Friday, 2 April 2021

LOWER PLIENSBACHIAN: ANDROGYNOCERAS

This gorgeous Lower Pliensbachian macroconch of the ammonite Androgynoceras lataecosta was found as a nodule from the Green Ammonite beds, Lower Pliensbachian, Stonebarrow Marl Member, Charmouth Mudstone Formation (190 MYA) at Charmouth Beach, Dorset Coast in the summer of 2020. 

This specimen was found, prepped and photographed by the lovely and talented folk at Stonebarrow Fossils. 

And what a delightful surprise! The large macroconch specimen here is 12 cm but is cuddled in with her is a lovely grouping of  the diminutive male microconchs of Androgynoceras (Hyatt, 1867) if you are lucky — sometimes a Tragophylloceras loscombi (Sowerby, 1814) — or nothing at all if you are not. 

We see a great variation in this species and the ammonite species that make up this population. Murray Edmunds from Chipping Norton, UK shared some of his insights on why we see such variation and how a phylogenetic species concept may be masking a continuum that tells a very different story.  

We are starting to recognise that these could all be variants of one interbreeding population — with a highly variable duration of a juvenile Capricorn stage. Palaeontologists use a phylogenetic species concept as you cannot test reproductive isolation in any but the most recent of fossils.

By definition, individuals within an interbreeding population cannot belong to different species, let alone different genera. In palaeontology, we can only interpret what we see with reference to what we understand of biology. 

In the Davoei Zone Liparoceratidae, we have a single lineage that evolves into Oistoceras. The microconchs (putative males) are small Capricorns, and the macroconchs (putative females) are very variable: they have a Capricorn juvenile stage that can be expressed for only a few mm (or not at all), or for many cm. But eventually, the adult macroconch body chamber acquires liparoceratid ornament — inflated and bipinnate with numerous secondary ribs. 

Unfortunately, the green ammonite beds at Charmouth preserve only juvenile macroconchs so we do not get to appreciate the similarity and differences of the mature adult shell form. These beauties can look very different from one another but are all the same species. 

Historically, this difference in appearance led to all the individuals — both micro and macroconchs — with prolonged Capricorn morphology being assigned to Androgynoceras and those macroconchs lacking the juvenile Capricorn stage (as is typical in their Ibex zone ancestors) to be Liparoceras

Different species were named for different variants. But this is a purely morphological approach to nomenclature and does not reflect the taxonomy used for extant organisms where we try to reflect phylogeny.

But as more and more examples are collected, we start to see that these specimens form a continuum. And as we follow them up through time, we see that all of them (microconchs and macroconchs, regardless of the extent of the Capricorn stage — although that tends to become more prolonged through time — simultaneously evolve progressively forwardly projected ribs across the venter, culminating in Oistoceras

This simultaneous evolutionary change across the entire Liparoceratid population more or less proves that we have a single interbreeding clade. And that it is separate from Becheiceras – through that’s another story! And they all go extinct simultaneously too, whereas Becheiceras carries on into the Margaritatus Zone. If you're a grad student looking to do your thesis, there is a very interesting story you could tell.

If you fancy a web stroll through some beautifully prepped specimens from Jurassic Coast, UK, or if you'd like to get some prepped, you can check out Stonebarrow Fossils here: https://www.stonebarrowfossils.co.uk/  / Photos: Stonebarrow Fossils

If you like podcasts, check out the Fossil Huntress — Palaeo Sommelier Podcast at https://anchor.fm/fossil-huntress / Spotify / Google Play / Apple Podcasts

Wednesday, 31 March 2021

LOVE THE WILD: MUSHROOMS OF IMMORTALITY

This glorious bit of business you see here with its showy orange and yellow colouring is a Reishi mushroom. This glorious adaptogen is known as the mushroom of immortality.

Mushrooms come in a variety of shapes, colours, sizes and edibility. Some help, some kill and many add their umami flavour to our food. 

We know mushrooms make for a delectable addition to any meal, but why are mushrooms so good for you? Mushrooms contain vital nutrients along with dietary fibre, protein and complex carbs. Eating them gives us the benefit of the goodness they contain including vitamins D and B, selenium and potassium, minerals, antioxidants, and other important micro-nutrients. 

Niacin and Copper found in mushrooms promote the function of the nervous system and keep our nerves healthy. Poetic, really, as fungi are the nervous systems of the forest. 

Mushrooms are rich in antioxidants, which helps reduce inflammation often found to be a prime suspect in neurodegeneration. Also, they’re one of the only non-animal sources of vitamin D, a component necessary for brain and neuron health.

Lion’s Mane is one variety of mushroom known to protect cognitive health. It stimulates nerve growth factor, a protein that promotes healthy brain cells. Lion’s Mane is a cognitive enhancer, and it helps creativity, motivation, and memory, as well as brain function.

Cordyceps mushrooms are reported to protect against Alzheimer’s as they prevent neuronal cell death and memory loss through its antioxidant and anti-inflammatory effects. Cordyceps are known for improving memory and promoting healthy aging.


Tuesday, 30 March 2021

YELLOW-BILLED KITE

This lovely boy is a Yellow-Billed Kite. The yellow-billed kite is the Afrotropic counterpart of the black kite, of which it is most often considered a subspecies. 

Their DNA studies suggest that the yellow-billed kite differs significantly from black kites in the Eurasian clade, and should be considered as a separate, allopatric species.

The yellow-billed kite is easily recognized by its entirely yellow bill, unlike that of the black kite (which is present in Africa as a visitor during the North Hemisphere winter). However, immature yellow-billed kites resemble the black kites of the corresponding age.

Monday, 29 March 2021

PLESIOSAUR: PREDATORS OF DEEP TIME

Plesiosaurus were a large, carnivorous air-breathing marine reptile with strong jaws and sharp teeth that moved through the water with four flippers. 

We had originally thought that this might not be the most aerodynamic design but it was clearly effective as they used the extra set to create a wee vortex that aided in their propulsion. 

In terms of mechanical design, they have a little something in common with an unlikely favourite of mine — dragonflies.

We have recreated plesiosaur movements and discovered that they were able to optimize propulsion to make use of their own wake. As their front flippers paddled in big circular movements, the propelled water created little whirlpools under their bellies. The back flippers would then paddle between these whirlpools pushing the plesiosaur forward to maximal effect. This use of air currents is similar to how dragonflies move through the air. 

They were very successful hunters, outcompeting ichthyosaurs who thrived in the Triassic but were replaced in the Jurassic and Cretaceous by these new aquatic beasties. 

Our ancient seas teemed with these predatory marine reptiles with their long necks and barrel-shaped bodies. Plesiosaurs were smaller than their pliosaur cousins, weighing in at about 450 kg or 1,000 lbs and reaching about 4.5 metres or 15 feet in length. For a modern comparison, they were roughly twice as long as a standard horse or about as long as a good size hippo.

Plesiosaurs first appeared in the latest Triassic, during the Rhaetian. They thrived in the Jurassic and vanished at the end of the Cretaceous in time with the K-Pg extinction event along with a host of other species. They are one of the marine reptiles that we associate with the infamous Mary Anning, a paleo darling of the early 19th century who found her first fossil specimens in the early 1800s.

Sunday, 28 March 2021

SPOTTED CLEANER SHRIMP

"Wash that for you, sir?" If you were a fish living in the warm turquoise waters off the coast of Bonaire in the southern Caribbean Sea, you may not hear those words, but you'd see the shrimp sign language equivalent. It seems Periclimenes yucatanicus or the Spotted Cleaner Shrimp are doing a booming business in the local reefs by setting up a Fish Wash service.

That's right, a Fish Wash. You'd be hard-pressed to find a terrestrial Molly Maid with two opposable thumbs as studious and hardworking as this wee marine beauty. You'll find them each day cleaning and snacking on a host of parasites. As many as twenty to thirty shrimp gather together to assemble a  highly-efficient marine cleaning station. They're even open to partnerships and mergers, partnering up with Cleaner Wrasse, or cleaner fish, for larger, high-end clients.

Spotted cleaner shrimp are about 2.5 cm long and have a delightful transparent body with telltale white and brown spots. Their legs, or chelae, are striped in purple, white and red. They live about 24 metres (or 79 ft) down on the seafloor in many of our planet's most beautiful waters. Aside from the Caribbean, they also enjoy the waters off of the Bahamas, southern Florida, Panama and Columbia. They are carnivorous crustaceans in the family, Palaemonidae.

This quiet marine mogul is turning out to be one of the ocean's top entrepreneurs. Keeping its host and diet clean and green, the spotted shrimp hooks up with the locals, in this case, local sea anemones and sets up a fish wash. Picture a car wash but without the noise and teenage boys. The signage posted is the shrimps' natural colouring which attracts fish from around the reefs. They sway back and forth to indicate that they are open for business.

Wash on, wash off.

Once within reach, the shrimp cleans the surface of the fish, giving the fish a buff and the shrimp its daily feed. This is good news for the shrimp, especially this time of year as they breed and brood their eggs in summer. 

After hatching, the larvae pass through a series of sadly, tasty planktonic stages before setting up a fish wash of their own. These cuties form a solid base for the oceanic food chain. Once they are older, they gain some protection from being eaten by their clients by a special signalling system that essentially shouts, "just here IN cooperation not as food." Here's to Periclimenes for keeping up the family business.

Saturday, 27 March 2021

ICHTHYOSAUR BASIOCCIPITAL BONE AND TELEOST FISH

Ichthyosaur Basioccipital Bone / Liam Langley
A very exciting find of an Ichthyosaur basioccipital bone. This is the bone next to the skull that connected to the vertebrae. He found this in situ so not very water warn as you might expect. This lovely bone was found by the deeply awesome Liam Langley on the Yorkshire Coast.

Ichthyosaurs became extinct during the Upper Cretaceous, about 30 million years before the K/T extinction event. There was an ocean anoxic event at the Cenomanian–Turonian stage boundary. The deeper layers of the seas became anoxic and poisoned by hydrogen sulphide. As life died off in the lower (benthos) levels of the sea, so did the predators at the top of the food chain. The last pliosaurs and ichthyosaurs became extinct.

Ichthyosaurs had been dwindling in numbers for some time; they were no longer the force they once were in the Upper Triassic and Lower Jurassic. By the middle Jurassic, it was thought they all belonged to the single clade, the Ophthalmosauridae. By the Cretaceous, it was thought that only three genera survived. For the last 50+ years, it has been thought that only one genus, Platypterygius, was known at the time of the anoxic event in the Upper Cretaceous.

Ichthyosaur Basioccipital Bone / Liam Langley
There was still diversity in ichthyosaurs a few million years before the extinction event. They may have survived right up to the extinction event. Ichthyosaurs had declined from their peak.

By the Cretaceous, they certainly had more competitors than in the Triassic and more elusive prey. The adaptive radiation of teleost fish meant their new prey was fast swimming and highly evasive.

The difference between teleosts and other bony fish lies mainly in their jawbones; teleosts have a movable premaxilla and corresponding modifications in the jaw musculature which make it possible for them to protrude their jaws outwards from the mouth.

This is of great advantage, enabling them to grab prey and draw it into the mouth. In more derived teleosts, the enlarged premaxilla is the main tooth-bearing bone, and the maxilla, which is attached to the lower jaw, acts as a lever, pushing and pulling the premaxilla as the mouth is opened and closed. Other bones further back in the mouth serve to grind and swallow food.

Another difference is that the upper and lower lobes of the tail (caudal) fin are about equal in size. The spine ends at the caudal peduncle, distinguishing this group from other fish in which the spine extends into the upper lobe of the tail fin.

The most basal of the living teleosts are the Elopomorpha, eels and their allies, and the Osteoglossomorpha, those whacky elephantfish and their friends. There are over 800 species of elopomorphs; each with thin leaf-shaped larvae known as leptocephali specialized for a marine environment.

Among the elopomorphs, eels have elongated bodies with lost pelvic girdles and ribs and fused elements in the upper jaw. The 200 species of osteoglossomorphs are defined by a bony element in the tongue. This element has a basibranchial behind it, and both structures have large teeth that are paired with the teeth on the parasphenoid in the roof of the mouth.

The clade Otocephala includes the Clupeiformes, tasty herrings, and Ostariophysi  — carp, catfish and their friends. Clupeiformes are made up of 350 living species of herring and herring-like fish. This group is characterized by an unusual abdominal scute and a different arrangement of the hypurals. In most species, the swim bladder extends to the braincase and plays a role in hearing. Ostariophysi, which includes most freshwater fishes, has developed some unique adaptations.

One is the Weberian apparatus, an arrangement of bones, called Weberian ossicles, connecting the swim bladder to the inner ear. This enhances their hearing, as sound waves make the bladder vibrate, and the bones transport the vibrations to the inner ear. They also have a chemical alarm system; when a fish is injured, the warning substance gets in the water, alarming nearby fish. Excellent for the predatory fish, less so for their poor injured brethren.

The teleosts included fast-swimming predatory fish, which would have been competing for similar food resources to our ichthyosaur friends. Had they complained about the teleosts they would have been deeply aghast to know what was coming next — big, hungry mosasaurs. The ichthyosaurs and pliosaurs were replaced in the marine ecology by the giant mosasaurs. The mosasaurs were probably ambush-hunters, whose sit-and-wait strategy apparently proved most successful. So, teleost fish, the ocean anoxic event and the rise of mosasaurs all contributed to the end of the ichthyosaurs.

Photos 1-2: By the awesome Liam Langley
Image 3: By Sir Francis Day - Fauna of British India, Fishes (www.archive.org), Public Domain, https://commons.wikimedia.org/w/index.php?curid=1919094

Friday, 26 March 2021

LOPHIIFORMES: ANGLERFISH

Humpback Anglerfish, Melanocetus johnsonii
The festive lassie you see here with her toothy grin and solo birthday-candle-style light is an Anglerfish.

They are bony fish of the teleost order Lophiiformes (Garman, 1899) and one of the most interesting, intriguing yet creepy, species on this planet.

There are over 200 species of anglerfish, most living in the pitch-black depths of the Atlantic and Antarctic oceans. They always look to be celebrating a birthday of some kind, albeit solo. This party is happening deep in our oceans right now and for those that join in, I hope they like it rough. The wee candle you see on her forehead is a photophore, a tiny bit of luminous dorsal spine. Many of our sea dwellers have photophores. We see them in glowing around the eyes of some cephalopods.

These light organs can be a simple grouping of photogenic cells or more complex with light reflectors, lenses, colour filters able to adjust the intensity or angular distribution of the light they produce. Some species have adapted their photophores to avoid being eaten, in others, it's an invitation to lunch but not in the traditional sense of that invite. In the anglerfish' world, it's dead sexy, an adaptation used to attract prey and mates alike, sometimes at the same time.

Deep in the murky depths of the Atlantic and Antarctic oceans, hopeful female anglerfish light up their sexy lures. When a male latches onto this tasty bit of flesh, he fuses himself totally.

He might be one of several potential mates. Each will take a turn getting close to her to see if she's the one. For her, it's not much of a choice. She's not picky, just hungry.

Mating is a tough business down in the depths. A friend asked if anglerfish mate for life. Well, yes... yes, indeed they do. Lure. Feed. Mate. Repeat. Once connected, the attachment is permanent. Her body absorbs his over time until all that's left are his testes. While unusual, it is only one of many weird and whacky ways our fishy friends communicate, entice, hunt and creatively survive and thrive. Ah, this planet has some evolutionary adaptations that are enough to break your brain. Anglerfish are definitely in with that lot.


Thursday, 25 March 2021

VICTORASPIS LONGCORNUALIS

This lovely specimen, showing both the positive and negative of the fossil, is an armoured agnatha jawless bony fish, Victoraspis longicornualis, from Lower Devonian deposits of Podolia, Ukraine.

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: Fossilero Fisherman

Wednesday, 24 March 2021

MANATEES OF TEXAS

Manatees do not live year-round in Texas, but these gentle sea cows are known to occasionally visit, swimming in for a 'summer vacation' and returning to warmer waters for the winter. New research has found fossil evidence for manatees along the Texas coast dating back to the most recent ice age. 

The discovery raises questions about whether manatees have been visiting for thousands of years, or if an ancient population of ice age manatees once called Texas home somewhere between 11,000 and 240,000 years ago.

The findings were published in Palaeontologia Electronica by lead author Christopher Bell, a professor at the UT Jackson School of Geosciences with co-authors Sam Houston State University Natural History Collections curator William Godwin and SHSU alumna Kelsey Jenkins — now a graduate student at Yale University — and SHSU Professor Patrick Lewis.

The eight fossils described in the paper include manatee jawbones and rib fragments from the Pleistocene, the geological epoch of the last ice age. Most of the bones were collected from McFaddin Beach near Port Arthur and Caplen Beach near Galveston during the past 50 years by amateur fossil collectors who donated their finds to the SHSU collections.

The Jackson Museum of Earth History at UT holds two of the specimens. A lower jawbone fossil, which was donated to the SHSU collections by amateur collector Joe Liggio, jumpstarted the research.

Manatee jawbones have a distinct S-shaped curve that immediately caught Godwin's eye. But Godwin said he was met with scepticism when he sought other manatee fossils for comparison. He recalls reaching out to a fossil seller who told him point-blank "there are no Pleistocene manatees in Texas."

But an examination of the fossils by Bell and Lewis proved otherwise. The bones belonged to the same species of manatee that visits the Texas coast today, Trichechus manatus. An upper jawbone donated by U.S. Rep. Brian Babin was found to belong to an extinct form of the manatee, Trichechus manatus bakerorum.

The age of the manatee fossils is based on their association with better-known ice age fossils and paleo-Indian artefacts that have been found on the same beaches.

It's assumed that the cooler ice age climate would have made Texas waters even less hospitable to manatees than they are today. But the fact that manatees were in Texas — whether as visitors or residents — raises questions about the ancient environment and ancient manatees. The Texas coast stretched much farther into the Gulf of Mexico and hosted wider river outlets during the ice age than it does today. Either the coastal climate was warmer than is generally thought, or ice age manatees were more resilient to cooler temperatures than manatees of today.

Subsurface imaging of the now flooded modern continental shelf reveals both a greater number of coastal embayments and the presence of significantly wider channels during ice age times.

If there was a population of ice age manatees in Texas, it's plausible that they would have ridden out winters in these warmer river outlets similar to how they do today in Florida and Mexico.

Reference: Christopher Bell, William Godwin, Kelsey Jenkins, Patrick Lewis. First fossil manatees in Texas: Trichechus manatus bakerorum in the Pleistocene fauna from beach deposits along the Texas Coast of the Gulf of Mexico. Palaeontologia Electronica, 2020; DOI: 10.26879/1006

Tuesday, 23 March 2021

DUGONGIDAE: STELLAR SEA COW

One of the most delightful creatures to ever grace this planet is the dugong — a species of sea cow found throughout the warm latitudes of the Indian and western Pacific Oceans. 

It is one of four living species of the order Sirenia, which also includes three species of manatees — their large, fully aquatic, mostly herbivorous marine mammal cousins.

The closest living relatives of sirenians are elephants. Manatees evolved from the same land animals as elephants over 50 million years ago. If not for natural selection, we might have a much more diverse showing of the Sirenia as their fossil lineage shows a much more diverse group of sirenians back in the Eocene than we have today. It is the only living representative of the once-diverse family Dugongidae; its closest modern relative, Steller's sea cow, was hunted to extinction in the 18th century. 

While only one species of the dugong is alive today – a second, the Steller's sea cow only left this Earth a few years ago. Sadly, it was hunted to extinction within 27 years of its discovery – about 30 species have been recovered in the fossil record

The first appearance of sirenians in the fossil record was during the early Eocene, and by the late Eocene, sirenians had significantly diversified. Inhabitants of rivers, estuaries, and nearshore marine waters, they were able to spread rapidly.

The most primitive sirenian known to date, Prorastomus, was found in Jamaica, not the Old World; however, more recently the contemporary Sobrarbesiren has been recovered from Spain. The first known quadrupedal sirenian was Pezosiren from the early Eocene. The earliest known sea cows, of the families Prorastomidae and Protosirenidae, are both confined to the Eocene and were about the size of a pig, four-legged amphibious creatures. By the time the Eocene drew to a close, the Dugongidae had arrived; sirenians had acquired their familiar fully aquatic streamlined body with flipper-like front legs with no hind limbs, powerful tail with horizontal caudal fin, with up and down movements which move them through the water, like cetaceans.

The last of the sirenian families to appear, Trichechidae, apparently arose from early dugongids in the late Eocene or early Oligocene. The current fossil record documents all major stages in hindlimb and pelvic reduction to the extreme reduction in the modern manatee pelvis, providing an example of dramatic morphological change among fossil vertebrates.

Since sirenians first evolved, they have been herbivores, depending on seagrasses and aquatic angiosperms, tasty flowering plants of the sea, for food. To the present, almost all have remained tropical (with the notable exception of Steller's Sea Cow), marine, and angiosperm consumers. Sea cows are shallow divers with large lungs. They have heavy skeletons to help them stay submerged; the bones are pachyostotic (swollen) and osteosclerotic (dense), especially the ribs which are often found as fossils.

Eocene sirenians, like Mesozoic mammals but in contrast to other Cenozoic ones, have five instead of four premolars, giving them a 3.1.5.3 dental formula. Whether this condition is truly primitive retention in sirenians is still under debate.

Although cheek teeth are relied on for identifying species in other mammals, they do not vary to a significant degree among sirenians in their morphology but are almost always low-crowned —brachyodont — with two rows of large, rounded cusps — bunobilophodont. The most easily identifiable parts of sirenian skeletons are the skull and mandible, especially the frontal and other skull bones. With the exception of a pair of tusk-like first upper incisors present in most species, front teeth — incisors and canines — are lacking in all, except the earliest sirenians.

Monday, 22 March 2021

ICHTHYOSAURS, SHARKS AND BLUBBER

We've learned much about the mighty ichthyosaur since first discovering their bones in Wales back in 1699. That's over three hundred years of knowledge.

We have classified them as an extinct order of marine reptiles from the Mesozoic era. We know that they were visibly dolphin-like in appearance and share some other qualities as well. They were warm-blooded, used their colouration as camouflage and had insulating blubber to keep them warm.

Ichthyosaurs are interesting because they have many traits in common with dolphins, but are not at all closely related to those sea-dwelling mammals. We aren't exactly sure of their biology either. They have many features in common with living marine reptiles like sea turtles, but we know from the fossil record that they gave live birth, which is associated with warm-bloodedness. This study reveals some of those biological mysteries.

We find their fossil remains in outcrops spanning the mid-Cretaceous to the earliest Triassic. As we look through the fossils, we see a slow evolution in body design moving towards that enjoyed by dolphins and tuna by the Upper Triassic, albeit with a narrower, more pointed snout.

Johan Lindgren, Associate Professor at Sweden's Lund University and lead author on the paper,  described the 180 million-year-old specimen, Stenopterygius, from outcrops in the Holzmaden quarry in Germany.

Both the body outline and remnants of internal organs are clearly visible in the specimen. Remarkably, the fossil is so well-preserved that it is possible to observe individual cellular layers within its skin.

Stenopterygius quadriscissus
Researchers identified cell-like microstructures containing pigment organelles on the surface of the fossil.

This ancient skin revealed a feature we recognized from marine dwelling animals, the ability to change colour, providing camouflage from potential predators. They also found traces of what might have been the animal's liver.

When they put some of the tissue through chemical analysis, it was consistent with what we'd look for in adipose tissue or blubber. Not surprising as dolphins today use blubber for buoyancy and to help to thermally insulate for thermal regulation in cold seas. It's a highly useful adaptation and one that led me to wonder what other vertebrates might use blubber or some other adaptation to maintain a warmer body temperature independent of icy cold conditions.

Today, blubber is an important part of the anatomy of seals, walruses and whales. It covers the core of their bodies, storing energy, insulating them from cold seas and providing extra buoyancy. 

A rather fetching Walrus, Odobenus rosmarus
Fat and blubber are not the same. The main differences are their consistency and blood supply —  blubber contains many more blood vessels than fat, and is far denser because it's made up of a mix of collagen fibres and lipids.

Blubber layers can be incredibly thick. Walruses deposit most of their body fat into a thick layer of blubber — a layer of fat reinforced by fibrous connective tissue that lies just below the skin of most marine mammals.

This blubber layer insulates the walrus and streamlines its body. It also functions as an energy reserve. Blubber covers the core of their bodies but does not grace their fins, flippers and flukes.

Not all marine animals need blubber. Our cold-blooded marine friends: sharks, crabs, fish, are able to let their body temperatures dropdown to very chilly levels, some as low as 36 degrees Fahrenheit.

They have a few tricks up their sleeves to make this happen. Sharks have evolved specialized physiology to keep their metabolic rate high and their hearts are able to contract in the icy depths because of a special protein. These adaptations allow sharks to enjoy a wide range of habitats and follow their food from warm tropical seas to the icy waters of the North Pacific.

Gray Shark, Carcharhinus amblyrhynchos
With the advent of genetics, we've now learned that the Great White Shark’s genetic code and many of the proteins they use to control metabolism are more closely related to humans than zebrafish, the quintessential fish model.

In a very cool bit of science, researchers sequenced a shark's heart transcriptome – the messenger molecules produced from the shark’s genome, including those active in making proteins. Then they categorized the proteins based on their functions.

What they found that the proportions of white shark proteins in many categories matched humans more closely than zebrafish. Of particular interest was that white shark had a closer match to humans for proteins involved in metabolism. Great White Sharks have a rare trait in fish called regional endothermy. This allows them to keep the body temperature of some of their organs warmer than the ambient water — a highly useful trait for fast swimming, digestion and hunting in colder waters.

References and additional reading:

Fancy a read? Check out the work by Michael Stanhope, professor of evolutionary genomics at Cornell’s College of Veterinary Medicine, and scientists at the Save Our Seas Shark Research Center at Nova Southeastern University (NSU). He published the shark genetic study in the November 2013 issue of BMC Genomics. It lays the foundation for genomic exploration of sharks and vastly expands genetic tools for their conservation.

Johan Lindgren, Peter Sjövall, Volker Thiel, Wenxia Zheng, Shosuke Ito, Kazumasa Wakamatsu, Rolf Hauff, Benjamin P. Kear, Anders Engdahl, Carl Alwmark, Mats E. Eriksson, Martin Jarenmark, Sven Sachs, Per E. Ahlberg, Federica Marone, Takeo Kuriyama, Ola Gustafsson, Per Malmberg, Aurélien Thomen, Irene Rodríguez-Meizoso, Per Uvdal, Makoto Ojika, Mary H. Schweitzer. Soft-tissue evidence for homeothermy and crypsis in a Jurassic ichthyosaur. Nature, 2018; DOI: 10.1038/s41586-018-0775-x

North Carolina State University. (2018, December 5). Soft tissue shows Jurassic ichthyosaur was warm-blooded, had blubber and camouflage. ScienceDaily. Retrieved September 7, 2019, from www.sciencedaily.com/releases/2018/12/181205134118.htm

Photo: By Haplochromis - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=5825284

Sunday, 21 March 2021

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/

Saturday, 20 March 2021

CAP OF THE HEVE, FRANCE

A lovely Torquirhynchia inconstans, brachiopod from the sommet des Bancs de plomb, Kimméridgien inférieur, Cap of the Hève in northwestern France.

The area is home to many beautiful marine fossils and Yves Lepage explored them this past month, May 2021 — kindly sharing some of his photos with me, and then me with all of you.

It is a beach site with gorgeous cliff faces and small to mid-sized boulders on the beach. Strolling between the Bout du Monde and Clos des Ronces with Jean-Jacques. Beautiful light and some finds. Yves Lepage

A pterosaur specimen, consisting of the associated anterior portions of upper and lower jaws, is reported from the upper Kimmeridgian Argiles d'Octeville, in the cliffs of the Cap de la Hève, near Le Havre in Normandy, northwestern France. It is described as a new taxon, Normannognathus wellnhoferi, and referred to the Germanodactylidae. 

Normannognathus wellnhoferi is distinguished by the association of jaws which bear teeth up to their anterior tip and a tall sagittal crest, formed by the premaxillae, which begins anterior to the nasopreorbital fenestra, has a concave anterior edge and is much higher than the maxilla at that level. 

The Dsungaripterus-like crest and the slightly upturned upper jaw support the idea of a close relationship between the Germanodactylidae and Dsungaripteridae.

Reference:

https://www.cambridge.org/core/journals/geological-magazine/article/abs/new-pterodactyloid-pterosaur-from-the-kimmeridgian-of-the-cap-de-la-heve-normandy-france/71D18DAB996FA40378D4979403B70AF9





Friday, 19 March 2021

HOODED SEALS: CYSTOPHORA CRISTATA

Hooded seals, Cystophora cristata, are large phocid seals in the family Phocidae, who live in some of the chilliest places on Earth, from 47° to 80° N in latitude. 

They frequent the eastern coast of North America north of Maine to the western tip of Europe, along the coast of Norway near Svalbard. 

These skilled divers are mainly concentrated around Bear Island, Norway, Iceland, and northeast Greenland. 

In rare cases, we find them in the icy waters in Siberia. They usually dive depths of 600 m (1,968 ft) in search of fishy treats but can go as deep as 1000 m (3,280 ft) when needed. That is deep into the cold, dark depths of our oceans. Sunlight entering the sea may travel as deep as 1,000 m (3,280 ft) under the right conditions, but there is rarely any significant light beyond 200 meters (656 ft). This is the dark zone and the place we find our bioluminescent friends. 

Hooded seals have a sparse fossil record. One of the first fossils found was a Pliocene specimen from Anvers, Belgium discovered in 1876. In 1983 a paper was published claiming there were some fossils found in North America thought to be from Cystophora cristata. Of the three accounts, the most creditable discovery was from a sewer excavation in Maine, the northeasternmost U.S. state, known for its rocky coastline, maritime history and nature areas like the granite and spruce islands of Acadia National Park. A scapula and humeri were found among other bones and thought to date to the post-Pleistocene. 

Of two other accounts, one was later reassigned to another species and the other left unsolved. (Folkow, et al., 2008; Kovacs and Lavigne, 1986; Ray, 1983)

The seals are typically silver-grey or white in colour, with black spots that vary in size covering most of the body. Hooded seal pups are known as "blue-backs" because their coats are blue-grey on the back with whitish bellies, though this coat is shed after 14 months of age when the pups moult.

Hooded seals live primarily on drifting pack ice and in deep water in the Arctic Ocean and North Atlantic. Although some drift away to warmer regions during the year their best survival rate is in colder climates. They can be found on four distinct areas with pack ice: near Jan Mayen Island (northeast of Iceland); off Labrador and northeastern Newfoundland; the Gulf of St. Lawrence; and the Davis Strait (off midwestern Greenland). 

Hooded Seal and pup
Males appear to be localized around areas of complex seabeds, such as Baffin Bay, Davis Strait, and the Flemish Cap. 

Females concentrate their habitat efforts primarily on shelf areas, such as the Labrador Shelf. 

Females reach the age of sexual maturity between 2 and 9 years old and it is estimated that most females give birth to their first young at around 5 years of age. 

Males reach sexual maturity a little later around 4 to 6 years old but often do not mate until much later. Females give birth to one young at a time through March and April. The gestation period is 240 to 250 days. 

During this time the fetus, unlike those of other seals, sheds its lanugo — a covering of fine soft hair that is replaced by thicker pelage — in the uterus. These young are precocious and at birth are able to move about and swim with ease. They are independent and left to fend for themselves immediately after they have been weaned.

Hooded seals are known to be a highly migratory species that often wander long distances, as far west as Alaska and as far south as the Canary Islands and Guadeloupe. Prior to the mid-1990s, hooded seal sightings in Maine and the east Atlantic were rare but began increasing in the mid-1990s. From January 1997 to December 1999, a total of 84 recorded sightings of hooded seals occurred in the Gulf of Maine, one in France and one in Portugal. 

From 1996 to 2006, five strandings and sightings were noted near the Spanish coasts in the Mediterranean Sea. There is no scientific explanation for the increase in sightings and range of the hooded seal.

Cystophora means "bladder-bearer" in Greek and pays homage to this species' inflatable bladder septum on the heads of adult males. The bladder hangs between the eyes and down over the upper lip in a deflated state. 

The hooded seal can inflate a large balloon-like sac from one of its nostrils. This is done by shutting one nostril valve and inflating a membrane, which then protrudes from the other nostril. I was thinking of Hooded seals when contemplating the nasal bladders of Prosaurolophus maximum, large-headed duckbill dinosaurs, or hadrosaurid, in the ornithischian family Hadrosauridae. Perhaps both species used these bladders in a similar manner — to warn predators and attract mates.

The hooded seal is known for its uniquely elastic nasal cavity located at the top of its head, also known as the hood. Only males possess this display-worthy nasal sac, which they begin to develop around the age of four. The hood begins to inflate as the seal makes its initial breath prior to going underwater. It then begins to repetitively deflate and inflate as the seal is swimming. The purpose of this is acoustic signalling. It occurs when the seal feels threatened and attempt to ward off hostile species when competing for resources such as food and shelter. It also serves to communicate their health and superior status to both other males and females they are attempting to attract. 

In sexually mature males, a pinkish balloon-like nasal membrane comes out of the left nostril to further aid it in attracting a mate. This membrane, when shaken, is able to produce various sounds and calls depending on whether the seal is underwater or on land. Most of these acoustic signals are used in an acoustic situation (about 79%), while about 12% of the signals are used for sexual purposes.

References: Ray, C. 1983. Hooded Seal, Cystophora cristata: Supposed Fossil Records in North America. American Society of Mammalogists, Vol. 64 No. 3: 509-512; Cystophora cristata, Hooded Seal", 2007; "Seal Conservation Society", 2001; Kovacs and Lavigne, 1986.

Thursday, 18 March 2021

CHOCOLATE CHEIRURID

This glorious rich chocolate showboat is the trilobite Cheirurus ingricus from Middle Ordovician limestone deposits in the Wolchow River Region of Saint Petersburg, Russia. 

We sometimes find these lovelies enrolled or semi-enrolled with their impossibly thin genal spines lifted in the air. The Cheirurids appeared about 500 million years ago and died out about 390 million years ago. They are definitely a favourite!

Wednesday, 17 March 2021

DR. DANNER: FOSSILS OF THE CHILLIWACK GROUP

In May 2001, Dr. Ted Danner, Professor Emeritus from UBC and my mentor gave a talk to the Vancouver Paleontological Society. For over fifteen years, we would meet for dinner on the third Thursday of every month. I would swing by to pick him up and we would head to his favourite restaurant for a meal and lively discussion. 

Dinner was a delight of banter, stories and paleontological debates. Dr. Danner had a keen mind and a sharp wit. The world lost a truly beautiful soul when he passed away in 2012. 

Wilbert R. Danner began teaching geology at UBC in 1954 and established the Beer-Pop Can-Bottle Deposit Refund Award in 1989 using proceeds from the return of bottles and cans collected on weekly scavenging treks on UBC’s Vancouver Campus.

Danner’s office was often full of cans ready to be taken to the recycling depot. He raised $46,000 from collected bottles and cans to support students before he passed away in 2012. He chose to name it the Beer-Pop Can-Bottle Deposit Refund Award to show that, over time, even small contributions can have a big impact.

“Ted taught UBC’s introductory geology course for many years,” says geologist and entrepreneur Ross Beaty, a former student of Danner and executor of his estate. “He was a quirky, enthusiastic professor who inspired many students to go into geoscience. What a wonderful legacy he’s now left for UBC and future generations of geologists.”

Danner’s bequest endows $320,000 for the Beer-Pop Can-Bottle Deposit Refund Award, which provides two awards annually to geology students who have demonstrated aptitude in fieldwork. Another $320,000 funds the newly established Ted Danner Memorial Entrance Bursary in Geology, provided to a student entering UBC enrolled in at least one geology course.

The estate also includes Danner’s extensive mineral collection, which now resides at UBC’s Pacific Museum of the Earth. It contains more than 2,000 specimens and is worth more than $500,000.

Beyond his annual award, Dr. Danner left a legacy in those he taught and mentored. Ted had a great fondness for the geology & fossils of the Chilliwack Group. A wonderful orator, Dr. Danner liked to reminisce about the Devonian quarry at Doaks Creek. He enjoyed hiking through the Late Mississippian limestone exposures on the east side of Red Mountain, where large crinoid columnals, corals and brachiopods have been found, sometimes partly silicified, on the weathered surfaces of the limestones and shales. 

Further up the west side of Red Mountain at the Kendle Quarry there are Late Mississippian exposures where you can find fragments of brachiopods & goniatites. Dr. Danner would often tell the tale of Reginald A. Daly who published a series of maps in 1912 of areas along the International Boundary where he found fusulinids in the Chilliwack Valley. It seems the markers Daly originally mapped have been slowly tipping to the south, with Canada gaining a small advantage over the United States each year.

Monday, 15 March 2021

SOUTH AMERICAN TAPIR

South American tapir, Tapirus terrestris
This little sweetie with his brown fur stripped and dotted with bits of white is a South American tapir, Tapirus terrestris.

He is a relative of the rhinoceros and like his rhino cousins, he loves the water. They play, swim, dive, and use it to protect themselves from predators.

Their feet are specially designed for swimming and walking on muddy shores. Each of their front feet has four splayed toes, a bit like having a fin or snowshoe on your feet. Their back feet have a similar design but with three toes. They nap and hide in the forest during the day and then head out at night to munch on leaves, shoots, fruit, and other green goodies in the Amazon Rainforest and the River Basin in South America, east of the Andes.

We find fossil remains of tapir first appearing in the middle Eocene, 41 million years ago. While many families of perissodactyls achieved very high levels of diversity, there have never been more than a few species of tapirs. Tapirs are also morphologically conservative - their teeth and skeletons resemble those of early ceratomorphs, and some have referred to them as living fossils. 

The skull is very specialized with many unique features related to the development of the proboscis. The four living species of tapirs use the prehensile proboscis to browse selectively on leaves, sprouts, and small branches, including aquatic plants and also ingest a great deal of fruit and seeds.

While modern tapir species are confined to tropical forests of South America and Asia, they originated and persisted for many millions of years in more northern regions, even during the ice ages, although their rarity as fossils suggests favourable habitats may have been scarce. Recently a huge fossil accumulation of late Miocene tapirs was discovered near Gray, Tennessee. It is the largest accumulation of fossil tapirs in the world and suggests that tapirs were once very common in some parts of North America.

Tuesday, 9 March 2021

HOW TO TELL FOSSIL BONE


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

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

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

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

Dinosaur Bone, Jurassic, Colorado, USA

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

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

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

Monday, 8 March 2021

HIKING TO THE FERNIE AMMONITE

The Fernie ammonite, Titanites occidentalis, from outcrops on Coal Mountain near Fernie, British Columbia, Canada. 

This beauty is the remains of a carnivorous cephalopod within the family Dorsoplanitidae that lived and died in a shallow sea some 150 million years ago.

If you would like to get off the beaten track and hike up to see this ancient beauty, you will want to head to the town of Fernie in British Columbia close to the Alberta border. 

Driving to the trail base is along an easy access road just east of town along Fernie Coal Road. There are some nice exposures of Cretaceous plant material on the north side (left-hand side) of the road as you head from Fernie towards Coal Creek. I recently drove up to Fernie to look at Cretaceous plant material and locate the access point to the now infamous Late Jurassic (Tithonian) Titanites (S.S. Buckman, 1921) site. While the drive out of town is on an easy, well-maintained road, the slog up to the ammonite site is a steep 3-hour push.

The first Titanites occidentalis was about one-third the size and was incorrectly identified as Lytoceras, a fast-moving nektonic carnivore. The specimen you see here is significantly larger at 1.4 metres (about four and a half feet) and rare in North America. 

Titanites occidentalis, the Western Giant, is the second known specimen of this extinct fossil species. The first was discovered in 1947 in nearby Coal Creek by a British Columbia Geophysical Society mapping team. When they first discovered this marine fossil high up on the hillside, they could not believe their eyes — both because it is clearly marine at the top of a mountain and the sheer size of this ancient beauty.

In the summer of 1947, a field crew was mapping coal outcrops for the BC Geological Survey east of Fernie. One of the students reported finding “a fossil truck tire.” Fair enough. The similarity of size and optics are pretty close to your average Goodridge. 

A few years later, GSC Paleontologist Hans Frebold described and named the fossil Titanites occidentalis after the large Jurassic ammonites from Dorset, England. The name comes from Greek mythology. Tithonus, as you may recall, was the Prince of Troy. He fell in love with Eos, the Greek Goddess of the Dawn. Eos begged Zeus to make her mortal lover immortal. Zeus granted her wish but did not grant Tithonus eternal youth. He did indeed live forever — ageing hideously. Ah, Zeus, you old trickster. It is a clever play on time placement. Dawn is the beginning of the day and the Tithonian being the latest age of the Late Jurassic. Clever Hans!

Hiking to the Fernie Ammonite

From the town of Fernie, British Columbia, head east along Coal Creek Road towards Coal Creek. The site is 3.81 km from the base of Coal Creek Road to the trailhead as the crow flies. I have mapped it here for you in yellow and added the wee purple GPS marker for the ammonite site proper. There is a nice, dark grey to black roadcut exposure of Cretaceous plants on the north side of the dirt road that is your cue to pull over and park.  

You access the trailhead on the south side of the road. You'll need to cross the creek to begin your ascent. There is no easy way across the creek and you'll want to tackle this one with a friend when the water level is low. 

The beginning of the trail is not clear but a bit of searching will reveal the trailhead with its telltale signs of previous hikers. This is a 2-3 hour moderate 6.3-kilometre hike up & back bush-whacking through scrub and fallen trees. Heading up, you'll make about a 246-metre elevation gain. You won't have a cellular signal up here but if you download the Google Map to your mobile, you'll have GPS to guide you. 

If you're coming in from out of town, the closest airport is Cranbrook. Then it is about an hour and change to Fernie and another 15-minutes or so to the site.

You will want to leave your hammers with your vehicle (no need to carry the weight) as this site is best enjoyed with a camera. This is a site you will want to wear hiking boots to access. Know that these will get wet as you cross the creek. If you'd like to see the ammonite but are not keen on the hike, a cast has been made by fossil preparator Rod Bartlett and is on display at the Courtenay Museum in Courtenay, Vancouver Island, Canada. Fernie Ammonite Palaeo Coordinates: 49°29'04"N 115°00'49"W

Saturday, 6 March 2021

MADAGASCAR GIANT: LOBOLYTOCERAS

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.

Friday, 5 March 2021

SUSAN'S HOLCOPHYLLOCERAS

What is wonderful about natural science is exploring new species. Take a look at this tremendously robust suturing on this lovely ammonite, Holcophylloceras mediterraneum, (Neumayr, 1871) from Late Jurassic (Oxfordian) deposits near Sokoja, Madagasgar. This particular specimen and post goes out to Susan Gerard who has provided lovely cabinetry that will become home for so many of these wonderfully preserved specimens.  

Madagascar is a treasure trove of outstanding fossil species and this Holcophylloceras ammonite is no exception.

The shells had many chambers divided by walls called septa. The chambers were connected by a tube called a siphuncle which allowed for the control of buoyancy with the hollow inner chambers of the shell acting as air tanks to help them float.

We can see the edges of this specimen's shell where it would have continued out to the last chamber, the body chamber, where the ammonite lived. Picture a squid or octopus, now add a shell and a ton of water.

Thursday, 4 March 2021

THE ELEPHANT BIRDS OF MADAGASCAR

One hundred and seventy million years ago, Madagascar was landlocked in the middle of the supercontinent Gondwana. It was sandwiched between land that would eventually become South America and Africa and land that would eventually become India, Australia, and Antarctica. Rather like puzzle pieces, these bits of continent came together and then were slowly pulled apart.

Riding the movements of the Earth's crust, Madagascar, along with India, first split away from Africa and South America. The plates continued to shift and Madagascar split next from Australia and then Antarctica before and started heading north. While this was all happening at what may seem a snail's pace of two to four inches each year, the cumulative movement changed the shape of our world.  

Around this same time, India smashed into Asia — forming the Himalayas in the process. Madagascar finally broke away from India and was marooned in the Indian Ocean. Beautiful and solo — Madagascar has been on its own for the past 88 million years.

With Madagascar being solo for so long, many of her species only exist — or briefly existed — here. One of the most interesting of these is the Elephant birds. They are members of the extinct ratite family Aepyornithidae, made up of enormous flightless birds that once lived on the island of Madagascar. A ratite is any of a diverse group of flightless and mostly large and long-legged birds of the infraclass Palaeognathae.

Elephant birds became extinct, around 1000–1200 CE, as a result of human hunting. Elephant birds comprised the genera Mullerornis, Vorombe and Aepyornis. While they were in close geographical proximity to the ostrich, their closest living relatives are the much smaller nocturnal Kiwi — found only in New Zealand — suggesting that ratites did not diversify by vicariance during the breakup of Gondwana but instead evolved from ancestors that dispersed more recently by flying.

Elephant birds were endemic to Madagascar. Phylogenetic, genetic, and fossil evidence all suggest that the elephant bird, along with the ostrich, arrived in Madagascar and India when these landmasses were still connected to Australia and Antarctica via a land bridge.

When India and Madagascar split, the elephant bird wound up surviving on Madagascar, while the ostrich was carried north with India and was eventually introduced to Eurasia when India collided with the continent. 

The presence of the elephant bird on Madagascar can be chalked up to vicariance; it was living on Madagascar land already when Madagascar broke off from India. Most of the species on Madagascar today seem to be descended from individuals that dispersed from Africa long after Madagascar was established as a separate island.

Very rarely, but occasionally, we find fossil eggs from Elephant Birds are found The National Geographic Society in Washington holds a specimen of an Aepyornis egg which was given to Luis Marden in 1967. The specimen is intact and contains the skeleton of the unhatched bird. The Denver Museum of Nature and Science (Denver, Colorado) holds two intact eggs, one of which is currently on display. 

Another giant Aepyornis egg is on display at the Harvard Museum of Natural History in Cambridge, MA and a complete, unbroken egg, is held at Leeds Discovery Centre, Leeds, UK. A cast of the egg is preserved at the Grant Museum of Zoology at London University. There is also a complete specimen in the collections of the Kuleli Military High School Museum, Istanbul, Turkey.

David Attenborough, an esteemed naturalist and my personal hero, owned an almost complete eggshell, dating from 600 to 700 CE, which he pieced together from fragments that were given to him while making his 1961 BBC series Zoo Quest to Madagascar. In March 2011, the BBC broadcast the 60-minute documentary Attenborough and the Giant Egg, presented by Attenborough, about his personal scientific quest to discover the secrets of the elephant bird and its egg.

Photo: Griffon, Gyps fulvus. The griffon vulture is a large Old World vulture in the bird of prey family Accipitridae.

Photo: Aepyornis skeleton. Quaternary of Madagascar by Monnier, 1913 by Monnier - http://digimorph.org/specimens/Aepyornis_maximus/Aepyornis.phtml digimorph.org, Public Domain, https://commons.wikimedia.org/w/index.php?curid=79655

Cooper, A., Lalueza-Fox, C., Anderson, S., Rambaut, A., Austin, J., and Ward, R. (2001). Complete mitochondrial genome sequences of two extinct moas clarify ratite evolution. Nature 409:704-707.

Goodman, S. M., and Benstead, J. P. (2005). Updated estimates of biotic diversity and endemism for Madagascar. Oryx 39(1):73-77.

Evolution Berkeley: https://evolution.berkeley.edu/evolibrary/news/091001_madagascar

Vences, M., Wollenberg, K. C., Vieites, D. R., and Lees, D. C. (2009). Madagascar as a model region of species diversification. Trends in Ecology and Evolution 24(8):456-465.

Saturday, 27 February 2021

GULF ISLANDS GREEN ISLE

Arbutus tree, Arbutus menziesii, reaching out to sea, Hornby Island
Windswept, peaceful, stormy and abundant, Hornby is a mix of everything desirable about the northern Gulf Islands of the west coast of British Columbia.

It is a very green island, both in the practices of those who live here and in the mixed forest that covers the land. 

We see the large conifers, Western red cedar, western hemlock, grand fir and lodgepole pine on the island.

You also see lovely examples of the smaller Pacific yew, Taxus brevifolia, a small evergreen that is used by First Nations carvers for bows and paddles for canoes.

 Many spectacular specimens of arbutus, Arbutus menziesii, grow along the water's edge. These lovely evergreens have a rich orange-red bark that peels away in thin sheets, leaving a greenish, silvery smooth appearance and a satiny sheen. And these trees, like all trees, have kin recognition. They can swap nutrients with one another using mycelium, the neural network of fungi, as their go-between. Arbutus, the broadleaf evergreen species is the tree I most strongly associate with Hornby. Hornby has its fair share of broadleaf deciduous trees. Bigleaf maple, red alder, black cottonwood, Pacific flowering dogwood, cascara and several species of willow thrive here.


There are populations of Garry oak, Quercus garryana, with their deeply lobed leaves, on the southern end of the island and at Helliwell Provincial Park on a rocky headland at the northeast end of Hornby. 

The island has about 260 acres (1.1 km2) of undisturbed stands of older forests. They take up a relatively small footprint, just under 3.5%, of the island's overall size. 1,330 acres (540 ha) of older second-growth stands cover just under 20% of the island. 

Beneath these ancient wonders are mycorrhizal networks, communicating, gathering and sharing nutrients between these ancient stands of trees. The fungi break down the plant matter and animal species that have lived and died since time immemorial. The ground you walk across is a patchwork of the true essence of Hornby — unique steps across this terra firma records the island's long history. 

Here, embedded and imprinted within the ground are the stories of its geologic past, a time of history of being beneath a great sea, uplifting, the scrapings of the ice ages. Higher still are the hydrocarbon remnants that record the ebb and flow, lives and deaths of the K'ómoks First Nation, who called this island Ja-dai-aich — then European explorers, Americans, farmers, fisherman and artisans who have explored or called Hornby home.

Douglas fir, Pseudotsuga menziesii
Most of the trees you see on the island are Douglas fir, Pseudotsuga menziesii, an evergreen conifer species in the pine family. The common name is a nod to the Scottish botanist, David Douglas, who collected and first reported on this large evergreen.

Sadly for Douglas, it is Archibald Menzies, a Scottish physician, botanist, naturalist — and David's arch-rival, whose name is commemorated for science. He's also credited with the scientific name for our lovely arbutus trees.

Menzies was part of the Vancouver Expedition (1791–1795) a four-and-a-half-year voyage of exploration commanded by Captain George Vancouver of the British Royal Navy.

Their voyage built on the work of James Cook. Cook was arguably the first ship's captain to ensure his crew remained scurvy free by implementing a practice of nutritious meals (those containing ascorbic acid also known as Vitamin C) and meticulous standards for onboard hygiene. Though he did much to lower the mortality rate amongst his crew, he made some terrible decisions that led to his early demise. Cook was attacked and killed in 1779 during his third exploratory voyage in the Pacific while attempting to kidnap the Island of Hawaii's monarch, Kalaniʻōpuʻu.

During the four and a half year Vancouver Expedition voyage, the crew and officers bickered amongst themselves, circumnavigated the globe, touching down on five continents. Little did they know, for many of them it would be the last voyage they would ever take. 

The expedition returned to a Britain more interested in its ongoing war than in Pacific explorations. Vancouver was attacked by the politically well-connected Menzies for various slights, then challenged to a duel by Thomas Pitt, the 2nd Baron of Camelford.

The fellow for whom the fair city of Vancouver is named never did complete his massive cartographical work. With health failing and nerves eroded, he lost the dual and his life. It was Peter Puget, whose name adorns Puget Sound, who completed Vancouver's — and arguably Cook's work on the mapping of our world.