Wednesday, July 31, 2013

Eldredgeia/Metacryphaeus Trilobites from Bolivia

In the last few years there have been some interesting Devonian aged fossils coming out of Bolivia. I have mostly been purchasing mine from this seller on E-bay. They are found in small, round concretions so you often get a mold and cast of the fossil. Among the fossils I have acquired are some fairly nice trilobites with the most common specimens labelled Eldredgeia venustus; although some specimens could be another closely related genera, Metacryphaeus. The only way to tell them apart is to count the number of lens facets that are in the eyes and by measuring the ratios of the glabellar furrows and lobes (the rounded parts on the head between the eyes).

Here is a specimen contorted into a "U" shape

This is the mold of the fossil

Another specimen is curled up a little differently

These next two photos are of the fossil's mold....

... that fits perfectly on top of the lower half.

These specimens come from the Belen formation (Devonian, Eifelian stage) south of the capitol of Bolivia, La Paz.

Monday, July 29, 2013

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!

Saturday, July 27, 2013

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

This page is from Christian's Flickr account and you can see a piece with intact cephalons from both Ctenocephalus exsulans and Bailiella impressa

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.

Thursday, July 25, 2013

Large Heliophylum coral from Gotland, Sweden

Another item that my friend Christian sent me was this giant Heliophylum coral. It is a little over 6in (15cm) long and nearly 3in (7.5cm) wide.

One side looks totally normal for a horn coral....

..but as you turn it you can see that one side is nearly flat.

This was the cup of the coral

The flat nature of the fossil is not a growth limit nor typical for the genera, rather it shows that this coral sat exposed on the seafloor after it died and toppled over. Time enough for the exposed surface to be eroded away before it finally became buried. I like fossils like this as it gives you some insight into the environment in which these animals used to live.

The fossil came from the Visby limestone near Häftingsklint on the island of Gotland, Sweden. The rocks are dated to the Wenlock stage of the Silurian.

Tuesday, July 23, 2013

Palaeocyclus porpitus coral from Gotland, Sweden

I pestered my friend Christian to send me some Palaeocyclus fossils from Gotland and he came through in our last exchange. These are small little solitary rugose corals that lived during the Silurian and colonized the substrate. They are an important fossil genera for correlation of rocks found across Europe but they are not so common here in North America.

Here is a loose specimen

And one that is embedded in the matrix.

Both specimens come from the Visby limestone beds near Hallshuk on the island of Gotland, Sweden. The Visby limestone is dated to the Wenlock stage of the Siluran.

Sunday, July 21, 2013

Eospirifer radiatus Brachiopod from Gotland, Sweden

Back in 2011, I wrote about a fossil I'd found in Indiana called Eospirifer radiatus. Last year I received a package from my friend Christian that had some brachiopods from Gotland, Sweden and included with them was a Eospirifer radiatus. This is a very good specimen compared to the one I found in Indiana but the same general features can be seen.

Brachial valve


Pedicle valve



The very fine detail of the ribbing and costae (the wavy folds) are preserved nicely. If the costae were more strongly expressed and continued farther across the shell towards the hinge line the fossil would then be called Eospirifer eudora as in this specimen from England or this one from Indiana.

A couple of detail shots of the attached Spirorbis and bryozoan epibonts.

The specimen comes from the Mulde limestones exposed on the island of Gotland in Sweden. The Mulde beds are Silurian in age (Wenlock stage).

Friday, July 19, 2013

Epacrosina fulva brachiopod from Australia

This is the first fossil I have in my collection from Australia. It's a brachiopod called Epacrosina fulva and has some cool bryozoan epibonts on the surface.

Pedicle valve

Brachial valve


Left profile

Right profile

Here are a couple of closeups of the Bryozoans. You can also see a barnacle spat or two on there. Based on how they grew on the brachiopod, the growths look post mortem as the Bryozoans seems to grow over the lips of the two shells on the anterior.

The specimen above came from the Pliocene aged Whalers Bluff formation near Dartmoor, Australia.