Tuesday, 31 March 2020

DESMATOCHELYS FROM THE PUNTLEDGE

Desmatochelys sculpture by P. Oudendag
A lovely fossil turtle, Desmatochelys cf. D. lowi (Williston, 1894) found by Richard Bolt in the shales of the Trent River Formation along the Puntledge River in the early 1990s. At the time, it was the first documented account of a Cretaceous marine vertebrate from the Pacific coast of Canada — a first which shows you how much we've learned about our Pacific coast in just the last few years.

Dr. Betsy Nicholls wrote up the paper and published in the Canadian Journal of Earth Sciences in 1992. She described the specimen from some postcranial elements and part of the mandible. Unfortunately, we were never able to recover the skull.

It was the Desmatchelys that inspired the 1999 BCPA Symposium conference logo held at UBC that year — a trilobite embedded within a turtle, celebrating recent significant contributions to Canadian palaeontology. It was also the inspiration for the sculpture you see here by Peter Odendag. I met Peter at the conference and was delighted to see his paleo inspired sculptures. Both his Desmatochelys and coelacanth now grace the displays at the Courtenay Museum on Vancouver Island.

While this was the first turtle find on Vancouver Island, the hunt for our fossilized reptilian friends goes back many years, but the hunt for Desmatochelys begins in the Bone Wars of the late 1800s. It was Samuel Wendell Williston who described the first specimen of Desmatochelys in the Kansas University Quarterly in 1895. Williston was a contemporary of C.H. Sternberg, Edward Drinker Cope and Othniel Charles Marsh. As history tells it, from 1877 to around 1892, both Cope and Marsh used their wealth and influence to finance their own expeditions and to procure the services and dinosaur bones from lesser fossil hunters. Williston was one of Marsh's boys.

Desmatochelys cf. D. lowi, Upper Cretaceous Haslam Formation 
In 1876, Williston wrote a letter to Marsh reporting that Sternberg had, "got one or two large turtles that are good and some pretty good saurians," (Shor, 1971:77) along the Smoky Hill River, upper Chalk Logan County. Williston's hunt for turtles continued and it was not long after that he would hold in his hand a new species on which he would both publish and name. The specimen had been found by a railroad worker near Fairbury, Nebraska. These were hard times and fossils were exchanged for hard currency then as they are today. The specimen was passed through the hands of one curiosity seeker after another until it eventually made its way to M. A. Low. Mister Low was more a man of science than currency and he generously donated to the University of Kansas in 1893.

That generosity was rewarded. Had the specimen not be accessioned into the collections at Kansas University by Low, it might well have been sold to Marsh and published under the name Marshanii. Instead, Williston was given the fossil to study. He published and in discovering it was a new species, chose the scientific name for the specimen. Williston tipped his hat to Low and called the new species Desmatochelys Iowi when published his finding on a well-preserved fossil turtle (KUVP 1200) from the Upper Cretaceous Benton Formation of Fairbury, Nebraska, later that year. The find included the skull, lower jaw and portions of the carapace, plastron, limbs and limb girdles. Williston described it as a new genus and species of marine turtle, Desmatochelys Iowi, and placed it in a new family, Desmatochelyidae. Since its first discovery at least five new specimens of D. lowi have been described from Cretaceous deposits in South Dakota, Kansas, Arizona, Canada, and Mexico.

In 1960, the carapace, limbs and limb girdles of a second specimen (CNHM PR 385) were found in Cretaceous sediment deposits with pre-Cambrian granites in a quarry on the South Dakota-western Minnesota border (Zangerl and Sloan, 1960). They pushed back on Williston's assertion that his new species belonged in the newly described family Desmatochelyidae, instead of recognizing it to be a primitive cheloniid within the family Cheloniidae — a family of large marine turtles characterized by their flat "hard-shells" with their streamlined, wide, rounded shapes and paddle-like forelimb flippers.

https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/cheloniidae

Monday, 30 March 2020

PUNTLEDGE ELASMOSAUR

Puntledge Elasmosaur found by Mike Trask
This lengthy beauty is an elasmosaur, a large marine reptile now housed in the Courtenay and District Museum on Vancouver Island.

This specimen was found by Mike Trask and his daughter in the winter of 1988 while fossil collecting along the Puntledge River. While he couldn't have known it at the time, it was this discovery and those that followed that would spark a renewed interest in palaeontology on Vancouver Island and the province of British Columbia.

Mike had foraged ahead, adding chalk outlines to interesting fossil and nodules in the 83 million-year-old shales along the riverbank. His daughter, Heather, was looking at the interesting features he had just outlined when they both noticed some tasty blocks and concretions in situ just a few meters away. Taking a closer look, they were thrilled to discover that they held the bones of a large marine reptile.

Unsure of what exactly they'd discovered but recognizing them as significant, Mike reached out to Dr. Betsy Nicholls at the Royal Tyrell Museum.

It was Betsy who'd written up the incomplete specimen of fossil turtle, Desmatochelys cf. D. lowi — Reptilia: Chelonioidea — found by Richard Bolt, VIPS, in the shales of the Trent River Formation along the Puntledge River in the early 1990s. Dr. Nicholls wrote up the paper and published in the Canadian Journal of Earth Sciences in 1992.

At that time, it was the first documented account of a Cretaceous marine vertebrate from the Pacific coast of Canada, which shows you how much we've learned about our Pacific coast in just the last few years.

The Desmatchelys find inspired the 1999 BCPA Symposium conference logo. Every second year, the BCPA hosts a symposium. The 1999 conference at UBC was the first time the Vancouver Paleontological Society had hosted a BCPA conference. The conference abstract was graced with a trilobite embedded within a turtle, celebrating recent significant contributions to Canadian palaeontology.

Elasmosaur skull and teeth found by Mike Trask
When Mike showed her the bones he'd found, Betsy confirmed them to be that of an elasmosaur, a large marine reptile with a small head, razor-sharp teeth and a long neck  — and the first discovery of an elasmosaur west of the Canadian Rockies — another first. It was one of those moments that lights up and inspires a whole community.

When the bones were fully excavated, this 15-meter marine beauty underwent a year of preparation to reveal the skeleton you see here. You can visit the fully prepped specimen and see the articulated bones beneath a glass case in the Courtenay Museum on Vancouver Island.

The Puntledge Elasmosaur has graced the cover of Canada's stamps and was voted as British Columbia's Provincial Fossil in 2019. This honour has the Puntledge Elasmosaur cozied up to other provincial symbols and emblems that include the Pacific Dogwood, Jade, the Steller's Jay, Western Red Cedar, Spirit Bear and Pacific Salmon. The runner-up for BC's Provincial Fossil was Shonisaurus sikanniensis, a massive 21-metre ichthyosaur found in Triassic outcrops in northern British Columbia. That beauty is a worthy reminder of what hunted in our ancient oceans some 220 million years ago.

BCPA Symposium / Heidi Henderson, Mike Trask, Adam Melzak
Since that first moment of discovery, many wonderful events transpired. In the Fall of 1991, Mike Trask was teaching a course on paleontology at the North Island College.

Two of his students were Ann and Joe Zanbilowitz. With the classroom portion of the course finished up, the group set out for a fossil expedition on the Puntledge River. Within five minutes of their search, Joe found a few small articulated vertebrae that we now know to be the type specimen of the mosasaur, Kourisodon puntledgensis. That find, along with some of the other paleontological goodies from the area, prompted the formation of the Vancouver Island Palaeontological Society from an idea to a registered society in 1992. By 1993 membership had grown from a dozen to 250.

In 1992, the Vancouver Island Palaeontological Society passed a motion to encourage the formation of a provincial umbrella group to act as an advocate to promote interaction amongst various paleontological organizations. Through the efforts of Mike Trask, Dan Bowen, Rolf Ludvigsen and others, the first meeting of the Board of Directors of the B.C. Paleontological Alliance was held in 1993.

Mike Trask hiking up at Landslide Lake, British Columbia
In 1994 the membership of the VIPS split into three regional societies, the original VIPS, the new VanPS in Vancouver, and the new VIPMS, the Vancouver island Paleontological Museum Society based in Qualicum.

In 1995, the Victoria Palaeontological Society, the VicPS, was formed. This was followed by the Tumbler Ridge Foundation (TRMF) and opening of the Dinosaur Discovery Gallery in Tumbler Ridge.

The British Columbia Paleontological Alliance and various regional societies, particularly the Vancouver Island Palaeontological Society (VIPS), continue to make significant contributions to paleontology. We've now found the fossil remains of an elasmosaur and two mosasaurs along the banks of the Puntledge River, says Dan Bowen, Chair of the Vancouver Island Palaeontological Society.

The first set of about 10 mosasaurs vertebrae (Platecarpus) was found by Tim O’Bear and unearthed by a team of VIPS and Museum enthusiasts led by Dr. Rolf Ludvigsen. Dan Bowen and Joe Morin of the VIPS later prepped these specimens for the Museum.

In 1993, just a few years later, a new species of mosasaur, Kourisodon puntledgensis, a razor-toothed mosasaur, was found upstream of the elasmosaur site by Joe Zembiliwich on a field trip led by Mike Trask. A replica of this specimen now calls The Canadian Fossil Discovery Centre in Morden home.
What is significant about this specimen is that it is a new genus and species. At 4.5 meters, it is a bit smaller than most mosasaurs and similar to Clidastes, but just as mighty.

Comox Valley Elasmosaur / Dino Stamps of Canada
Interestingly, this species has been found in this one locality in Canada and across the Pacific in the basal part of the Upper Cretaceous — middle Campanian to Maastrichtian — of the Izumi Group, Izumi Mountains and Awaji Island of southwestern Japan. We see an interesting correlation with the ammonite fauna from these two regions as well.

The Courtenay and District Museum, the community surrounding it and allied organizations like the Vancouver Island Palaeontological Society (VIPS), have a lot to be proud of. Their outreach and educational programs continue to inspire young and old alike. These discoveries led to the expansion of the local museum, the elasmosaur excavation area becoming a provincial heritage site and the impetus for many, many teaching programs since.

Oh, and Mike Trask — he continues to be deeply awesome, intuitive and exceptionally observant. The good Master Trask went on to find the first hadrosauroid in the province. While Alberta is littered with them, a Hadrosauroid dinosaur is a rare occurrence in this part of Canada and further evidence of the terrestrial influence in the Upper Cretaceous, Nanaimo Group of Vancouver Island. Perhaps one day we'll be seeing a duck-billed dinosaur from British Columbia gracing Canada's stamps. Fancy that.

References: Nicholls, E. L. and Meckert, D. (2002). Marine reptiles from the Nanaimo Group (Upper Cretaceous) of Vancouver Island. Canadian Journal of Earth Science 39(11):1591-1603.
Tanimoto, M. (2005). "Mosasaur remains from the Upper Cretaceous Izumi Group of Southwest Japan" (PDF). Netherlands Journal of Geosciences. 84: 373–378. doi:10.1017/s0016774600021156.
Ferocious new mosasaur skeleton coming to Morden | CBC News". CBC. Retrieved 2018-07-16.

Sunday, 29 March 2020

SAUROPTERYGIAN REPTILES

Libonectes atlasense / Andy Chua Collection
A beautifully preserved mandible of Libonectes atlasense, an elasmosaurid plesiosaur from early Turonian, Upper Cretaceous,  deposits of the Akrabou Formation near Asfla Village, Goulmima, Errachidia Province in eastern central Morocco.

The collecting area is in the region of Drâa-Tafilalet. You may know Errachidia as Ksar Souk. It was renamed My Rachid, in honour of the Moroccan royal family. Libonectes is a genus of sauropterygian reptile belonging to the plesiosaurs. Specimens have been found in the Britton Formation of Texas and the Akrabou Formation of Morocco.

Sauropterygian reptiles were a diverse taxon of extinct aquatic reptiles that arose from terrestrial ancestors just after the Permian extinction event. They flourished during the Triassic then all but the plesiosaurs became extinct at the end of the Triassic — with the plesiosaurs dying out at the end of the Cretaceous.

The holotype of Libonectes atlasense is an almost complete skeleton from Upper Cretaceous (mid-Turonian) rocks of the Goulmima area in eastern Morocco. Sven Sachs from the Naturkunde-Museum Bielefeld and Benjamin P. Kear from Uppsala University co-authored a paper redescribing the elasmosaurid plesiosaurian Libonectes atlasense from the Upper Cretaceous of Morocco. They did an initial assessment of the specimen in 2005, proposing a generic referral based on stratigraphical contemporaneity with Libonectes morgani from the CenomanianeTuronian of Texas, U.S.A.

Relative differences in the profile of the premaxillary-maxillary tooth row, position of the external bony nasal opening, number of teeth and rostrad inclination of the mandibular symphysis, proportions of the axial neural arch, and number of cervical and pectoral vertebrae were used to distinguish between these species.

Libonectes Scale Drawing / Hyrotrioskjan
As part of an on-going comparative appraisal of elasmosaurid plesiosaurian osteo-anatomy, they re-examined the type and formally referred material of both L. atlasense and L. morgani in order to establish species validity, as well as compile a comparative atlas for use in future works.

Their work revealed that these reportedly distinct species-level fossils are in fact virtually indistinguishable in gross morphology.

Indeed, the only substantial difference occurs in relative prominence of the midline keel along the mandibular symphysis, which might be explained by intraspecific variation. Their observations permit an amendment to the published generic diagnosis of Libonectes with the confirmation of important states such as the likely presence of a pectoral bar, distocaudad expansion of the humerus, and an epipodial foramen.

And we see some entirely new features. Novel features include a prominent ‘prong-like’ ventral midline process on the coracoids and the development of a median pelvic bar that encloses a central fenestration. Their work shows that the composite remains of L. morgani thus constitute one of the most complete elasmosaurid skeletal hypodigms documented worldwide, and evidence a trans-Atlantic distribution for this apparently dispersive species during the early Late Cretaceous. The impressive mandible you see here is in the collection of Andy Chua.

Sachs, Sven and Kear, Benjamin. (2017). Redescription of the elasmosaurid plesiosaurian Libonectes atlasense from the Upper Cretaceous of Morocco. Cretaceous Research. 74. 205-222. 10.1016/j.cretres.2017.02.017.

Photo: Libonectes atlasense specimen, Andy Chua

Drawing By Hyrotrioskjan - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=57716018

Saturday, 28 March 2020

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 to process.

We'll we've 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 coloration 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

Friday, 27 March 2020

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

Thursday, 26 March 2020

INDIGO: NATURAL DYES

Natural dyes are dyes or colourants derived from plants, invertebrates, or minerals. The majority of natural dyes are vegetable dyes from plant sources — roots, berries, bark, leaves, and wood — and other biological sources such as fungi and lichens.

Archaeologists have found evidence of textile dyeing dating back to the Neolithic period. In China, dyeing with plants, barks and insects has been traced back more than 5,000 years and looks to be our first attempt at the practice of chemistry.

The essential process of dyeing changed little over time. Typically, the dye material is put in a pot of water and then the textiles to be dyed are added to the pot, which is heated and stirred until the colour is transferred. Sometimes, we use workers with stout marching legs to mix this up.

Traditional dye works still operate in many parts of the world. There is a revival of using natural indigo in modern Egypt — although their indigo dye is mostly imported. The same is true further south in Sudan. They've been importing cloth from Upper Egypt as far back as we have written records and continue the practice of the cloth and dye imports today. Clean white cotton is more the style of western Sudan and Chad, but they still like to throw in a bit of colour.

Traditional Dye Vats
So do the folk living in North Africa. Years ago, I was travelling in Marrakesh and saw many men with noticeably orange, blueish or purplish legs. It wasn't one or two but dozens of men and I'd wondered why this was.

My guide took me to the top of a building so I could look down on rows and rows of coloured vats. In every other one was a man marching in place to work the dye into the wool. Their legs took on the colour from their daily march in place in huge tubs of liquid dye and sheared wool. This wool would be considered textile fibre dyed before spinning — dyed in the wool — but most textiles are yarn-dyed or piece-dyed after weaving.

Many natural dyes require the use of chemicals called mordants to bind the dye to the textile fibres; tannin from oak galls, salt, natural alum, vinegar, and ammonia from stale urine were staples of the early dyers.

Many mordants and some dyes themselves produce strong odours. Urine is a bit stinky. Not surprisingly, large-scale dyeworks were often isolated in their own districts.

Woad, Isatis tinctoria
Plant-based dyes such as Woad, Isatis tinctoria, indigo, saffron, and madder were raised commercially and were important trade goods in the economies of Asia and Europe. Across Asia and Africa, patterned fabrics were produced using resist dyeing techniques to control the absorption of colour in piece-dyed cloth.

Dyes such as cochineal and logwood, Haematoxylum campechianum, were brought to Europe by the Spanish treasure fleets, and the dyestuffs of Europe were carried by colonists to America.

Throughout history, people have dyed their textiles using common, locally available materials, but scarce dyestuffs that produced brilliant and permanent colours such as the natural invertebrate dyes. Crimson kermes became highly prized luxury items in the ancient and medieval world. Red, yellow and orange shades were fairly easy to procure as they exist as common colourants of plants. It was blue that people sought most of all and purple even more so.


Indigofera tinctoria, a member of the legume or bean family proved just the trick. This lovely plant —  named by the famous Swedish botanist Carl Linneaus, the father of formalized binomial nomenclature — grows in tropical to temperate Asia and subtropical regions, including parts of Africa.

The plants contain the glycoside indican, a molecule that contains a nitrogenous indoxyl molecule with some glucose playing piggyback. Indigo dye is a product of the reaction of indoxyl by a mild oxidizing agent, usually just good old oxygen.

To make the lovely blue and purple dyes, we harvest the plants and ferment them in vats with urine and ash. The fermentation splits off the glucose, a wee bit of oxygen mixes in with the air (with those sturdy legs helping) and we get indigotin — the happy luxury dye of royalty, emperors and kings.

While much of our early dye came from plants — now it is mostly synthesized — other critters played a role. Members of the large and varied taxonomic family of predatory sea snails, marine gastropod mollusks, commonly known as murex snails were harvested by the Phoenicians for the vivid dye known as Tyrian purple.

While the extant specimens maintained their royal lineage for quite some time; at least until we were able to manufacture synthetic dyes, it was their fossil brethren that first captured my attention. There are about 1,200 fossil species in the family Muricidae. They first appear in the fossil record during the Aptian of the Cretaceous.

Their ornate shells fossilize beautifully. I'd first read about them in Addicott's Miocene Gastropods and Biostratigraphy of the Kern River Area, California. It's a wonderful survey of 182 early and middle Miocene gastropod taxa.

References:

George E.Radwin and Anthony D'Attilio: The Murex shells of the World, Stanford University press, 1976, ISBN 0-8047-0897-5

Pappalardo P., Rodríguez-Serrano E. & Fernández M. (2014). "Correlated Evolution between Mode of Larval Development and Habitat in Muricid Gastropods". PLoS ONE 9(4): e94104. doi:10.1371/journal.pone.0094104

Miocene Gastropods and Biostratigraphy of the Kern River Area, California; United States Geological Survey Professional Paper 642  This article incorporates text from this source, which is in the public domain.

Wednesday, 25 March 2020

FOSSILS, TEXTILES AND URINE

You may recall the eight-metre Type Specimen of the ichthyosaur, Temnodontosaurus crassimanus, found in an alum quarry in Yorkshire.

The Yorkshire Museum was given this important ichthyosaur fossil back in 1857 when alum production was still a necessary staple of the textile industry. Without that industry, many wonderful specimens would likely never have been unearthed.

These quarries are an interesting bit of British history as they helped shape the Yorkshire Coast, created an entirely new industry and gave us more than a fixative for dyes. With them came the discovery of many remarkable fossil specimens and, oddly, local employment in the collection of urine.

In the 16th century, alum was essential in the textile industry as a fixative for dyes. By the first half of the 16th century, the clothing of the Low Countries, German states, and Scandinavia had developed in a different direction than that of England, France, and Italy, although all absorbed the sobering and formal influence of Spanish dress after the mid-1520s. Those fashions held true until the Inquisition when both politics and fashion underwent a much-needed overhaul to something lighter.

Fashion in Medieval Livonia (1521): Albrecht Dürer
Elaborate slashing was popular, especially in Germany. In the depiction you see here, an artist pokes a bit of fun at Germanic fashion from the time. Bobbin lace arose from passementerie in the mid-16th century in Flanders, the Flemish Dutch-speaking northern portion of Belgium. Black was increasingly worn for the most formal occasions.

This century saw the rise of the ruff, which grew from a mere ruffle at the neckline to immense, slightly silly, cartwheel shapes. They adorned the necklines of the ultra-wealthy and uber-stylish men and women of the age.

At their most extravagant, ruffs required wire supports and were made of fine Italian reticella, a cutwork linen lace.

16th Century Fashion / Ruff Collars and Finery
In contrast to all that ruff, lace and cutwork linen, folk needed dyed fabrics. And to fix those dyes, they needed Alum. For a time, Italy was the source of that alum.

The Pope held a tidy monopoly on the industry, supplying both alum and the best dyes. He also did a nice trade in the colourful and rare pigments for painting. And for a time, all was well with dandy's strutting their finery to the local fops in Britain.

All that changed during the Reformation. Great Britain, heathens as they were, were cut-off from their Papal source and found themselves needing to fend for themselves.

The good Thomas Challoner took up the charge and set up Britain's first Alum works in Guisborough. Challoner looked to paleontology for inspiration. Noticing that the fossils found on the Yorkshire coast were very similar to those found in the Alum quarries in Europe, he hatched a plan to set-up an alum industry on home soil. As the industry grew, sites along the coast were favoured as access to the shales and subsequent transportation was much easier.

Alum House, Photo: Joyce Dobson and Keith Bowers
Alum was extracted from quarried shales through a large scale and complicated process which took months to complete. The process involved extracting then burning huge piles of shale for 9 months, before transferring it to leaching pits to extract an aluminum sulphate liquor. This was sent along channels to the alum works where human urine was added.

At the peak of alum production, the industry required 200 tonnes of urine every year. That's the equivalent of all the potty visits of more than 1,000 people. Yes, strange but true.

The steady demand was hard to keep up with and urine became an imported resource from markets as far away as London and Newcastle upon Tyne in the northeast of England. Wooden buckets were left on street corners for folk to do their business then carted back to the south to complete the alum extraction process. The urine and alum would be mixed into a thick liquid. Once mixed, the aromatic slosh was left to settle and then the alum crystals were removed.

I'm not sure if this is a folktale or plain truth, but as the story goes, one knows when the optimum amount of alum had been extracted as you can pop an egg in the bucket and it floats on its own.

Alum House. Photo: Ann Wedgewood and Keith Bowers
The last Alum works on the Yorkshire Coast closed in 1871. This was due to the invention of manufacturing synthetic alum in 1855, then subsequently the creation of aniline dyes that contained their own fixative.

There are many sites along the Yorkshire Coast which bear evidence of the alum industry. These include Loftus Alum Quarries where the cliff profile is drastically changed by extraction and huge shale tips remain.

Further South are the Ravenscar Alum Works, which are well preserved and enable visitors to visualize the processes which took place. The photos you see here are of Alum House at Hummersea. The first shows the ruin of Alum House printed on a postcard from 1906. The second (bottom) image shows the same ruin from on high with Cattersty Point in the background.

The good folk at the National Trust in Swindon are to thank for much of the background shared here. If you'd like to learn more about the Yorkshire area or donate to a very worthy charity, follow their link below.

Reference: https://www.nationaltrust.org.uk/yorkshire-coast/features/how-alum-shaped-the-yorkshire-coast

Tuesday, 24 March 2020

TEMNODONTOSAURUS CRASSIMANUS

Temnodontosaurus crassimanus
This big beastie is the ichthyosaur, Temnodontosaurus crassimanus, who graced our ancient oceans 180 million years ago. The species was originally named by Richard Owen, the first superintendent of the Natural History Museum. Owen lived at the height of the gentleman scientist and it was Owen who first coined the name dinosaur.

The fellow you see here is the Type Specimen for the species and he lives on display in the Yorkshire Museum. As the reference specimen for the species, all hopeful specimens that may belong to this species are checked against the Type Specimen to see if they share diagnostic features.

The Yorkshire Museum was given this important ichthyosaur fossil back in 1857, albeit in bits and pieces. The first bits of fossil bones were found near Whitby on the North Yorkshire coast by workmen quarrying alum. They recognized the bones as belonging to a fossilized reptile and alerted local authorities who in turn alerted the good Master Owen.

It was quite an undertaking to recover as it was found in more than fifty pieces in massive shale blocks and the alum quarry was active at the time. Alum quarrying helped share the Yorkshire Coast as an important staple of the textile industry going back to the 16th-century. By the 1860s, alum quarrying was slowing down. The ability to manufacture synthetic alum by 1855 had shifted the industry and it died out entirely by 1871. Lucky for us, the last years of alum production gifted us this well-preserved eight-metre specimen, one of the largest ichthyosaurs ever discovered in the UK.

Monday, 23 March 2020

YORKSHIRE ICHTHYOSAUR TAIL

Ichthyosaur Tail Section. Photo: Liam Langley
A beautiful piece of ichthyosaur tail section found on the Yorkshire Coast in 2019 by the deeply awesome Liam Langley.

Ichthyosaurus are an extinct marine reptile first described from fossil fragments found in 1699 in Wales. Shortly thereafter, fossil vertebrae were published in 1708 from the Lower Jurassic and the first member of the order Ichthyosauria to be discovered.

Over time, we discovered a number of these fossil specimens and a picture of the overall look and size began to emerge. We found fossils that ranged from quite small, just a foot or two, to well over twenty-six metres in length and resembled both modern fish and dolphins. This specimen holds a well-deserved spot of honour on Liam's mantle. The detail is tremendous and just look at that masterful prep work.

Sunday, 22 March 2020

Saturday, 21 March 2020

DIGITS AND PHALANGES

While they resembled fish and dolphins, Ichthyosaurs were large marine reptiles belonging to the order known as Ichthyosauria or Ichthyopterygia.

In 2018, Benjamin Kear and his team delved into a new are of study through technology that allows us to look at ichthyosaur remains at the molecular level. Their findings suggest ichthyosaurs had skin and blubber quite similar to our modern dolphins.

While ichthyosaurs evolved from land-dwelling, lung-breathing reptiles, they returned to our ancient seas and evolved into the fish-shaped creatures we find in the fossil record today. Their limbs fully transformed into flippers, sometimes containing a very large number of digits and phalanges.

Their flippers tell us they were entirely aquatic as they were not well-designed for use on land. And it was their flippers that first gave us the clue that they gave birth to live young; a find later confirmed by fossil embryo and wee baby ichy finds. They thrived during much of the Mesozoic era; based on fossil evidence, they first appeared around 250 million years ago (Ma) and at least one species survived until about 90 million years ago into the Late Cretaceous.

During the early Triassic period, ichthyosaurs evolved from a group of unidentified land reptiles that returned to the sea. They were particularly abundant in the later Triassic and early Jurassic periods before being replaced as a premier aquatic predator by another marine reptilian group, the Plesiosauria, in the later Jurassic and Cretaceous.

In the Late Cretaceous, ichthyosaurs were hard hit by the Cenomanian-Turonian anoxic event. As the deepest benthos layers of the seas became anoxic, poisoned by hydrogen sulphide, deep water marine life died off. This caused a cascade that wreaked havoc all the way up the food chain. At the end of that chain were our mighty predaceous marine reptiles.

Bounty turned to scarcity and a race for survival began. The ichthyosaurs lost that race as the last lineage became extinct. It may have been their conservative evolution as a genus when faced with a need for adaptation to the world in which they found themselves and/or being outcompeted by early mosasaurs.

There are promising discoveries coming out of strata from the Cretaceous epeiric seas of Texas, USA from Nathan E. Van Vranken. His published paper from 2017, "An overview of ichthyosaurian remains from the Cretaceous of Texas, USA," looks at ichthyosaurian taxa from the mid-Cretaceous (Albian–Cenomanian) time interval in North America with an eye to ichthyosaurian distribution and demise.

Photo: This beautifully preserved Ichthyosaur paddle with its incredible detail is from Early Jurassic (183 Million Years) deposits in the Ohmden, Posidonia Shale Formation, Baden-Württemberg, east of the Rhine, southwestern Germany.

Friday, 20 March 2020

BLUE LIAS ICHTHYOSAUR

This well-preserved partial ichthyosaur was found in the Blue Lias shales by Lewis Winchester-Ellis in 2018. The vertebrae you see here are from the tail section of this marine reptile.

The find includes stomach contents which tell us a little about how this particular fellow liked to dine.

As with most of his brethren, he enjoyed fish and cephalopods. Lewis found fishbone and squid tentacle hooklets in his belly. Oh yes, these ancient cephies had grasping hooklets on their tentacles. I'm picturing them wiggling all ominously. The hooklets were the only hard parts of the animal preserved in this case as the softer parts of this ancient calamari were fully or partially digested before this ichthyosaur met his end.

Ichthyosaurus was an extinct marine reptile first described from fossil fragments found in 1699 in Wales. Shortly thereafter, fossil vertebrae were published in 1708 from the Lower Jurassic and the first member of the order Ichthyosauria to be discovered.

To give that a bit of historical significance, this was the age of James Stuart, Jacobite hopeful to the British throne. While scientific journals of the day were publishing the first vertebrae ichthyosaur finds, he was avoiding the French fleet in the Firth of Forth off Scotland. This wasn’t Bonnie Prince Charlie, this was his Dad. Yes, that far back.

The first complete skeleton was discovered in the early 19th century by Mary Anning and her brother Joseph along the Dorset Jurassic Coast. Joseph had mistakenly, but quite reasonably, taken the find for an ancient crocodile. Mary excavated the specimen a year later and it was this and others that she found that would supply the research base others would soon publish on.

Mary's find was described by a British surgeon, Sir Everard Home, an elected Fellow of the Royal Society, in 1814. The specimen is now on display at the Natural History Museum in London bearing the name Temnodontosaurus platyodon, or “cutting-tooth lizard.”

Ichthyosaurus communis
In 1821, William Conybeare and Henry De La Beche, a friend of Mary's, published a paper describing three new species of unknown marine reptiles based on the Anning's finds.

Rev. William Buckland would go on to describe two small ichthyosaurs from the Lias of Lyme Regis, Ichthyosaurus communis and Ichthyosaurus intermedius, in 1837.

Remarkable, you'll recall that he was a theologian, geologist, palaeontologist AND Dean of Westminster. It was Buckland who published the first full account of a dinosaur in 1824, coining the name, "Megalosaurus."

The Age of Dinosaurs and Era of the Mighty Marine Reptile had begun.

Ichthyosaurs have been collected in the Blue Lias near Lyme Regis and the Black Ven Marls. More recently, specimens have been collected from the higher succession near Seatown. Paddy Howe, Lyme Regis Museum geologist, found a rather nice Ichthyosaurus breviceps skull a few years back. A landslip in 2008 unveiled some ribs poking out of the Church cliffs and a bit of digging revealed the ninth fossil skull ever found of a breviceps, with teeth and paddles to boot.

Specimens have since been found in Europe in Belgium, England, Germany, Switzerland and in Indonesia. Many tremendously well-preserved specimens come from the limestone quarries in Holzmaden, southern Germany.

Ichthyosaurs ranged from quite small, just a foot or two, to well over twenty-six metres in length and resembled both modern fish and dolphins.

Dean Lomax and Sven Sachs, both active (and delightful) vertebrate paleontologists, have described a colossal beast, Shonisaurus sikanniensis from the Upper Triassic (Norian) Pardonet Formation of northeastern British Columbia, Canada, measuring 3-3.5 meters in length. The specimen is now on display in the Royal Tyrrell Museum of Palaeontology in Alberta, Canada. It was this discovery that tipped the balance in the vote, making it British Columbia's Official Fossil. Ichthyosaurs have been found at other sites in British Columbia, on Vancouver Island and the Queen Charlotte Islands (Haida Gwaii) but Shoni tipped the ballot.

The first specimens of Shonisaurus were found in the 1990s by Peter Langham at Doniford Bay on the Somerset coast of England.

Dr. Betsy Nicholls, Rolex Laureate Vertebrate Palaeontologist from the Royal Tyrrell Museum, excavated the type specimen of Shonisaurus sikanniensis over three field sessions in one of the most ambitious fossil excavations ever ventured. Her efforts from 1999 through 2001, both in the field and lobbying back at home, paid off. Betsy published on this new species in 2004, the culmination of her life’s work and her last paper as we lost her to cancer in autumn of that year.

Roy Chapman Andrews, AMNH 1928 Expedition to the Gobi Desert
Charmingly, Betsy had a mail correspondence with Roy Chapman Andrews, former director of the American Museum of Natural History, going back to the late 1950s as she explored her potential career in palaeontology. Do you recall the AMNH’s sexy paleo photos of expeditions to the Gobi Desert in southern Mongolia in China in the early 20th century? I've posted a picture here to jog your memory. Roy Chapman Andrews was the lead on that trip. The man was dead sexy. His photos are what fueled the flames of my own interest in paleo.

We've found at least 37 specimens of Shonisaurus in Triassic outcrops of the Luning Formation in the Shoshone Mountains of Nevada, USA. The finds go back to the 1920s. The specimens that may it to publication were collected by M. Wheat and C. L. Camp in the 1950s.  The aptly named Shonisaurus popularis became the Nevada State Fossil in 1984. Our Shoni got around. Isolated remains have been found in a section of sandstone in Belluno, in the Eastern Dolomites, Veneto region of northeastern Italy. The specimens were published by Vecchia et al. in 2002.

For a time, Shonisaurus was the largest ichthyosaurus known.

Move over, Shoni, as a new marine reptile find competes with the Green Anaconda (Eunectes murinus) and the Blue Whale (Balaenoptera musculus) for size at a whopping twenty-six (26) metres.

The find is the prize of fossil collector turned co-author, Paul de la Salle, who (you guessed it) found it in the lower part of the intertidal area that outcrops strata from the latest Triassic Westbury Mudstone Formation of Lilstock on the Somerset coast. He contacted Dean Lomax and Judy Massare who became co-authors on the paper.

The find and conclusions from their paper put "dinosaur" bones from the historic Westbury Mudstone Formation of Aust Cliff, Gloucestershire, UK site into full reinterpretation.

And remember that ichthyosaur the good Reverend Buckland described back in 1837, the Ichthyosaurus communis? Dean Lomax was the first to describe a wee baby. A wee baby ichthyosaur! Awe. I know, right? He and paleontologist Nigel Larkin published this adorable first in the journal of Historical Biology in 2017.

They had teamed up previously on another first back in 2014 when they completed the reconstruction of an entire large marine reptile skull and mandible in 3-D, then graciously making it available to fellow researchers and the public. The skull and braincase in question were from an Early Jurassic, and relatively rare, Protoichthyosaurus prostaxalis. The specimen had been unearthed in Warwickshire back in the 1950s. Unlike most ichthyosaur finds of this age, it was not compressed and allowed the team to look at a 3-D specimen through the lens of computerized tomography (CT) scanning.

Another superb 3-D ichthyosaur skull was found near Lyme Regis by fossil hunter-turned-entrepreneur-local David Sole and prepped by the late David Costain. I'm rather hoping it went into a museum collection as it would be wonderful to see the specimen studied, imaged, scanned and 3-D printed for all to share. Here's hoping.


Ichthyosaurus somersetensis Credit: Dean R Lomax
Lomax and Sven Sachs also published on an embryo from one of the largest ichthyosaurs known, a new species named Ichthyosaurus somersetensis.

Their paper in the ACTA Palaeontologica Polonica from 2017, describes the third embryo known for Ichthyosaurus and the first to be positively identified to species level. The specimen was collected from Lower Jurassic strata (lower Hettangian, Blue Lias Formation) of Doniford Bay, Somerset, UK and is housed in the collection of the Niedersächsisches Landesmuseum (Lower Saxony State Museum) in Hannover, Germany.

We've learned a lot about them in the time we've been studying them. We now have thousands of specimens, some whole, some as bits and pieces. Many specimens that have been collected are only just now being studied and the tools we are using to study them are getting better and better.

Link to Lomax Paper: https://journals.plos.org/plosone/article…

Link to Nathan's Paper: https://www.tandfonline.com/…/10.1080/03115518.2018.1523462…

Nicholls Paper: E. L. Nicholls and M. Manabe. 2004. Giant ichthyosaurs of the Triassic - a new species of Shonisaurus from the Pardonet Formation (Norian: Late Triassic) of British Columbia. Journal of Vertebrate Paleontology 24(4):838-849 [M. Carrano/H. Street]

Thursday, 19 March 2020

PLESIOSAURS OF THE YORKSHIRE COAST

These two lovely Plesiosaur vertebrae were found by Liam Langley on fossil field trips to the Yorkshire Coast on the east coast of England.

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

We've 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. 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 specimen in the winter of 1823. These two vertebrae grace the home of the talented Mr. Langley. Anning's plesiosaur can be viewed in London's Natural History Museum.

Wednesday, 18 March 2020

SHONISAURUS OF NEVADA

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

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

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

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

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

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

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

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

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

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

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

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

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

Tuesday, 17 March 2020

CENOMANIAN-TURONIAN IMPACT

Ichthyosaur and Plesiosaur by Edouard Riou, 1863
During the early Triassic period, ichthyosaurs evolved from a group of unidentified land reptiles that returned to the sea. They were particularly abundant in the later Triassic and early Jurassic periods before being replaced as a premier aquatic predator by another marine reptilian group, the Plesiosauria, in the later Jurassic and Cretaceous periods.

In the Late Cretaceous, ichthyosaurs were hard hit by the Cenomanian-Turonian anoxic event. As the deepest benthos layers of the seas became anoxic, poisoned by hydrogen sulphide, deep water marine life died off. This caused a cascade that wreaked havoc all the way up the food chain. At the end of that chain were our mighty predaceous marine reptiles.

Bounty turned to scarcity and a race for survival began. The ichthyosaurs lost that race as the last of their lineage became extinct. It may have been their conservative evolution as a genus when faced with a need for adaptation to the world in which they found themselves and/or being outcompeted by early mosasaurs.

Sunday, 15 March 2020

CONFOUNDING CONFUCIUSORNIS

Confuciusornis was about the size of a modern pigeon, with a total length of 50 centimetres (1.6 feet) and a wingspan of up to 70 cm (2.3 ft). Its body weight has been estimated to have been as much as 1.5 kilograms (3.3 lb), or less than 0.2 kg (0.44 lb). Confuciusornis feducciai was about a third longer than average specimens of Confuciusornis sanctus.

Confuciusornis is an interesting species as it shows a mix of basal and derived traits. It was more "advanced" or derived than Archaeopteryx in possessing a short tail with a pygostyle — a bone formed from a series of short, fused tail vertebrae — and a bony sternum or breastbone, but more basal or "primitive" than modern birds in retaining large claws on the forelimbs, having a primitive skull with a closed eye-socket, and a relatively small breastbone.

At first, the number of basal characteristics was exaggerated: Hou assumed in 1995 that a long tail was present and mistook grooves in the jaw bones for small degenerated teeth. I suppose we see what we want to see and our expectations colour our vision.

Confuciusornis sanctus, Cincinnati Museum of Natural History and Science
The skull morphology of Confuciusornis has been difficult to determine. Many of the specimens are crushed and deformed but we can piece some of it together.

Their skulls were near triangular in side view, and the toothless beak was robust and pointed. The front of the jaws had deep neurovascular foramina and grooves, associated with the keratinous rhamphotheca — horn-covered beak.

The skull was rather robust, with deep jaws, especially the mandible. The tomial crest of the upper jaw — a bony support for the jaw's cutting edge — was straight for its entire length. The premaxillae —front bones of the upper jaw — were fused together for most of the front half of the snout, but were separated at the tip by a V-shaped notch. The frontal processes that projected hindwards from the premaxillae were thin and extended above the orbits (eye openings) like in modern birds, but unlike Archaeopteryx and other primitive birds without pygostyles, where these processes end in front of the orbits. The maxilla (the second large bone of the upper jaw) and premaxilla articulated by an oblique suture, and the maxilla had an extensive palatal shelf. The nasal bone was smaller than in most birds and had a slender process that directed down towards the maxilla.

The orbit was large, round, and contained sclerotic plates — the bony support inside the eye. A crescent-shaped element that formed the front wall of the orbit may be an ethmoidolacrimal complex similar to that of pigeons, but the identity of these bones is unclear due to bad preservation, and the fact that this region is very variable in modern birds. The external nares, bony nostrils, were near triangular and positioned far from the tip of the snout. The borders of the nostrils were formed by the premaxillae above, the maxilla below, and the nasal wall at the back.

Birds: Living Dinosaurs
Few specimens preserve the sutures of the braincase, but one specimen shows that the frontoparietal suture crossed the skull just behind the postorbital process and the hindmost wall of the orbit.

This was similar to Archaeopteryx and Enaliornis, whereas it curves back and crosses the skull roof much farther behind in modern birds, making the frontal bone of Confuciusornis small compared to those of modern birds. 

A prominent supraorbital flange formed the upper border of the orbit and continued as the postorbital process, which had prominent crests that projected outwards to the sides, forming an expansion of the orbit's rim.

The squamosal bone was fully incorporated into the braincase wall, making its exact borders impossible to determine, which is also true for adult modern birds.

Various interpretations have been proposed of the morphology and identity of the bones in the temporal region behind the orbits, but it may not be resolvable with the available fossils. Confuciusornis was considered the first known bird with an ancestral diapsid skull — with two temporal fenestrae on each side of the skull — in the late 1990s, but in 2018, Elzanowski and colleagues concluded that the configuration seen in the temporal region of confuciusornithids was autapomorphic — a unique trait that evolved secondarily rather than having been retained from a primitive condition — for their group.

The quadrate bone and the back end of the jugal bar were bound in a complex scaffolding that connected the squamosal bone with the lower end of the postorbital process. This scaffolding consisted of two bony bridges, the temporal bar and the orbitozygomatic junction, which gave the appearance of the temporal opening being divided similarly to diapsid skulls, though this structure is comparable to bridges over the temporary fossa in modern birds.

The mandible, lower jaw, is one of the best-preserved parts of the skull. It was robust, especially at the front third of its length. The tomial crest was straight for its entire length, and a notch indented the sharp tip of the mandible. The mandible was spear-shaped when viewed from the side due to its lower margin slanting downwards and back from its tip for the front third of its length — the jaw was also deepest at a point one third from the tip. The symphyseal part — where the two halves of the lower jaw connected — of the dentary was very robust. The lower margin formed an angle at the level of the front margin of the nasal foramen, which indicates how far back the rhamphotheca of the beak extended.

The dentary had three processes that extended backwards into other bones placed further back in the mandible. The articular bone at the back of the mandible was completely fused with the surangular and prearticular bones. The mandible extended hindwards beyond the cotyla — which connected with the condyle of the upper jaw — and this part was therefore similar to a retroarticular process as seen in other taxa. The surangular enclosed two mandibular fenestrae. The hindmost part of the surangular had a small foramen placed in the same position as similar openings in the mandibles of non-bird theropods and modern birds. The splenial bone was three-pronged — as in some modern birds, but unlike the simple splenial of Archaeopteryx — and its lower margin followed the lower margin of the mandible. There were large rostral mandibular fenestra and a small, rounded caudal fenestra behind it.

Though only two specimens preserve parts of the beak's keratinous covering, these show that there would have been differences between species not seen in the skeleton. The holotype of C. dui preserves the outline of an upwards curving beak which sharply tapers towards its tip, while a C. sanctus specimen has an upper margin that is almost straight and a tip that appears to be slightly hooked downwards.

Photo One: Zhiheng Li, Zhonghe Zhou, Julia A. Clarke - http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0198078, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=78911418

Photo Two: James St. John, Ohio State University, Newark - https://www.flickr.com/photos/jsjgeology/15236217920/, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=36907383