Showing posts with label teachers. Show all posts
Showing posts with label teachers. Show all posts

Monday, March 25, 2024

DESMOCERAS OF MAHAJANGA

This lovely dark rust chunky monkey is the ammonite Desmoceras (Pseudouhligella) latidorsatum from the Lower Cretaceous, Lower Albian, Douvilliceras inequinodum Zone, Ambarimaninga, Mahajanga Province, Madagascar.

Ammonites were predatory, squid-like creatures that lived inside coil-shaped shells. Like other cephalopods, ammonites had sharp, beak-like jaws inside a ring of squid-like tentacles. 

They used their tentacles to snare prey, — plankton, vegetation, fish and crustaceans — similar to the way a squid or octopus hunt today.

Saturday, March 16, 2024

DRIFTWOOD CANYON FOSSIL BEDS / KUNGAX

Puffbird similar to Fossil Birds found at Driftwood Canyon 
Driftwood Canyon Provincial Park 

Driftwood Canyon Provincial Park covers 23 hectares of the Bulkley River Valley, on the east side of Driftwood Creek, a tributary of the Bulkley River, 10 km northeast of the town of Smithers in northern British Columbia. 

Wet'suwet'en First Nation

The parklands are part of the asserted traditional territory of the Wet'suwet'en First Nation which includes lands around the Bulkley River, Burns Lake, Broman Lake, and François Lake in the northwestern Central Interior of British Columbia. 

The Wetʼsuwetʼen are part of the Dakelh or Carrier First Nation, and in combination with the Babine First Nation are referred to as the Western Carrier. They speak Witsuwitʼen, a dialect of the Babine-Witsuwitʼen language which, like its sister language Carrier, is a member of the Athabaskan family.

Their oral history or kungax recounts a time when their ancestral village, Dizkle or Dzilke, once stood upstream from the Bulkley Canyon. This cluster of cedar houses on both sides of the river was said to be abandoned because of an omen of impending disaster. The exact location of the village has been lost but their stories live on. 

The neighbouring Gitxsan, collectively the People of Smooth Waters—the Gilseyhu Big Frog Clan, the Laksilyu Small Frog Clan, the Tsayu Beaver Clan, the Gitdumden Wolf and Bear Clan and the Laksamshu Fireweed and Owl Clan—each phratry or kinship group calling the Lax Yip home—33,000 km2 of land and water in northwestern ​British Columbia along the waters of the Skeena River and its tributaries—have a similar tale—though the village in their versions is referred to as Dimlahamid or Temlahan depending on which house group or wilp is sharing the tale—as well as where they are located as dialects differ. 

Gitksan speak Sim'algaxthe real or true language. Within the Gitxsan communities there are two slightly different dialects. The Gyeets (Downriver) dialect spoken in Gijigyukwhla (Gitsegukla), Gitwangax, and Gitanyow—and the Gigeenix (Upriver) dialect is spoken in Ansbayaxw (Kispiox), Sik-E-Dakh and Gitanmaax.

Driftwood Canyon Fossil Beds

Driftwood Canyon's Fossil Beds record life in the earlier portion of the Eocene when British Columbia — and indeed our world — was much warmer than it is today. This site was discovered in the beginning of the 20th century and is now recognized as containing significant fossil material. 

The fossils found here—and their superb preservation—provide a fascinating opportunity to understand the area’s evolutionary processes of both geology and biology over the past fifty million years or so. The fossils themselves are 51.7 million years old and look remarkably like many of the species we recognize today. 

The park that contains these beautiful fossils is fifty-seven years old. It was created in 1967 by the generosity of the late Gordon Harvey (1913–1976). He donated the land to protect fossil resources that he truly loved and wanted to see preserved. The fossil beds are on the east side of Driftwood Creek. 

Metasequoia, the Dawn Redwood
Exploring the region today, we see a landscape dominated by conifers blanketing the area. 

Forests teem with the aromatic Western Red Cedar, Pacific Silver Fir with its many medicinal properties, the tall and lanky Subalpine Fir with its soft, brittle and quickly decaying wood, the slender scaly Lodgepole Pine, the graceful and slightly forlorn looking Western Hemlock. Across the landscape you see several species of Spruce, including the impressive Sitka. 

Some of the tallest on view would have been mere seedlings, colonizing the glacial moraines centuries ago when the glaciers retreated. Collectively, these conifers tell the tale of the region's cool climate today. 

The Gitsan territory boasts seven of the 14 biogeoclimatic zones of the province—the Alpine Tundra, Spruce-Willow-Birch, Boreal White and Black Spruce, Sub-Boreal Pine-Spruce, Sub-Boreal Spruce, Engelmann Spruce-Subalpine Fir and Interior Cedar-Hemlock. 

The fossil material we find here speaks to a warmer climate in this region's past. We find fossil plants, fish—including specimens of salmon, suckerfish and bowfin, a type of air breathing fish—and insect fossil here—wasps and water striders—fossil plants including Metasequoia, the Dawn Redwood, alder—and interesting vertebrate material. Bird feathers are infrequently collected from the shales; however, two bird body fossils have been found here.

In 1968, a bird body fossil was collected in the Eocene shales of the Ootsa Lake Group in Driftwood Canyon Provincial Park by Pat Petley of Kamloops. 

Pat donated the specimen in 2000 to the Thompson Rivers University (TRU) palaeontology collections. This fossil bird specimen is tentatively identified as the puffbird, Piciformes bucconidae, of the genus Primobucco.

Primobucco is an extinct genus of bird placed in its own family, Primobucconidae. The type species, Primobucco mcgrewi, lived during the Lower Eocene of North America. It was initially described by American paleo-ornithologist Pierce Brodkorb in 1970, from a fossil right-wing, and thought to be an early puffbird. However, the discovery of a further 12 fossils in 2010 indicate that it is instead an early type of roller.

Related fossils from the European Messel deposits have been assigned to the two species P. perneri and P. frugilegus. Two specimens of P. frugilegus have been found with seeds in the area of their digestive tract, which suggests that these birds were more omnivorous than the exclusively predaceous modern rollers. The Driftwood specimen has never been thoroughly studied. If there is a grad student out there looking for a worthy thesis, head on down to the Thompson Rivers University where you'll find the specimen on display.

Another fossil bird, complete with feathers, was collected at Driftwood Canyon in 1970, This one was found by Margret and Albrecht Klöckner who were travelling from Germany. Theirs is a well-travelled specimen, having visited many sites in BC as they toured around, then to Germany and finally back to British Columbia when it was repatriated and donated to the Royal British Columbia Museum in Victoria. 

I am not sure if it is still on display or back in collections, but it was lovingly displayed back in 2008. There is a new grad student, Alexis, looking at Eocene bird feathers down at the RBCM, so perhaps it is once again doing the rounds. 

This second bird fossil is of a long-legged water bird and has been tentatively identified by Dr. Gareth Dyke of the University of Southampton as possibly from the order Charadriiformes, a diverse order of small to medium-ish water birds that include 350 species of gulls, plovers, sandpipers, terns, snipes, and waders. Hopefully, we'll hear more on this find in the future.

A Tapir showing off his prehensile nose trunk
Tapirs and Tiny Hedgehogs

The outcrops at Driftwood Canyon are also special because they record a record of some of the first fossil mammals ever to be found in British Columbia at this pivotal point in time. 

Wee proto-hedgehogs smaller than your thumb lived in the undergrowth of that fossil flora. They shared the forest floor with an extinct tapir-like herbivore in the genus Heptodon that looked remarkably similar to his modern, extant cousins (there is a rather cheeky fellow shown here so you get the idea) but lacked their pronounced snout (proboscis). I am guessing that omission made him the more fetching of his lineage.

In both cases, it was a fossilized jaw bone that was recovered from the mud, silt and volcanic ash outcrops in this ancient lakebed site. And these two cuties are significant— they are the very first fossil mammals we've ever found from the early Eocene south of the Arctic.

How can we be sure of the timing? The fossil outcrops here are found within an ancient lakebed. Volcanic eruptions 51 million years ago put loads of fine dust into the air that settled then sank to the bottom of the lake, preserving the specimens that found their way here — leaves, insects, birds, mammals.

 As well as turning the lake into a fossil making machine—water, ash, loads of steady sediment to cover specimens and stave off predation—the volcanic ash contains the very chemically inert—resistant to mechanical weathering—mineral zircon which we can date with uranium/lead (U/Pb). 

The U/Pb isotopic dating technique is wonderfully accurate and mighty helpful in dating geologic events from volcanic eruptions, continental movements to mass extinctions. This means we know exactly when these lovelies were fossilized and, in turn, their significance.

Know Before You Go

If you fancy a visit to Driftwood Canyon Park, the park is accessible from Driftwood Road from Provincial Highway 16. You are welcome to view and photograph the fossils found here but collecting is strictly forbidden. 

Driftwood Canyon is recognized as one of the world’s most significant fossil beds. It provides park users with a fascinating opportunity to understand the area’s evolutionary processes of both geology and biology. The day-use area is open from May 15 to September 2. There is a short, wheelchair-accessible interpretative trail that leads from the parking are to the fossil beds. Pets are welcome on leash. Signs along the trail provide information on fossils and local history. 

Below a cliff face at the end of the trail is a viewing area that has interpretive information and viewing area overlooking Driftwood Creek.

This park proudly operated by Mark and Anais Drydyk
Email: kermodeparks@gmail.com / Tel: 1 250 877-1482 or 1 250 877-1782

Palaeo Coordinates: Latitude: 50° 51' 59" N / Longitude: 116° 27' 37" W
Lat/Long (dec): 50.86665,-116.46042 / GUID: d3a6bd3e-68d6-42cf-9b2c-d20a30576988

Driftwood Canyon Provincial Park Brochure: 
https://bcparks.ca/explore/parkpgs/driftwood_cyn/driftwood-canyon-brochure.pdf?v=1638723136455


Saturday, February 3, 2024

OPHTHALMOPLAX BRASILIANA

Ophthalmoplax brasiliana  / Photo: José F. Ventura‎
Ventral view of the carnivorous portunoid crab Ophthalmoplax brasiliana (Maury, 1930) from the latest Maastrichtian (~66.2 Ma.) deposits near Coahuila, northern Mexico.

This marine species was originally thought to have been found only in the upper Member (Owl Creek Formation) Late/Upper Maastrichtian deposits of Tippah County in Mississippi, USA. 

Sohl and Koch published on the Mississippian finds in the USGS in 1983. Fedorov and Nyborg published on this same species again in 2017. Paleocoordinates: (34.8° N, 88.9° W: 38.3° N, 66.2° W)

Sunday, January 28, 2024

THE SLOW RACE OF TIME: LIVING FOSSILS

Horseshoe crabs are marine and brackish water arthropods of the order Xiphosura — a slowly evolving, conservative taxa.

Much like (slow) Water Striders (Aquarius remigis), (relatively sluggish) Coelacanth (Latimeria chalumnae) and (the current winner on really slow evolution) Elephant Sharks (Callorhinchus milii), these fellows have a long history in the fossil record with very few anatomical changes. 

But slow change provides loads of great information. It makes our new friend, Yunnanolimulus luoingensis, an especially interesting and excellent reference point for how this group evolved. 

We can examine their genome today and make comparisons all the way back to the Middle Triassic (with this new find) and other specimens from further back in the Ordovician — 445 million years ago. 

These living fossils have survived all five mass extinction events. They are generalists who can live in shallow or deep water and will eat pretty much anything they can find on the seafloor.

The oldest horseshoe crab fossil, Lunataspis aurora, is found in outcrops in Manitoba, Canada. Charmingly, the name means crescent moon shield of the dawn. It was palaeontologist Dave Rudkin and team who chose that romantic name. Finding them as fossils is quite remarkable as their shells are made of protein which does not mineralized like typical fossils.

Even so, the evolution of their exoskeleton is well-documented by fossils, but appendage and soft-tissue preservation are extremely rare. 

A new study analyzes details of the appendage and soft-tissue preservation in Yunnanolimulus luoingensis, a Middle Triassic (ca. 244 million years old) horseshoe crab from Yunnan Province, SW China. The remarkable anatomical preservation includes the chelicerae, five pairs of walking appendages, opisthosomal appendages with book gills, muscles, and fine setae permits comparison with extant horseshoe crabs.

The close anatomical similarity between the Middle Triassic horseshoe crabs and their recent analogues documents anatomical conservatism for over 240 million years, suggesting persistence of lifestyle.

The occurrence of Carcinoscorpius-type claspers on the first and second walking legs in male individuals of Y. luoingensis tells us that simple chelate claspers in males are plesiomorphic for horseshoe crabs, and the bulbous claspers in Tachypleus and Limulus are derived.

As an aside, if you hadn't seen an elephant shark before and were shown a photo, you would likely say, "that's no freaking shark." You would be wrong, of course, but it would be a very clever observation.

Callorhinchus milii look nothing like our Great White friends and they are not true sharks at all. Rather, they are ghost sharks that belong to the subclass Holocephali (chimaera), a group lovingly known as ratfish. They diverged from the shark lineage about 400 million years ago.

If you have a moment, do a search for Callorhinchus milii. The odd-looking fellow with the ironic name, kallos, which means beautiful in Greek, sports black blotches on a pale silver elongate body. And their special feature? It is the fishy equivalent of business in the front, party in the back, with a dangling trunk-like projection at the tip of their snout and well-developed rectal glands near the tail.

As another small point of interest with regards to horseshoe crabs, John McAllister collected several of these while working on his MSc to see if they had microstructures similar to trilobites (they do) and whether their cuticles were likewise calcified. He found no real calcification in their cuticles, in fact, he had a rather frustrating time getting anything measurable to dissolve in acid in his hunt for trace elements. 

Likewise, when looking at oxygen isotopes (16/18) to get a handle on water salinity and temperature, his contacts at the University of Waterloo had tons of fun getting anything at all to analyze. It made for some interesting findings. Sadly, for a number of reasons, he abandoned the work, but you can read his very interesting thesis here: https://dr.library.brocku.ca/handle/10464/1959

Ref: Hu, Shixue & Zhang, Qiyue & Feldmann, Rodney & Benton, Michael & Schweitzer, Carrie & Huang, Jinyuan & Wen, Wen & Zhou, Changyong & Xie, Tao & Lü, Tao & Hong, Shuigen. (2017). Exceptional appendage and soft-tissue preservation in a Middle Triassic horseshoe crab from SW China. Scientific Reports. 7. 10.1038/s41598-017-13319-x.