Thursday, 28 February 2019

OUR CAMBRIAN PAST

Wanneria dunnae / Eager Formation
There is so much more to Canada than meets the eye. Deep in the ground beneath our feet is window into our past. It speaks of ancient oceans, continents on the move, powerful forces upthrusting whole coastlines and creating mountains.

And through that window, on the west side of the Kootenay River at its confluence with the St. Mary's, we find some of the oldest fossils in Canada.

This specimen of Wanneria dunnae is from the Lower Cambrian Eager Formation of British Columbia and is typical of the group.

He's from the Rifle Range outcrop near Cranbrook. The site is just a shade older than the Burgess Shale, Middle Cambrian deposits though the species found here are much less varied. 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.

Back in the late 1990's and early 2000's, it was a glorious place for fossil collecting. I have many beautifully preserved Wanneria and abundant Olellenus from here along with a few rare and treasured Tuzoia.

The shale matrix lends itself to amazing preservation. This specimen of Wanneria is a big fellow. Five inches long and four inches wide. Wanneria are slightly less common here than Olenellus. Olenellus are slightly smaller in size with a large, semi-circular head, a body of 15 segments and a long spine on the 15th segment with a wee tail. You find a mixture of complete specimens and head impressions from years of perfectly preserved molts.

The Wanneria are their bruising cousins by comparison with their large heads lacking conspicuous furrows and a robust body without an expanded third segment.

As luck would have it, the plate he is in split him right down the centre. Bless the hardness of shale for preservation and it's sheer irony for willfully cracking exactly where you least desire it.

What is missing in this photograph is any detail around the specimen's eyes. Trilobite eyes were compound like those found in modern crustaceans and insects.

The eyes of these earliest trilobites are not well known. They were built in such a way that the visual surface dropped away and was lost during molting or after death throwing a wrench in studying them.

We may learn more from the Burgess Shale and the lovely soft mud that was the foundation of their preservation.

Wednesday, 27 February 2019

FUSED RIBS: TURTLES

Turtle ribs fuse together with some of their vertebrae so they have to pump air in and out of the lungs with their leg muscles instead?

Another unusual feature in turtles is their limb girdles (pectoral and pelvic) have come to lie 'within' their rib cage, a feature that allows some turtles to pull its limbs inside the shell for protection. Sea turtles didn't develop this behaviour (or ability) and do not retract into their shells like other turtles.

Turtle shells are different from the armoured “shells” we see on dinosaurs like the ankylosaurs. Turtles are covered by a special bony or cartilaginous shell developed from their ribs that acts as a shield. It is fundamentally different from the armour seen on our other vertebrate pals. Turtle armour is made of dermal bone and endochondral bones of the vertebrae and rib cage.

Armadillos have armour formed by plates of dermal bone covered in relatively small, overlapping epidermal scales called "scutes," composed of bone with a covering of horn. In crocodiles, their exoskeletons form their armour. It is made of protective dermal and epidermal components that begin as rete Malpighii: a single layer of short, cylindrical cells that lose their nuclei over time as they transform into a horny layer.

Depending on the species and age of the turtle, turtles eat all kinds of food including seagrass, seaweed, crabs, jellyfish, and shrimp,. That tasty diet shows up in the composition of their armour as they have oodles of great nutrients to work with. The lovely example you see here is from the Oxford Museum collections.

Tuesday, 26 February 2019

MAMMOTH HOT SPRINGS

Mammoth Hot Springs Yellowstone National Park

Monday, 25 February 2019

SILURIAN SEA SCORPION

The impressive homeotype specimen of a Eurypterus lacustris duo hails from Late Silurian deposits of New York. These lovelies are now housed in UCMP Berkeley's paleontological collections.

About two dozen families of eurypterids “sea scorpions” are known from the fossil record. Although these ancient predators have a superficial similarity, including a defensive needle-like spike or telson at their tail end, they are not true scorpions.

They are an extinct group of arthropods related to spiders, ticks, mites and other extant creepy crawlies.

Eurypterids hunted fish in the muddy bottoms of warm shallow seas before moving on to hunting grounds in fresh and brackish water during the latter part of their reign.They declined in numbers and diversity until becoming extinct during the Permian–Triassic extinction event (or sometime shortly before) 251.9 million years ago. As to the oldest and youngest of the order, we can look to the Stylonurina. Members of the suborder are collectively and informally known as "stylonurine eurypterids" or "stylonurines". They are known from deposits primarily in Europe and North America, but also in Siberia.

Compared to the suborder, Eurypterina, the stylonurines were comparatively rare and retained their posterior prosomal appendages for walking. Despite their rarity, the stylonurines have the longest temporal range of the two suborders. The suborder contains some of the oldest known eurypterids, such as Brachyopterus, from the Middle Ordovician as well as the youngest known eurypterids, from the Late Permian. They remained rare throughout the Ordovician and Silurian, though the radiation of the mycteropoids (a group of large sweep-feeding forms) in the Late Devonian and Carboniferous is the last major radiation of the eurypterids before their extinction in the Permian.

Sunday, 24 February 2019

Saturday, 23 February 2019

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.

Friday, 22 February 2019

FOSSIL TURTLE

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

Thursday, 21 February 2019

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.

Wednesday, 20 February 2019

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.

Tuesday, 19 February 2019

Monday, 18 February 2019

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.

Sunday, 17 February 2019

Saturday, 16 February 2019

Friday, 15 February 2019

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.

Tuesday, 12 February 2019

Sunday, 10 February 2019

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.

Saturday, 9 February 2019

CAMPANIAN NAUTILUS

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

Friday, 8 February 2019

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.

Thursday, 7 February 2019

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.

Wednesday, 6 February 2019

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 ❤️

Tuesday, 5 February 2019

EOCENE FOSSIL PALM FROND


Eocene Fossil Palm Frond

Monday, 4 February 2019

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.

Sunday, 3 February 2019

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.

Saturday, 2 February 2019

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.

Friday, 1 February 2019