Monday, 13 February 2017

Sunday, 12 February 2017

SCAPHOPODA: TUSK SHELLS

The Oligocene Lincoln Creek Formation has produced several dozen different species of infaunal molluscs, burrowing worms and is well-known for crabs.

This specimen is from the massive, tuffaceous siltstone and sandstone that runs through the town of Porter on the east side of the road.

The fossil-rich bedding planes are well-exposed with concretionary beds throughout.

Collecting was possible in the late 1990’s and early 2000’s but may be forbidden (or heavily discouraged today) as the site is on a busy roadway. I made multiple trips to Porter back in the day with folk from Vancouver and Washington State. The primary focus in the early 2000’s were the crabs. They were just in the early stages of being written-up and much excitement surrounded them.

But to each his own -- as it happens, this wee tusk shell is one of my favourite fossils from the site as my trips to Porter were focused mainly on the molluscs.

Tusk shells, are members of a class of shelled marine mollusc with a global distribution. Shells of species within this class range from about 0.5 to 15 cm in length. This fellow is 8 cm end to end, so near smack dab in the centre of his cohort.

The Scaphopoda get their nickname "tusk shells" because their shells are conical and slightly curved to the dorsal side, making the shells look like tiny tusks (picture a walrus or mammoth tusk in your mind’s eye). The scientific name Scaphopoda means "shovel foot," a term that refers to the "head" of the animal, which lacks eyes and is used for burrowing in marine sediments.

The most distinctive feature of scaphopods, however, and one that differentiates them from most molluscs, is the duo openings on their tubular shells. Most molluscs are open at just one end.

We could call scaphopods the great deniers. They live their adult lives with their heads literally buried in the sand. A tiny bit of their posterior end sticks up into the seawater for water exchange. Water is circulated around the mantle cavity by the action of numerous cilia.

When the available dissolved oxygen runs low for this fellow he ejects water from the yop end of his shell by contraction of his "foot."

Thursday, 9 February 2017

Wednesday, 8 February 2017

EXPLORING WRANGELLIA

Douvelliceras spiniferum, Cretaceous Haida Formation
Haida Gwaii or the Queen Charlotte Islands lay at the western edge of the continental shelf due west of the central coast of British Columbia.

They form Wrangellia, an exotic tectonostratiphic terrane that includes Vancouver Island, parts western British Columbia and Alaska.

The Geological Survey of Canada sponsored many expeditions to these remote islands and has produced numerous reference papers on this magnificent terrain, exploring both the geology and paleontology of the area.

Joseph Whiteaves, the GSC 's chief palaeontologist in Ottawa, published a paper in 1876 describing the Jurassic and Cretaceous faunas of Skidegate Inlet, furthering his reputation globally as both a geologist, paleontologist as well as a critical thinker in the area of science.

The praise was well-earned and foreshadowed his significant contributions to come. Sixteen years later, he wrote up and published his observations on a strange Mount Stephen fossil that resembled a kind of headless shrimp with poorly preserved appendages. Because of the unusual pointed shape of the supposed ventral appendages and the position of the spines near the posterior of the animal, Whiteaves named it Anomalocaris canadensis. The genus name "Anomalocaris" meant "unlike other shrimps" and the species name "canadensis" referred to the country of origin.

Whiteaves work on the paleontology of the Queen Charlotte Island provided us with excellent reference tools, particularly his work on the Cretaceous exposures and fauna that can be found there.

One of our fossil field trips was to the ruggedly beautiful Cretaceous exposures of Lina Island. We’d planned this trip as part of our “trips of a lifetime.” Both John Fam and Dan Bowen can be congratulated for their efforts in researching the area and ably coordinating a warm welcome by the First Nations community and organizing fossil field trips to some of the most amazing fossil localities in the Pacific Northwest.

With great sandstone beach exposures, the fossil-rich Haida formation provided ample specimens, some directly in the bedding planes and many in concretion. Many of the concretions contained multiple specimens of typical Haida Formation fauna, providing a window into this Cretaceous landscape.

It is always interesting to see who was making a living and co-existing in our ancient oceans at the time these fossils were laid down. We found multiple beautifully preserved specimens of the spiny ammonite, Douvelliceras spiniferum along with Brewericeras hulenense, Cleoniceras perezianum and many cycads in concretion.

Photo: Pictured above is Douvilliceras spiniferum with his naturally occurring black, shiny appearance. Proudly part of my collection. He is 6 inches long and 5 inches deep, typical of the species. 

As it happens, I have yet to prep most of the concretions I collected on Lina. I’ve left them intact and perfect, waiting for technology and time to advance so I can give them the love and attention they need in preparation.

Tuesday, 7 February 2017

Monday, 6 February 2017

Sunday, 5 February 2017

Saturday, 4 February 2017

LATE OLIGOCENE SOOKE FORMATION

Desmostylus, Royal Ontario Museum Collection
The late Oligocene Sooke Formation outcrops at several coastal localities along the South-west coast of Vancouver Island. The most well-known and most collected of these are the exposures to the west of Muir Creek.

The formation contains marine fossils including a diversity of intertidal and near shore gastropods, bivalves, abundant barnacle (Balanus) plates, and rare coral, echinoid (sand dollar) and mammal (Desmostylus) fossils.

When these fossils were laid down, the Northeastern Pacific had cooled to near modern levels and the taxa that were preserved as fossils bear a strong resemblance to those found living today beneath the Strait of Juan de Fuca. In fact, many of the Sooke Formation genera are still extant.

We find near shore and intertidal genera such as Mytilus (mussels) and barnacles, as well as more typically subtidal predatory globular moon snails, surf clams (Spisula, Macoma), and thin, flattened Tellin clams.

In several places, there are layers thickly strewn with fossils, suggesting that they were being deposited along a strand line. The rock is relatively coarse-grained sandstone, suggesting a high energy environment as would be found near a beach.

The outcrops at Muir Creek make for a great day trip. This is a family friendly site best enjoyed and collected at low tide.

Friday, 3 February 2017

Thursday, 2 February 2017

LATE JURASSIC CADOCERAS TONNIENSE

Cadoceras tonniense, Mysterious Creek Formation

Wednesday, 1 February 2017