Friday, November 21, 2014

Asaphellus fazovataensis trilobite from Morocco

A recent addition to my Moroccan trilobites is this Asaphellus fezouataensis from the Ordovician (Floian stage), Fezouata Formation in the Draa Valley near Zagora, Morocco (Western Sahara). I bought this at a fossil show and it was fairly inexpensive. I see some now on E-bay that are priced much higher so either I got a good deal, I found it early enough on the market or (more likely) the sellers are trying to get as much as they can for it.



The fossil looks very similar to Isotelus species that are found here in North America within late Orodvician rocks.

Wednesday, November 19, 2014

Furcaster palaeozoicus starfish from the Hunsruck slate near Bundenbach, Germany

In the last post I showed you some pictures of fossils from the Hunsruck Slate (Emsian stage of the Devonian) in Bundenbach, Germany that were on display at a rock, fossil and mineral show. Today I'm going to show you the piece of the Hunsruck that graces my collection. At the same show that I saw the display of fossils from Bundenbach, I also came across this piece of slate with two Fucaster palaeozoicus starfish showing some current orientation.

The plate is 22cm along the longest edge and 17 cm along the shorter edge. They are both ventral views with some nice detail.

This specimen is 12cm long by 5.5cm wide

The "halo" that surrounds the central star shape and arm bases is the soft body of the animal. Unlike the arms, the body didn't have any special armor to protect it.


The second specimen is shorter at 7cm long, since part of one arm extends off the plate, and 4cm wide.
I also love the little string of white quartz that cuts across the right specimen. It lends some authenticity to the piece and adds some interest. The obvious star shape in the middle of the body is the result of the muscles that controlled the mouth relaxing after the animal died. Normally they would be closed and the bottom of the animal would look more armored.

Monday, November 17, 2014

Bundenbach fossil display

The name Bundenbach is one which excites me because it is the name of a town that is near a layer of rock, called the Hunsruck Slate, that preserves some extraordinary fossils. It's what is called a Lagerstätte which are sedimentary rocks that have exceptional preservation of fossils, sometimes including soft parts which usually rot away before being fossilized. The Burgess Shale outcrop in Yoho National Park, BC, Canada is the perhaps the ultimate example of this type of fossil treasure trove but they exist all over the world.

So what attracts me to Bundenbach? Well, it preserves a slice of the Devonian period, which is my favorite era to collect fossils from, the fossils are preserved in slate, which is what happens to shale when it is metamorphosized by tremendous heat and pressure, and many of the animals that are preserved are Starfish, which is very rare. Not that Starfish are the only animals preserved in the Hunsruck Slate, there are also trilobites, crinoids, various arthropods, cephalopods, corals, cystoids, worms, and fish among others. The fossil deposit preserves a window in time that showcases animals swept into anoxic waters and buried that we don't normally see preserved.

At the 2014 NY/NJ Fossil, Gem And Mineral Show, they had a display of fossils from the Hunsruck Slate that I was able to drool over. Here are the cases that the fossils were on display in.

And here are some of the fossils:

Urasterella asperula

Euzonosoma tischbeinianum

Phacops ferdinandi

Mimetaster hexagonalis - This guy is on my bucket list of specimens I'd like in my collection! It's an arthropod related to the Burgess shale fossil Marrella splendens.

A crinoid (didn't get a pic of it's label, sorry)

And a phyllocarid (didn't get a pic of it's label, sorry) 

I took many more pictures but most turned out blurry so they are not as useful as I would like. Chalk it up to taking pictures through a glass display case with a cell phone camera.

It turns out that one of the dealers at the show was also the guy who'd brought the display and had this booklet that he'd written with him. I purchased a copy and he was kind enough to sign it for me. It is a nice souvenir to remind me of the awesome fossils I saw that day.

I highly recommend the book "Visions of a Vanished World" by Kühl, Bartels, Briggs and Rust. It has a very thorough explanation of the deposit, it's history and the fossils found within. Note: I do not get any compensation for the Amazon.com link above.

Friday, November 14, 2014

Fossil Paleosol with root impressions

While exploring an old coal strip mine in Gilberton, PA I noticed that there was an exposed wall of rock that used to be covered in overburden. The wall was relatively smooth but had some grooves in it. Upon closer inspection, the grooves turned out to be the impressions of tree roots called Stigmaria. Since these are roots, and they appear to have been preserved in situ, makes me think that the exposed rock is a Paleosol or fossil soil horizon.

I encourage you to click on the photos to examine the detail.
 

Above is one section of an exposed Stigmaria with a length over six feet. It actually is exposed a little more as it heads right but it dives under some rock and is less visible.

Here is the wall from father away.

And I took a bunch of photos to make a panorama of a closer view of the wall was well.
What is preserved in this wall is a glimpse of a forest from long ago. Sure, it may not have lots of leaf or bark impressions but the fact that there are so many long, spindly roots preserved gives an indication about how crowded the forest must have been.

Monday, November 10, 2014

Results of a recent hunt in some old Coal tailings

I've been very busy these last few weeks going collecting and that has caused me to be a little backed up on the blog. Once the weather turns cold I will have more time to focus on writing entries. In the meantime, posts may be a little more sporadic and focused on what I'm finding in the field. Today is just such a post and I'm showing off some Lepidodendron bark impressions that I found this past weekend near Gilberton, PA. They were collected from some old coal mine tailings piles. The coal mines in Schuylkill County, where Gilberton is located, exploited the anthracite coal seams of the Llwellyn formation which is Upper Carboniferous in age (Kasimovian-Gzhelian stage of the ICS or Upper Westphalian to Stephanian stage in Europe).

I first found this hunk of sandstone with a very nice bark impression. The sandstone is normally grey but is stained yellow-orange by iron deposits.

Next I found this larger piece which is in shale. It is damaged some but I brought home a couple of pieces with better definition.

Then I found this branch impression of what I think in Sigillaria. It's hard to see from the photo but there is curvature to the fossil. It was too delicate to remove so it was left in place.

Lastly I found this partial log (or stump?) partially buried in the pile. Once I excavated it I found that it was about 20" wide, 18" tall and 8" thick. No detail remained on the cast so I couldn't tell what kind of tree it was.


Unfortunately the piece was too heavy for me to try and haul back to my car, let alone lift it into the trunk. It must have weighed more than 100 lbs! It would have looked nice in my yard but I left it behind for some other, more enterprising collector to find.