Monday 21 April 2003
WHEN THE TIDE IS OUT THE TABLE IS SET
Have you ever watched salmon jump, twist and leap their way past the many hurtles to return to their place of birth to spawn?
We are all familiar with the image of salmon returning to fresh water, to the rivers of their youth, to spawn and complete their lifecycle, in fact, it is one of the staple images of British Columbia. As adults, we bring our children to witness this cycle, rushing to the banks of our local rivers to watch as the adults, keen in their fight for reproduction and survival, struggle to complete their epic journeys against currents and predators. Arriving as they do, year upon year, season upon season, it seems to us that this is how it has been since time immemorial.
But we now have evidence that migration to the sea may be a relatively recent behaviour. Fossil beds at Driftwood Canyon, near Smithers, contain large numbers of fossil salmonid remains from the Eocene age, approximately 45 million years ago. What is interesting is that the fossil beds are filled equally with both juvenile and larger adults.
If these salmon were heading off to sea in their juvenile form and returning to spawn as adults we would expect to find an abundance of larger carcasses in the lake sediments and relatively few juveniles. Given the equal numbers, we can conclude that the salmonids of the Eocene, lived out their lifecycle as a landlocked species, the way Kokanee do today.
Sunday 9 February 2003
GRIZZLY & BLACK BEARS
Both grizzly and black bears 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 large descendents.
Monday 3 February 2003
Friday 24 January 2003
Wednesday 18 December 2002
FOSSILS OF THE OLYMPIC PENINSULA
I have been exploring Washington State for many years. It is rugged, windswept and has amazing fossil exposures all along its northern edge. The area goes by the name of the Olympic Peninsula and it is a wilderness playground. The sites I usually visit are Majestic Beach for its rare but prized fossil whale bone.
Further west are the beach exposures that have fossil echinoids in matrix and Ghost shrimp claws in concretion. There is a clay mine that holds wonderful nautiloids like the creamy Aturia you see here. Sometimes they are cemented together and come out whole. Sometimes calcified and show yellow, brown and white when you hold them to the light. Further up are the beach exposures along Clallam Bay.
Aturia is an extinct genus of Paleocene to Miocene nautilids within Aturiidae, a monotypic family, established by Campman in 1857 for Aturia Bronn, 1838, and is included in the superfamily Nautilaceae in Kümmel, 1964.
Aturia is characterized by a smooth, highly involute, discoidal shell with a complex suture and subdorsal siphuncle.
Their shells are rounded ventrally and flattened laterally; the dorsum is deeply impressed. The suture is one of the most complex within Nautiloidea. It has a broad flattened ventral saddle, narrow pointed lateral lobes, broad rounded lateral saddles, broad lobes on the dorso-umbilical slopes, and a broad dorsal saddle divided by a deep, narrow median lobe.
The siphuncle is moderate in size and located subdorsally in the adapical dorsal flexure of the septum. Based on the feeding and hunting behaviours of living nautiluses, Aturia most likely preyed upon small fish and crustaceans. It is well worth exploring the exposures at Clallam Bay. The local clay quarry is on private land so you would need to seek permission. I have also seen calcified beauties of this species collected from river sites within the Olympic Peninsula range, though I have not explored these myself.
Friday 15 November 2002
INSPIRATION: MOR-PHAR
What inspires us to explore the world? Sometimes it is the area in which we live, the encouragement of those we love blended with a natural curiosity. The two pivital players in my life were and are my grandfather and father. Both wonderful naturalists in their own right. The world was our playground. That legacy carries on in the like-minded community of those I write, kayak and fossil collect with. Amazing people who fill me with wonder as they take in the beauty, rugged strength and delicate balance of this imperfect yet utterly perfect world.
Sunday 20 October 2002
Saturday 31 August 2002
Wednesday 19 June 2002
Wednesday 5 June 2002
FOSSIL COLLECTING 007-STYLE
Eleven elite paleo enthusiasts were flown into the Tyaughton area near Castle Peak north of Goldbridge 007-style in a shiny new Jet Ranger helicopter. We were interested in the local geology and fossils from the Jurassic/Triassic exposures high in the alpine. Camping at about 7,500 ft, we were treated to all four seasons and some great collecting over the course of the week. Past trips have included grizzlies at close quarters. This trip we saw fresh tracks and scat, but the bears were actively avoiding our camp, just leaving enough evidence to give us the heads up that this is their territory.
Over the course of the week we collected beautiful marine specimens and saw a buck with a sexy set of horns, flocks of Franciscans and a majestic lone wolf.
The area is home to active research by UBC paleontologist, Louise Longridge and boasts abundant marine fauna - ammonites, bivalves, belemnites and have a chance to see the Triassic-Jurassic boundary – a rare treat.
As with all fossil collecting, our search for treasure has a higher goal. All of our finds are lovingly photographed, catalogued and available for study. If fossils are your thing, visit www.bcfossils.ca to find a local society and get on out there.
Originally published at getawaybc.com
Wednesday 15 May 2002
Thursday 2 May 2002
Wednesday 24 April 2002
Sunday 21 April 2002
Thursday 14 March 2002
Wednesday 13 March 2002
Sunday 3 February 2002
Sunday 27 January 2002
Thursday 24 January 2002
Saturday 20 October 2001
Sunday 23 September 2001
GEOLOGY & PALEONTOLOGY OF THE CHILLIWACK GROUP
A while ago, I had the pleasure of hearing Dr. Ted Danner, professor emeritus from the University of British Columbia and my mentor, give a talk on the geology and fossils of the Chilliwack Group, British Columbia.
Dr. Danner has a fantastic way with words and took us on a visual journey to the Devonian quarry at Doaks Creek.
He also walked us through the Late Mississippian limestone exposures on the east side of Red Mountain, where large crinoid columnals, corals and brachiopods have been found, sometimes partly silicified, on the weathered surfaces of the limestones and shales.
Further up the west side of Red Mountain at the Kendle Quarry, we had a chance to see slides of Late Mississippian exposures where you can find fragments of brachiopods & goniatites.
Dr. Danner gave the history of Reginald A. Daly who published a series of maps in 1912 of areas along the International Boundary where he found fusulinids in the Chilliwack Valley. Fusilinids were a family of single celled organisms that existed during the Pennsylvanian (a subperiod of the Carboniferous) and the Permian period, roughly 323-225 million years ago. Fusilinids died out when a mass extinction of many life forms occurred at the end of the Permian but their lives live on in the fossil record as fossil tests (their hard outer shells).
It seems the markers Daly originally mapped have been slowly tipping to the south, with Canada gaining a small advantage over the United States each year. Look out America. Geology always wins!
Tuesday 14 August 2001
Monday 13 August 2001
Wednesday 11 July 2001
Sunday 1 July 2001
JOHN LEAHY AND DAVE LANGEVIN
 |
| John Leahy and Dave Langevin at McAbee Fossil Beds |
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 ginkgo, 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, 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 over a hundred highly probable species from the site. Though rare, McAbee has also produced spiders, birds (and lovely individual feathers) along with multiple specimens of the freshwater crayfish, Aenigmastacus crandalli.
For insects, we see dragonflies, damselflies, cockroaches, termites, earwigs, aphids, leafhoppers, 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 Eocene sites in Republic and Chuckanut, Washington.
Tuesday 19 June 2001
Tuesday 12 June 2001
Tuesday 24 April 2001
Sunday 22 April 2001
Wednesday 18 April 2001
Tuesday 10 April 2001
Tuesday 13 March 2001
Friday 9 February 2001
Thursday 1 February 2001
Saturday 27 January 2001
Sunday 31 December 2000
ANCIENT MARINE PREDATORS
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.
Saturday 30 December 2000
HOPLOSCAPHITES MACROCONCH
Hoploscaphites nebrescensis is an upper Maastrichtian species and index fossil. It marks the top of ammonite zonation for the Western Interior.
It has been recorded from Fox Hills Formation in North and South Dakota as well as the Pierre Shale in southeastern South Dakota and northeastern Nebraska.
It is unknown from Montana, Wyoming, and Colorado due to the deposition of coeval terrestrial units. It has possibly been recorded in glacial deposits in Saskatchewan and northern North Dakota, but that is hearsay. Outside the Western Interior, this species has been found in Maryland and possibly Texas in the Discoscaphites Conrad zone. Collection of the deeply awesome (and enviable) José Juárez Ruiz.
Wednesday 27 December 2000
Thursday 23 November 2000
Subscribe to:
Posts (Atom)