Bathyuriscus fimbriatus trilobite from the Marjum formation

Here is an uncommon trilobite from the Marjum formation of Utah, Bathyuriscus fimbriatus. This comes from the same area as the millions of Elrathia kingii fossils that are ubiquitous at fossil show, but from a slightly younger layer. You can tell this species apart from E. kingii by the larger pygidium and the thorax segments that extend just a little father than the margin of the pygidium. This specimen is missing the free checks, or librigena .

There is a good picture of a complete specimen of Bathyuriscus fimbriatus that can be seen on the Western Trilobite Association webpage.

The Marjum formation is middle Cambrian in age, Drumian stage (503 mya).

Bristolia insolens Trilobite from the Latham Shale

Today I have a rather odd bug to show you. It's a partial cephalon from a Trilobite called Bristolia insolens.  It comes from the Latham shale of the Marble Mountains in California. B. insolens is odd in that it has a pair of genal spines that are attached to the front of the cephalon rather than extending from the sides or rear corners.

This particular species is well known and specific to a time period in the Cambrian and is used to designate a faunal zone. That means that if you are finding specimens of B. insolens in the rock then you should be able to find a very specific set of other fauna associated with it as well and it has a very specific age.  In this case, B. insolens is isolated to the base of the Wuliuan stage of the Miaolingian series within the Cambrian period (509 mya).

A complete specimen of this species of trilobite can be seen at the Western Trilobites webpage here.

I used the Wikipedia page on the genus Bristolia to fill out some of the details of my post.

Digging in the Wheeler Shale

I found some pictures I took while on a trip to Utah back in 2007. I was in the House Range area of Utah, west of the town of Delta, digging around in the Wheeler Shale. The Wheeler Shale (middle Cambian age) is well know for it's abundant and well preserved trilobite fossils and I was looking to add some to my collection. There are a couple of pay dig areas in the area like U-Dig and A New Dig but not many know that you can literally find trilobite fossils in at just about any exposure in the area.

This is a prospect that I saw from the road as I was driving around. Someone had come it and was digging shale out of the ground and splitting.

I looked around the spoil heaps a little and then sat down with my flat chisel to try my hand at splitting.

Some of my finds.

I think this is a worm trail or could it be some kind of algae?

Here is a shot of another, more extensive quarry where they had borught in machinery to remove the rock from a hill. Notably, the shale layers were tan in color rather then the usual light grey I'd seen everywhere else. At this site the trilobites were colored red rather than black.

Some trilobites from the Wheeler Shale

Continuing my clean out of a folder with some older pictures, here are some Trilobites from the Wheeler Shale near Delta, Utah.


These first few specimens are Agnostid type trilobites which are fairly common in some layers of the Wheeler Shale. I believe these are called Peronopsis interstrictus. I collected them about six years ago from an outcrop that was teeming with the little guys.

Next up is a large (2" long) Elrathia kingi that popped off the shale matrix. This is somewhat common, especially if the shale is weathered a little bit. The trilobites are preserved with Calcite which is a bit tougher than the soft, layered shales they are contained in. I purchased this specimen and the next one from West Desert Rock Art, a small rock and fossil shop in the town of Delta, Utah.

Lastly we have an Asaphiscus wheeleri.

The three trilobite species shown above are the most common fossils in the Wheeler Shale. There are dozens of other species that can be found but some are more rare, or restricted to certain layers within the shale. The Wheeler Shale dates to the middle Cambrian. Here is a great page from Trilobites.info concerning the Wheeler Shale.

The fossils are so abundant, and exposures so easy to find/mine that there are a couple of fee quarries that you can try out while in Delta. One, that I have visited, is U-Dig Fossils. If you follow that link to their web site you will see that they now offer a service where they will ship you some of the fossiliferous shale that you can split at home. A fine alternative if you can't make it out there yourself.

Agnostus pisiformis trilobites from Sweden

Continuing with the theme from my last post, here are some pieces of coquinoid limestone that are composed primarily of Agnostus pisiformis molts. They come from the Late Cambrian Alum Shale formation near Kinnekulle in Vastergotland, Sweden. It's amazing to see so many Trilobite molts all clumped together. There must have been so many of the animals that they looked like a swarm of bees or gnats or possibly a school of fish.

Thanks to Christian for sending me these fossils!

Olenus & Ctenocephalus Trilobites from Sweden

From my exchanges with my friend Christian in France, here are some Trilobite fossils that he collected in Sweden.

First up are a couple of black shale pieces that have partial cephalon pieces from two species of Trilobites: Ctenocephalus exsulans and Bailiella impressa - Cambrian - Brantevik, Sweden

Here are some links to pages with more info on Bailiella impressa
http://trilobites.naturalforum.net/t1387-bailiella-impressa

This page is from Christian's Flickr account and you can see a piece with intact cephalons from both Ctenocephalus exsulans and Bailiella impressa
http://www.flickr.com/photos/supergrevling/5513007208/in/set-72157608639773962


Next up are some Olenus truncatus (BRUNNICH, 1789) fossils from the Late Cambrian Alum Shale formation near Scania, Andrarum, Sweden.

Specimen #1

Specimen #2

Specimen #3

Thanks to Christian for these fossils. They help expand the Cambrian portion of my collection!

As I was researching these trilobites I came across Per Hansson's website and suggest a visit if you have even a passing interest in Trilobites. He has an impressive page of Trilobites that he has collected from various locations in Sweden.

I also came across an interesting paper here that discusses the environmental record saved within the Alum Shale formation.

A couple of Bohemeian trilobites

No, this post is not about Trilobites that hang out in coffee shops reading poetry, rather it's to display two fossils from the western region of the Czech Republic.

The first is Aulacopleura konincki. It comes from the Liten fm. near Lodenice and is dated to the Silurian (Wenlock series).

The second fossil is Ellipsocephalis hoffi from the Jince fm. near Jince and is dated to the middle Cambrian period.

The website Trilobites.info has a page dedicated to the Trilbites found in the Jince formation.

Burgess Shale toys

When I visited the Royal Ontario Museum in Toronto last year I found a set of "Toys" for sale in the gift shop. In my mind they are models and could only be considered toys due to their bright colors. Then again, I still play with toys so maybe I'm wrong.

The set depicts five animals that are found in the Burgess shale and related communities of British Columbia. Here are all five together so you can see the approximate scale of each piece to each other. They are not to scale otherwise.



Included in the set is the Trilobite Olenoides (which is an important index fossil for the Cambrian):



Antenna and legs are depicted with a fair amount of detail



Then there is Wiwaxia which is an oddball but thought to be related to the molluscs:


The flat vertical spines that project along the sides are among the most odd features of the creature.


They even included what looks like the mouth or feeding apparatus on the underside. This is a neat detail to put on the model despite the fact that most people would likely not look for it or know what it is.


Next up is Opabina, one of my favorite creatures found in the Burgess shale. It has five compound eyes on stalks and a trunk like extension with a clamping mouth on the end. One wonders how this primitive Arthropod lived?








Laggania is related to Anomalocaris and both were top predators in their time. It's body is shorter than Anomalocaris and the eyes are positioned on top of the head rather than the sides.





The disc like mouth and segmented feeding arms are well detailed.


The last piece in the set is Pikaia which is thought to be a protochordate which means it may be the oldest ancestor of all animals that possess a backbone including fish, dinosaurs and humans.



I'm not sure what the rib or fin like projections are supposed to be on the underside. Maybe it was the ancestor of the super model.






The set is reasonably priced at $30 Cdn. and can be purchased at the museum gift shop or from their website: http://rom.enssc.com/ On the left hand side menu, click on ROM Reproductions and the set will be listed near the bottom.

Orusia lenticularis brachiopod from Sweden

Here is a piece of matrix that I received from my friend Christian that he collected in Brantevik, Sweden. It has many impressions and shells of the brachiopod Orusia lenticularis.

The specimen comes from the upper Cambrian which is nice as I don't have very many Cambrian aged fossils in my collection.