Showing posts with label fossil. Show all posts
Showing posts with label fossil. Show all posts

Saturday, 8 February 2025

NANAIMO MOTOR CROSS PIT FOSSIL SITE

Steller's Jay, Cyanocitta stelleri
One of the classic Vancouver Island fossil localities is the Santonian-Maastrichtian, Upper Cretaceous Haslam Formation Motocross Pit near Brannen Lake, Nanaimo, British Columbia, Canada.

The quarry is no longer active as such though there is a busy little gravel quarry a little way down the road closer to Ammonite falls near Benson Creek Falls.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. 

In these easily accessible (with permission) outcrops we find well-preserved nautiloids and ammonites — Canadoceras, Pseudoschloenbachia, Epigoniceras — the bivalves — Inoceramus, Sphenoceramus— gastropods, and classic Nanaimo Group decapods — Hoploparia, Linuparus. We also find fossil fruit and seeds which tell the story of the terrestrial history of Vancouver Island.

Upper Cretaceous Haslam Formation Motocross Pit near Brannen Lake
It was John Fam, Vice-Chair, Vancouver Island Paleontological Society (VanPS), who originally told me about the locality. John is one of the most delightful and knowledgeable people you'd be well-blessed to meet.

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.

Upper Cretaceous Haslam Formation Motocross Pit near Brannen Lake
There were some no trespassing signs up but no people around, so I walked the periphery looking for the bedrock of the Haslam.

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.

Candoceras yokoyama, Photo: John Fam, VanPS
As I walked along the bedrock of the Haslam, a Steller's Jay, Cyanocitta stelleri, followed me from tree to tree making his guttural shook, shook, shook call. Instructive, he seemed to be encouraging me, timing his hoots to the beat of my hammer.

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

Hylonomus lyelli, Ancestor of all dinosaurs
The fossil cliffs at Joggins are one of Canada's gems, now a UNESCO World Heritage Site, you can visit to see our ancient world frozen in time. 

Preserved in situ is a snapshot of an entire food chain of a terrestrial Pennsylvanian Coal Age wetland.

The outcrop holds fossil plant life — including impressive standing lycopsid trees that formed the framework of these wetlands — decomposing detritivores in the invertebrates and tetrapods, the predatory carnivores of the day.

The Coal Age trees were fossilized where they stood 300-million-years ago with the remains of the earliest reptiles entombed within. The preservation is quite marvellous with the footprints of creatures who once lived in these wetlands are frozen where they once walked and the dens of amphibians are preserved with remnants of their last meal. 

Nowhere is a record of plant, invertebrate and vertebrate life within now fossilized forests rendered more evocatively. The fossil record at Joggins contains 195+ species of plants, invertebrates and vertebrates. The fossil plant life became the vast coal deposits for which this period of Earth's history is named. 

Recorded in the rock are vertebrate and invertebrate fauna both aquatic and terrestrial. This broad mix of specimens gives us a view into life back in the Pennsylvanian and sets us up to understand their ecological context.
Pennsylvanian Coal Age Ecosystem, 300-Million-Years-Old
The fossil record includes species first defined at Joggins, some of which are found nowhere else on Earth. 

It was here that Sir Charles Lyell, with Sir William Dawson, founder of modern geology, discovered tetrapods — amphibians and reptiles — entombed in the upright fossil trees. 

Later work by Dawson would reveal the first true reptile, Hylonomus lyelli, ancestor of all dinosaurs that would rule the Earth 100 million years later. 

This tiny reptile serves as the reference point where animals finally broke free of the water to live on land. This evolutionary milestone recorded at Joggins remains pivotal to understanding the origins of all vertebrate life on land, including our own species. 

Sir Charles Lyell, author of Principles of Geology, first noted the exceptional natural heritage value of the Joggins Fossil Cliffs, calling them “...the finest example in the world of a natural exposure in a continuous section ten miles long, occurs in the sea cliffs bordering a branch of the Bay of Fundy in Nova Scotia.” Indeed, the world-famous Bay of Fundy with its impressive tides, the highest in the world, and stormy nature exposed much of this outcrop. 

Geological accounts of the celebrated coastal section at Joggins first appear in the published literature in 1828–1829, by Americans C.T. Jackson and F. Alger, and by R. Brown and R. Smith, managers for the General Mining Association in the Sydney and Pictou coal fields. Brown and Smith’s account is the first to document the standing fossil trees.

Joggins Fossil Cliffs Map (Click to Enlarge)
Plan Your Joggins Fossil Cliffs Staycation

Joggins Fossil Cliffs is a Canadian gem — and they welcome visitors. They offer hands-on learning and discovery microscope activities in their Fossil Lab.

You can explore interpretive displays in the Joggins Fossil Centre before heading out to the beach and cliffs with an interpreter.

Their guided tours of the fossil site include an educational component that tells you about the geology, ecology, palaeontology and conservation of this very special site. 

Joggins / Chegoggin / Mi'kmaq L'nu

We know this area as Joggins today. In Mi'kmaw, the language spoken in Mi'kma'ki, the territory of the Mi'kmaq L'nu, the area bears another name, Chegoggin, place of fishing weirs.

Booking Your Class Field Trip

If you are a teacher and would like to book a class field trip, contact the Director of Operations via the contact information listed below. They will walk you through Covid safety and discuss how to make your visit educational, memorable and fun.

Know Before You Go

The Bay of Fundy has the highest tides in the world. Beach walks are scheduled according to the tides and run regardless of the weather. Good low tides but raining, the beach walk goes on. Lovely and sunny but with a high tide, the beach walk must wait. So, you will want to dress for it as they will not be cancelled in the event of rain. Should severe weather be a factor, bookings may need to be rescheduled at the discretion of the Joggins staff.

Any questions about booking your school field trip? Feel free to email:  operations@jogginsfossilcliffs.net or call: 1 (902) 251-2727 EXT 222.

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

We can trace the lineage of barnacles back to the Middle Cambrian. That is half a billion years of data to sift through. 

If you divide that timeline in half yet again, we begin to understand barnacles and their relationship to other sea-dwelling creatures — with a lens that reveals ancient migration patterns.

Barnacles are in the infraclass Cirripedia in the class Maxillopoda and phylum Crustacea. The name "Cirripedia" comes from the Latin and translates to "curl-footed," an apt description of some from this class. They are marine arthropods related to crabs and lobsters. 

In the Kwak̓wala language of the Kwakwaka'wakw First Nations, speakers of Kwak'wala, of the Pacific Northwest, barnacles are known as k̕wit̕a̱'a and broken barnacle shells are known as t̕sut̕su'ma. 

Unless scraped off, barnacles live on one single sturdy object for their entire lives — 8 to 20 years — while chowing down on tasty snacks like plankton and algae they absorb from the surrounding water.

One of the most interesting aha moments in paleontology came from the study of 270,000 million-year-old k̕wit̕a̱'as. These sticky wee crustaceans have enabled us to trace the course of ancient whale migration. 

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

The Miocene pillow basalts from the Lake Roosevelt National Recreation Area of central Washington hold an unlikely fossil. 

What looks to be a rather unremarkable ballooning at the top of a cave is actually the mould of a small rhinoceros, preserved by sheer chance as its bloated carcass sunk to the bottom of a shallow lake just prior to a volcanic explosion.

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.

Diceratherium tridactylum (Marsh, 1875)
Diceratherium (Marsh, 1875) is known from over a hundred paleontological occurrences from eighty-seven collections.

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

Cibelella Coronata / Photo: Alexei Molchanov
A spectacular creamy toned specimen of the trilobite Cibelella Coronata striking a very animated pose. 

The Genal spines give this fellow a bit of a starship look as though taking off in flight. 

This beauty is from upper Ordovician deposits along the Neva River at the head of the Gulf of Finland on the Baltic Coast, Saint Petersburg, Russia.


Saturday, 11 January 2025

OH MEDUSA

Mesmerizing, delicate and seemingly impossible — this lovely luminescent denizen of the sea has been living in our oceans for more than half a billion years.

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

Light in the oceans? It is chemistry, my friends. 

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. 

Cotylorhiza Tuberculata Jellyfish
In this close up of a Cotylorhiza Tuberculata Jellyfish, you can see the luminosity of her blue and white tentacles. The occurrence of identical luciferins for different types of organisms may suggest a dietary source for some groups strengthening the adage, you are what you eat, or perhaps you glow how you eat

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. 

Most of this lighting up of our world happens on land or in saltwater. There are almost no bioluminescent organisms native to freshwater.

In terrestrial plants and animals — fireflies, beetles and fungi like this Ghost Fungus, Omphalotus nidiformis, a gilled basidiomycete mushroom — we commonly find green, yellow, and sometimes red. 

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

One of my favourite pairs of earrings are a simple set of pearls. I have worn them pretty much every day since 2016 when I received them as a gift. What is it about pearls that makes them so appealing? I am certainly not alone in this. 

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

Our dear penguins, seals, sea lions, walruses, whales, crocodiles and sea turtles were once entirely terrestrial. Yes, they lived mostly or entirely on land. 

Many of these once land-dwelling animals returned to the sea throughout evolutionary history. We have beautifully documented cases from amphibians, reptiles, birds and mammals from over 30 different lineages over the past 250 million years.

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/register/59/xyy07flg 

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

We can trace the lineage of barnacles back to the Middle Cambrian. That is half a billion years of data to sift through. 

If you divide that timeline in half yet again, we begin to understand barnacles and their relationship to other sea-dwelling creatures — with a lens that reveals ancient migration patterns.

Barnacles are in the infraclass Cirripedia in the class Maxillopoda. They are marine arthropods related to crabs and lobsters. 

In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, barnacles are known as k̕wit̕a̱'a and broken barnacle shells are known as t̕sut̕su'ma. Unless scraped off, barnacles live on one single sturdy object for their entire lives — 8 to 20 years — while chowing down on tasty snacks like plankton and algae they absorb from the surrounding water.

One of the most interesting aha moments in palaeontology came from the study of 270,000 million-year-old k̕wit̕a̱'as. These sticky wee crustaceans have enabled us to trace the course of ancient whale migration. 

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

Fossils from the Okanagan Highlands, an area centred in the Interior of British Columbia, provide important clues to our ancient climate. 

Okanagan Highlands refers to an arc of Eocene lakebed sites that extend from Smithers in the north, down to the fossil site of Republic Washington. 

The grouping includes the fossil sites of Driftwood Canyon, Quilchena, Allenby, Tranquille, McAbee, Princeton and Republic.

These fossil sites range in time from Early to Middle Eocene, and the fossil they contain give us a snapshot of what was happening in this part of the world because of the varied plant fossils they contain.

We can infer the difference in climates between the sites. McAbee was not as warm as some of the other Middle Eocene sites, a fact inferred by what we see and what is conspicuously missing. In looking at the plant species, it has been suggested that the area of McAbee had a more temperate climate, slightly cooler and wetter than other Eocene sites to the south at Princeton, British Columbia and Republic and Chuckanut, Washington. Missing are the tropical Sabal (palm), seen at Princeton and the impressive Ensete (banana) and Zamiaceae (cycad) found at Republic in north-central Washington, in the Swauk Formation near Skykomish and the Chuckanut Formation of northern Washington state.

Wednesday, 6 November 2024

LIVING FOSSILS: MASTERS OF MASS EXTINCTION EVENTS

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Tuesday, 5 November 2024

CTENOPHORES: COMB JELLIES

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Friday, 1 November 2024

SHONISAURUS OF NEVADA

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

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

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

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

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

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

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

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

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

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

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

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

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

Tuesday, 29 October 2024

SAKARA MADAGASGAR: OXFORDIAN OUTCROPS

This big beastie is a superb specimen of the ammonite Lobolytoceras costellatum showing the intricate fractal pattern of its septa. 

This lovely measures to a whopping 230 mm and hails from Oxfordian outcrops near Sakara, Madagascar. Lovingly prepped by the supremely talented José Juárez Ruiz.

Ammonites were predatory, squidlike creatures that lived inside coil-shaped shells. Like other cephalopods, ammonites had sharp, beak-like jaws inside a ring of squid-like tentacles that extended from their shells. They used these tentacles to snare prey — plankton, vegetation, fish and crustaceans — similar to the way a squid or octopus hunt today.

Catching a fish with your hands is no easy feat, as I'm sure you know. Ammonites did the equivalent, catching prey in their tentacles. They were skilled and successful hunters. They caught their prey while swimming and floating in the water column. 

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.

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.

They were a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids — octopuses, squid, and cuttlefish) then they are to shelled nautiloids such as the living Nautilus species.

Ammonites have intricate and complex patterns on their shells called sutures. The suture patterns differ across species and tell us what time period the ammonite is from. If they are geometric with numerous undivided lobes and saddles and eight lobes around the conch, we refer to their pattern as goniatitic, a characteristic of Paleozoic ammonites.

Ammonites first appeared about 240 million years ago, though they descended from straight-shelled cephalopods called bacrites that date back to the Devonian, about 415 million years ago, and the last species vanished in the Cretaceous–Paleogene extinction event.

They were prolific breeders that evolved rapidly. If you could cast a fishing line into our ancient seas, it is likely that you would hook an ammonite, not a fish. They were prolific back in the day, living (and sometimes dying) in schools in oceans around the globe. We find ammonite fossils (and plenty of them) in sedimentary rock from all over the world.

In some cases, we find rock beds where we can see evidence of a new species that evolved, lived and died out in such a short time span that we can walk through time, following the course of evolution using ammonites as a window into the past.

For this reason, they make excellent index fossils. An index fossil is a species that allows us to link a particular rock formation, layered in time with a particular species or genus found there. Generally, deeper is older, so we use the sedimentary layers rock to match up to specific geologic time periods, rather the way we use tree-rings to date trees. A handy way to compare fossils and date strata across the globe.

Monday, 28 October 2024

SMILODON NORTH OF THE 49TH PARALLEL

This fierce predator with the luxurious coat is Smilodon fatalis — a compact but robust killer that weighed in around 160 to 280 kg and was 1.5 - 2.2 metres long.

Smilodon is a genus of the extinct machairodont subfamily of the felids. It is one of the most famous prehistoric mammals and the best known saber-toothed cat. Although commonly known as the saber-toothed tiger, it was not closely related to the tiger or other modern cats.

Up until a few years ago, all the great fossil specimens of this apex predator were found south of us in the United States. That was until some interesting bones from Medicine Hat, Alberta got a second look.

A few years ago, a fossil specimen caught the eye of researcher Ashley Reynolds as she was rummaging through the collections at the Royal Ontario Museum in Toronto. 

Back in the 1960s,  University of Toronto palaeontologist C.S. Churcher and his team had collected and donated more than 1,200 specimens from their many field seasons scouring the bluffs of the South Saskatchewan River near Medicine Hat, Alberta.

Churcher is a delightful storyteller and a palaeontologist with a keen eye. I had the very great pleasure of listening to many of his talks out at the University of British Columbia and a few Vancouver Paleontological Society meetings in the mid-2000s. 

"Rufus" was a thoroughly charming storyteller and shared many of his adventures from the field. 

He moved out to the West Coast for his retirement, first to Gabriola Island then to Victoria, but his keen love of the science kept him giving talks to enthralled listeners keen to hear about his survey of the Dakhleh Oasis in the Western Desert of Egypt, geomorphology, stratigraphy, recent biology, Pleistocene and Holocene lithic cultures, insights learned from Neolithic Islamic pottery to Roman settlements.

The specimens he had collected had been roughly sorted but never examined in detail. Reynolds, who was researching the growth patterns and life histories of extinct cats saw a familiar-looking bone from an ancient cat's right front paw. That tiny paw bone had reached through time and was positively identified as Canada's first Smilodon.

These Apex Predators used their exceptionally long upper canine teeth to hunt large mammals. 

Isotopes preserved in the bones of S. fatalis in the La Brea Tar Pits in California tell us that they liked to dine on bison (Bison antiquus) and camels (Camelops) along with deer and tapirs. Smilodon is thought to have killed its prey by holding it still with its forelimbs and biting it. And that was quite the bite!

Their razor-sharp incisors were arranged in an arch. Once they bit down, the teeth would hold their prey still and stabilize it while the canine bite was delivered — and what a bite that was. They could open their mouths a full 120 degrees.

Smilodon died out at the same time that most North and South American megafauna disappeared, about 10,000 years ago. Its reliance on large animals has been proposed as the cause of its extinction, along with climate change and competition with other species. 

Thursday, 24 October 2024

BRONZE BEAUTY: EIFELIAN PARALEJURUS

This bronzed beauty is the Middle Devonian, Eifelian (~395 mya) trilobite, Paralejurus rehamnanus (Alberti, 1970) from outcrops near Issoumour, Alnif, Morocco in North Africa. 

It was the colour of this amazing trilobite that captured the eye of David Appleton in whose collection it now resides. He is an avid collector and coming into his own as a macro photographer. I have shared three of his delightful photos for you here.

It initially thought that the gold we see here was added during prep, particularly considering the colouration of the matrix, but macro views of the surface show mineralization and the veins running right through the specimen into the matrix. There is certainly some repairs but that is common in the restoration of these specimens. Many of the trilobites I have seen from Morocco have bronze on black colouring but not usually this pronounced. Even so, there is a tremendous amount of fine anatomy to explore and enjoy in this wonderfully preserved specimen.  

Paralejurus is a genus of trilobite in the phylum Arthropoda from the Late Silurian to the Middle Devonian of Africa and Europe. These lovelies grew to be up to nine centimetres, though the fellow you see here is a wee bit over half that size at 5.3 cm. 

Paralejurus specimens are very pleasing to the eye with their long, oval outline and arched exoskeletons. 

Their cephalon or head is a domed half circle with a smooth surface.  The large facet eyes have very pleasing crescent-shaped lids. You can see this rather well in the first of the photos here. The detail is quite remarkable.

As you move down from his head towards the body, there is an almost inconspicuous occipital bone behind the glabella in the transition to his burnt bronze thorax.

The body or thorax has ten narrow segments with a clearly arched and broad axial lobe or rhachis. The pygidium is broad, smooth and strongly fused in contrast to the genus Scutellum in the family Styginidae, which has a pygidium with very attractive distinct furrows that I liken to the look of icing ridges on something sweet — though that may just be me and my sweet tooth talking. In Paralejurus, they look distinctly fused — or able to fuse — to add posterior protection against predators with both the look and function of Roman armour.

In Paralejurus, the axillary lobe is rounded off and arched upwards. It is here that twelve to fourteen fine furrows extend radially to complete the poetry of his body design. 

Trilobites were amongst the earliest fossils with hard skeletons and they come in many beautiful forms. While they are extinct today, they were the dominant life form at the beginning of the Cambrian. 

As a whole, they were amongst some of the most successful of all early animals — thriving and diversifying in our ancient oceans for almost 300 million years. The last of their brethren disappeared at the end of the Permian — 252 million years ago. Now, we enjoy their beauty and the scientific mysteries they reveal about our Earth's ancient history.

Photos and collection of the deeply awesome David Appleton. Specimen: 5.3 cm. 

Sunday, 20 October 2024

ALCIDS AUKS: PUFFLINGS AND DUTIFUL PARENTS

Puffins are any of three small species of alcids or auks in the bird genus Fratercula with a brightly coloured beak during the breeding season.

Their sexy orange beaks shift from a dull grey to bright orange when it is time to attract a mate. While not strictly monogamous, most Puffins choose the same mate year upon year producing adorable chicks or pufflings (awe) from their mating efforts.

Female Puffins produce one single white egg which the parents take turns to incubate over a course of about six weeks. Their dutiful parents share the honour of feeding the wee pufflings five to eight times a day until the chick is ready to fly. Towards the end of July, the fledgeling Puffins begin to venture from the safety of their parents and dry land. Once they take to the seas, mom and dad are released from duty and the newest members of the colony are left to hunt and survive on their own.

These are pelagic seabirds that feed primarily by diving in the water. They breed in large colonies on coastal cliffs or offshore islands, nesting in crevices among rocks or in burrows in the soil. Two species, the tufted puffin and horned puffin are found in the North Pacific Ocean, while the Atlantic puffin is found in the North Atlantic Ocean. 

This lovely fellow, with his distinctive colouring, is an Atlantic Puffin or "Sea Parrot" from Skomer Island near Pembrokeshire in the southwest of Wales. Wales is bordered by Camarthenshire to the east and Ceredigion to the northeast with the sea bordering everything else. It is a fine place to do some birding if it's seabirds you're after.

These Atlantic Puffins are one of the most famous of all the seabirds and form the largest colony in Southern Britain. They live about 25 years making a living in our cold seas dining on herring, hake and sand eels. Some have been known to live to almost 40 years of age. They are good little swimmers as you might expect, but surprisingly they are great flyers, too! They are hindered by short wings, which makes flight challenging but still possible with effort. Once they get some speed on board, they can fly up to 88 km an hour.

The oldest alcid fossil is Hydrotherikornis from Oregon dating to the Late Eocene while fossils of Aethia and Uria go back to the Late Miocene. Molecular clocks have been used to suggest an origin in the Pacific in the Paleocene. Fossils from North Carolina were originally thought to have been of two Fratercula species but were later reassigned to one Fratercula, the tufted puffin, and a Cerorhinca species. Another extinct species, Dow's puffin, Fratercula dowi,  was found on the Channel Islands of California until the Late Pleistocene or early Holocene.

The Fraterculini are thought to have originated in the Pacific primarily because of their greater diversity in the region. There is only one extant species in the Atlantic, compared to two in the Pacific. The Fraterculini fossil record in the Pacific extends at least as far back as the middle Miocene, with three fossil species of Cerorhinca, and material tentatively referred to that genus, in the middle Miocene to late Pliocene of southern California and northern Mexico.

Although there no records from the Miocene in the Atlantic, a re-examination of the North Carolina material indicated that the diversity of puffins in the early Pliocene was as great in the Atlantic as it is in the Pacific today. This diversity was achieved through influxes of puffins from the Pacific; the later loss of species was due to major oceanographic changes in the late Pliocene due to closure of the Panamanian Seaway and the onset of severe glacial cycles in the North Atlantic.