerable advantage while hunting at depth.
The red light may function as an invisible searchlight of sorts because most animals in the ocean cannot see red light, while the eyes of M. niger are red-sensitive. It is much easier to find and eat something that cannot see you, particularly if it is lit up like a tasty red holiday snack.
Reference: https://latzlab.ucsd.edu/bioluminescence/
Sunday, 22 December 2024
ANCIENT ARAGONITE: FOSSIL PEARLS
A simple search will show you a vast array of pearls being used for their ornamental value in cultures from all over the world. I suppose the best answer to why they are appealing is just that they are.
If you make your way to Paris, France and happen to visit the Louvre's Persian Gallery, do take a boo at one of the oldest pearl necklaces in existence — the Susa necklace. It hails from a 2,400-year-old tomb of long lost Syrian Queen. It is a showy piece with three rows of 72 pearls per strand strung upon a bronze wire.
A queen who truly knew how to accessorize.
I imagine her putting the final touches of her outfit together, donning the pearls and making an entrance to wow the elite of ancient Damascus. The workmanship is superb, intermixing pure gold to offset the lustre of the pearls. It is precious and ancient, crafted one to two hundred years before Christ. Perhaps a gift from an Egyptian Pharaoh or from one of the Sumerians, Eblaites, Akkadians, Assyrians, Hittites, Hurrians, Mitanni, Amorites or Babylonian dignitaries who sued for peace but brought war instead.
Questions, good questions, but questions without answers. So, what can we say of pearls? We do know what they are and it is not glamorous. Pearls form in shelled molluscs when a wee bit of sand or some other irritant gets trapped inside the shell, injuring the flesh. As a defensive and self-healing tactic, the mollusc wraps it in layer upon layer of mother-of-pearl — that glorious shiny nacre that forms pearls.
They come in all shapes and sizes from minute to a massive 32 kilograms or 70 pounds. While a wide variety of our mollusc friends respond to injury or irritation by coating the offending intruder with nacre, there are only a few who make the truly gem-y pearls.These are the marine pearl oysters, Pteriidae and a few freshwater mussels. Aside from Pteriidae and freshwater mussels, we sometimes find less gem-y pearls inside conchs, scallops, clams, abalone, giant clams and large marine gastropods.
Pearls are made up mostly of the carbonate mineral aragonite, a polymorphous mineral — the same chemical formula but different crystal structure — to calcite and vaterite, sometimes called mu-calcium carbonate. These polymorphous carbonates are a bit like Mexican food where it is the same ingredients mixed in different ways. Visually, they are easy to tell apart — vaterite has a hexagonal crystal system, calcite is trigonal and aragonite is orthorhombic.
As pearls fossilize, the aragonite usually gets replaced by calcite, though sometimes by vaterite or another mineral. When we are very lucky, that aragonite is preserved with its nacreous lustre — that shimmery mother-of-pearl we know and love.
Molluscs have likely been making pearls since they first evolved 530 million years ago. The oldest known fossil pearls found to date, however, are 230-210 million years old.
This was the time when our world's landmass was concentrated into the C-shaped supercontinent of Pangaea and the first dinosaurs were calling it home. In the giant ancient ocean of Panthalassa, ecosystems were recovering from the high carbon dioxide levels that fueled the Permian extinction. Death begets life. With 95% of marine life wiped out, new species evolved to fill each niche.
While this is where we found the oldest pearl on record, I suspect we will one day find one much older and hopefully with its lovely great-great grandmother-of-pearl intact.
Wednesday, 11 December 2024
OF LAND AND SEA
Some dipped a toe or two into freshwater ponds, but make no mistake, they were terrestrial. Each of these animals had ancestors that tried out the sea and decided to stay. They evolved and employed a variety of adaptations to meet their new saltwater challenges. Some adapted legs as fins, others became more streamlined, and still, others developed specialized organs to extract dissolved oxygen from the water through their skin or gills. The permutations are endless.
Returning to the sea comes with a whole host of benefits but some serious challenges as well. Life at sea is very different from life on land. Water is denser than air, impacting how an animal moves, sees and hears. More importantly, it impacts an air-breathing animal's movement on a pretty frequent basis. If you need air and haven't evolved gills, you need to surface frequently. Keeping your body temperature at a homeostatic level is also a challenge as water conducts heat much better than air. Even with all of these challenges, the lure of additional food sources and freedom of movement kept those who tried the sea in the sea and they evolved accordingly.
Most major animal groups appear for the first time in the fossil record half a billion years ago. We call this flourishing of species the Cambrian Explosion. While this was a hugely intense period of species radiation, the evolutionary origins of animals are likely to be significantly older. About 700 million years ago the Earth was covered in ice and snow. This was an ice age so intense we refer to this time in our ancient history as Snowball Earth. Once that ice receded, it exposed rocks that contained a variety of weird and wonderful fossils that speak to ancient animals that are only now being studied.
Dr Frankie Dunn, a palaeontologist and an Early Career Research Fellow at the Oxford University Museum of Natural History and Merton College is one of the folks who are examining this early history of some of our first animals. Her research focuses on the origin and early evolution of animals and particularly on the fossil record of the late Ediacaran Period (570 – 540 million years ago). Dr Dunn's research is exploring ancient species like the long-extinct Rangeomorpha to help understand how animal body plans evolved in deep time well before the divergence of the extant (living) animal lineages.
Andy Temple (bless him) sent me a link for an online talk Dr Dunn is giving, The Chronicles of Charnia, Wed, June 17th at 7PM. She's based in Oxford so adjust your timezone accordingly. The talk is free but booking is required. Here's the link: https://event.webinarjam.com/
This is an interesting article from Alicia Ault writing for the Smithsonian who interviewed Nick Pysenson and Neil Kelley about some of their research that touches on this area. They published a paper on it in the journal Science. Here's the link: https://science.sciencemag.org/content/348/6232/aaa3716
And Ault's work is definitely worth a read: https://www.smithsonianmag.com/smithsonian-institution/take-deep-dive-reasons-land-animals-moved-seas-180955007/
Thursday, 28 November 2024
TRACKING WHALES WITH BARNACLES
University of California Berkeley doctoral student Larry Taylor published some clever findings on how fossil barnacles hitched a ride on the backs of humpback and grey whales millions of years ago and used this data to reconstruct the migrations of ancient whale populations.
The barnacles record details about the whales’ yearly travels in the fossil record. By following this barnacle trail, Taylor et al. were able to reconstruct migration routes of whales from millions of years in the past.
Today, Humpback whales come from both the Southern Hemisphere (July to October with over 2,000 whales) and the Northern Hemisphere (December to March about 450 whales along with Central America) to Panama (and Costa Rica). They undertake annual migrations from polar summer feeding grounds to winter calving and nursery grounds in subtropical and tropical coastal waters.
One surprise find is that the coast of Panama has been a meeting ground for humpback whales going back at least 270,000 years. To see how the barnacles have travelled through the migration routes of ancient whales, the team used oxygen isotope ratios in barnacle shells and measured how they changed over time with ocean conditions.
Did the whale migrate to warmer breeding grounds or colder feeding grounds? Barnacles retain this information even after they fall off the whale, sink to the ocean bottom, and become fossils. As a result, the travels of fossilized barnacles can serve as a proxy for the journeys of whales in the distant past.
Barnacles can play an important role in estimating paleo-water depths. The degree of disarticulation of fossils suggests the distance they have been transported, and since many species have narrow ranges of water depths, it can be assumed that the animals lived in shallow water and broke up as they were washed down-slope.
Barnacles have few predators. Their one nemesis is the whelk. It seems that catching a lifetime's ride on a passing whale would have extended their ability to feed on plankton in a variety of settings whelk-free and likely live longer than they might have cemented to something closer to the seafloor.
Friday, 15 November 2024
FOSSIL SITES OF THE OKANAGAN HIGHLANDS
Wednesday, 6 November 2024
LIVING FOSSILS: MASTERS OF MASS EXTINCTION EVENTS
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.
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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 |
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 |
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.


























