PERFECTLY ROLLED TRILOBITE

GASTROPODS

Gastropods, or univalves, are the largest and most successful class of molluscs. They started as exclusively marine but have adapted well and now their rank spends more time in freshwater than in salty marine environments.

Many are marine, but two-thirds of all living species live in freshwater or on land. Their entry into the fossil record goes all the way back to the Cambrian.

Slugs and snails, abalones, limpets, cowries, conches, top shells, whelks, and sea slugs are all gastropods. They are the second-largest class of animals with over 60,000–75,000 known living species.

The gastropods are originally sea-floor predators, though they have evolved to live happily in many other habitats. Many lines living today evolved in the Mesozoic. The first gastropods were exclusively marine and appeared in the Upper Cambrian (Chippewaella, Strepsodiscus).

By the Ordovician, gastropods were a varied group present in a variety of aquatic habitats. Commonly, fossil gastropods from the rocks of the early Palaeozoic era are too poorly preserved for accurate identification. Still, the Silurian genus Poleumita contains fifteen identified species.

Most of the gastropods of the Palaeozoic era belong to primitive groups, a few of which still survive today. By the Carboniferous, many of the shapes we see in living gastropods can be matched in the fossil record, but despite these similarities in appearance the majority of these older forms are not directly related to living forms. It was during the Mesozoic era that the ancestors of many of the living gastropods evolved.

In Mesozoic rocks, gastropods are more common as fossils and their shells often very well preserved. While not all gastropods have shells, the ones that do fossilize more easily and consequently, we know a lot more about them. We find them in fossil beds from both freshwater and marine environments, in ancient building materials and as modern guests of our gardens.

FOSSIL TURTLE

Fossil Turtle. Photo credit: Luis Lima. Lisbon Museum Collection

URSAVUS: BLACK BEAR CUB

Hiking in BC, both grizzly and black bear sightings are common. Nearly half the world's population, some 25,000 grizzlies, roam the Canadian wilderness.

Both bear families descend from a common ancestor, Ursavus, a bear-dog the size of a raccoon who lived more than 20 million years ago. Seems an implausible lineage given the size of their very large descendents. An average Grizzly weighs in around 800 lbs (363 kg), but a recent find in Alaska tops the charts at 1600 lbs (726 kg). This mighty beast stood 12' 6' high at the shoulder, 14' to the top of his head. It is one of the largest grizzly bears ever recorded.

PERFECT SYMMETRY: BRACHIOPODS

Brachiopods are bottom-feeding marine animals that appeared at the beginning of the Cambrian. They are abundant little fellows with more than 35,000 known species. Some have lived their time on Earth and are now extinct. Others have done well and we see them in our oceans today.

FOSSIL CRINOID: UINTACRINUS OF UTAH

Crinoids are one of my favourite echinoderms. It is magical when all the elements come together to preserve a particularly lovely specimen in such glorious detail. 

If you look closely at the detail here you can see a stunning example of Upper Cretaceous, Santonian age, Uintacrinus socialis — named by O.C. Marsh for the Uinta Mountains of Utah nearly 150 years ago.  

These lovelies are best known from the Smoky Hills Niobrara Formation of central Kansas. 

Crinoids are unusually beautiful and graceful members of the phylum Echinodermata. They resemble an underwater flower swaying in an ocean current. 

But make no mistake they are marine animals. Picture a flower with a mouth on the top surface that is surrounded by feeding arms. Awkwardly, add an anus right beside that mouth. 

Crinoids with root-like anchors are called sea lilies. They have graceful stalks that grip the ocean floor. Those in deeper water have longish stalks up to 3.3 ft or a meter in length. Then there are other varieties that are free-swimming with only vestigial stalks. They make up the majority of this group and are commonly known as feather stars or comatulids. 

Unlike the sea lilies, the feather stars can move about on tiny hook-like structures called cirri. It is these same cirri that allow crinoids to latch to surfaces on the seafloor. Like other echinoderms, crinoids have pentaradial symmetry. The aboral surface of the body is studded with plates of calcium carbonate, forming an endoskeleton similar to that in starfish and sea urchins.

These make the calyx somewhat cup-shaped, and there are few, if any, ossicles in the oral (upper) surface, an area we call the tegmen. It is divided into five ambulacral areas, including a deep groove from which the tube feet project, and five interambulacral areas between them. 

Crinoids are alive and well today. They are also some of the oldest fossils on the planet. We have lovely fossil specimens dating back to the Ordovician — if one ignores the enigmatic Echmatocrinus of the Burgess Shale. And they can be quite plentiful. Crinoid fossils, and in particular disarticulated crinoid columnals, can be so abundant that they at times serve as the primary supporting clasts in sedimentary rocks.

NATURAL HISTORY MUSEUM LISBON

Natural History Museum, Lisbon / Photo credit: Luis Lima

This beautiful "old school" gallery you see here is in the National Museum of Natural History and Science in Lisbon, Portugal. To the locals, it is the Museu Nacional de História Natural e da Ciência and is the country's main museum focusing on nature.

Its rich collections, gathered over more than 250 years, span zoology, anthropology, geology and botany.

The museum has activities for the promotion of natural history and science awareness, with space for artistic exhibitions, conferences, debates, workshops and courses.

The Museum Director is Professor Miguel Magalhaes Ramalho, geologist, researcher coordinator and former professor of the University of Lisbon.

ICELANDIC PONIES

FOSSIL PREPARATION

GLORIOUS SHARK OF CHUBUT

Carcharocles chubutensis, meaning "glorious shark of Chubut," from the ancient Greek is an extinct species of prehistoric mega-toothed sharks in the genus Carcharocles.

These big beasties lived during Oligocene, Miocene, and Pliocene, 28-5 million years ago. This fellow is considered to be a close relative of the famous prehistoric mega-toothed shark, C. megalodon, although the classification of this species is still disputed.

Swiss naturalist Louis Agassiz first identified this shark as a species of Carcharodon in 1843. In 1906, Ameghino renamed this shark as C. chubutensis. In 1964, shark researcher, L. S. Glikman recognized the transition of Otodus obliquus to C. auriculatus. In 1987, shark researcher, H. Cappetta reorganized the C. auriculatus - C. megalodon lineage and placed all related mega-toothed sharks along with this species in the genus Carcharocles. At long last, the complete Otodus obliquus to C. megalodon progression became clear and has since gained the acceptance of his peers. The specimen you see here is in the Geological Museum in Lisbon. Photo credit: Luis Lima.

HIKING BIG WHITE

BRITISH COLUMBIAN ICE AGE

It has long been accepted that the most recent series of ice ages began approximately 1.6 million years ago, beginning as ice accumulations at higher altitudes with the gradual cooling of the climate. Four times the ice advanced and receded, most recently melting away somewhere around 10,000 years ago. Ice retreated from southwestern British Columbia and the Puget Sound area around 15,000 years ago.

In the southern Interior, ice built up first in the northern Selkirk Mountains, then slowly flowed down into the valleys. Once the valleys were filled, the depth of the ice increased until it began to climb to the highlands and finally covered most of the Interior of British Columbia.

Between ice advances, there were times when the Kamloops area was ice free and the climate warm and hospitable. Glacial ice was believed to have initiated its most recent retreat from the South Thompson area around 11,000 to 12,000 years ago, but salmon remains from 18,000 years ago suggest that it may have actually began its northwest decline much earlier and indicating a much warmer climate in the Interior than archaeologists or geologists had originally estimated.

CAMPANIAN NAUTILUS

A picture perfect Campanian nautilus, Eutrophoceras irritilansis, from deposits near Coahuila, northern Mexico. Collection of Jose Ventura.

SUMAS FOSSIL SLIDE SITE

George Mustoe, Sumas Fossil Slide Site

The Sumas Fossil Slide Site revealed wonderfully preserved Eocene plant fossils. Here a fossil Palm Trunk impression is getting prepped by George Mustoe.

In 2009, there was a large downpour that hit Washington State causing massive slides. The blocks you see here all came crashing down on the hillside. Once the skies cleared, hikers found plant impressions in the rock and alerted the local paleo community. I was invited to tag along on a trip to photograph the site while George Mustoe took moulds of the palm trunks and trackways. The slide site at Sumas Mountain revealed many large exposures of fossil plants. Some exposures were 10 feet across. There was great excitement at seeing shorebird tracks and trackways of the large flightless bird Diatryma.

WASHINGTON FOSSIL FIELD TRIP

Sumas Slide Site, Sumas, Washington State

Two hundred million years ago, Washington was two large islands, bits of continent on the move westward, eventually bumping up against the North American continent and calling it home.

The shifting continues, subtling changing the landscape like a breath. We only notice when pockets of resistance manifest as earthquakes, some newsworthy, some all but unnoticed. For now, the more extreme movement has subsided laterally and continues vertically, pushing California towards the North Pole. Hello Baja-BC.

The upthrusting of plates moves our mountain ranges skyward – the path of least resistance. And it is this dynamic movement that's created the landscape we see today.

The 3,000 meters of stratigraphic section on Chuckanut Drive spans an age range of just a few million years. The lower part is late Paleocene with a radiometric age of around 56 million years. The upper part of the section is early Eocene. The fossils found here lived and died very close to where they are now but in a much warmer, wetter, swampy setting.

The exposures of the Chuckanut Formation were once part of a vast river delta; imagine, if you will, the bayou country of the Lower Mississippi. The siltstones, sandstones, mudstones and conglomerates of this formation were laid down during a time of luxuriant plant growth in the subtropical flood plain that covered much of the Pacific Northwest.

This ancient wetland provided ideal conditions to preserve the many trees, shrubs and plants that thrived here giving us a lot of information about climate, temperature, the water cycle and humidity of the region.

The Chuckanut flora is made up predominantly of plants whose modern relatives live in tropical areas such as Mexico and Central America. While less abundant, evidence of the animals that called this ancient swamp home are also found here. Rare bird, reptile, and mammal tracks have been immortalized in the outcrops of the Chuckanut Formation.

Tracks of a type of archaic mammal of the Orders Pantodonta or Dinocerata (blunt foot herbivores), footprints from a small shorebird, and tracks from an early equid or webbed bird track give evidence to the vertebrates that inhabited the swamps, lakes and river ways of the Pacific Northwest 50 million years ago.

Fossil mammals and bird trackways from Washington cause great excitement. The movement of these celebrity vertebrates was captured in the soft mud on the banks of a river, one of the only depositional environments favorable for track preservation.

Hence the terrestrial paleontological record of Washington State at sites like Chuckanut and Racehorse Creek (U-Pb 53 Ma.) is primarily made up of plant material with some wonderfully enticing mammal, shorebird and large Diatryma bird tracks to shake things up.

YORKSHIRE COAST AMMONITE

A stunning example of the ammonite Androgynoceras from the Yorkshire Coast, England. This beauty is in the collection of the deeply awesome Harry Tabiner ❤️

EOCENE FOSSIL PALM FROND

Eocene Fossil Palm Frond

MASSIVE BOULDERS: SUMAS SLIDE SITE

Sumas Fossil Slide Site

There was a large downpour that hit Washington State causing massive slides. The blocks you see here all came crashing down on the hillside.

Once the skies cleared, hikers found plant impressions in the rock and alerted the local paleo community. I was invited to tag along on a trip to photograph the site while George Mustoe took molds of the palm trunks and trackways.

The slide site at Sumas Mountain revealed many large exposures of fossil plants. Some exposures were 10 feet across. There was great excitement at seeing shorebird tracks and trackways of the large flightless bird Diatryma.

FORTUNE FAVORS THE BOLD

Audaces fortuna iuvat

Ursus curious! A young Black Bear (Ursus americanus) cub checks out a frisky, startled Striped Skunk (Mephitis mephitis) both native species in southern British Columbia. Generally, the aroma from a skunk is enough of a deterrent to keep curiosity at bay. Not in this case.

Bear cubs are known for being playful and all together too curious. They usually stick pretty close to Mamma but sometimes an intriguing opportunity for discovery will cross their path and entice them to slip away just for a few minutes to check it out.

The karma gods were good to this wee one. Nobody was skunked in this quest for exploration, though not for lack of trying.

LASALLE LIMESTONE CRINOIDS

Two beautiful fossil crinoid specimens, Stellarocrinus virgilensis and Braneocrinus, from Pennsylvanian deposits, Bond Formation, LaSalle limestone, Ocoya, Illinois. Collection of Michael O'Shea.

BOBBING IN THE BRINE

APODEROCERAS, YOUR GRACE

This stunning specimen with her regal ridges (and small anomaly) is an Apoderoceras ammonite. Apoderoceras are an extinct genus of cephalopod, an active predatory mollusk belonging to the subclass Ammonoidea.

Apoderoceras is, in fact, a wonderful example of sexual dimorphism within ammonites as the macroconch (putative female) shell grew to diameters in excess of 40 cm – many times larger than the diameters of the microconch (putative male) shell. Apoderoceras has been found in the Lower Jurassic of Argentina, Hungary, Italy, Portugal, and most of North-West and central Europe, including as this one is, the United Kingdom. She was found on the beaches of Charmouth in West Dorset, then prepped expertly by the lovely and talented Lizzie Hingley. 

Neither Apoderoceras nor Bifericeras donovani are strictly index fossils for the Taylori subzone, the index being Phricodoceras taylori. Note that Bifericeras is typical of the earlier Oxynotum Zone, and ‘Bifericeras’ donovani is doubtfully attributable to the genus.

The International Commission on Stratigraphy (ICS) has assigned the First Appearance Datum of genus Apoderocerasas and of Bifericeras donovani the defining biological marker for the start of the Pliensbachian Stage of the Jurassic, 190.8 ± 1.0 million years ago.  As the brilliant Murray Edmunds points out, this lovely large specimen (macroconch) of Apoderoceras is likely a female. Her larger body perfected for egg production.

Cat's Paw Suture Walls of Apoderoceras

Apoderoceras (Family Coeloceratidae) appears ‘out of nowhere’ in the basal Pliensbachian and dominates the ammonite faunas of NW Europe. It is superficially similar to the earlier Eteoderoceras (Family Eoderoceratidae, of the Raricostatum Zone), but on close inspection can be seen to be quite different.  It is, therefore, an ‘invader’ and its ancestry is cryptic.

The Pacific ammonite Andicoeloceras, known from Chile, appears quite closely related and may be ancestral, but the time correlation of Pacific and NW European ammonite faunas is challenging. Even if Andicoeloceras is ancestral to Apoderoceras, no other preceding ammonites attributable to Coeloceratidae are known. (Maybe there are clues in the Lias of Canada?) Apoderoceras remains present in NW Europe throughout the Taylori Subzone, showing endemic evolution.

It becomes progressively more inflated during this interval of time, the adult ribs more distant, and there is evidence that the diameter of the macroconch evolved to become larger. At the end of the Taylori Subzone, Apoderoceras disappeared as suddenly as it appeared in the region, and ammonite faunas of the remaining Jamesoni Zone are dominated by the Platypleuroceras–Uptonia lineage, generally assigned (but erroneously, IMO!) to the Family Polymorphitidae.

In the NW European Taylori Subzone, Apoderoceras is accompanied (as well as by the Eoderoceratid, B. donovani, which is only documented from the Yorkshire coast, although I know of examples from Northern Ireland) by the oxycones Radstockiceras (quite common) and Oxynoticeras (very rare), the late Schlotheimid, Phricoderoceras (uncommon: note P. taylori is a microconch, and P. lamellosum the macroconch), and the Eoderoceratid, Tetraspidoceras (very rare).

Thank you to Murray Edmunds for his advice, guidance and corrections as we explore Apoderoceras and the ammonite faunas of the Pacific and NW Europe. You are deeply awesome, my friend!
Check out Murray’s Research Gate site for more interesting tidbits!

https://www.researchgate.net/profile/Murray_Edmunds; the photo above of the Cat's Paw Sutures of an Apoderoceras from Dorset are from the lovely Simon Guscott. Appreciate you!

DINOGORGON: TERROR OF THE LATE PERMIAN

Dinogorgon Rubidgei / Photo: Jonathan Blair / Corbis

A quarter of a billion years ago, long before dinosaurs or mammals evolved, this three-metre (10-foot) gorgonopsid, Dinogorgon, terrorized the floodplains of what is now South Africa and Tanzania during the Late Permian.

For many years, we've believed that these mighty hunters reigned and died out in less than a million years. Dinogorgon is meant to have vanished during one of the greatest mass extinction events on the planet, the Permian Extinction. We've recorded five mass extinction events in our humble 4.6 billion year history. The event from the Permian wiped our about nine of every ten plant and animal species on the planet. New fossil evidence suggests that there were actually two mass extinctions during this time, with a sixth event happening around 260 million years ago.

UPPER CRETACEOUS NANAIMO GROUP

Upper Cretaceous Nanaimo Group / Denman Island

The Upper Cretaceous Nanaimo Group of southwest British Columbia is a four-kilometre thick succession of mostly deep marine siliciclastics sitting directly above the Insular Superterrane.

This succession has been the focus of many paleomagnetic, isotope geochemistry, paleontology, and sedimentology studies with the aim of untangling the tectonic history and paleolatitude of the Insular Superterrane during the Nanaimo Group deposition some 90 to 65 million years ago.

One would think that these research papers would support each other in terms of that deposition. Much to our chagrin, we're still working through the strata to define both the formal stratigraphy, untangle if it was deposited in single or multiple basins and match it up with local and regional correlations.

The upper two-thirds of the succession is continuously and well exposed on Denman and Hornby islands and represents the best example of this part of the succession in the northern half of what we consider the single Nanaimo Basin. This area includes the previously only informally defined type areas for the Geoffrey and Spray formations, defined here formally for the first time with type sections and detailed descriptions. New interpretations of the geology of these islands demonstrate that previously interpreted major faults do not exist, resulting in stratigraphic and age controls that are both different and simpler than previously interpreted. The redefined stratigraphy of the northern part of the basin is remarkably similar to that of southern areas in both type and age, affirming both a single basin evolution and a single stratigraphic nomenclature.

FOSSIL TRACKWAYS

Ichnofossil Trackways. Photo credit: Luis Lima. Lisbon Museum Collection

SHONISAURUS POPULARIS

ICHTHYOSAUR VERTEBRAE AND RIBS

A very well preserved 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.

Ichthyosaurs are an extinct order of marine reptiles from the Mesozoic era. They evolved from land-dwelling, lung-breathing reptiles who 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 coloration 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. 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 period, ichthyosaurs evolved from a group of unidentified land reptiles. 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. The block you see here is from Middle Triassic (Anisian/Ladinian) outcrops in the West Humboldt Mountains, Nevada.

ROLLED TRILOBITE

FOSSIL CROCODILE

Fossil Crocodile, Lisbon Natural History Museum. Photo: Luis Lima

This well-preserved fossil crocodile is around 12 million years old and hails from Chelas, a locality near the airport in Lisbon. This fellow was quite the beast. The complete crocodile would have been 8-9 meters in length.

This specimen is housed in the Geological Museum of Lisbon. The museum was built in 1857 and is home to beautiful paleontology, archaeology and mineral specimens.

DEVONIAN FISH