Showing posts with label destination. Show all posts
Showing posts with label destination. Show all posts

Sunday, October 9, 2022

TANGLEFOOT MOUNTAIN TRILOBITES

After a phenomenal collecting trip to the Goat Haven Mountain of the East Kootenay region near Cranbrook, we headed out to the classic Tanglefoot site following in the footsteps of Brian Chatterton. 

Brian Chatterton has been visiting the East Kootenay region for many years. In 1998, he and Rolf Ludvigsen published the pivotal work on the "calcified trilobites" we had begun hearing about in the late 1990s. 

There were tales of blue trilobites in calcified layers guarded by a resident Grizzly. This was years before logging roads had reached this pocket of paleontological goodness and hiking in — bear or no bear — was a daunting task. 

In his Cambridge University Press paper, Chatterton describes the well-preserved fauna of largely articulated trilobites from three new localities in the Bull River Valley. 

All the trilobites from these localities are from the lower or middle part of the Wujiajiania lyndasmithae Subzone of the Elvinia Zone, lower Jiangshanian, in the McKay Group. 

Access is via a bumpy ride on logging roads 20 km northeast of Fort Steele that includes fording a river (for those blessed with large tires and a high wheelbase) and culminating in a hot, dusty hike and death-defying 5-story traipse down a 35-degree slope to the localities.

Two new species were proposed with types from these localities: Aciculolenus askewi and Cliffia nicoleae

The trilobite (and agnostid) fauna from these localities includes at least 20 species that read like a who's who of East Kootenay palaeontology: 

Aciculolenus askewi n. sp., Agnostotes orientalis (Kobayashi, 1935), Cernuolimbus ludvigseni Chatterton and Gibb, 2016, Cliffia nicoleae n. sp., Elvinia roemeri (Shumard, 1861), Grandagnostus? species 1 of Chatterton and Gibb, 2016, Eugonocare? phillipi Chatterton and Gibb, 2016, Eugonocare? sp. A, Housia vacuna (Walcott, 1912), Irvingella convexa (Kobayashi, 1935), Irvingella flohri Resser, 1942, Irvingella species B Chatterton and Gibb, 2016, Olenaspella chrisnewi Chatterton and Gibb, 2016, Proceratopyge canadensis (Chatterton and Ludvigsen, 1998), Proceratopyge rectispinata (Troedsson, 1937), Pseudagnostus cf. P. josepha (Hall, 1863), Pseudagnostus securiger (Lake, 1906), Pseudeugonocare bispinatum (Kobayashi, 1962), Pterocephalia sp., and Wujiajiania lyndasmithae Chatterton and Gibb, 2016.

It has been the collaborative efforts of Guy Santucci, Chris New, Chris Jenkins, Don Askew and Stacey Gibb that has helped open up the region — including finding and identifying many new species or firsts including Pseudagnostus securiger, a widespread early Jiangshanian species not been previously recorded from southeastern British Columbia. 

Other interesting invertebrate fossils from these localities include brachiopods, rare trace fossils, a complete silica sponge (Hyalospongea), and a dendroid graptolite. 

The species we find here are more diverse than those from other localities of the same age in the region — and enjoy much better preservation. 

The birth of new species into our scientific nomenclature takes time and the gathering of enough material to justify a new species name. Fortunately for Labiostria gibbae, specimens had been found of this rare species had been documented from the upper part of Wujiajiania lyndasmithae Subzone — slightly younger in age. 

Combined with an earlier discovery, they provided adequate type material to propose the new species — Labiostria gibbae — a species that honours Stacey Gibb and which will likely prove useful for biostratigraphy.

Reference: https://www.cambridge.org/core/journals/journal-of-paleontology/article/abs/midfurongian-trilobites-and-agnostids-from-the-wujiajiania-lyndasmithae-subzone-of-the-elvinia-zone-mckay-group-southeastern-british-columbia-canada/E8DBC8BD635863E840715122C05BB14A#

Friday, October 7, 2022

DESTINATION BC: EAST KOOTENAY REGION

The East Kootenay region on the south-eastern edge of British Columbia is a land of colossal mountains against a clear blue sky. 

That is not strictly true, of course, as this area does see its fair share of rain and temperature extremes — but visiting in Autumn every view is a postcard of mountainous terrain.

Rocks from deep within the Earth's crust underlie the entire East Kootenay region and are commonly exposed in the areas majestic mountain peaks, craggy rocky cliffs, glaciated river canyons, and rock cuts along the highways. Younger Ice Age sediments blanket much of the underlying rock.

I've been heading to the Cranbrook and Fernie area since the early 1990s. My interest is the local geology and fossil history that these rocks have to tell. I'm also drawn to the warm and welcoming locals who share a love for the land and palaeontological treasures that open a window to our ancient past.  

Cranbrook is the largest community in the region and is steeped in mining history and the opening of the west by the railway. It is also a stone's throw away from Fort Steele and the Lower Cambrian exposures of the Eager Formation. These fossil beds rival the slightly younger Burgess Shale fauna and while less varied, produce wonderful examples of olenellid trilobites and weird and wonderful arthropods half a billion years old. 

Labiostria westriopi, McKay Group
The Lower Cambrian Eager Formation outcrops at a few localities close to Fort Steele, many known since the early 1920s, and up near Mount Grainger near the highway. 

Further east, the Upper Cambrian McKay Group near Tanglefoot Mountain is a palaeontological delight with fifteen known outcrops that have produced some of the best-preserved and varied trilobites in the province — many of them new species. 

The McKay Formation also includes Ordovician outcrops sprinkled in for good measure.

Other cities in the area and the routes to and from them produce other fossil fauna from Kimberley to Fernie and the district municipality of Invermere and Sparwood. This is an arid country with native grasslands and forests of semi-open fir and pine. Throughout there are a host of fossiliferous exposures from Lower Cretaceous plants to brachiopods. 

The area around Whiteswan Lake has wonderful large and showy Ordovician graptolites including Cardiograptus morsus and Pseudoclimacograptus angustifolius elongates — some of our oldest relatives. A drive down to Flathead will bring you to ammonite outcrops and you can even find Eocene fresh-water snails in the region. 

The drive from Cranbrook to Fernie is about an hour and change through the Cambrian into the Devonian which flip-flops and folds over revealing Jurassic exposures. 

Fernie Ichthyosaur Excavation, 1916
The Crowsnest Highway into Fernie follows Mutz Creek. From the highway, you can see the Fernie Group and the site along the Elk River where an ichthyosaur was excavated in 1916. 

The Fernie Formation is Jurassic. It is present in the western part of the Western Canada Sedimentary Basin in western Alberta and northeastern British Columbia. 

It takes its name from the town of Fernie, British Columbia, and was first defined by W.W. Leach in 1914. The town of Fernie is rimmed by rugged mountains tipped with Devonian marine outcrops. In essence, all these mountains are upside down with the oldest layers flipped to the top and a good 180 million years older than those they sit upon. 

Before they were mountains, these sedimentary rocks were formed as sediment collected in a shallow sea or inland basin. About 360 million years ago, the rocks that you see in Fernie today were down near the equator. They road tectonic plates, pushing northeast smashing into the coastline of what would become British Columbia. A little push here, shove there — compression and thrust faulting — and the rock was rolled over on its head — repeatedly. But that is how mountains are often formed, though not usually pushed so hard that they flip over. But still, it is a slow, relentless business. 

Cretaceous Plant Material, Fernie, BC
Within Fernie, there are small exposures of Triassic and Jurassic marine outcrops. East of the town there are Cretaceous plant sites, and of course, the Jurassic 1.4-metre Titanites occidentalis ammonite up on Coal Mountain.

The regional district's dominant landform is the Rocky Mountain Trench, which is flanked by the Purcell Mountains and the Rocky Mountains on the east and west, and includes the Columbia Valley region. The southern half of which is in the regional district — its northern half is in the Columbia-Shuswap Regional District. 

The regional district of Elk Valley in the southern Rockies is the entryway to the Crowsnest Pass and an important coal-mining area. 

Other than the Columbia and Kootenay Rivers, whose valleys shape the bottomlands of the Rocky Mountain Trench, the regional districts form the northernmost parts of the basins of the Flathead, Moyie and Yahk Rivers. 

The Moyie and Yahk are tributaries of the Kootenay, entering it in the United States, and the Flathead is a tributary of the Clark Fork into Montana.

Photo One: Tyaughton Mountain, Mckay Group; Photo Two: Labiostria westriopi, Upper Cambrian McKay Group, Site ML (1998); John Fam Collection; Photo Three: Ichthyosaur Excavation, Fernie, British Columbia, 1916; Photo Four: Cretaceous Plant Fossils, east of Fernie towards Coal Mountain. The deeply awesome Guy Santucci as hand-model for scale. 

Monday, June 13, 2022

AMYLASE: YOU ARE WHAT YOU EAT


The old adage, you are what you eat, might be best amended to you are what you can digest. 

For all the mammals, you and I included, we need the amylase gene (AMY). It codes for a starch-digesting enzyme needed to break down the vegetation we eat. 

Humans, dogs and mice have record numbers of the amylase gene. The AMY gene copy number increases in mammal populations where starch-based foods are more abundant. Think toast and jam versus raw chicken.

A good example of this is seen when we compare wolves living in the wild to dogs from agricultural societies. Dogs split off the lineage from wolves around 30,000–40,000 years ago. 

Domesticated dogs have extra copies of amylase and other genes involved in starch digestion that contribute to an increased ability to thrive on a starch-rich diet, allowing Fido to make the most of those table scraps. Similar to humans, some dog breeds produce amylase in their saliva, a clear marker of a high starch diet. So do mice, rats, and pigs, as expected as they live in concert with humans. Curiously, so do some New World monkeys, boars, deer mice, woodrats, and giant African pouched rats. 

More like cats and less like other omnivores, dogs can only produce bile acid with taurine and they cannot produce vitamin D, which they obtain from animal flesh. Also, more like cats, dogs require arginine to maintain their nitrogen balance. These nutritional requirements place dogs halfway between carnivores and omnivores.

The amount of AMY and starch in the diet varies among subspecies, and sometimes even amongst geographically distinct populations of the same species. I was at a talk recently given by Alaskan wolf researchers who shared that two individual packs of wolves separated by less than a kilometre ate vastly different diets. This had me thinking about what we eat and it is mostly driven by what is on offer. 

Diet impacts our genetics and this, in turn, allows the fittest to eat, digest and survive. While wolves win the carnivore contest, they will still eat opportunistically and that includes vegetation when other food is scarce. Would they evolve similar levels of AMY as humans, dogs and mice? Maybe if their diets evolved to be similar. Likely. The choice would be that or starvation.

The evolution of amylase in other domesticated or human commensal mammals remains an alluring area of inquiry.

Reference: 

Amylase in Dietary Food Preferences in Mammals: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6516957/