KERMODE SPIRIT BEAR: GREAT BEAR RAINFOREST

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

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

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

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

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

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

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

KEPPLERITES FROM THE KURSK REGION

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

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

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

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

PTERASPIDID WITH TAIL

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

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

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

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

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

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

Photo & collection of the awesome Fossilero Fisherman

INNER EAR HESPERORNIS

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

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

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

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

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

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

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

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

NORWAY: HAPPY NATIONAL DAY

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

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

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

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

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

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

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

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

TUSK SHELL: OYSTER BAY FORMATION

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

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

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

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

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

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

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

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

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

AMMONITES FROM THE GAULT

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

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

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

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

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

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

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

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

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

ANCIENT ARMADILLOS

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

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

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

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

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

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

The ancient Armadillo Glyptodon asper

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

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

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

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

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

GIANT TORTOISES & THE ISLAND RULE

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

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

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

BALEARITES OF MOROCCO

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

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

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

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

GREEK MYTHOLOGY AND ANCIENT BONES

Tetralophodon

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

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

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

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

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

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

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

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

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

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

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

EIFELIAN PARALEJURUS

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

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

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

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

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

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

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

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

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

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

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

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

LEANCHOILIA: CHENGJIANG

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

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

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

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

References:

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

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

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

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

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