Thursday, 20 June 2019

MAMMOTH HOT SPRINGS

Mammoth Hot Springs Yellowstone National Park

Wednesday, 19 June 2019

CAVEATIS PORCINA CEDRUS

Anavitrinella pampinaria / Dan Bowden Photography
A Common gray moth of the family Geometridae. These lovelies live in North America from Mexico to Alaska and do a wonderful job at camouflage. While not a perfect hiding spot, this fellow has chosen to settle in for the evening on a young yellow cedar tree, Chamaecyparis nootkatensis, in Vancouver's city-owned Stanley Park.

The thin, greyish-brown and scaly bark provides a pretty good cover. He was caught unawares and photographed beautifully by the hugely talented, Dan Bowden, on one of his recent visits to the city.

Tuesday, 18 June 2019

ANCIENT SALMON

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.

Eighteen thousand year-old salmon also challenge the archaeological notion that aboriginal people of the Interior have had access to salmon as a significant protein source for only a few thousand years. In the popular view, people living in the Okanagan and Thompson Valleys were felt to have moved to settlements that were semi-permanent about 4,500 years ago.

By that time they would have had a seasonally regulated diet composed primarily of salmon and supplemented by local game - deer, elk, small mammals – and available shellfish, birds and plant foods. If salmon were present much earlier, it is possible that this pattern of food utilization may have arisen earlier than thought.

Monday, 17 June 2019

HAIDA GWAII BOUNTY

Seafood Bounty / Haida Gwaii, British Columbia
“When the tide is out, the table is set.” This wisdom from those who call Haida Gwaii home is still true today. 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.

Archaeological evidence tells us that by roughly five thousand years ago, gathering shellfish replaced hunting and fishing as a primary food source on the islands. The shellfish meat was skewered on sticks, smoked and stored for use in winter or for travel.

Sunday, 16 June 2019

RED-TAILED RAPTOR

Red-Tailed Raptor / Buteo jamaicensis
The majestic Buteo jamaicensis are easily identified by the red upper surface of their broad tails. They are powerful raptors with strong hunting skills.

Most red-tailed hawks have rich brown upper parts with a streaked belly and a dark bar on the underside of the wing, easily viewed when seen from below. The fine detail in their plumage is breathtaking, like little-feathered works of art.

Saturday, 15 June 2019

PLEISTOCENE SOCKEYE SALMON


Pleistocene Fossil Salmon
Salmon have permeated First Nations mythology and have been prized as an important food source for thousands of years. 

For the Salish people of the Interior of British Columbia, Canada, salmon was the most important of the local fishing stock and salmon fishing season was a significant social event which warranted the nomination of a “Salmon Chief” who directed the construction of the hooks, weirs and traps and the distribution of the catch.

In the Interior of the province, archaeological evidence dates the use of salmon as a food source back 3,500 years. Sheri Burton and Catherine Carlson were able to isolate and amplify mitochondrial DNA from salmon remains from archaeological sites near Kamloops, and identified the species as Oncorhynchus nerka, or Sockeye salmon. No older salmon remains had been found in the Kamloops area until the 1970’s, when fossil salmon concretions were collected on the south shore of Kamloops Lake.

These concretions were originally dated as Miocene (24 – 5.5 million years old) by the Geological Survey of Canada, based on analysis of pollen grains found in the concretions. However, many local experts, including UBC geology professor W.R. Danner and the late geologists W.H. Mathews and Richard Hughes, suspected the remains were from the much more recent, Late Pleistocene epoch.

It was not until the early 1990s that Catherine Carlson and Ken Klein found definitive proof of this.

By good luck, the fish remains in the Kamloops Lake concretions had not been completely replaced by minerals – enough of the original organic bone collagen remained for radiocarbon dating. The corrected date is approximately 18,000 years. It is likely that erosion during the time of deposition had carried pollen down from Miocene layers in surrounding hills, to be deposited around the dead fish, causing the initial over-estimation of the age of the concretions.

This lovely specimen is Oncorhynchus nerka, a Late Pleistocene Fossil Sockeye Salmon, from the fine-grained, silty clays on the south shore of Kamloops Lake, British Columbia, Canada. The site was originally collected in the 1970's by the late geologist and paleontologist Richard Hughes. I was introduced to the site much later after it's redescovery by Catherine Carlson and Kenneth Klein in the fall of 1991 with the help of local and gracious host, Bill Huxley.

They later wrote up and published a chapter in Rolf Ludvigsen's "Life in Stone: A Natural History of British Columbia's Fossils." It was Huxley who shared it's location with John Leahy, a local Kamloops resident and avid fossil hunter, and him with me. 

This specimen was collected by him in the 1990's, his tenth partial salmon from this site, and the sole one in my collection.

An age of 18,000 plus years – sets the fossils firmly as the only salmonids of the Late Pleistocene in North America, a very significant find. The date also changed our ideas about the early climate of the Interior; the Thompson Valley could not have been covered by glacial ice for as long as originally thought. Indeed, it makes the Interior ice-free only 2,000 years after the Last Glacial Maximum and some 4,000 years before our western continental coastline and the Rocky Mountain Foothills.  

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.

Eighteen thousand year-old salmon also challenge the archaeological notion that aboriginal people of the Interior have had access to salmon as a significant protein source for only a few thousand years. In the popular view, people living in the Okanagan and Thompson Valleys were felt to have moved to settlements that were semi-permanent about 4500 years ago. 

By that time they would have had a seasonally regulated diet composed primarily of salmon and supplemented by local game - deer, elk, small mammals – and available shellfish, birds and plant foods. If salmon were present much earlier, it is possible that this pattern of food utilization may have arisen earlier than thought.

Richard Hughes had originally identified the fossilized Kamloops salmon as Oncorhynchus nerka or Sockeye salmon, the same species found in the 3,500 year old archaeological sites. But, using the carbon-13 isotope ratio, Klein and Carlson were able to determine that these salmon did not feed on protein from a marine source and relied solely on a freshwater diet. 

In other words, they could not have spent part of their life in the ocean, as modern Sockeye salmon do. Based on the specimens’ smaller heads and stunted bodies, the longest measuring in at a pint-sized 11.5 cm, Klein and Carlson feel that the fossils are likely Kokanee, a modern landlocked variety of Sockeye.

Friday, 14 June 2019

CRETACEOUS CRANBERRY ARMS

Middle Campanian Plant Fossils / Cranberry Arms
Back in 1996, Vancouver Island local, Jim Bell was moving rocks with his excavator near the Cranberry Arms Pub as part of the Duke Point Highway construction. During one of those loads, he saw a massive fossil palm frond on the side of a rock -- a real showstopper. This wasn't just any frond, he'd scooped up the biggest Geonomites Imperialis ever found.

The fossil caused a stir amongst his construction colleagues but it was nothing compared to the whoops and squeals from local paleo enthusiasts. And rightly so. What do you think of when you envision palm trees? You see warm, tropical beaches, hammocks swaying in the wind, am I right? Most of the fossils found in the Nanaimo Group of Vancouver Island are marine, so a tropical terrestrial site was hot news!

I learned about the site from a very excited paleo colleague calling late one night. He excitedly shared that they'd found a new Late Cretaceous plant site up near Cedar on Vancouver Island.

While this is exciting for some, the construction company was nonplussed. These were plant fossils after all, and not some new species of dinosaur or ancient hominid. The construction was briefly paused to allow some collecting to take place but was set to continue the following week. They did have a highway to build. Many keen volunteers swooped in to see what could be unearthed. Phone calls were made. Shifts were scheduled. Headlamps were employed as folks took to digging in the dark to maximize the limited collecting window.

Many beautiful specimens were collected. The fossilized leaves, branches and plant remains from broadleaf trees, shrubs, conifers and ferns were immortalized as they slipped into the muds and fine sand of a balmy river environment and slowly buried. 70 million years later, we were doing our best to dig them right back up again.

The fossils included plants and seeds you would expect to find in a much warmer, wetter environment than the climate enjoyed on Vancouver Island today. Perhaps as much as 10° warmer. We see similar specimens of Ensete (banana) and Zamiaceae (cycad) down in Washington State in the Eocene Chuckanut Formation. It is thrilling to see the correlation and transition in both faunal species and environmental conditions for the Pacific Northwest from the Cretaceous to the Eocene. The specimen you see here was generously gifted as a souvenir to attendees of the Third BCPA Symposium in Victoria, British Columbia. Specimen: Middle Campanian Plant Fossils from the Protection Formation, Reserve Member, Cranberry Arms, Cedar, Vancouver Island, British Columbia, Canada.

Thursday, 13 June 2019

CRETACEOUS CAPILANO RIVER

Cretaceous Plant Material / Three Brothers Formation
Vancouver has a spectacular mix of mountains, lowlands all wrapped lovingly by our deep blue Pacific. When we look to the North Shore, the backdrop is made more spectacular by the Coast Mountains with a wee bit of the Cascades tucked in behind.

If you were standing on the top of the Lion's Gate Bridge looking north you'd see the Capilano Reservoir is tucked in between the Lions to the west and Mount Seymour to the east on the North Shore. The bounty of that reservoir flows directly into your cup! If you look down from the reservoir you'll see the Capilano River as it makes it's way to the sea.

The Capilano River on Vancouver's North Shore flows through the Coast Mountains and our coastal rainforest down to the Capilano watershed enroute to Burrard Inlet. The headwater's are at the top of Capilano up near Furry Creek. They flow down through the valley, adding in water from rain, snow melt and many tributaries before flowing into Capilano Lake. The lake in turn flows through Capilano Canyon and feeds into the Capilano River.

The Capilano River's path, water levels and sediment deposition have been significantly altered by our hand.

We have Ernest Albert Cleveland to thank for much of our drinking water as it is caught and stored by the dam that bears his name. It was his vision to capture the bounty from our watershed and ensure it made its way into our cups and not the sea. Both the water and a good deal of sediment from the Capilano would flow into Burrard Inlet if not held back by the 91 meter concrete walls of the Cleveland Dam. While it was not Ernest's intention, his vision and dam had a secondary benefit. In moving the mouth of the Capilano River he altered the erosion pattern of the North Shore and unveiled a Cretaceous Plant Fossil outcrop that is part of the Three Brothers Formation.

The fossil site is easily accessible from Vancouver and best visited in the summer months when water levels are low. The level of preservation of the fossils is quite good. The state in which they were fossilized, however, was not ideal. They look to have been preserved as debris that gathered in eddies in a stream or delta.

There are a mix of Cretaceous species found only in the sandstone. You will see exposed shale in the area but it does not contain fossil material. Interesting, but again not fossiliferous, are the many granitic and limestone boulders which look to have been brought down by glaciers from as far away as Texada Island. Cretaceous plant material (and modern material) found here include Poplar (cottonwood)  Populus sp. Bigleaf Maple, Acer machphyllum, Alder, Alnus rubra, Buttercup  Ranvuculus sp., Epilobrium, Red cedar, Blackberry and Sword fern.

From downtown Vancouver, drive north through Stanley Park and over the Lion’s Gate Bridge. Take the North Vancouver exit toward the ferries. Turn right onto Taylor Way and then right again at Clyde Avenue. Look for the Park Royal Hotel. Park anywhere along Clyde Avenue.

From Clyde Avenue walk down the path to your left towards the Capilano River. Watch the water level and tread cautiously as it can be slippery if there has been any recent rain. Look for beds of sandstone about 200 meters north of the private bridge and just south of the Highway bridge. The fossil beds are just below the Whytecliff Apartment high rises.


Wednesday, 12 June 2019

A RARE BIT OF TURTLE

Fossil Turtle / Aspideretes subquadratus
A rare bit of Turtle Shell from an Aspideretes subquadratus, Upper Cretaceous, Belly River Formation on Sand Creek, Red Deer River, Alberta, Canada.

The holotype (No. 5724) is housed at the Royal Ontario Museum of Palaeontology. It was collected 100 years ago, on a University of Toronto Fossil Expedition in 1919. It was found by Canada's own George F. Sternberg.

Tuesday, 11 June 2019

MCABEE FOSSIL SITE RE-OPENS

Eocene Plant Fauna / Eohiodon Fish Fossil / McAbee
An Eohiodon rosei and Eocene plant fossils from the McAbee Fossil Beds. McAbee is part of an old lake bed deposited 52 million years ago and is one of the most diverse fossil sites known in British Columbia.

The McAbee beds are known worldwide for their incredible abundance, diversity and quality of fossils including lovely plant, insect and fish species. The site received was designated a Provincial Heritage Site under British Columbia's Heritage Conservation Act and closed to in July of 2012. But this decision is soon to be reversed.

McAbee is set to re-open to the public at 10AM on June 21, 2019, with plans to build out a visitor's centre and educational programs. Funding is in place to have two staff on site this summer to welcome visitors from the general public Thursday to Monday 10AM-5PM.

Collecting will be open access with no fees charged. The Province is committed to providing access to scientists, the lay public and tourists interested in local First Nations history. The direction on what happens next at McAbee is being driven by the Heritage Branch in consultation with members of the Shuswap Nation and Bonaparte Band.

Local members of the Bonaparte Band want to share the spiritual significance of the area from a First Nations perspective and see McAbee as an indigenous tourism destination. So it looks like it will be paleontology, archaeology with a cultural focus to add spice. In any case, collection of fossils will continue, likely through the use of day-permits with oversight to ensure significant fossil finds make there way to museums. It is an exploratory year for those running it. They'll be asking a lot of questions from those who drop by then collating that information to make recommendations, seek funding and set a plan for the future. 

Monday, 10 June 2019

DAIHUA FLOWERS

Daihua sanqi, Yunnan Province, China
This lovely fossil is Daihua sanqiong, an unusual 518-million year old sea creature that shares characteristics with our modern comb jelly. The animal’s 18 tentacles are all fine and feather-like, with rows of large cilia adorning the exterior.

The specimen was found in mudstones south of Kunming in the Yunnan Province of southern China by co-author of the study, Professor Hou Xianguang.

This isn’t the first biological discovery found in this particular region. It was named the Daihua Sanqiong after the Dai tribe in Yunnan and “hua” which means “flower” in Mandarin in honor of its flower-like shape. I met the colorful Dai several times while in Kunming in 2018. They are beautiful people with a rich cultural history. It pleases me that this specimen will be named for them.

Sunday, 9 June 2019

SHONISAURUS SIKANNIENSIS

Shonisaurus sikanni / Sikanni Chief River
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.

More than 200 million years ago, the Shonisaurus sikanniensis swan in our ancient seas. A 70-foot long specimen encased in limestone was unearthed on the banks of the Sikanni Chief River. Many beautiful souls contributed to our knowledge and excavation of Shoni including Dean Lomax, Sven Sachs and our own Betsy Nicholls.

Saturday, 8 June 2019

CIBELELLA CORONATA

Cibelella Coronata / Photo: Alexei Molchanov
A spectacular specimen of the trilobite Cibelella Coronata from upper Ordovician deposits along the Neva River at the head of the Gulf of Finland on the Baltic Coast, Saint Petersburg, Russia

Friday, 7 June 2019

URSUS ARCTOS CARNIVORA

Grizzly Bear / North American Brown Bear
A slow stroll down to the river to fish, this Grizzly (North American brown bear) is an excellent fisher. Her high fat, protein-rich diet has contributed to her lovely coat and larger size. Grizzlies are the kings of the Keto diet. She and her kin are omnivores, eating plants, animals and even human food if they can get at it. She'll likely gain around 400 lbs or 180 kg before winter comes in preparation for hibernation and to produce milk for her offspring.

At age five, female (sows) grizzlies begin mating and bearing young, usually two cubs every other year. The cubs arrive over the winter and feast on their mother's milk all snuggled inside a wintery den.

The great ancestors of the North American brown bear are the Ursavus, a bear-dog the size of a raccoon who lived more than 20 million years ago. Taking a look at this beauty, it seems an implausible lineage.

Thursday, 6 June 2019

ROCKY MOUNTAIN TRENCH

Trapper Cabin on Isaac Lake / Bowron Provincial Park
The Bowron Canoe Circuit is a 149,207 hectare geologic wonderland, where a fortuitous combination of plate tectonics and glacial erosion have carved an unusual 116 kilometre near-continuous rectangular circuit of lakes, streams and rivers bound on all sides by snow capped mountains.

From all descriptions, something like heaven.

The east and south sides of the route are bound by the imposing white peaks of the Cariboo Mountains, the northern boundary of the Interior wet belt, rising up across the Rocky Mountain Trench, and the Isaac Formation, the oldest of seven formations that make up the Cariboo Group (Struik, 1988).

Some 270 million years ago, had one wanted to buy waterfront property in what is now British Columbia, you’d be looking somewhere between Prince George and the Alberta border. The rest of the province had yet to arrive but would be made up of over twenty major terranes from around the Pacific. The rock that would eventually become the Cariboo Mountains and form the lakes and valleys of Bowron was far out in the Pacific Ocean, down near the equator.

With tectonic shifting, these rocks drifted north-eastward, riding their continental plate, until they collided with and joined the Cordillera in what is now British Columbia. Continued pressure and volcanic activity helped create the tremendous slopes of the Cariboo Range we see today with repeated bouts of glaciation during the Pleistocene carving their final shape.

Wednesday, 5 June 2019

EVENING ON ISAAC LAKE

Isaac Lake / Bowron Provincial Park
Isaac is the longest of the pristine lakes in the Bowron Lake circuit in Bowron Lake Provincial Park. It is beautiful to paddle and offers well-appointed camping sites on the shore after a full day on the water.

Isaac is picture perfect, nestled between Mount Falkner and Kaza Mountains to the west and southwest and Mount Amos along with the reindeer-themed, Vixen and Dasher Peaks to the east.

Tuesday, 4 June 2019

EOCENE FOSSIL FEATHER

Eocene Fossil Feather / McAbee Fossil Beds
This wee feather is from the Eocene fossil beds at McAbee. McAbee is part of an old lake bed deposited 52 million years ago and is one of the most diverse fossil sites known in British Columbia.

The McAbee beds are known worldwide for their incredible abundance, diversity and quality of fossils including lovely plant, insect and fish species.

The site received was designated a Provincial Heritage Site under British Columbia's Heritage Conservation Act and closed to in July of 2012. But this decision is soon to be reversed.

McAbee will re-open to the public at 10AM on June 21, 2019, with plans to build out a visitor's centre and educational programs. McAbee will be open to the public this summer from Thursday to Monday 10AM-5PM.

We are still learning about how the collecting will take place. The Province is committed to providing access to the site to scientists and the lay public. The direction on what happens next at McAbee is being driven by the Heritage Branch in consultation with members of the Shuswap Nation and Bonaparte Band.

Local members of the Bonaparte Band want to share the spiritual significance of the area from a First Nations perspective and see McAbee as an indigenous tourism destination. So it looks like it will be paleontology, archaeology with a cultural focus to add spice. In any case, collection of fossils will continue, likely through the use of day-permits with oversight to ensure significant fossil finds make there way to museums.

While the area is referred to as the Okanagan, the term is used in a slightly misleading fashion to describe an arc of Eocene lakebed sites that extend from Smithers in the north, down to the fossil site of Republic Washington, in the south. The grouping includes the fossil sites of Driftwood Canyon, Quilchena, Allenby, Tranquille, McAbee, Princeton and Republic.

Fossils from the Okanagan highlands, an area centred in the Interior of British Columbia, provide important clues to our ancient climate. The fossils range in age from Early to Middle Eocene and provide significant the most a snapshot of ancient life and the climate at that time. McAbee had a more temperate climate, slightly cooler and wetter than other Eocene sites to the south at Princeton, British Columbia and Republic and Chuckanut, Washington.

The McAbee fossil beds consist of 30 metres of fossiliferous shale in the Eocene Kamloops Group.
The fossils are preserved here as impressions and carbonaceous films. We see gymnosperm (16 species); a variety of conifers (14 species to my knowledge); two species of ginko, a large variety of angiosperm (67 species); a variety of insects and fish remains, the rare feather and a boatload of mashed deciduous material. Nuts and cupules are also found from the dicotyledonous Fagus and Ulmus and members of the Betulaceae, including Betula and Alnus.

We see many species that look very similar to those growing in the Pacific Northwest today. Specifically, we see cypress, dawn redwood, fir, spruce, pine, larch, hemlock, alder, birch, dogwood, beech, sassafras, cottonwood, maple, elm and grape. If we look at the pollen data, we see 103 (highly probable) species from the site. Though rare, McAbee has also produced spiders, birds and a single specimen of the freshwater crayfish, Aenigmastacus crandalli.

For insects, we see dragonflies, damselflies, cockroaches, termites, earwigs, aphids, leaf hoppers, spittlebugs, lacewings, a variety of beetles, gnats, ants, hornets, stick insects, water striders, weevils, wasps and March flies. The insects are particularly well-preserved.

Missing are the tropical Sabal (palm), seen at Princeton and the impressive Ensete (banana) and Zamiaceae (cycad) found at Republic and Chuckanut, Washington.

My first trips up there were as a teenager, dragging my mother, sister and pretty near anyone else I could convince to hike up into the outback. This was years before Dave Langevin and John Leahy, mineral rights/lease-holder and resident curator, respectively, began working at the site.

Once they did a whole new world opened up with their efforts. Much of the overburden was removed and new exposures revealed. John also used to leave a jeep at the base of the hill with a bit of gas in it that we'd hot wire and use to avoid the hike heading up and pack down fossils heading back. Good man, John. He was an avid collector and meticulous in his curation. Most of his collection is now in the Royal BC Museum in Victoria, British Columbia.

McAbee is located just east of Cache Creek, just north of and visible from Highway 1/97. 14.5 km to be exact and exactly the distance you need to drink one large coffee and then need a washroom. I've measured. Luckily, they've just installed some so you're in luck! There are telltale hoodoos on the ridge to let you know you've reached the right spot. If you have a GPS, pop in these coordinates and you're on your way. 50°47.831′N 121°8.469′W.


Monday, 3 June 2019

SINEMURIAN AMMONITES OF THE ROCKIES

Arnioceras semicostatum & Arnioceras miserable
These beauties are from a fossil field trip to the Arnioceras beds. The fossils found here are from the Lower Jurassic, Lower Sinemurian, Little Paradise Member of the Last Creek formation. The site is high up in the Canadian Rocky Mountains near Last Creek, British Columbia, Canada and best explored in the warm summer months as there are frequent snowfalls year-round.

This site is part of the research area for Dr. Howard Tipper, GSC (who is hugely missed) and Dr. Louise Longridge, University of British Columbia.

Several ammonites species can be found here including Arnioceras semicostatum & Arnioceras miserable. The two gastropods you see in the central block have yet to be identified to species. Here's hoping a nice grad student takes an interest. The rare but lovely gastros from this area would make an excellent thesis. Perhaps comparing their distribution to their counterparts in Europe.

Sunday, 2 June 2019

MIGHTY MARINE REPTILES: ICHTHYOSAURUS

Blue Lias Ichthyosaur / Photo: Lewis Winchester-Ellis
Ichthyosaurs were particularly abundant in the later Triassic and early Jurassic periods, until they were replaced as the top aquatic predators 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.

Saturday, 1 June 2019

NORTH CASCADES

North Cascades, Cascade Range, western North America