Monday, 30 November 2020

ANCIENT SEAS: HOKKAIDO

A very beautiful Lower Campanian block from Haroto, Hokkaido, Japan. This specimen contains an ancient undersea world at a glance.

The beautiful block you see here was prepared, photographed and is in the collections of José Juárez Ruiz. In it, you can see a lovely Pseudoxybeloceras (Parasolenoceras) soyaense (143 mm), Polyptychoceras jimboi (134 mm), Polyptychoceras sp. (114 mm), Gaudryceras mite (48 and 45 mm), Gaudryceras tenuiliratum (Hirano, 1978) at (48 and 20 mm), and a wee fragment of wood (69 mm).

Matsumoto published on the ammonites from the Campanian (Upper Cretaceous) of northern Hokkaido back in 1984, in the Palaeontological Society of Japan Special Series Papers, Number #27.

This was my first look at the glorious fauna from northern Japan. The species and preservation are truly outstanding. Since then, many of the Japanese palaeontologists have made their way over to Vancouver Island, to look at ammonites, inoceramids and coleoid jaws from the Nanaimo Group and compare them to the Japanese species.

Rick Ross and Pat Trask, both of Courtenay on Vancouver Island, collaborated with Dr. Kazushige Tanabe and Yoshinori Hikida of Japan, to produce a wonderful paper in the Journal of Paleontology, 82 (2), 2008, pp 398-408, on Late Cretaceous Octobrachiate Coleoid Lower Jaws from the North Pacific Regions. They compared eight well-preserved cephalopod jaws from Upper Cretaceous (Santonian and Campanian) deposits of Vancouver Island, Canada, and Hokkaido, Japan. Seven of these were from Santonian to lower Campanian strata of the Nanaimo Group in the northeastern region of Vancouver Island. The eighth specimen was from Santonian strata of the Yezo Group in the Nakagawa area, northern Hokkaido, Japan. 

While they were collaborating on identifying coleoid jaws from the Comox Valley, Rick was visited twice by Dr. Kazushige Tanabe who was joined by his colleague Akinori Takahashi. Takahashi is an expert on temporal species-diversity changes in Japanese Cretaceous inoceramid bivalves.

They had the very great pleasure of visiting many fossil sites and seeing personal and museum collections. If you'd like to read Matsumoto's paper, here is the link: http://www.palaeo-soc-japan.jp/download/SP/SP27.pdf  I have a pdf copy of the Coleoid paper from Rick. It has very nice photos and illustrations, including a drawing of the holotypes of Paleocirroteuthis haggerti n. gen. and Paleocirroteuithis pacifica.

Here's a link to one of Takahashi's papers: https://bioone.org/journals/paleontological-research/volume-9/issue-3/prpsj.9.217/Diversity-changes-in-Cretaceous-inoceramid-bivalves-of-Japan/10.2517/prpsj.9.217.short

Sunday, 29 November 2020

LATE JURASSIC PHYLLOCERAS

Phylloceras consanguineum (Gemmellaro 1876) a fast-moving carnivorous ammonite from Late Jurassic (Middle Oxfordian) deposits near Sokoja, Madagascar, off the southeast coast of Africa.

This classical Tethyan Mediterranean specimen is very well preserved, showing much of his delicate suturing in intricate detail. Phylloceras were primitive ammonites with involute, laterally flattened shells.

They were smooth, with very little ornamentation, which led researchers to think of them resembling plant leaves and gave rise to their name, which means leaf-horn. They can be found in three regions that I know of.  In the Jurassic of Italy near western Sicily's Rosso Ammonitico Formation, Lower Kimmeridgian fossiliferous beds of Monte Inici East and Castello Inici (38.0° N, 12.9° E: 26.7° N, 15.4° E) and in the Arimine area, southeastern Toyama Prefecture, northern central Japan, roughly, 36.5° N, 137.5° E: 43.6° N, 140.6° E. And in Madagascar, in the example seen here found near Sokoja, Madagascar, off the southeast coast of Africa at 22.8° S, 44.4° E: 28.5° S, 18.2° E.

Saturday, 28 November 2020

FRACTAL BUILDING: AMMONITES

Argonauticeras besairei, Collection of  José Juárez Ruiz.
An exceptional example of fractal building of an ammonite septum, in this clytoceratid Argonauticeras besairei from the awesome José Juárez Ruiz.

Ammonites were predatory, squidlike creatures that lived inside coil-shaped shells.

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

Catching a fish with your hands is no easy feat, as I'm sure you know. But the Ammonites were skilled and successful hunters. They caught their prey while swimming and floating in the water column. Within their shells, they had a number of chambers, called septa, filled with gas or fluid that were interconnected by a wee air tube. By pushing air in or out, they were able to control their buoyancy in the water column.

They lived in the last chamber of their shells, continuously building new shell material as they grew. As each new chamber was added, the squid-like body of the ammonite would move down to occupy the final outside chamber.

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

The Ammonoidea can be divided into six orders:
  • Agoniatitida, Lower Devonian - Middle Devonian
  • Clymeniida, Upper Devonian
  • Goniatitida, Middle Devonian - Upper Permian
  • Prolecanitida, Upper Devonian - Upper Triassic
  • Ceratitida, Upper Permian - Upper Triassic
  • Ammonitida, Lower Jurassic - Upper Cretaceous
Ammonites have intricate and complex patterns on their shells called sutures. The suture patterns differ across species and tell us what time period the ammonite is from. If they are geometric with numerous undivided lobes and saddles and eight lobes around the conch, we refer to their pattern as goniatitic, a characteristic of Paleozoic ammonites.

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

Hoplites bennettiana (Sowby, 1826).
If they have lobes and saddles that are fluted, with rounded subdivisions instead of saw-toothed, they are likely Jurassic or Cretaceous. If you'd like to see a particularly beautiful Lower Jurassic ammonite, take a peek at Apodoceras. Wonderful ridging in that species.

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

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

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

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

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

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

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

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

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

Friday, 27 November 2020

LOWER CAMBRIAN EAGER FORMATION


This specimen of a mature olenellid trilobite, Wanneria dunnae, is from the Lower Cambrian Eager Formation of British Columbia. 

He is from the Rifle Range outcrop near Cranbrook where you can find numerous fragments and complete specimens of the olenellid trilobites Ollenellus sp. and the larger, more robust Wanneria sp. you see here. 

The site outcrops at a few locations as you head east out of Cranbrook towards Fort Steele. 

The first trilobites were discovered with the building of the Kootenay Highway connecting Cranbrook to Fort Steele and beyond. Several other localities, including the outcrops at the Silhouette Rife Range — which is literally on a Rifle Range where folks go to shoot at things — is a shade older than the Middle Cambrian Burgess Shale but the fauna here is much less varied. 

The site has been known and collected since the 1920s. Back in the day, fossil collecting was a family affair with folks heading out in their lightly coloured finery to picnic and surface collect the eroding exposures. Cranbrook local, Clement Hungerford Pollen was an engineer and avocational palaeontologist. He promoted collecting the exposures of the Eager Formation around 1921. As a pedigreed Englishman of considerable means, he had invested in the Kootenay Central Railway, revitalizing the town by opening up railway access within the region.

Olenellus ricei, Eager Formation
Olenellus is an extinct genus of redlichiid trilobites, with species of average size (about 5 centimetres or 2.0 inches long). He lived during the Botomian and Toyonian stages, Olenellus-zone, 522 to 510 million years ago, in what is currently North-America, part of the paleocontinent Laurentia.

These extinct arthropods are common in Early Cambrian rocks — 542 million to 521 million years old — and thus a useful guide fossil for the Early Cambrian. 

Olenellus had a well-developed semi-circular head, large and crescentic eyes, and a poorly developed, small tail. Telltale features are his fifteen body segments with the third being much longer than the others. The fellow you see had a bit of his tail crushed as he turned to stone.

Trilobites were amongst the earliest fossils with hard skeletons. While they are extinct today, they were the dominant life form at the beginning of the Cambrian and it is what we find as the primary fossil fauna in the Eager Formation. The Eager Formation has produced many beautifully preserved Wanneria, abundant Olellenus and a handful of rare and treasured Tuzoia. The shale matrix lends itself to amazing preservation. The specimens of Wanneria from here are large. Some are up to thirteen centimetres long and ten centimetres wide. You find a mixture of complete specimens and head impressions from years of perfectly preserved moults.

Wednesday, 25 November 2020

FROM RUSSIA WITH LOVE: AULACOSTEPHANUS

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

Kaluga is known for its most famous resident, Konstantin Tsiolkovsky, a rocket science pioneer who worked here as a school teacher. 

The Tsiolkovsky State Museum of the History of Cosmonautics in Kaluga is dedicated to his theoretical achievements and their practical implementations for modern space research, hence the motto on the city's coat of arms: "The Cradle of Space Exploration."

Kaluga, founded in the mid-14th century as a border fortress on the southwestern borders of the Grand Duchy of Moscow, first appears in the historical record in chronicles in the 14th century as Koluga; the name comes from Old Russian Kaluga - "bog, quagmire." 

During the period of Tartar raids, it was the western end of the Oka bank defence line. The Great Stand on the Ugra River was fought just to the west. In the Middle Ages Kaluga was a minor settlement owned by the Princes Vorotynsky. The ancestral home of these princes lies southwest of the modern city.

On 19 January 1777, the Kaluga drama theatre opened its first theatrical season, established with the direct participation of the Governor-General M. N. Krechetnikov.

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

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

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

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

Monday, 23 November 2020

WEYLA OF THE SUNRISE FORMATION

Weyla (Nielsen, 1963) New York Canyon, Nevada
A lovely example of the large bivalve, Weyla (Nielsen, 1963), from the earliest known Jurassic Ferguson Hill Member (Hettangian and Sinemurian) of the Sunrise Formation in the New York Canyon area of west-central Nevada, USA.

The end-Triassic mass extinction was global, severe, and accompanied by worldwide disturbance to carbonate ramp and platform sedimentation. We see the effects played out in the Ferguson Hill Member of the Sunrise Formation. These outcrops are the result of the earliest known Jurassic carbonate ramp produced in the back-arc basin along NE Panthalassa following the extinction event to determine the biotic constituents and timing of local ecological recovery.

The Ferguson Hill Member (Hettangian and Sinemurian) of the Sunrise Formation in the New York Canyon area of west-central Nevada, USA has a lovely counterpart in the Rockies of British Columbia, Canada, explored over three field seasons in the early 2000s before being closed off as a provincial park.

In the Hettangian, post-extinction biosiliceous sedimentation extended to the inner ramp, where an ooid and grapestone shoal marked the outermost extent of a narrow belt of carbonate sedimentation. An early recovery phase in the late Hettangian is characterized by widespread, laterally homogeneous, demosponge-dominated level-bottom sedimentation across the mid- to inner-ramp, in addition to limited trophic tiering (sessile epifaunal suspension-feeding and mobile infaunal deposit-feeding), substantial ramp aggradation, and poor settling conditions for competitive benthic colonizers (e.g., corals, crinoids, infaunal bivalves).

Within 1.6–2 Myr after the extinction (in the early Sinemurian), a late recovery phase is recognized by the appearance of epifaunal grazers (gastropods, echinoids) and suspension feeders (crinoids, solitary scleractinian corals), phototrophic microbialites (oncoids, and possibly photosymbionts within corals), and infaunal deposit or suspension feeders (bivalves).

Although the late recovery faunas included more trophic levels than pre-extinction carbonate ramp habitats, development and progradation of the first Jurassic carbonate ramp still relied heavily on sponge, microbialite, and abiotic mineralization.

Sunday, 22 November 2020

JURASSIC SUNRISE FORMATION OF NEVADA

The entrance to the Pliensbachian-Toarcian localities at Joker Peak and Mina Peak Members of the Sunrise Formation, Nevada, USA.

The Jurassic ammonites of this section were first studied by Dr. Paul Smith, past Chair of Earth and Ocean Sciences, University of British Columbia and more recently by Andrew Caruthers et al.

Caruthers and his team took a goodly look at the Early Jurassic coral fauna. It is nice to see the other marine invertebrates getting the attention they deserve. Caruthers is an interesting cat. He uses a combination of invertebrate palaeontology and isotope geochemistry to ponder the effects of paleoclimate change and mass extinction. He has turned his eye in recent years to the Paleozoic of the Michigan Basin AND he's based in Kalamazoo, MI. Yep, Kalamazoo.

Others have taken up the mantle of discovery from these sites. Pengfei Hou did his 2014 Masters thesis comparing the Sinemurian (Early Jurassic) stratigraphic sections of Last Creek, British Columbia and Five Card Draw, Nevada including a detailed taxonomic study from the Involutum Zone to the lower part of the Harbledownense Zone of the Sinemurian.

Saturday, 21 November 2020

ICHTHYOSAUR RIB SECTION

A tasty ichthyosaur block with three distinct vertebrae and some ribs just peeking out. You can see the edges of the ribs nicely outlined against the matrix of this lovely articulated block. This beauty is but one piece of a complete ichthyosaur found in situ in Middle Triassic (Anisian/Ladinian) outcrops in the West Humboldt Mountains, Nevada.

Ichthyosaurs are an extinct order of marine reptiles from the Mesozoic era. They 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.

They were visibly dolphin-like in appearance but seem to share some other qualities as well. These lovelies were warm-blooded and used their colouration as camouflage. The smaller of their lineage to avoid being eaten and the larger to avoid being seen by prey. Ichthyosaurs also had insulating blubber, a lovely adaptation to keep them warm in cold seas.

Over time, 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 hypothesis later confirmed by fossil embryo and wee baby ichy specimens.

We find their fossil remains in outcrops spanning from 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. 

During the early Triassic, 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. 

Friday, 20 November 2020

HOPLOSCAPHITES NEBRASCENSIS


This sweet macroconch with her lovely oil-in-water colouring is a Hoploscaphites nebrascensis (Owen, 1852). This is the female form of the ammonite that has a larger shell than the male, or microconch.

Hoploscaphites nebrascensis is an upper Maastrichtian species and index fossil. It marks the top of ammonite zonation for the Western Interior. This species has been recorded from Fox Hills Formation in North and South Dakota as well as the Pierre Shale in southeastern South Dakota and northeastern Nebraska.

It is unknown from Montana, Wyoming, and Colorado due to the deposition of coeval terrestrial units. It has possibly been recorded in glacial deposits in Saskatchewan and northern North Dakota, but that is hearsay. 

Outside the Western Interior, this species has been found in Maryland and possibly Texas in the Discoscaphites Conrad zone. This lovely one is in the collection of the deeply awesome (and enviable) José Juárez Ruiz. A big thank you to Joshua DrSlattmaster J Slattery for his insights on this species.

Thursday, 19 November 2020

EUHOPLITES OF FOLKSTONE

Euhoplites Ammonite, Collection of José Juárez Ruiz
A beautiful Euhoplites ammonite from Folkstone, UK. Euhoplites is an extinct ammonoid cephalopod from the Lower Cretaceous, characterized by strongly ribbed, more or less evolute, compressed to inflated shells with flat or concave ribs, typically with a deep narrow groove running down the middle.

In some, ribs seem to zigzag between umbilical tubercles and parallel ventrolateral clavi. In others, the ribs curve forward from the umbilical shoulder and lap onto either side of the venter.

Its shell is covered in the lovely lumps and bumps we associate with the genus. The function of these adornments are unknown. I wonder if they gave them greater strength to go deeper into the ocean to hunt for food. 

They look to have been a source of hydrodynamic drag, likely preventing Euhoplites from swimming at speed. Studying them may give some insight into the lifestyle of this ancient marine predator. Euhoplites had shells ranging in size up to a 5-6cm. We find them in Lower Cretaceous, middle to upper Albian age strata. Euhoplites has been found in Middle and Upper Albian beds in France where it is associated respectively with Hoplites and Anahoplites, and Pleurohoplites, Puzosia, and Desmoceras; in the Middle Albian of Brazil with Anahoplites and Turrilites; and in the Cenomanian of Texas.

This species is the most common ammonite from the Folkstone Fossil Beds in southeastern England where a variety of species are found, including this 37mm beauty from the collections of José Juárez Ruiz.

Wednesday, 18 November 2020

UNRAVELLING THE CARNIAN-NORIAN BOUNDARY

Berlin-Ichthyosaur State Park
The Berlin-Ichthyosaur State Park in central Nevada is an important locality for our understanding of the Carnian-Norian boundary (CNB) in North America.

The area is also known worldwide as one of the most important ichthyosaur Fossil-Lagerstätte because of the sheer volume of remarkably well-preserved, fully articulated specimens of Shonisaurus popularis.

Rich ammonoid faunas outcrop in the Upper Triassic (Early Norian, Kerri zone), Luning Formation, West Union Canyon, Nevada. They were studied by N. J. Silberling (1959) and provide support for the definition of the Schucherti and Macrolobatus zones of the latest Carnian — which are here overlain by well-preserved faunas of the earliest Norian Kerri Zone. 

The genus Gonionotites, very common in the Tethys and British Columbia, is for the moment, unknown in Nevada. The Upper Carnian faunas are dominated by Tropitidae, while Juvavitidae are conspicuously lacking. 

Middle Triassic Ammonoids
Despite its importance, no further investigations had been done at this site for a good 50 years. That changed in 2010 when Jim Haggart, Mike Orchard and Paul Smith — all local Vancouverites — collaborated on a project that took them down to Nevada to look at the conodonts and ammonoids. They did a bed-by-bed sampling of ammonoids and conodonts in West Union Canyon during October of that year.

October is an ideal time to do fieldwork in this area. There are a few good weeks between screaming hot and frigid cold. It is also tarantula breeding season so keep your eyes peeled. Those sweet little burrows you see are not from rodents but rather largish arachnids. 

The eastern side of the canyon provides the best record of the Macrolobatus Zone, which is represented by several beds yielding ammonoids of the Tropites group, together with Anatropites div. sp. 

Conodont faunas from both these and higher beds are dominated by ornate metapolygnthids that would formerly have been collectively referred to Metapolygnathus primitius, a species long known to straddle the CNB. Within this lower part of the section, they resemble forms that have been separated as Metapolygnathus mersinensis. Slightly higher, forms close to Epigondolella' orchardi and a single Orchardella n. sp. occur. This association can be correlated with the latest Carnian in British Columbia.

Higher in the section, the ammonoid fauna shows a sudden change and is dominated by Tropithisbites. Few tens of metres above, but slightly below the first occurrence of Norian ammonoids Guembelites jandianus and Stikinoceras, two new species of conodonts (Gen et sp. nov. A and B) appear that also occur close to the favoured Carnian/Norian boundary at Black Bear Ridge, British Columbia. Stratigraphically higher collections continue to be dominated by forms close to M. mersinensis and E. orchardi after BC's own Mike Orchard.

The best exposure of the Kerri Zone is on the western side of the West Union Canyon. Ammonoids, dominated by Guembelites and Stikinoceras div. sp., have been collected from several fossil-bearing levels. Conodont faunas replicate those of the east section. The collected ammonoids fit perfectly well with the faunas described by Silberling in 1959, but they differ somewhat from coeval faunas of the Tethys and Canada. 

The ammonoid fauna paints a compelling picture of Tethyan influence with a series of smoking guns. We see an abundance of Tropitidae in the Carnian, a lack of Pterosirenites in the Norian, copious Guembelites, the Tethyan species G. philostrati, the stratigraphic position of G. clavatus and the rare occurrence of Gonionotites. Their hallelujah moment was likely finding an undescribed species of the thin-shelled bivalve Halobia similar to Halobia beyrichi — the clincher that perhaps seals this deal on Tethyan influence. 

I'll take a boo to see what Christopher McRoberts published on the find. A jolly good idea to have him on this expedition as it would have been easy to overlook if the focus remained solely on the conodonts and ammonoids. McRoberts has published on the much-studied Pardonet Formation up in the Willison Lake Area of Northeastern, British Columbia. He knows a thing or two about Upper Triassic Bivalvia and the correlation to coeval faunas elsewhere in the North American Cordillera, and to the Boreal, Panthalassan and Tethyan faunal realms. 

If you fancy a read, they published a paper: "Towards the definition of the Carnian/Norian Boundary: New data on Ammonoids and Conodonts from central Nevada," which you can find in the proceedings of the 21st Canadian Paleontology Conference; by Haggart, J W (ed.); Smith, P L (ed.); Canadian Paleontology Conference Proceedings no. 9, 2011 p. 9-10.

Fig. 1. Location map of Berlin-Ichthyosaur State Park

Marco Balini, James Jenks, Riccardo Martin, Christopher McRoberts, along with Mike Orchard and Norman Siberling, did a bed by bed sampling in 2013 and published on The Carnian/Norian boundary succession at Berlin-Ichthyosaur State Park (Upper Triassic, central Nevada, USA) and published in January 2014 in Paläontologische Zeitschrift 89:399–433. That work is available for download from ResearchGate. The original is in German, but there is a translation available.

After years of reading about the correlation between British Columbia and Nevada, I had the very great pleasure of walking through these same sections in October 2019 with members of the Vancouver Paleontological Society and Vancouver Island Palaeontological Society. It was with that same crew that I'd originally explored fossil sites in the Canadian Rockies in the early 2000s. Those early trips led to paper after paper and the exciting revelations that inspired our Nevada adventure.

If you plan your own adventure, you'll want to keep an eye out for some of the other modern fauna — mountain lions, snakes, lizards, scorpions, wolves, coyotes, foxes, ground squirrels, rabbits, falcons, hawks, eagles, bobcats, sheep, deer and pronghorns.

Figure One: Location map of Berlin-Ichthyosaur State Park. A detailed road log with access information for this locality is provided in Lucas et al. (2007).

Tuesday, 17 November 2020

TRACKING THROUGH THE TRIASSIC

Grambergia sp. Middle Triassic Ammonoid of  BC, Canada
In the early 1980s, Tim Tozer, Geological Survey of Canada was looking at the spread of marine invertebrate fauna in the Triassic of North America. 

In the western terranes of the Cordillera, marine faunas from southern Alaska and Yukon to Mexico are known from the parts that are obviously allochthonous with regard to the North American plates.

Lower and upper Triadic faunas of these areas, as well as some that are today up to 63 ° North, have the characteristics of the lower paleo latitudes. As far as is known, Middle Triadic faunas in these zones do not provide any significant data.

In the western Cordillera, these faunas of the lower paleo latitudes can be found up to 3,000 km north of their counterparts on the American plate. This indicates a tectonic shift of significant magnitude. There are marine triads on the North American plate over 46 latitudes from California to Ellesmere Island. For some periods, two to three different faunal provinces can be distinguished. The differences in faunal species are linked, not surprisingly, to their paleolatitude. They are called LPL, MPL, HPL (lower, middle, higher paleolatitude).

Nevada provides the diagnostic features of the lower (LPL); northeastern British Columbia that of the middle (MPL) and Sverdrup Basin, the large igneous province on Axel Heiberg Island and Ellesmere Island, Nunavut, Canada near the rifted margin of the Arctic Ocean, that of the higher paleolatitude (HPL).

A distinction between the provinces of the middle and the higher paleo-situations can not be made for the lower Triassic and lower Middle Triassic (anise). However, all three provinces can be seen in the deposits of Ladin, Kam and Nor.

In the early 2000s, as part of a series of joint UBC, VIPS and VanPS fossil field trips (and then Chair of the VanPS), I explored much of the lower faunal outcrops of northeastern British Columbia. It was my first time seeing many of British Columbia's Triassic outcrops. Years later, and fueled by seeing paper after paper correlating the faunal assemblages of BC to those of Nevada, I had the very great pleasure of walking through the Nevada strata with John Fam (VanPS, Vice-Chair), Dan Bowen (VIPS, Chair) and Betty Franklin (VIPS, Goddess of Everything and BCPA, Treasurer) — and witnessing first-hand the correlation between the Nevada fauna and those from the Triassic of British Columbia, Canada.

Triassic ammonoids, West Humboldt Mountains, Nevada, USA
The Nevada faunal assemblages are a lovely match. The quality of preservation at localities like Fossil Hill in the Humboldt Mountains of Nevada, perhaps the most famous and important locality for the Middle Triassic (Anisian/Ladinian) of North America, is truly outstanding.

Aside from sheer beauty and spectacular preservation, the ammonoids and belemnites were tucked in cozily with very well preserved ichthyosaur remains.

Tozer's interest in our marine invert friends was their distribution. How and when did certain species migrate, cluster, evolve — and for those that were prolific, how could their occurrence — and therefore significance — aide in an assessment of plate and terrane movements that would help us to determine paleolatitudinal significance. I share a similar interest but not exclusive to our cephalopod fauna. The faunal collection of all of the invertebrates holds appeal.

Middle Triassic (Anisian/Ladinian) Fauna
This broader group held an interest for J.P. Smith who published on the marine fauna in the early 1900s based on his collecting in scree and outcrops of the West Humboldt Mountains, Nevada. He published his first monograph on North American Middle Triassic marine invertebrate fauna in 1914.

N. J. Siberling from the US Geological Survey published on these same Nevada outcrops in 1962. His work included nearly a dozen successive ammonite faunas, many of which were variants on previously described species. Both their works would inform what would become a lifelong piecing together of the Triassic puzzle for Tozer.

If one looks at the fauna and the type of sediment, the paleogeography of the Triassic can be interpreted as follows: a tectonically calm west coast of the North American plate that bordered on an open sea; in the area far from the coast, a series of volcanic archipelagos delivered sediment to the adjacent basins. Some were lined or temporarily covered with coral wadding and carbonate banks. Deeper pools were in between. The islands were probably within 30 degrees of the triadic equator. They moved away from the coast up to about 5000 km from the forerunner of the East Pacific Ridge. The geographical situation west of the back was probably similar.

Jurassic and later generations of the crust from near the back have brought some of the islands to the North American plate; some likely to South America; others have drifted west, to Asia. There are indications that New Guinea, New Caledonia and New Zealand were at a northern latitude of 30 ° or more during the Triassic period.

The terranes that now form the western Cordillera were probably welded together and reached the North American plate before the end of the Jurassic period.

Marine Triassic occurs on the North American Plate over a latitudinal spread of 46 degrees, from California to Ellesmere Island. At some intervals of time faunas on the Plate permit the discrimination of two or three provinces with distinctively different coeval faunas. The faunal differences are evidently related to paleolatitude and the provinces are designated LPL, MPL, HPL (low, mid, high paleolatitude). Nevada provides the diagnostic characters of the LPL province; northeastern British Columbia the MPL; the Sverdrup Basin the HPL. In the Lower Triassic and early Middle Triassic (Anisian), the distinction between the MPL and HPL provinces cannot be made. All three provinces are recognized in the Ladinian, Carnian and Norian deposits.

Juvavites sp. Geological Survey of Canada. Photo: John Fam
In the western tracts of the Cordillera, the part formed of suspect terranes, apparently allochthonous with respect to the North American Plate, marine faunas are known all the way from southern Alaska and Yukon to Mexico.

Lower and Upper Triassic faunas from these terranes, including some which today are at 63 degrees north, have the characters of the LPL province.

Middle Triassic faunas from the terranes, as presently known, do not contribute significant data. In the terranes of the Western Cordillera, LPL faunas were now up to 3,000 km north of their counterparts on the American Plate. Through the fossil fauna assemblages, we can see this level of tectonic displacement.

Taking into account the faunas and the nature of the rocks, the Triassic paleogeography is interpreted as a tectonically quiet west shore for the North American Plate, bordered by an open sea or ocean; then, well off-shore, a series of volcanic archipelagos shedding sediment into adjacent basins. Some were fringed or intermittently covered by coralline shoals and carbonate banks. Deeper basins were in between. The islands probably were within 30 degrees of the Triassic equator and extended offshore for about 5000 km, to the spreading ridge directly ancestral to the East Pacific Rise. The geography west of the spreading ridge was probably comparable.

Jurassic and later generation of crust at the ridge had driven some of the islands into the North American Plate; some probably to South America; others have gone west to Asia. Evidence is given that northern New Guinea, New Caledonia and New Zealand may have been at a north latitude of 30 degrees or more in the Triassic. The terranes now forming the Western Cordillera had probably amalgamated, and reached the North American Plate, before the end of the Jurassic.

At the end of the Rhaetian (part of the Triassic period), most of the ammonites had died out. The Hettangian, a rather poorly understood 3 million year time interval followed the Triassic-Jurassic mass extinction event.

During the Hettangian, the new or  Neoammonites developed quite quickly. Within a million years, a fairly large, diverse selection of genera and species had risen to fill the void. The gap created by the Triassic-Jurassic extinction event was re-filled and our ability to "read the rocks' to understand their continued movement through tectonic plate shifting recommenced.

Alsatites proaries, Hettangian Ammonite
It is during the Hettangian that the smooth shelled ammonite genus Psiloceras first appears. They span the time between 201.3 ± 0.2 Ma and 199.3 ± 0.3 Ma (million years ago). For my European friends, the Hettangian is the time span in which the marine limestone, shales and clay Lias of western Europe were deposited.

This Hettangian ammonite, Alsatites proaries, is a lovely example of the cephalopods cruising our ancient oceans at that time. Alsatites is an extinct genus of cephalopod belonging to the Ammonite subclass. They lived during the Early Jurassic, Hettangian till the Sinemurian and are generally extremely evolute, many whorled with a broad keel. Or, as described by one of my very young friends, he looks like a coiled snake you make in pottery class.

The Hettangian is an interesting little period of our history. It spans the time between 201.3 ± 0.2 Ma and 199.3 ± 0.3 Ma (million years ago). For my European friends, the Hettangian is the time in which the marine limestone, shales and clay Lias of western Europe were deposited. In British Columbia, Canada, we see the most diverse middle and late Hettangian (Early Jurassic) ammonite assemblages in the Queen Charlotte Islands (Haida Gwaii), an archipelago about 50 km off British Columbia's northern Pacific coast. In total, 53 ammonite taxa are described of which Paradasyceras carteri, Franziceras kennecottense, Pleuroacanthites charlottensis, Ectocentrites pacificus and Curviceras haidae are new.

In general, North American Early Jurassic ammonites are of Tethyan affinity or endemic to the eastern Pacific. For this reason, a separate zonation for the Hettangian and Sinemurian of the Western Cordillera of North America was established. Taylor et al. (2001), wrote up and published on much of this early research though, at the time, very little Canadian information was included.

Longridge, L. M., et al. “Three New Species of the Hettangian (Early Jurassic) Ammonite Sunrisites from British Columbia, Canada.” Journal of Paleontology, vol. 82, no. 1, 2008, pp. 128–139. JSTOR, www.jstor.org/stable/20144175. Accessed 27 Jan. 2020.

Tozer, ET (Tim): Marine Triassic faunas of North America: Their significance for assessing plate and terrane movements. Geol Rundsch 71, 1077-1104 (1982). https://doi.org/10.1007/BF01821119

Danner, W. (Ted): Limestone resources of southwestern British Columbia. Montana Bur. Mines & Geol., Special publ. 74: 171-185, 1976.

Davis, G., Monger, JWH & Burchfiel, BC: Mesozoic construction of the Cordilleran “collage”, central British Columbia to central California. Pacific Coast Paleography symposium 2, Soc. Economic Paleontologists and Mineralogists, Los Angeles: 1-32, 1978.

Gibson, DW: Triassic rocks of the Rocky Mountain foothills and front ranges of northeastern British Columbia and west-central Alberta. Geol. Surv. Canada Bull. 247, 1975.

Photo of the large belemnite (Atractites sp?) and ammonites (Sunrisites & Badouxia) from the Lower Jurassic (Late Hettangian), Last Creek Formation (Castle Pass member), Taseko Lakes area, British Columbia, Canada in the collection of the deeply awesome John Fam.

Photo: A drawer of Juvavites sp. in the collections of the Geological Survey of Canada. These rarely seen Upper Triassic (Carnian to Norian) ammonoids were collected over many decades by geologists of the Geological Survey of Canada from Northeastern British Columbia. Photo care of the deeply awesome John Fam.

Photo: Grambergia sp. from the Early Anisian (Middle Triassic) ammonoid biostratigraphy of northeastern British Columbia, Canada. Collection of Fossil Huntress.

Photo: Alsatites proaries, Coll. Reiter, Neoammoniten, 30 July 2011, 19:26:10

Sunday, 15 November 2020

TALES FROM HAIDA GWAII

A wreck with tales to tell at Naikoon, Haida Gwaii. The islands have gone by many names. To the people who call the islands home, Haida Gwaii means “island of the people,” it is a shortened version of an earlier name, Haadala Gwaii-ai, or “taken out of concealment.” 

Back at the time of Nangkilslas, it was called Didakwaa Gwaii, or “shoreward country.” By any name, the islands are a place of rugged beauty and spirit and enjoy a special place in both the natural and supernatural world. The enormous difference between high and low tide in Haida Gwaii – up to twenty three vertical feet – means that twice a day, vast swathes of shellfish are unveiled, free for the taking. 

An ancient Haida saying is still often heard today, “When the tide is out, the table is set.” Archaeological evidence shows that by about five thousand years ago, gathering shellfish replaced hunting and fishing as their primary food source. The shellfish meat was skewered on sticks, smoked and stored for use in winter or for travel.

Steeped in mist and mythology, the islands of Haida Gwaii abound in local lore that surrounds their beginnings. Today, the Hecate Strait is a tempestuous 40-mile wide channel that separates the mist-shrouded archipelago of Haida Gwaii from the BC mainland. Haida oral tradition tells of a time when the strait was mostly dry, dotted here and there with lakes. During the last ice age, glaciers locked up so much water that the sea level was hundreds of feet lower than it is today. Soil samples from the sea floor contain wood, pollen, and other terrestrial plant materials that tell of a tundra-like environment.

The islands of Haida Gwaii are at the western edge of the continental shelf and form part of Wrangellia, an exotic terrane of former island arcs, which also includes Vancouver Island, parts of western mainland British Columbia and southern Alaska. 

Brewericeras hulenense (Anderson, 1938)
While we’ll see that there are two competing schools of thought on Wrangellia’s more recent history, both sides agree that many of the rocks, and the fossils they contain, were laid down somewhere near the equator. 

They had a long, arduous journey, first being pushed by advancing plates, then being uplifted, intruded, folded, and finally thrust up again. It’s reminiscent of how pastry is balled up, kneaded over and over, finally rolled out, then the process is repeated again.

This violent history applies to most of the rock that makes up the Insular Belt, the outermost edge of the Cordillera. Once in their present location, the rocks that make up the mountains and valleys of this island group were glaciated and eroded to their present form. Despite this tumultuous past, the islands have arguably the best-preserved and most fossil-rich rocks in the Canadian Cordillera, dating from very recent to more than 200 million years old. 

The fossils found in the Triassic rock of Wrangellia are equatorial or low latitude life forms quite different from those found today on the Continent at the latitude of Haida Gwaii. This suggests those rocks were in the equatorial region during the Late Triassic, just over 200 million years ago. 

The Lower Jurassic ammonite faunas found at Haida Gwaii are very similar to those found in the Eastern Pacific around South America and in the Mediterranean. The strata exposed at Maple Island, Haida Gwaii are stratigraphically higher than the majority of Albian localities in Skidegate Inlet. The macrofossil fauna belonged to the Upper part of the Sandstone Member of the Haida formation.

The western end of the island contains numerous well-preserved inoceramids such as Birostrina concentrica and a few rare ammonites of Desmoceras bearskinese. The eastern shores are home to unusual ammonite fauna in the finer grained sandstones. Here we find the fossils as extremely hard concretions while others were loose in the shale. Species include Anagaudryceras sacya and Tetragonites subtimotheanus. A large whorl section of the rare Ammonoceratites crenucostatus has also been found here. The ammonites, Desmoceras; Brewericeras hulenense; Cleoniceras perezianum, Douvelliceras spiniferum are all found in Lower Cretaceous, Middle Albian, Haida Formation deposits.

Saturday, 14 November 2020

THE MIGHTY MARINE REPTILES

This well-preserved partial ichthyosaur was found in the Blue Lias shales by Lewis Winchester-Ellis in 2018. The vertebrae you see 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.

Though not often referenced in the literature, the very first well-articulated ichthyosaur skeleton was discovered in 1749 by German physician, Albert Mohr. Mohr found the fossil specimen near Bad Boll in Upper Swabia, a municipality in the district of Göppingen in Baden-Württemberg, Germany. But at the time, Mohr did not realize exactly what he had found. He thought the bones to be those of a fish — possibly a shark or ray. Georg Friedrich Jaeger wrote up a monograph in 1824 celebrating — and slightly inflating the interpretation of Mohr's work — though Jaeger's manuscript was produced in Latin so not often referenced in an ever Anglicized field of science.

Not long after Mohr's discovery, another fairly well-articulated skeleton was discovered by Mary Anning & 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.

Mohr does not often get credited — those accolades usually go to Mary Anning. 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, in 1837.

Lithography from William Buckland's 1824 Paper
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

Here is an image from that 1824 publication showing a lithograph of the anterior extremity of the right lower jaw of the Megalosaurus from Stonesfield near Oxford. 

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 palaeontologists, 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 Haida Gwaii but Shonisaurus 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 the autumn of that year. 

I recently connected with John-Paul (JP) Zonneveld, Professor, Palaeontologist, Sedimentary Geologist and Field Scientist at the University of Alberta, who worked with Betsy on the original Shonisaurus sikanniensis site many years ago. "She was an awesome person, a dear friend and an outstanding field scientist." I could not agree more. She was delightful.

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? You’d remember if you’d seen them. Roy Chapman Andrews was the lead on that trip. His photos are what fueled the flames of my own interest in paleo.

Shonisaurus popularise
We've found at least 37 specimens of Shonisaurus in Triassic outcrops of the Luning Formation in the Shoshone Mountains in northwestern Nye County of Nevada, USA. The finds go back to the 1920s. They were later brought back into the spotlight by the collecting efforts of Margaret Wheat of Fallon and Dr C. L. Camp, UCMP, in the 1950s.  

The aptly named Shonisaurus popularis became the Nevada State Fossil in 1977. 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. And 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 the dinosaur bones from the historic Westbury Mudstone Formation of Aust Cliff, Gloucestershire, UK site into full reinterpretation.

And remember the Ichthyosaur communis the good Reverend Buckland described back in 1837? Dean Lomax was the first to describe a wee baby. A wee baby ichthyosaur! Awe. I know, right? He and palaeontologist 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 3D, 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 3D specimen through the lens of computerized tomography (CT) scanning. 

Another superb three-dimensional 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 3D printed for all to share. Here's hoping.

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 the 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.

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 were able to study 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 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 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.

Image One: The find and photos are all credited to Lewis Winchester-Ellis. Thank you for sharing your tremendous specimen with us. Lewis did much of the preparation of the specimen, removing the majority of the matrix. The spectacular final prep is credited to Lizzie Hingley, Stonebarrow Fossils, Oxfordshire. Her skill with an air scribe is unparalleled.

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]

Image Two: Lithography from William Buckland's "Notice on the Megalosaurus or great Fossil Lizard of Stonesfield", 1824. Anterior extremity of the right lower jaw of the Megalosaurus from Stonesfield near Oxford. Mary Morland (later Buckland; 1797–1857) - Plate 40 (XL) of William Buckland: Notice on the Megalosaurus or great Fossil Lizard of Stonesfield. Transactions of the Geological Society of London. Series 2, vol. 1, no. 2, 1824, S. 390–396 (digital copy at geolsoc.org.uk).

HOME, E. (1814) Some Account of the Fossil Remains of an Animal more nearly allied to Fishes than any of the Other Classes of Animals. Phil. Trans. R. Soc. Lond. 104, 571- 577.

JAEGER, G.F. (1824) De Ichthyosauri sive Proteosauri fossils speciminibus in Agro Bollensi in Wurtembergia repertis. Stuttgart.

LHUYD, E. (1699) Lithophylacii Britannici Ichnographia. London.


Friday, 13 November 2020

DOUVELLICERAS SPINIFERUM

Douvelliceras spiniferum, Cretaceous Haida Formation
The islands of Haida Gwaii lay at the western edge of the continental shelf due west of the central coast of British Columbia. 

They form Wrangellia, an exotic tectonostratigraphic terrane that includes Vancouver Island, parts western British Columbia and Alaska.

The Geological Survey of Canada (GSC) sponsored many expeditions to these remote islands and has produced numerous reference papers on this magnificent terrain, exploring both the geology and palaeontology of the area.

Joseph Whiteaves, the GSC's chief palaeontologist in Ottawa, published a paper in 1876 describing the Jurassic and Cretaceous faunas of Skidegate Inlet, furthering his reputation globally as both a geologist and palaeontologist.

The praise was well-earned and foreshadowed his significant contributions to come. Sixteen years later, he wrote up and published his observations on a strange Mount Stephen fossil that resembled a kind of headless shrimp with poorly preserved appendages. Because of the unusual pointed shape of the supposed ventral appendages and the position of the spines near the posterior of the animal, Whiteaves named it Anomalocaris canadensis. The genus name "Anomalocaris" meant "unlike other shrimps" and the species name "canadensis" referred to the country of origin.

Whiteaves work on the palaeontology of Haida Gwaii provided excellent reference tools, particularly his work on the Cretaceous exposures and fauna that can be found there.

One of our fossil field trips was to the ruggedly beautiful Cretaceous exposures of Lina Island. We’d planned this trip as part of our “trips of a lifetime.” Both John Fam and Dan Bowen can be congratulated for their efforts in researching the area and ably coordinating a warm welcome by the First Nations community and organizing fossil field trips to some of the most amazing fossil localities in the Pacific Northwest. With great sandstone beach exposures, the fossil-rich (Albian to Cenomanian) Haida formation provided ample specimens, some directly in the bedding planes and many in concretion. Many of the concretions contained multiple specimens of typical Haida Formation fauna, providing a window into this Cretaceous landscape.

It is always interesting to see who was making a living and co-existing in our ancient oceans at the time these fossils were laid down. We found multiple beautifully preserved specimens of the spiny ammonite, Douvelleiceras spiniferum along with Brewericeras hulenense, Cleoniceras perezianum and many cycads in concretion.

Pictured above is Douvilleiceras spiniferum with his naturally occurring black, shiny appearance. Choosing my favourite fossil is a tricky business as there are so many wonderful specimens to choose from but if I had to choose, this would be favourite. This satisfying chunky monkey is 6 inches long and 5 inches deep, and a beautiful example of the species. Missing from this trip log are tales of Rene Savenye, who passed away in the weeks before this trip. While he wasn't there in body, he was with us in spirit. I thought of him often on the mist-shrouded days of collecting. Many of the folk on who joined me on those outcrops were friends of Rene's and would go on to receive the Rene Savenye Award. There is a certain palaeo poetry in that. 

Thursday, 12 November 2020

BRACHIOPODA: LOPHOTROCHOZOANS

Looking down at the pebbly sand, you see just the wee top of this lovely fossil brachiopod poking out. Glee, delight and wonder follow as you roll it over in your hands and notice how it differs from clams you may be more familiar with.

Clams or bivalves are molluscs, the second-largest phylum of invertebrates with about 85,000 extant species. While brachiopods share some similarities with their molluscan friends they are in a phylum all their own.

Brachiopods are small marine shellfish that are not so common today but back in the Palaeozoic they were plentiful the world over. The two valves that make up a brachiopods shell are of different sizes and if you look closely you'll see that the hinge runs top and bottom  -- versus left and right like a clam.

Brachiopods had evolved from an ancestor similar to Halkieria, a slug-like Cambrian animal with "chain mail" on its back and a shell at the front and rear end; it was thought that the ancestral brachiopod converted its shells into a pair of valves by folding the rear part of its body under its front. 

New fossils found in the last few years have shown us that the "chain mail" of tommotiids formed the tube of a sessile animal; one tommotiid resembled phoronids, which are close relatives or a subgroup of brachiopods, while the other tommotiid bore two symmetrical plates that might be an early form of brachiopod valves. Lineages of brachiopods that have both fossil and extant taxa appeared in the early Cambrian, Ordovician, and Carboniferous periods, respectively. 

Other lineages have arisen and then become extinct, sometimes during severe mass extinctions. At their peak in the Paleozoic era, the brachiopods were among the most abundant filter-feeders and reef-builders and occupied other ecological niches, including swimming in the jet-propulsion style of scallops. Brachiopod fossils have been useful indicators of climate changes during the Paleozoic. However, after the Permian–Triassic extinction event, brachiopods recovered only a third of their former diversity. 

Brachiopods were especially vulnerable to the Permian–Triassic extinction, as they built calcareous hard parts — made of calcium carbonate — and had low metabolic rates and weak respiratory systems. It was often thought that brachiopods went into decline after the Permian–Triassic extinction, and were out-competed by bivalves, but both brachiopod and bivalve species increased from the Paleozoic to modern times, with bivalves increasing faster; after the Permian–Triassic extinction, brachiopods became for the first time less diverse than bivalves.

Their lineage dates back to the Cambrian with over 12,000 fossil species and 350 living relatives sorted between 6,000 genera. There are two major groups of brachiopods, articulate with toothed hinges and simple open and closing muscles to manipulate their shells and inarticulate brachiopods with untoothed hinges and a more complex set of muscles used to control the brachial supports used to open and close their shells.

Wednesday, 11 November 2020

FOSSIL BONANZA: LAGERSTÄTTEN

Florissantia from Quilchena
Highly recommend the tasty paleo goodies shared on the Fossil Bonanza website and podcast. Both sites are dedicated to Fossil-Lagerstätten — the passion of Andy Connolly, a museum educator out of Utah. 

Fossil-Lagerstätten are unusual fossil sites found across the globe. A Lagerstätte is a sedimentary deposit with extraordinary fossils preservation. If we are truly lucky, this includes the preservation of soft tissues in remarkable detail. 

Fossil-Lagerstätten can be formed in a number of ways. Sometimes an animal or plant is buried in an anoxic or low oxygen environment with minimal bacteria to break down the organic material. In this case, decomposition is minimized. 

Even better if the burial happens quickly so that no scavengers can enjoy a tasty snack and the entire specimen is preserved. This type of burial preserves both the gross and fine biological features. If you look at the Florissantia petals above, they look like you may have pressed a modern blossom between the pages of a book. While this lovely is from Ypresian, Early Eocene, deposits near Quilchena, British Columbia, it looks as though it could reasonably have been plucked this year. In the case of Quilchena, the perfect blossom was preserved in a lakebed setting with fine silt that quickly covered and pressed down upon the pedals so that they are preserved here as impressions and carbonaceous films.

The Earth occasionally blesses us with Lagerstätten which can amass thousands, sometimes millions of preserved fossils in stunning quality. Birds can be found with their bones perfectly intact and feathers arranged in a beautiful display. 

Flowers are captured in full bloom — as in the case of the lovely Florissantia above — and leaves look as if they had just fallen from a tree. Even amber-entombed insects have their tiny, delicate hairs untouched. Some of these fossil sites are quite well known: La Brea Tar Pits in California or Dinosaur National Monument in Utah and Colorado. 

Others fly under the collective radar — Grube Messel in Germany or the Naracoorte Caves in Australia. Nevertheless — these sites all contribute vast quantities of knowledge about our ancient worlds and fill in the gaps that would otherwise be empty forever. 

Konservat-Lagerstätten preserves lightly sclerotized and soft-bodied organisms or traces of organisms that are not otherwise preserved in the usual shelly and bony fossil record; thus, they offer more complete records of ancient biodiversity and behaviour and enable some reconstruction of the palaeoecology of ancient aquatic communities. 

In 1986, Simon Conway Morris calculated only about 14% of genera in the Burgess Shale had possessed biomineralized tissues in life. The affinities of the shelly elements of conodonts were mysterious until the associated soft tissues were discovered near Edinburgh, Scotland, in the Granton Lower Oil Shale of the Carboniferous. 

Information from the broader range of organisms found in Lagerstätten has contributed to recent phylogenetic reconstructions of some major metazoan groups. Lagerstätten seem to be temporally autocorrelated, perhaps because global environmental factors such as climate might affect their deposition

I've popped the link here for you. Definitely worth checking out! https://fossilbonanza.com/about/

Tuesday, 10 November 2020

MIGUASHA BOTHRIOLEPIS CANADENSIS

Bothriolepis canadensis
A stunning replica of Bothriolepis canadensis from Upper Devonian (Frasnian), Escuminac formation, Parc de Miguasha, Baie des Chaleurs, Gaspé, Québec, Canada.

Over the past 170 years, the Late Devonian Miguasha biota from eastern Canada has yielded a diverse aquatic assemblage including 20 species of lower vertebrates —anaspids, osteostra-cans, placoderms, acanthodians, actinopterygians and sarcopterygians — a more limited invertebrate assemblage, and a continental component including plants, scorpions and millipedes.

Originally interpreted as a freshwater lacustrine environment, recent paleontological, taphonomic, sedimentological and geochemical evidence corroborates a brackish estuarine setting. 

Over 18,000 fish specimens have been recovered showing various modes of fossilization, including uncompressed material and soft-tissue preservation. Most vertebrates are known from numerous, complete, articulated specimens. Exceptionally well-preserved larval and juvenile specimens have been identified for 14 out of the 20 species of fishes, allowing growth studies. 

Numerous horizons within the Escuminac Formation are now interpreted as either Konservat or Konzentrat–Lagerstätten — and perhaps a contender for Andy Connolly's Fossil Bonanza podcast. What's say, Andy? 

This replica was purchased at the Musée d'Histoire Naturelle, Miguasha (MHNM) and is in the collection of the deeply awesome (and well-travelled) John Fam, Vice-Chair of the Vancouver Paleontological Society.

Great Canadian Lagerstätten 4. The Devonian Miguasha Biota (Québec): UNESCO World Heritage Site and a Time Capsule in the Early History of Vertebrates, Richard Cloutier, Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, 300 allée des Ursulines, Rimouski, QC, Canada, G5L 3A1, richard_cloutier@uqar.ca, http://dx.doi.org/10.12789/geocanj.2013.40.008

Sunday, 8 November 2020

BURGESS, WALCOTT & WAVING CAMBRIAN WORMS

High up in the Canadian Rockies in an area known as Burgess Pass is one of the most unlikely, perfect and improbable fossil sites on Earth. The Burgess Shale sits high up on the glacier-carved cliffs of the Canadian Rockies.

The fine-grained shales from the Burgess were once part of the ancient landmass known as Laurentia, the ancient geologic core of the North American continent, and are home to some of the most diverse and well-preserved fossils in the world. The sedimentary shales here contain fossils that open a window to marine life half a billion years old.

The site is made up of a few quarries and includes the Stephen Formation — Mount Wapta and Mount Field — and the upper Walcott Quarry with its Phyllopod Bed. There is also a lower quarry named for Professor Piercy Raymond who opened the site in 1924.

It is one of the rare locations in the world where both soft tissues and hard body parts have been fossilized amidst the layers of black shale that form Fossil Ridge and the surrounding areas.

Discovered just over a hundred years ago on an unlikely day in 1909 by Charles D. Walcott, the site has continued to wow scientists and the community at large year after year. Charles was in Canada after losing his first wife to a train crash in Connecticut. He met Mary Morris Vaux, an amateur naturalist from a wealthy family and this new love and her interest in the wilds of Canada had brought him back.

Walcott was a geologist, palaeontologist and administrator of the Smithsonian Institution in Washington, DC, USA. He was an expert in Cambrian fossils for his time. A company man, he joined the US Geological Survey in 1879 and rose to become a director in 1894.  He served as President of the American Association for the Advancement of Science in 1923 and was an advisor to President Theodore Roosevelt.

Picture the world at this time. Coca-Cola sold their first soft drink, in Germany, Wilhelm Roentgen developed the first x-ray and it was a year before the United States Supreme Court ruled that "separate but equal" public facilities for whites and blacks ought to be legal.

So, up and coming Walcott was up exploring in the Rockies and stopped to rest his horse. Always a rock man, he had his hammer handy and split some likely blocks. They contained trilobites and other arthropods now famous from the site.

While he recognized the significance of the site, it wasn’t until 1960 through the work of Alberot Simonella and others that the Burgess received the scientific attention it deserved.

In 1967, Harry Whittington initiated the Cambridge Project to re-open the Burgess files and build on the work of his predecessors. He brought two grad students on board to do the heavy lifting as a means to publish or perish. Simon Conway Morris (Worms) and Derek Briggs (Arthropods) completed the trio and together they formed the foundation of what was to become some of the most significant work of our time.

Imagine the first palaeontologists working on these weird and wonderful specimens. Wondering at the strange and unlikely creatures made real before their eyes. It is a rare and exquisite thing to see soft-bodied organisms fossilized.

Every year, a new species or magnificent specimen is unearthed. In 2011, a hiker discovered a rare fossil of Ovatiovemis, a genus of filter-feeding lobopodians. Picture a marine worm with nine arms waving to you. Yep, that’s him. The specimen she found is now described as Ovatiovermis cribratus and is one of only two known specimens of Oviatiovermis from the Burgess.

This important site in the Canadian Rockies has been awarded protection as a UNESCO World Heritage Site (1981) in recognition of the exceptional fossil preservation and diversity of the species found here.

With countless hours of research and study, we now know the Burgess Shale contains the best record we have of Cambrian animal fossils. It reveals the most complete record of creatures that proliferated the Earth showcasing the Cambrian explosion 545 to 525 million years ago.

It was a time of oceanic life in all its splendour. The land may have been inhospitable, barren and uninhabited but our oceans were teeming with new species. Great soft fine-grained mudslides slid onto an ecosystem in a deep-water basin. Millions of years later, this unlikely event was revealed to us through the fossils preserved at Burgess.

Photo: The view from Burgess Pass