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.

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.

Edestus heinrichi tooth and jaw section from Illinois

Below are pictures of a rare shark tooth and jaw section from a bizarre shark called Edestus heinrichi. It was called the "Scissor tooth" shark because reconstructions of it have long jaws sticking out from the face of the shark with teeth lining them. Envision them like a large pair of pinking shears on the body of a shark where the mouth would be. The jaws of these odd group of fish never shed their teeth and just continued to grow outward. Each tooth was rooted in a chunk of cartilage and would stack on the previous piece of cartilage. In this way the shark had a mouth full of teeth at all times.

Edestus was related to a group of sharks that have modern representatives in the Ratfish (Chimaera) and are better represented by the whorl tooth possessing Helicoprion. Both Edestus and Helicoprion lived during the end of the Carboniferous period (upper Pennsylvanian stage). The fossil below was among many found by coal miners in Illinois. Why was it found in a coal mine when it was shark that lived in water? Edestus lived and died in brackish waters in between growth of the coal swamps. As the coal was removed in the mine these non coal bearing rocks were exposed with some of them being marine in origin.

The specimen I own has just a single tooth in a piece of the jaw. There are some terrific examples of more complete jaw sections on the web like this group of pictures from the Illinois state Museum.  This thread on the Fossil Forum has pictures of some nice specimens in other people's collections.

A couple of Carboniferous plant fossils from Spain

I'm cleaning out a folder of images on my computer and I found these pictures of some plants from the Carboniferous of Spain.

The first specimen is of Neuropteris ovata

The second specimen is Annularia stellata

Both specimens come from near La Magdalena in the state of León, Spain. They are estimated to be from the Stephanian B stage (of the Carboniferous in Western Europe which correlates to the Kasimovian stage of the ICS and the upper Pennsylvanian period (Missourian stage) in North America. Check out this page on Paleontology Online for a handy reference chart of the regional stages of the Carboniferous.

Random Fossil Post

I have lots of fossils from my younger collecting days that have no label or sparse information. Some are among my favorites but with little info they get relegated to Random Fossil Posts.

Today we have this Collignoniceras sp. ammonite from the Cretaceous (Cenomarian) of Wyoming. It's a beautiful little ammonite with one of the chamber walls visible near the end of the sprial.

Next are a couple of fossils from the Mazon Creek flora of Illinois. This flora, named after the locality where they were first found, is preserved in ironstone (Siderite) nodules. I have this Macroneuropteris leaf....

and some annularia.

Phricodothryis perplexa from Texas

Today's fossil is Phricodothyris perplexa from the Pennsylvanian aged Mineral Wells formation of Palo Pinto, Texas. It reminds me of the genera Athyris but with a much more exaggerated beak on the pedicle valve.

Brachial valve

Anterior

Pedicle valve

Posterior

Profile

Punctospirifer kentuckeyensis from Texas

A common brachiopod fossil of the Pennsylvanian is Punctospifier kentuckyensis. It's easy to ID based on the coarse ribbing, broad hinge line and small size. This particular specimen comes from the Harpersville formation which is part of the Canyon series near Breckinridge, Texas.

Brachial valve

Anterior

Pedicle valve

Posterior

Profile

A couple more specimens

Hustedia mormoni brachiopod from Kansas

Hustedia mormoni is a small rynchonellid type brachiopod that is common in Pennsylvanian aged rocks. This specimen came from Kansas, but that is all the label says. I found this specimen in the Yale Collection that has a provenance of: Late Pennsylvanian, Virgilian, Shawnee Grp, Oread Ls.

Brachial valve

Anterior

Pedicle valve

Posterior

Profile

Here is another link to a specimen from Missouri.

Conostichus trace fossils

Today I have some odd trace fossils to show you. They are called Conostichus and come from the Pennsylvanian rocks of Texas. Most often found as conical shaped masses of sediment Conostichus are thought to represent the infilling of a burrow of some sort.

These were some odd fossils and I know very little about them and what they were. I posted pictures of these oddball fossils to the Fossil Forum to see if anyone could help me out. I got a lot of good responses especially from my friend Barry (Indy is his forum name) who pointed out that:

Conostichus (a fossil with a confusing history) was formerly thought to be a jellyfish resting trace. It is now regarded as a burrow infilling or feeding structure of an unidentified organism. These fossils were first described by Lesquereux in 1876 as a marine algae and then by later authors
as roots, stems, sponges or worms. C.C. Branson wrote a number of articles circa 1956/1962 in which he discusses numerous separate species. In a 1959 article he states "It is possible to state at this time that the genus Conostichus has but one species, C. ornatus; that some of the marine specimens may be medusoids; that some of the types are probably marine worms. Close examination of specimens in place in the rock and of the associated biota is necessary to a real understanding of these four similar types of fossil." In later articles he describes a number of new species. Joeckel, 2008 states "A trace-fossil hypothesis for the origin of the structures remains plausible...possible feeding structures---albeit problematic".

Barry is a smart guy and has his own website filled with good reading about his local rocks in the Missouri area at Paleontology and Geology of Missouri.

Here is another specimen of Conostichus that shows a slightly different shape and structure.

I don't have much locality info to go on with this specimen. All I could find with the label was "Pennsylvanian" and "Texas". I think it might be from the Finis Shale but I can't be sure.

Calamites and Stigmaria from Hazard, KY

Calamites is a fossil genera that are common fossils in the Pennsylvanian swamp deposits. They often grew up to 30' high then although today the extant species are much smaller. The specimen below is part of a much larger fossil that represents the trunk of one of these ancient trees. It's from the coal mines near Hazard, KY.

Another fossil from Hazard is this Stigmaria root cast. Stigmaria is considered to be the roots of the scale trees like Lepidodendron or Sigillaria but early paleontologists didn't understand the anatomy of these fossils as they didn't find them articulated. It was only later as better specimens were found that the connection was made. In the specimen below each dimple would have had a smaller rootlet extending straight out like a bristle brush.

Up here in Pennsylvania I don't find these fossils as three dimensional casts. Instead they have been compressed and flattened by geologic processes. I'm very glad to have these two specimens as part of my collection and my thanks to Herb M. for giving them to me.