OUR EARLY ATMOSPHERE

Our early Earth was a molten world

When the Earth formed 4.5 billion years ago, it was an inhospitable place. 

Even with a Sun some 25 per cent weaker than it is today, ours was a molten world that needed to undergo a long period of cooling before the conditions for life would arise.

And arise they did. On the planet's surface, volcanoes spewed lava and volatile gasses into what would become our earliest atmosphere. 

Again, in composition, it looked very different from the one we know today. Nitrogen, carbon dioxide, ammonia, methane and small amounts of water vapour made up the gassy soup surrounding our world.

But that first water would change everything. As the water vapour condensed, it came back to the surface bit by bit. Over a very long period of time, those waters pooled and gathered and became our first oceans. It was in this early ocean some 2.7 billion years ago that cyanobacteria, or blue-green algae, wonderous photosynthetic microbes, would take up that weakened sunlight and water vapour to process the carbon dioxide from the atmosphere, producing other chemical compounds and oxygen as a by-product.  

RED LIPPED BATFISH

Red Lipped Batfish, Ogcocephalus darwini

This sexy monkey with her luscious red pucker is a Red Lipped Batfish, Ogcocephalus darwini.

Our world's oceans have some of the most amazing, beautiful, ugly and interesting creatures on the planet. Red Lipped Batfish are no exception. They can be found along the sandy ocean floor and reefs around the Galapagos Islands and off the shores of Peru.

Their most distinguishing feature is revealed in their name and one look at this photo gives it away — they have very distinctive bright red lips. They also have a rather fetching illicium, the dangling projection you see here. It's a lure to attract prey to those luscious lips so she can enjoy a tasty snack. Above the illicium is an esca, an unusual feature that emits a bright light. Between the light and the lure, small fish and curious invertebrates — shrimp, molluscs, crab — deep in the Southeast Pacific investigate the light and get swallowed up by those lips.

Most of their flattened flounder-like bodies are light brown and a greyish in colour with white colouring on the underside. They are roughly the size of a dinner plate. On the top side of the batfish, there is usually a dark brown stripe starting at the head and going down the back to the tail.

Their face has a definite red sheen. Comically, with the red face and bored expressions, it looks like they're perpetually unimpressed and slightly embarrassed.

Once you get past those lips, the next thing that stands out with these interesting beauties is how they move. They're not terribly good swimmers but do walk rather well on their highly adapted fins. They march or waddle across the seafloor in search of more interesting sights to practise the art of deep-sea fishing.

Batfish are descendants of lophiiform fishes. In 2011, a new genus and species of batfish, Tarkus squirei, was described from Eocene (Ypresian) limestone deposits in the celebrated locality of Monte Bolca, Italy. Tarkus squirei was a tropical batfish that inhabited the inner-shelf palaeobiotopes of the central-western Tethys Sea.  Tarkus gen. nov. shows a certain degree of phenetic affinity with the extant shallow-water batfish genera Halieutaea and —more particularly — Halieutichthys. The specimens of this taxon are the first articulated skeletal remains of the Ogcocephalidae ever recorded as fossils, also representing the oldest members of the family known to date.

Reference: CARNEVALE, G., & PIETSCH, T. (2011). Batfishes from the Eocene of Monte Bolca. Geological Magazine, 148(3), 461-472. doi:10.1017/S0016756810000907

FROM RUSSIA WITH LOVE: AULACOSTEPHANUS

A beautiful example of Aulacostephanus undorae (Pavlow, 1886), a Late Jurassic, Upper Kimmeridgian, upper zone Eudoxus ammonite from an old quarry near the river Serena, near the village Lipitsy, Kaluga Region, Russia. 

Kaluga is known for its most famous resident, Konstantin Tsiolkovsky, a rocket scientist who pioneered astronautic theory.

The Tsiolkovsky State Museum of the History of Cosmonautics in Kaluga is dedicated to his work and its practical applications for space research. The city's coat of arms and motto gives a respectful nod to work — the Cradle of Space Exploration.

Kaluga, founded in the mid-14th century as a border fortress on the southwestern borders of the Grand Duchy of Moscow. The city's name has changed over time. If you poke through historical records and chronicles from the 14th century, you'll see it written as Koluga — derived from the Old Russian word for bog or quagmire. 

Historically, Kolunga has sat on the sidelines of history. It is the sort of place you might have a country home away from the hubbub of the bustling city. Indeed, the area has served as such for many of Russia's Royals. In the Middle Ages Kaluga was a smallish settlement owned by the Princes Vorotynsky whose relationship with the townsfolk looked more akin to how you and I might picture slaver versus a liege lord. 

Over time, the village grew more prosperous and opened its first drama theatre in 1777. As in many parts of the world, the first geologic exploration and mapping were done to locate natural resources that would be used to fund monarchies, wars and infrastructure.  

Kaluga is connected to Moscow by a railway line and by the ancient roadway, the Kaluga Road (now partly within Moscow — as Starokaluzhskoye Shosse - the Old Kaluga Highway — partly the A101 road. This road offered Napoleon his favoured escape route from the Moscow trap in the fall of 1812. 

General Kutuzov repelled Napoleon's advances in this direction and forced the retreating French army onto the old Smolensk road, previously devastated by the French during their invasion of Russia — an event that may be attributed to poor planning and tin buttons, but that is for another post.

On several occasions during the Russian Empire Kaluga was the residence of political exiles and prisoners such as the last Crimean khan Şahin Giray (1786), the Kyrgyz sultan Arigazi-Abdul-Aziz (1828), the Georgian princess Thecla (1834–1835), and the Avar leader Imam Shamil (1859–1868).

The German army briefly occupied Kaluga during the climactic Battle of Moscow, as part of Operation Barbarossa. The city was under full or partial German occupation from October 12th to December 30, 1941. In 1944, the Soviet Government used its local military buildings to intern hundreds of Polish prisoners of war — soldiers of the Polish underground Home Army — whom the advancing Soviet front had arrested in the area around Vilnius. This specimen is in the collection of the deeply awesome Emil Black. Maximum diameter of 58mm. 

FOOL'S GOLD: A PERSONAL GOLD RUSH

When I was little, maybe 5 or 6 years old, I struck gold! Well, it wasn't real gold, but I was most convinced. 

Someone had dumped a tailings pile near the woods where I lived and in the sun, those crushed pieces of rock sparkled. I had already been bitten by the love of minerals and fossils and so naturally I filled my pockets and brought as much home as a youngster can carry.

Where I was told that it was Fool's Gold. 

But, still... it was so compelling and just so gold-like. So, secretly I continued my forays and dragged as many of those lovely sparkly bits home as I could. The pile soon amassed to what could not be concealed in a youngsters room — those socks have to live somewhere. So we struck a bargain. My folks would let me keep my gold if I kept it under the house. I suspect it is still there to this day. 

I did eventually find gold up in Atlin, British Columbia — and loads of it — but none that I could keep. I met a fellow who pans for it and had built out a sluicing system to great success. He showed me an ice cream bucket full of gold nuggets that I still ponder to this day.

So, what exactly is Fool's Gold? Is it gold mixed with another mineral or something else altogether? Turns out it is pyrite which has a brass-yellow colour and metallic lustre similar to gold, but pyrite is brittle and will break rather than bend as gold does. 

A good field test is to give it a streak test. Gold leaves a yellow streak, while pyrite’s streak is brownish-black. 

Pyrite is named from the Greek word for fire, "pyr" because pyrite can create sparks for starting a fire when struck against metal or stone — also fun to try in the field. Pyrite was once a source of sulfur and sulfuric acid, but today most sulfur is obtained as a byproduct of natural gas and crude oil processing.

We sometimes see pyrite sold as a novelty item or made into costume jewellery. But pyrite does have its uses beyond amusing youngsters dreaming of their own gold rush. 

Pyrite can sometimes help you find real gold because the two form together under similar conditions. Gold can even occur as inclusions inside pyrite, sometimes in mineable quantities depending on how effectively the gold can be recovered.

Fool’s Gold is truly pyrite or iron sulfide (FeS2) and is one of the most common sulfide minerals. Sulfide minerals are a group of inorganic compounds containing sulfur and one or more elements. 

I still have a fondness for it and share a wry smile when I find it out in the field. It is remarkably common. And, I do still want it to be real gold even though my grown-up brain knows it is not. 

When I am very lucky, however, I find pyritized fossils — even better than gold!

FOSSILS OF THE LONDON CLAY

Birds, Snakes & Mammals, London Clay

Birds, mammals, snakes and crocodiles — these do not immediately spring to mind when you think of marine deposits — but these are some of the wonderful fossil specimens that make the London Clay so interesting to collect from.

The London Clay Formation is a marine geological formation of Ypresian (early Eocene Epoch, c. 56–49 Ma) age which outcrops in the southeast of England. 

The exposures are well-known for their variety of fossil fauna. The fossils from the lower Eocene sections tell us about a moderately warm, tropical to subtropical climate.

It was with the greatest pleasure that I came across some of the wonderful fossil specimens found by Martin Rayner and his father over the better part of 40-years worth of dedicated collecting. These excellent examples of the London Clay fauna hail from Sheppey, Seasalter and Tankerton. 

You may recall that Martin is a co-author of London Clay Fossils of Kent and Essex.  The book is a collectors' guide to the fossil animals and plants of the London Clay from river and coastal exposures in Kent and Essex. It is known locally as the Fossil Bible.

This superb book is published by the Medway Fossil and Mineral Society and was written by four of the Society members, David Rayner, Tony Mitchell, Martin Rayner and Fred Clouter. 

It the essential field guide for use by both beginners and the more experienced — and likely the definitive work on the subject for many years to come. 

The book includes when to collect, equipment, cleaning, preparation and preservation of specimens, sieving, storage and cataloguing, geology and a list of fourteen collecting sites  — six with site location maps, access details and collecting techniques.

There is a hugely useful identification section and comprehensive terminology for the invertebrates, vertebrates and plants of the London Clay. Here you'll find all of the yummy foraminifera, bryozoa, worms, trace fossils, corals, barnacles, lobsters, stomatopods, crabs, insects, brachiopods, bivalves, scaphopods, gastropods, nautili, coleoids, crinoids, echinoids and starfish. Also included are the sharks, rays, chimaera, bony fish, otoliths, turtles, snakes, crocodiles, birds, mammals and plant material.

If you fancy picking up a copy, here is the UKGE link: https://www.ukge.com/en-ie/London-Clay-Fossils-of-Kent-and-Essex__p-3291.aspx

Photo One: Martin Rayner: Snake, Bird and Mammal finds from the London Clay, mostly from Sheppey and Seasalter, UK

Photo Two: Martin Rayner: A rare skull from the remains of the sea snake Palaeophis toliapicus.  

EOSUCHUS OF SEASALTER

Most people consider the Early Eocene, Ypresian fossils of the Isle of Sheppey off the northern coast of  Kent, UK to be the best site for collecting London Clay fossils. Indeed, this area has been known for its outstanding fossils since the early part of the 18th Century. 

But for Martin Rayner and his father, the best finds hail from nearby Seasalter, a village in the Canterbury District on the northern coast of Kent. It was here, during the mid-1990s, that Martin found this spectacular Eosuchus sp. fossil crocodile along the foreshore.

Eosuchus or the Dawn Crocodile, is an extinct genus of eusuchian crocodylomorph, generally regarded as a gavialoid crocodilian. It might have been among the most basal of all gavialoids, lying crownward of all other known members of the superfamily, including earlier putative members such as Thoracosaurus and Eothoracosaurus. 

We find their fossil remains at Seasalter in the UK, in France and along the eastern seaboard of  North America in Maryland, Virginia, and New Jersey. Their remains date back to the late Paleocene and early Eocene.

Martin's Eosuchus sp. was found in-situ spread out over a small area of Seasalter's clay rich foreshore. His significant find was originally collected in hundreds of pieces, many of these fragmented and spread around before fossilization. Careful excavation, preparation and articulation over a two year period was necessary to piece them all together. 

It took another year or more to reconstruct the skull and much more time again to research the find with the help of those working at the Natural History Museum in London. 

A few of the pieces you see here were generously donated to Martin by fellow collectors who had plucked some of the bones from the collecting site then realized each held a small part of a large important specimen.

Once fully articulated, the near complete specimen measures around 1.2 meter in length. Had all the bones been recovered, the complete specimen would likely be closer to 2m in length.

We now get to enjoy this magnificent specimen in its entirety. It also shows what can be found in the foreshore material and will hopefully encourage those used to collecting on Seasalter's beaches to give this prolific area the attention is surely deserves.  

On the foreshore where the clay is exposed it is possible to find fossils in situ and washing out. The foreshore platforms are constantly eroding and at a faster rate than the nearby cliffs. It is a large area to search, but the large expanses of foreshore offer newly revealed specimens, often in stunning condition.

When you visit Seasalter, you may arrive after wind and tide have scoured away the silt and exposed the fossiliferous clay. You can find nice crab fossils and other marine goodies. 

There are far more London Clay sites without cliff exposures than ones with cliff exposures. As at Sheppey, Seasalter's foreshore exposures yield a large amount of fossil specimens in addition to the beach finds derived from the cliffs. Foreshore sites are scientifically significant as they provide a snapshot of a more specific time versus the fossils retrieved from cliff falls which can often span millions of years.

The photo above shows all of the bones laid out together. A frame has been created for them into which each individual vertebrae fit snug so that it can be displayed at potential shows and exhibitions.

Martin's Seasalter find helps us to understand both the anatomy of Eosuchus and place this basal gavialoid geographically. It is the occurrence of Eosuchus in the London Clay that pushes the gavialoid clade beyond the Paleocene and firmly and unambiguously into the early Eocene.

The strata from which both species of Eosuchus have been found were thought to have formed in a marginal marine depositional environment, and thus probably reflect the actual environments that these animals would have inhabited. It has been proposed that early gavialoids were originally salt-tolerant coastal forms, and the evidence seen in the case of Eosuchus is consistent with this theory. 

When we are lucky, the fossil evidence comes together to paint a picture of the environment and provide clues to our ancient world. One specimen of E. minor from the Aquia Formation, USNM 299730, has a fossil oyster attached to the dorsal surface of the rostrum.

The fact that the two species of Eosuchus lived on either side of the Atlantic Ocean implies that these populations may have been separated geographically from one another while not necessarily having to be separated stratigraphically (that is, if the temporal ranges of the two species coincide with one another). 

More importantly, the separate biogeographic ranges of the two species may be evidence for a transoceanic dispersal event from one continent to the other. Since the presumed ages of the localities from which specimens have been found are quite similar yet inexact, it is currently unknown just what continent this dispersal event may have originated. A recent reevaluation of the holotype material of E. lerichei, which in the past has been poorly studied, suggests that it is the more basal species and thus would have been the ancestor of E. minor in Europe.

We'll likely find more Eosuchus material which will provide additional insights. More specimens will likely be found at Seasalter. The London Clay fossils at Seasalter are found out on the foreshore at low tides in the bay between Seasalter and Whitstable Harbour to the east. 

If you're headed out and want to try your luck, walk the area from the bottom of the beach halfway or more toward the oyster nets. The fossil material you will find will be 50 million years old.

If you fancy a read and armchair inspiration, check out the wonderfully informative book on the London Clay Fossils of Kent and Essex by David Rayner, Tony Mitchell, Martin Rayner and Fred Clouter. These four genius minds have produced the definitive book on the area — greatly expanding our insight and understanding through their years of earned knowledge.  

References:

Dollo, L. (1907). "Les reptiles de l'Éocène Inférieur de la Belgique et des régions voisines". Bulletin de la Société Belge de Géologie, de Paléontologie et d'Hydrologie. 21: 81–85.

Norell, M. A.; Storrs, G. W. (1986). "Catalogue and review of the type fossil crocodilians in the Yale Peabody Museum". Postula. 203: 1–28.

Brochu, C. A. (2006). "Osteology and phylogenetic significance of Eosuchus minor (Marsh, 1870) new combination, a longirostrine crocodylian from the Late Paleocene of North America". Journal of Paleontology. 80 (1): 162–186. doi:10.1666/0022-3360(2006)080[0162:OAPSOE]2.0.CO;2.

Michael S. Y. Lee; Adam M. Yates (2018). "Tip-dating and homoplasy: reconciling the shallow molecular divergences of modern gharials with their long fossil record". Proceedings of the Royal Society B: Biological Sciences. 285 (1881): 20181071. doi:10.1098/rspb.2018.1071. PMC 6030529. PMID 30051855.

Taplin, L. E.; Grigg, G. C. (1989). "Historical zoogeography of the eusuchian crocodilians: A physiological perspective". American Zoologist. 29: 885–901. doi:10.1093/icb/29.3.885.

Delfino, M.; Pira, P.; Smith, T. (2005). "Anatomy and phylogeny of the gavialoid crocodylian Eosuchus lerichei from the Paleocene of Europe". Acta Palaeontologica Polonica. 50 (3): 565–580.

Broom, Robert (1925). "On the South African rhynchocephaloid reptile "Eosuchus" colletti, Watson". Records of the Albany Museum. 3: 300–306.

WETTERSTEIN LIMESTONE

Ammonoid and gastropod coquina, Wetterstein Limestone

A very busy white to light cream ammonoid and gastropod coquina of Upper Triassic (Carnian/Julian) Wetterstein limestone.

The lovely example of the Wetterstein limestone you see here is equivalent in age to the typically creamy orange limestones from nearby Hallstatt. The Wetterstein limestones are an adjacent  Ladinian to Lower Carnian reef facies that provide a window into the end of the Carnian Pluvial Event (CPE). 

The Carnian Pluvial Event is sometimes called the Carnian Pluvial Episode and is also known as Reingrabener Wende (meaning Reingrabener turnover), or Raibl Event — named after the Raibl area, Friuli-Venezia Giulia region of northeastern Italy.

By any name, the Carnian Pluvial Event (CPE) was a time of major change in our global climate and biotic turnover in the early Late Triassic, between 234 and 232 million years ago. For its significance, it is all but neglected in the body of our palaeontological studies that favour other global ecosystem turnovers during the Mesozoic. It had a huge impact on marine and terrestrial ecosystems. This interval saw a climatic shift from the arid climate of the Late Triassic to the markedly more humid conditions of the Carnian Pluvial Event (CPE), then back to arid again.

The base of the CPE is marked by a ≈4‰ negative shift in carbon stable isotopes (δ13C) of fossil molecules (n-alkanes) from higher plants and total organic carbon. 

A ≈1.5‰ negative shift in oxygen stable isotopes (δ18O) of conodont apatite suggests a global warming of 3 to 4 °C and a change in seawater salinity.

Major changes in organisms responsible for calcium carbonate production occurred during the CPE. In the world's oceans, we see mass biological turnover. Conodonts, ammonoids, bryozoa, and green algae were severely hit by the CPE and experienced high extinction rates. 

Most noticeable were the radiations of, among other groups, calcareous nanofossils, corals, and crinoids. 

This is especially interesting as ammonoids and conodonts, the two most important groups for the biostratigraphy of the Triassic, had a significant turnover.

Outside of Austria, many localities in Itlay place a primary role in our understanding of the CPE as paradigmatic examples of the geological and biotic processes that were occurring during this interesting moment in time — particularly concerning our future understanding of the evolution of shallow marine and terrestrial groups. 

The collective research to date has been focussed on more global and on the deepwater records of the CRP. Italy boasts the most expanded and complete shallow-water successions in the Raible area of northeastern Italy and the most prolific amber site with reef associations in the Dolomites near Veneto.

A halt of carbonate sedimentation is observed in nearby southern Italy in deepwater settings that were probably caused by the rise of the carbonate compensation depth (CCD). High extinction rates occurred among ammonoids, conodonts, bryozoa, and crinoids. 

Major evolutionary innovations followed the CPE, as the first occurrence of dinosaurs, lepidosaurs, an expansion of coniferous trees, calcareous nanofossils and scleractinian corals

After the CPE, reef growth starts again. We see this as the Dachsteinkalk — the Dachstein Formation or Dachstein Limestones — a Norian geologic formation in the Alps and other Tethyan mountain ranges in Austria

The beautiful block you see here was kindly prepared by mother nature. She did most of the prep but Andreas did the excavation, soaked it for a few days in water and carefully washed it clean to photograph. A very special thank you to him for continuing to inspire me with his wonderful eye and deep knowledge of our world.

Photo: Andreas / Size: 15 cm x 15 cm.

TURTLE SHELLS: HOME SWEET ARMOUR

Turtle shells are different from the body armour or armoured shells we see adorning dinosaurs like the ankylosaurs. 

Ankylosaurs were blessed with huge plates of bone embedded into their skin that acted as a natural shield against predators. Crocodilians have these same bony plates, or osteoderms, embedded in their skin to give them extra protection. 

We find similar body armour on armadillos. Yet, armadillos, crocodiles and ankylosaurs each evolved body armour that differs significantly from that found in turtles. 

Remarkably, the carapace we see in fully grown turtles is formed from different parts of their skeletons. And, once fully formed, turtle shell fully integrates with the backbone and ribs, growing over the animal in a domed carapace — both protection and home sweet home. 

When we look to the oldest known members of the turtle lineage, Proterochersis and Proganochelys, found as fossils in 210 million-year-old outcrops in present-day Germany and Poland. Like the turtles we find today, these stem-turtles already had fully formed shells — special bony or cartilaginous shell that originates in their ribs. It is a useful adaptation to help deter predators as their soft interior makes for a tasty snack. 

Though I have never eaten turtle (and never will), it was a common and sought after meat for turtle soup. Years ago, I read of Charles Darwin craving it after trying it for the first time on his trip in 1831 aboard the HMS Beagle. It seems Charlie like to taste every exotic new species he had the opportunity to try.

Turtle armour is made of dermal bone and endochondral bones from their vertebrae and rib cage. It is fundamentally different from the armour seen on our other vertebrate friends and the design creates some unique features in turtles. 

Because turtle ribs fuse together with some of their vertebrae, they have to pump air in and out of the lungs with their leg muscles. 

Another unusual feature in turtles is their limb girdles, pectoral and pelvic, which have come to lie within their rib cage, a feature that allows some turtles to pull their limbs inside the shell for protection. 

Sea turtles didn't develop this behaviour or ability and do not retract into their shells like other turtles.

Armadillos have armour formed by plates of dermal bone covered in relatively small, overlapping epidermal scales called scutes, composed of bone with a covering of horn. In crocodiles, their exoskeletons form their armour, similar to ankylosaurs. A bit of genius design, really. It is made of protective dermal and epidermal components that begin as rete Malpighii: a single layer of short, cylindrical cells that lose their nuclei over time as they transform into a horny layer.

Depending on the species and age of the turtle, turtles eat all kinds of food including seagrass, seaweed, crabs, jellyfish, and shrimp,. That tasty diet shows up in the composition of their armour as they have oodles of great nutrients to work with. The lovely example you see here is from the Oxford Museum collections.

JOSE BONAPARTE: MASTER OF THE MESOZOIC

One of the most delightful palaeontologists to grace our Earth was José Fernando Bonaparte (14 June 1928 – 18 February 2020). 

We often think of those who have shaped our past and found many of the firsts of their region as living in ancient history, but José left us just this past year in February. 

He was a prolific and hard-working Argentinian palaeontologist who you'll know as the discoverer of some of Argentina's iconic dinosaurs — Carnotaurus, along with Amargasaurus, Abelisaurus, Argentinosaurus and Noasaurus. 

His first love was mammals and over the course of his career, he unearthed the remains of some of the first South American fossil mammals from the Mesozoic. 

Between 1975 and 1977, Bonaparte worked on excavation of the Saltasaurus dinosaur with Martín Vince and Juan C. Leal at the Estancia "El Brete."  Bonaparte was interested in the anatomy of Saltasaurus, particularly the armoured plates or osteoderms embedded in its skin. 

Based on this discovery, together with twenty examples of Kritosaurus australis and a lambeosaurine dinosaur found in South America, Bonaparte hypothesized that there had been a large-scale migration of species between the Americas at the end of the Mesozoic period.

The supercontinent of Pangea split into Laurasia in the north and Gondwana in the south during the Jurassic. During the Cretaceous, South America pulled away from the rest of Gondwana. The division caused a divergence between the northern biota and the southern biota, and the southern animals appear strange to those used to the more northerly fauna. 

Bonaparte's finds illustrate this divergence. His work is honoured in his moniker given to him by palaeontologist Robert Bakker — "Master of the Mesozoic."

If you fancy a listen, he is the honoured guest in absentia on an episode of the Fossil Huntress Podcast. You can find the link here to listen: https://anchor.fm/.../Jos-Bonaparte-Master-of-the...

KERMODE SPIRIT BEAR: GREAT BEAR RAINFOREST

Spirit Bears or Kermode bears, Ursus americanus kermodei, are a subspecies of the North American black bear. They get their colouring from a rare recessive gene that makes their fur a lovely cream to white. They are not pure white nor are they albinos — they have pigment in their skin and eyes.

These beauties hail from my part of the world — the Central and North Coast regions of British Columbia, Canada. 

They walk through the moist, moss-covered terrane of the Great Bear Rainforest, a 6.4 million hectare stretch of ecosystem on the very far west coast of Canada, feasting on Pacific salmon, berries, nuts, roots and seeds. They'll eat insects, fawns and carrion in a pinch but salmon is by far their favourite snack. 

Spirit Bears are the official provincial mammal of British Columbia and symbol of Terrace, British Columbia. And they are rare. Their population numbers around 400 individuals. About one in ten black bears are pale and the spirit bear gene is recessive, meaning both parents must carry the gene for a white cub to be produced.

The main dangers to Spirit Bears are much larger grizzlies who stake out and chase them off the prime areas of salmon stocks. Humans are the next largest threat. We cut down the cedar trees that they use for hibernation and birthing of their cubs. And, charmingly, the government of British Columbia allows the hunting of grizzly and black bears in the Great Bear Rainforest. Yes, really. So while it is illegal to kill a spirit bear, hunters may shoot a black bear that carries the crucial gene.

Interested in learning more — and how you can help to protect British Columbia's wildlife? Read about the stewardship of the Great Bear Rainforest by the Kitasoo/Xai’ais First Nation and folk like Christina Service, a wildlife biologist working with them. Get involved. Use your voice for those who have lost theirs.

Link: Science and Indigenous history team up to help spirit bears | Science News for Students
 

KEPPLERITES FROM THE KURSK REGION

This glorious chocolate block contains the creamy grey ammonite Kepplerites gowerianus (Sowerby 1827) with a few invertebrate friends, including two brachiopods: Ivanoviella sp., Zeilleria sp. and the deep brown gastropod Bathrotomaria sp. There is also a wee bit of petrified wood on the backside.

These beauties hail from Jurassic, Lower Callovian outcrops in the Quarry of Kursk Magnetic Anomaly (51.25361,37.66944), Kursk region, Russia. Diameter ammonite 70мм. 

Back in the USSR — in the mid-1980s — during the expansion and development of one of the quarries, an unusual geological formation was found. This area had been part of the seafloor around an ancient island surrounded by Jurassic Seas. 

The outcrops of this geological formation turned out to be very rich in marine fossils. This ammonite block was found there years ago by the deeply awesome Emil Black. Sadly, he has not been able to collect there for some time. In more recent years, the site has been closed to fossil collecting and is in use solely for the processing and extraction of iron ore deposits.

PTERASPIDID WITH TAIL

This lovely specimen, showing the articulated tail section of the fish is an armoured agnatha jawless bony fish, Victoraspis longicornualis, from Lower Devonian deposits of Podolia, Ukraine. Fully articulated specimens are rare. This is the first one to be unearthed in more than five years by those who dig them regularly.

Podolia is a historic region in Eastern Europe in the west-central and south-western parts of the Ukraine. This area has had human inhabitants since at least the beginning of the Neolithic period. 

Herodotus mentions it as the seat of the Graeco-Scythian Alazones and possibly Scythian Neuri. Subsequently, the Dacians and the Getae arrived. The Romans left traces of their rule in Trajan's Wall, which stretches through the modern districts of Kamianets-Podilskyi, Nova Ushytsia and Khmelnytskyi.

During the Great Migration Period, many nationalities passed through this territory or settled within it for some time, leaving numerous traces in archaeological remains. Nestor in the Primary Chronicle mentions four apparently Slavic tribes: the Buzhans and Dulebes along the Southern Bug River, and the Tivertsi and Ulichs along the Dniester. The Avars invaded in the 7th century. The Bolokhoveni occupied the same territory in Early Medieval times but they were mentioned in chronicles only until the 14th century.

And, as you can see here, it boasts some wonderful Devonian deposits. Victoraspis longicornualis was named by Anders Carlsson and Henning Bloom back in 2008. The new osteostracan genus and species were described based on material from Rakovets' present-day Ukraine. This new taxon shares characteristics with the two genera Stensiopelta (Denison, 1951) and Zychaspis (Javier, 1985).

Agnatha is a superclass of vertebrates. This fellow looks quite different from our modern Agnatha, which includes lamprey and hagfish. Ironically, hagfish are vertebrates that do not have vertebrae. Sometime in their evolution, they lost them as they adapted to their environment. 

Photo & collection of the awesome Fossilero Fisherman

INNER EAR HESPERORNIS

If palaeontologists had a wish list, it would likely include insights into two particular phenomena: how dinosaurs interacted with each other and how they began to fly. 

By all accounts, it is a very long bucket list of wants, but these two would certainly make mine.

The problem is, using fossils to deduce such behaviour is a tricky business. But a new, Yale-led study offers a promising entry point — the inner ear of an ancient reptile. The shape of the inner ear offers reliable signs as to whether an animal soared gracefully through the air, flew only fitfully, walked on the ground, or sometimes went swimming. In some cases, the inner ear even indicates whether a species did its parenting by listening to the high-pitched cries of its babies.

The inner ear of Hesperornis, an 85-million-year-old aquatic bird first discovered by the Peabody’s O.C. Marsh, is helping us to better understand how these ancient species moved, parented, and communicated. 

The Peabody is a marvellous museum — home to the world’s only Hesperornis fossil that preserves the tiny structure in all three dimensions. It was used in a just-published study, led by Yale University Ph.D. student Michael Hanson and curator Bhart-Anjan Bhullar.

Photo: Hesperornis, Yale Peabody Museum of Natural History.  Photographer: Robert Lorenz

Care to read all about it? Here's the link:

https://news.yale.edu/2021/05/06/what-can-dinosaurs-inner-ear-tell-us-just-listen?fbclid=IwAR0ZqbxsMkBoLRhxGCiKWoj5s3F7BfXE-Sahk9R15LC0i_7bOjRvZOqBLZE

NORWAY: HAPPY NATIONAL DAY

The 17th of May is National Day in Norway. It is a time of celebrations, flags, parades, dressing up and eating ice cream. 

Back in 1814, the day originally honoured the independence of Norway and her new constitution but now honours the Royal Family and is a celebration for families and children.

Children have enjoyed a special role in the celebrations for many years. Initially, the children's parade was all boys. Now, boys and girls participate and the greater part of the event is dedicated to them. The children’s parades include a whole lot of marching, waving homemade red, navy and white Norwegian flags and proudly carrying school banners.

Parades vary in size from a few dozen people in the villages to several tens of thousands of participants in Oslo. Children in Oslo pass the Royal Palace, where royal family members wave back from the balcony. 

The Royal Family and ordinary folk dress in Bunads, traditional costumes of red, white, black, blue and green. Sometimes, other costumes are worn. The Norwegians love to dress up!

Each year, around 40,000 graduating high school students called “Russ” can be recognized with their Russ hats and uniforms. The traditional Russ celebration starts in spring and ends on the 17th of May. The day is marked by Russ parties, Russ buses, Russ newspapers and Russ Cards.

The colour of the uniform matches the graduate’s line of study: Red for students geared towards higher education — the most common colour — blue for those going into business, economics or management, white for medical and social studies, black for engineering and green for agricultural fields.

Amongst Norwegians, the day is referred to simply as syttende mai, Nasjonaldagen or Grunnlovsdagen, although the latter is used less frequently. To help get you into the spirit of Norge, I am sharing the cold, stark and beautiful fishing village of Hamnoy in the Lofoten Islands, Norway. So, feel free to enjoy it while eating some hotdogs, ice cream and a tasty beverage today. Skal!

TUSK SHELL: OYSTER BAY FORMATION

The lovely large creamy tusk shell, Dentalium sp., you see here is in the collections of John Fam, Vice-Chair, Vancouver Paleontological Society.  

This particular scaphopod, or Tusk Shell, is one of many species of molluscs helping to untangle the complex geology of Vancouver Island. He hails from Early Paleocene - Early Eocene, Oyster Bay Formation, Appian Way Beds, near Cambell River, Vancouver Island, British Columbia, Canada. 

This area was mapped by the Geological Survey of Canada and initially included as part of the Cretaceous Nanaimo group. 

It was extensive collecting by members of the Vancouver Island Palaeontological Society that led to a revision of the geology of this area. Many of the fossils found in more recent years are a match for those found in the early Cenozoic of western North America, including the beautiful marine community captured in the block you see here.

Tusk shells are members of a class of shelled marine mollusc with a global distribution. Shells of species within this class range from about 0.5 to 15 cm in length. This fellow is 8 cm end to end, so near smack dab in the centre of his cohort.

The Scaphopoda get their nickname "tusk shells" because their shells are conical and slightly curved to the dorsal side, making the shells look like tiny tusks (picture a walrus or mammoth tusk in your mind’s eye). The scientific name Scaphopoda means "shovel foot," a term that refers to the "head" of the animal, which lacks eyes and is used for burrowing in marine sediments.

The most distinctive feature of scaphopods, however, and one that differentiates them from most molluscs, is the duo openings on their tubular shells. Most molluscs are open at just one end.

We could call scaphopods the great deniers. They live their adult lives with their heads literally buried in the sand. A tiny bit of their posterior end sticks up into the seawater for water exchange. Water is circulated around the mantle cavity by the action of numerous cilia.

When the available dissolved oxygen runs low for this fellow he ejects water from the top end of his shell by contraction of his "foot."

AMMONITES FROM THE GAULT

The chunky ammonite Proeuhoplites subtuberculatus, bed II (iv), Folkstone Gault Clay, county of Kent, southeast England.

This matrix you see here is the Gault Clay, known locally as the Blue Slipper. This fine muddy clay was deposited 105-110 million years ago during the Lower Cretaceous (Upper and Middle Albian) in a calm, fairly deep-water continental shelf that covered what is now southern England and northern France.

Lack of brackish or freshwater fossils indicates that the gault was laid down in open marine environments away from estuaries. The maximum depth of the Gault is estimated 40-60m a figure which has been reached by the presence of Borings made by specialist Algal-grazing gastropods and supported by a study made by Khan in 1950 using Foraminifera. Estimates of the surface water temperatures in the Gault are between 20-22°c and 17-19°c on the seafloor. These estimates have been reached by bulk analysis of sediments which probably register the sea surface temperature for calcareous nanofossils.

It is responsible for many of the major landslides around Ventnor and Blackgang the Gault is famous for its diverse fossils, mainly from mainland sites such as Folkestone in Kent.

Folkestone, Kent is the type locality for the Gault clay yielding an abundance of ammonites, the same cannot be said for the Isle of Wight Gault, however, the south-east coast of the island has proved to be fossiliferous in a variety of ammonites, in particular, the Genus Hoplites, Paranahoplites and Beudanticeras.

While the Gault is less fossiliferous here on the island it can still produce lovely marine fossils, mainly ammonites and fish remains from these muddy mid-Cretaceous seas. The Gault clay marine fossils include the ammonites (such as Hoplites, Hamites, Euhoplites, Anahoplites, and Dimorphoplites), belemnites (such as Neohibolites), bivalves (notably Birostrina and Pectinucula), gastropods (including the lovely Anchura), solitary corals, fish remains (including shark teeth), scattered crinoid remains, and crustaceans (look for the crab Notopocorystes).

Occasional fragments of fossil wood may also be found. The lovely ammonite you see here is from the Gault Clays of Folkstone. Not all who name her would split the genus Euhoplites. There’s a reasonable argument for viewing this beauty as a very thick form of E. loricatus with Proeuhoplites being a synonym of Euhoplites. Collected, photographed and prepped by Thomas Miller. Approx 35mm across.

Jack Wonfor shared a wealth of information on the Gault and has many lovely examples of the ammonites found here in his collections. If you wish to know more about the Gault clay a publication by the Palaeontological Association called 'Fossils of the Gault clay' by Andrew S. Gale is available in Dinosaur Isle's gift shop.

There is a very good website maintained by Fred Clouter you can look at for reference. It also contains many handy links to some of the best fossil books on the Gault Clay and Folkstone Fossil Beds. Check it out here: http://www.gaultammonite.co.uk/

ANCIENT ARMADILLOS

Glyptodonts are the early ancestors of our modern armadillos that roamed North and South America during the Pleistocene. 

Armadillos, both living and extinct, range in size from the size of an armoured car to the size of a small, family dog. As they evolved over time, the smaller they have become. 

Glyptodonts became extinct at the end of the last ice age. They, along with a large number of other megafaunal species, including pampatheres, the giant ground sloths, and the Macrauchenia, left this Earth but their bones tell a story of brief and awesome supremacy.

Today, Glyptodonts live on through their much smaller, more lightly armoured and flexible armadillo relatives. They defended themselves against Sabre Tooth Cats and other predators but could not withstand the arrival of early humans in the Americas. Archaeological evidence suggests that these humans made use of the animal's armoured shells and enjoyed the meat therein. Glyptodonts possessed a tortoise-like body armour, made of bony deposits in their skin called osteoderms or scutes. Beneath that hard outer coating was a food source that our ancestors sought for their survival.

Each species of glyptodont had a unique osteoderm pattern and shell type. With this protection, they were armoured like turtles; glyptodonts could not withdraw their heads, but their armoured skin formed a bony cap on the top of their skull. Glyptodont tails had a ring of bones for protection. Doedicurus possessed a large mace-like spiked tail that it would have used to defend itself against predators and, possibly, other Doedicurus. Glyptodonts had the advantage of large size.

Many, such as the type genus, Glyptodon, were the size of modern automobiles. The presence of such heavy defences suggests they were the prey of a large, effective predator. At the time that glyptodonts evolved, the apex predators in the island continent of South America were phorusrhacids, a family of giant flightless carnivorous birds.

The ancient Armadillo Glyptodon asper

In physical appearance, glyptodonts superficially resembled the much earlier dinosaurian ankylosaurs and, to a lesser degree, the recently extinct giant meiolaniid turtles of Australia.

These are examples of the convergent evolution of unrelated lineages into similar forms. The largest glyptodonts could weigh up to 2,000 kilograms. Like most of the megafauna in the Americas, they all became extinct at the end of the last ice age 10,000 years ago. The deeper you get in time, the larger they were. Twenty thousand years ago, they could have ambled up beside you in what would become Argentina and outweighed a small car.

A few years back, some farmers found some interesting remains in a dried-out riverbed near Buenos Aires. The find generated a ton of palaeontological excitement. Fieldwork revealed this site to contain two adults and two younger specimens of an ancient armadillo. These car-size beasties would have been living and defending themselves against predators like Sabre Tooth Cats and other large predators of the time by employing their spiked club-like tails and thick bony armour.

Glyptodonts were unlikely warriors. They were grazing herbivores. Like many other xenarthrans, they had no incisor or canine teeth but had a number of cheek teeth that would have been able to grind up tough vegetation, such as grasses. They also had distinctively deep jaws, with large downward bony projections that would have anchored their powerful chewing muscle.

Image Two: By Arentderivative work: WolfmanSF (talk) -  http://de.wikipedia.org/wiki/Bild:Glyptodon-1.jpg, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=665483

GIANT TORTOISES & THE ISLAND RULE

Giant tortoises and other organisms that live and evolve on islands undergo a different set of selective pressures than those who live on our continental land masses. We call this the 'island rule'. Species develop unusual traits, becoming larger or smaller than their continental brethren.

Food is often restrictive or unvaried and predators are often reduced or all together absent. We see the evolutionary impact in the Giant tortoises of the Aldabra Atoll and Fregate Island in the Seychelles and Galápagos Islands in Ecuador.

They belong to an ancient group of reptiles, appearing about 250 million years ago and evolving to their large size by the Late Cretaceous, 70 or 80 million years ago. And they are big, weighing as much as 417 kg (919 lb) and can grow to be 1.3 m (4 ft 3 in) long. The Galapagos giant tortoise is a wee bit smaller, weighing 215 kg (475 lb) with the males generally outweighing the females. They snack on plants and some have a slight curve to the shell behind their heads to allow them to reach up a wee bit higher to reach more food. The females lay their eggs in a pit dug specifically for this purpose. Once the hatchlings have incubated, they dig themselves out. I'm sure you've seen the adorable photos or videos of them hatching then making their way to the sea. 

BALEARITES OF MOROCCO

Collection of José Juárez Ruiz. The specimen is 202 mm.

This beautifully prepped specimen of a Balearites cf. balearis (Nolan, 1984) ammonite is from Upper Hauterivian deposits near Tamri, a small seaside town and rural commune in Agadir-Ida Ou Tanane Prefecture, Souss-Massa, Morocco. Aside from wonderful fossil localities, this area of Morocco has some of the most amazing surfing and banana plantations.

Balearites, with their planispiral shell (conch) and compressed whorls, is an extinct ancyloceratin genus ammonite in the family Crioceratitidae, suborder Ancyloceratina.

We find fossils of this genera in Romania, Slovakia, Austria, France, Spain, Switzerland, Hungary, Italy, Russia, Bulgaria and Morocco. This specimen is in the collection of José Juárez Ruiz and is roughly 202 mm. If you find this lovely interesting, you'll enjoy reading more on this genus and others in Arkell, W. J. et al., 1957. Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology Part L, Mollusca 4. 1957.

GREEK MYTHOLOGY AND ANCIENT BONES

Tetralophodon

During the Miocene and Pliocene, 12-1.6 million years ago, a diverse group of extinct proboscideans, elephant-like animals walked the Earth.

Most of these large beasts had four tusks and likely a trunk similar to modern elephants. They were creatures of legend, inspiring myths and stories of fanciful creatures to the first humans to encounter them.

Beyond our Neanderthal friends, one such fellow was Quintus Sertorius, a Roman statesman come general, who grew up in Umbria. Born into a world at war just two years before the Romans sacked Corinth to bring Greece under Roman rule, Quintus lived much of his life as a military man far from his native Norcia. Around 81 BC, he travelled to Morocco, the land of opium, massive trilobites and the birthplace of Antaeus, the legendary North African ogre who was killed by the Greek hero Heracles.

The locals tell a tale that Quintus requested proof of Antaeus, hard evidence he could bring back to Rome to support their tales so they took him to a mound near Tingis, the ancient name for Tangier, Morocco. It was here they unearthed the bones of an extinct elephantoid, Tetralophodon.

Tetralophodon bones are large and skeletons singularly impressive. Impressive enough to be taken for something else entirely. By all accounts, these proboscidean remains were that of the mythical giant, Antaeus, son of the gods Poseidon and Gaea and were thus reported back to Rome as such. Antaeus went on to marry the goddess Tinge and it is from her, in part, that Tangier in northwestern Morocco gets its name. Together, Antaeus and Tinge had a son, Sophax. He is credited with having the North Africa city take her name. Rome was satisfied with the find. It would be hundreds of years later before the bones true ancestry was known and in that time, many more wonderful ancient proboscideans remains were unearthed..

There were other early proboscideans, of course. The earliest known proboscidean is Eritherium, followed by Phosphatherium, a small animal about the size of a fox. Both date from late Paleocene deposits of Morocco.

Proboscideans evolved in Africa, where they increased in size and diversity during the Eocene and early Oligocene. Several primitive families from these epochs have been described, including the Numidotheriidae, Moeritheriidae, and Barytheriidae, all found exclusively in Africa. 

The Anthracobunidae from the Indian subcontinent were also believed to be a family of proboscideans, but were excluded from the Proboscidea by Shoshani and Tassy (2005) and have more recently been assigned to the Perissodactyla.

When Africa became connected to Europe and Asia after the shrinking of the Tethys Sea, proboscideans migrated into Eurasia, with some families eventually reaching the Americas. Proboscideans found in Eurasia as well as Africa include the Deinotheriidae, which thrived during the Miocene and into the early Quaternary, Stegolophodon, an early genus of the disputed family Stegodontidae; the highly diverse Gomphotheriidae and Amebelodontidae; and the much loved Mammutidae, or mastodons.

I traveled and hiked through much of Morocco to explore the countryside, ancient Roman ruins and many splendid outcrops when I was eighteen. I wish I had known more of the fossil sites before that trip but many had yet to be discovered. I will share more of those stories — and there are plenty — in future posts.

Photo: Henan Geological Museum, Zhengzhou, China. Complete indexed photo collection at WorldHistoryPics.com.

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. 

LEANCHOILIA: CHENGJIANG

This lovely specimen, with the remarkable strippy black and purple body, is the arthropod Leanchoilia illecebrosa from the Early Cambrian (~525 million years) Chengjiang Lagerstätte, Quiongzhusi Section, Yu’anshan Member, Heilinpu Formation, Jiansghan, Anning, Kunming, Yunnan Province, southwestern China.  

Leanchoilia is a megacheiran arthropod who we first met from Cambrian deposits in the Burgess Shales of Canada where they make up about 0.1% of the fauna of the Greater Phyllopod beds. These distinctive predatory arthropods are about 5 centimetres (2.0 in) in length with whip-like feelers mounted on frontal arm-like appendages. You can see the amazing level of detail in the preservation here. If we are very lucky, we sometimes from their internal organs preserved in three dimensions which adds a whole host of data to explore.

Several species are tentatively accepted today: the type species L. superlata, L. obesa and the recently revalidated and poetically named, L. persephone. Naming is a tricky business when we are dealing with fossilized specimens as ontogeny and sexual dimorphism can confuse the issue. It is not always clear if we are seeing a new species, a juvenile or noting differences between mature males and females. 

Specimen: 5.2 cm. Photo and collection of York Yuxi Wang.

References:

"Burgess Shale: Leanchoilia superlata (an arthropod)". Smithsonian Institution National Museum of Natural History. Retrieved 6 July 2017.

Nicholas J. Butterfield (2002). "Leanchoilia guts and the interpretation of three-dimensional structures in Burgess Shale-type fossils". Paleobiology. 28 (1): 155–171. doi:10.1666/0094-8373(2002)028<0155:LGATIO>2.0.CO;2.

Brigitte Schoenemann & Euan N. K. Clarkson (2012). "The eyes of Leanchoilia". Lethaia. 45 (4): 524–531. doi:10.1111/j.1502-3931.2012.00313.x.

Diego C. García-Bellido & Desmond Collins (2007). "Reassessment of the genus Leanchoilia (Arthropoda, Arachnomorpha) from the Middle Cambrian Burgess Shale, British Columbia, Canada". Palaeontology. 50 (3): 693–709. doi:10.1111/j.1475-4983.2007.00649.x.

Caron, Jean-Bernard; Jackson, Donald A. (October 2006). "Taphonomy of the Greater Phyllopod Bed community, Burgess Shale". PALAIOS. 21 (5): 451–65. doi:10.2110/palo.2003.P05-070R. JSTOR 20173022.

THE LURE OF THE 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.

VERTEBRATES AND INVERTEBRATES

You and I are vertebrates, we have backbones. Having a backbone or spinal column is what sets apart you, me and almost 70,000 species on this big blue planet.

So, which lucky ducks evolved one? Well, ducks for one. Warm-blooded birds and mammals cheerfully claim those bragging rights. They're joined by our cold-blooded, ectothermic friends, the fish, amphibians and reptiles. All these diverse lovelies share this characteristic.

And whether they now live at sea or on land, all of these lineages evolved from a marine organism somewhere down the line, then went on to develop a notochord and spinal column. Notochords are flexible rods that run down the length of chordates and vertebrates. They are handy adaptations for muscle attachment, helping with signalling and coordinating the development of the embryonic stage. The cells from the notochord play a key role in the development of the central nervous system and the formation of motor neurons and sensory cells. Alas, we often take our evolution for granted.

Let's take a moment to appreciate just how marvellous this evolutionary gift is and what it allows us to do. Your backbone gives your body structure, holds up that heavy skull of yours and connects your tasty brain to your body and organs. Eating, walking, fishing, hunting, your morning yoga class, are all made possible because of this adaptation. Pick pretty near anything you love to do and it is only possible because of your blessed spine.

And it sets us apart from our invertebrate friends.

While seventy thousand may seem like a large number, it represents less than three to five per cent of all described animal species. The rest is made up of the whopping 97%'ers, our dear invertebrates who include the arthropods (insects, arachnids, crustaceans, and myriapods), molluscs (our dear chitons, snails, bivalves, squid, and octopus), annelids (the often misunderstood earthworms and leeches), and cnidarians (our beautiful hydras, jellyfish, sea anemones, and corals). 

You will have noticed that many of our invertebrate friends occur as tasty snacks. Having a backbone provides a supreme advantage to your placement in the food chain. Not always, as you may include fish and game on your menu. But generally, having a backbone means you're more likely to be holding the menu versus being listed as an appetizer. So, enjoy your Sunday 'downward dog' and thank your backbone for the magical gift it is.

FRACTAL BUILDING: AMMONITES

Argonauticeras besairei, Collection of  José Juárez Ruiz.

An exceptional example of fractal building of an ammonite septum, in this clytoceratid Argonauticeras besairei from the awesome 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. But the Ammonites 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) than they are to shelled nautiloids such as the living Nautilus species.

The Ammonoidea can be divided into six orders:

• Agoniatitida, Lower Devonian - Middle Devonian
• Clymeniida, Upper Devonian
• Goniatitida, Middle Devonian - Upper Permian
• Prolecanitida, Upper Devonian - Upper Triassic
• Ceratitida, Upper Permian - Upper Triassic
• Ammonitida, Lower Jurassic - Upper Cretaceous

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.

If they are ceratitic with lobes that have subdivided tips; giving them a saw-toothed appearance and rounded undivided saddles, they are likely Triassic. For some lovely Triassic ammonites, take a look at the specimens that come out of Hallstatt, Austria and from the outcrops in the Humboldt Mountains of Nevada.

Hoplites bennettiana (Sowby, 1826).

If they have lobes and saddles that are fluted, with rounded subdivisions instead of saw-toothed, they are likely Jurassic or Cretaceous. If you'd like to see a particularly beautiful Lower Jurassic ammonite, take a peek at Apodoceras. Wonderful ridging in that species.

One of my favourite Cretaceous ammonites is the ammonite, Hoplites bennettiana (Sowby, 1826). This beauty is from Albian deposits near Carrière de Courcelles, Villemoyenne, near la région de Troyes (Aube) Champagne in northeastern France.

At the time that this fellow was swimming in our oceans, ankylosaurs were strolling about Mongolia and stomping through the foliage in Utah, Kansas and Texas. Bony fish were swimming over what would become the strata making up Canada, the Czech Republic and Australia. Cartilaginous fish were prowling the western interior seaway of North America and a strange extinct herbivorous mammal, Eobaatar, was snuffling through Mongolia, Spain and England.

In some classifications, these are left as suborders, included in only three orders: Goniatitida, Ceratitida, and Ammonitida. Once you get to know them, ammonites in their various shapes and suturing patterns make it much easier to date an ammonite and the rock formation where is was found at a glance.

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.

References: Inoue, S., Kondo, S. Suture pattern formation in ammonites and the unknown rear mantle structure. Sci Rep 6, 33689 (2016). https://doi.org/10.1038/srep33689
https://www.nature.com/articles/srep33689?fbclid=IwAR1BhBrDqhv8LDjqF60EXdfLR7wPE4zDivwGORTUEgCd2GghD5W7KOfg6Co#citeas

Photo: Hoplites Bennettiana from near Troyes, France. Collection de Christophe Marot