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Friday, February 28, 2020

Carcharocles angustidens teeth from the Belgrade/River Bend formation

In a bag of fossil shark teeth that I purchased I found a number of these triangular shaped teeth. The bag was labelled "Belgrade Quarry" with no other information. I spent a hour or so looking for fossil shark tooth pictures on Google Images that matched what I had and the closest were Carcharocles angustidens. A quick posting to the Fossil Forum website confirmed that these were indeed C. angustidens teeth and that they could be found at the Belgrade quarry.

More web searches ultimately led me to Wikipedia and to the follow logic: These fossils come from the Belgrade quarry in North Carolina. Rocks exposed in that quarry range from the Eocene to the Miocene epochs. C. angustidens existed in the late Oligocene and early Miocene (33-22 mya, Rupelian stage to Aquitanian stage).  That narrows the formations they could have been found in to the River Bend formation (Late Oligocene) and the Belgrade formation (Early Miocene). Both of those formations at one point or another were considered part of the Trent marl which was originally dated to the Eocene epoch. Oh yeah, and C. angustidens was an relative of the Megalodon (no biggie) 1,2,3.

It's nice to have a little bit more information on these fossils as they are a species I did not have in my collection previously. Three of the specimens below would have been found on the front of the shark's jaw while the last one has a little bit more of a curve in it so likely came from along the side or back of the jaw.

Specimen 1


Specimen 2


Specimen 3


Specimen 4




These teeth were found at the Belgrade Quarry near Maysville, in North Carolina in the Belgrade /River Bend formations.

1. Wikipedia - Carcharocles angustidens article
2. Wikipedia - Belgrade formation article
3. Wikipedia - River Bend formation article

Wednesday, February 26, 2020

Dinophyton spinosus Plant fossil from the Stockton formation

Dinophyton spinosus is an odd plant that is found in the late Triassic of rocks across the US. It's often found as a small branch or sprig of tiny rounded leaves. Paleontologists have been trying to figure out how it fits within the evolution of plants but have so far been frustrated. What research I have found (Source 1, Source 2, Source 3)says that it is a gymnosperm (it's seeds are not protected by a fruit) which puts it close to conifers, Ginko's and cycads. The specimens below come from the late Triassic aged Stockton formation near Phoenixville, PA. This is practically in my back yard and I'd never heard, let alone seen anything like these before. 

During the late Triassic, Southeastern PA was a rift zone as Pangea split up. The Stockton formation was deposited on a level plain during drier, savanna like conditions. It inter-tongues with the Lockatong formation which represents lake sediments that would wax and wane as the climate changed. The specimens below were probably preserved in small, temporary ponds.

Sample 1 - Just a small leaf cluster on this piece.


Sample 2 - This piece has a few more sprigs of Dinophyton spinosus.




Previously, I blogged about some Conchostracans that I found from the Lockatong formation.

The Stockton formation is dated to the Triassic, roughly Carnian stage. I purchased these fossils in 2018.

Monday, February 24, 2020

Rhynchosauroides sp. swim traces from the Newark Supergroup

Today I have a fossil trackway to show you. This is more properly called an Ichnofossil as the body of the animal is not present. On this piece of shale are what appear to be scratch marks. I lost the original tag that came with the specimen but I recall that they were traces from swimming. An inquiry to the Fossil Forum website and the hive mind came up with Rhynchosauroides sp. as the name of the traces.  These represent a primitive reptile that was swimming in a pond or pool near a river. The creature floated in the water but it was shallow enough that it's claws grazed the sediment below and left traces. The pond may have been temporary and subject to frequent flooding as the substrate was firm enough to preserve the initial traces before they washed away, and then get buried with a new layer of sediment.   As I mentioned before, I lost the original tag but I believe this was Triassic aged and came from the rocks of the Newark Supergroup in Pennsylvania.  These rocks were originally laid down in a rift valley as the super continent Pangea was breaking up.





Saturday, February 22, 2020

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).

Thursday, February 20, 2020

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.

Tuesday, February 18, 2020

Climacograptus typicalis graptolite from the Whitby formation

As Climacograptus typicalis is the most common graptolite found at Bowmanville, and in my experience everywhere in the upper Ordovician, I should not be surprised to find it in the Collingswood member of the Whitby formation. I have only found one specimen so far and it is super hard to get a good photo of the black carbonaceous film on black shale. But in the second photo below you can see the square shape of the thecae where the animals lived.



The Whitby formation is Ordovician in age (late Ordovician, Katian/Mohawkian stage).
These fossils were collected from the St. Mary's Limestone Quarry in Bowmanville, Ontario. I used William Hessin's book "South Central Ontario Fossils", 2009, Self Published, pg. 263 to help identify these fossils.

Sunday, February 16, 2020

Plaesiomys sp. brachiopod from the Whitby formation

Another Brachiopod genus that I've found in the Collingswood member of the Whitby formation is Plaesiomys sp. This is a small round shell with the pedicle valve having a prominent beak and deeper shell than the brachial valve. I have two specimen, both of which I believe are pedicle valves.

Specimen #1



Specimen #2


William Hessin states in his book that in order to ID down to the species level you need to count the number of ribs.  Neither specimen is preserved well enough for me to say for sure which species they are. Especially as he writes "Plaesiomys subquadrata (Hall) has from fifty to seventy five ribs whereas Plaesiomys iphigenia (Billings) generally has fewer; from forty five to sixty ribs." I am not sure if those number ranges are based on the starting number of ribs near the beak, and then the end number of ribs near the margin, or just a range of the total number of ribs that are found along the margin.

The Whitby formation is Ordovician in age (late Ordovician, Katian/Mohawkian stage).
These fossils were collected from the St. Mary's Limestone Quarry in Bowmanville, Ontario. I used William Hessin's book "South Central Ontario Fossils", 2009, Self Published, pg. 122 to help identify these fossils.

Friday, February 14, 2020

Pseudogygites latimarginatus trilobite from the Whitby formation

The main reason to collect in the black shales of the Collingswood member of the Whitby formation is in the hopes of finding an articulated Pseudogygites latimarginatus. Most of the time the only parts found are the isolated pygidiums.  I have been fortunate enough to find one mostly intact example.

Specimen #1 - The large slab with a partially disarticulated example

Closer view of the specimen

This the the counterpart on a smaller flake of shale


Specimen #2 - An isolated pygidium


Specimen #3 - another pygidium

The Whitby formation is Ordovician in age (late Ordovician, Katian/Mohawkian stage).
These fossils were collected from the St. Mary's Limestone Quarry in Bowmanville, Ontario. I used William Hessin's book "South Central Ontario Fossils", 2009, Self Published, pg. 200 to help identify these fossils.

Wednesday, February 12, 2020

Rafinesquina alternata and Sowerbyella sericea brachiopods from the Whitby formation

This slab is a two for one in terms of species present. It has an example of Rafinesquina alternata as well as Sowerbyella sericea. It's from the Collingswood member of the Whitby formation. These are both uncommon fossils to find in the Collingswood member and could be washed in from another location by a storm as black shales generally represent anoxic, deeper water conditions.

Overview of the slab

Rafinesquina alternata



Sowerbyella sericea

The Whitby formation is Ordovician in age (late Ordovician, Katian/Mohawkian stage).
These fossils were collected from the St. Mary's Limestone Quarry in Bowmanville, Ontario. I used William Hessin's book "South Central Ontario Fossils", 2009, Self Published, pg. 125-126, 128 to help identify these fossils.

Monday, February 10, 2020

Triarthrus eatoni Trilobite from the Whitby formation

Certain layers within the Collingswood member of the Whitby formation are rife with the shed exuviae of the Trilobite Triarthrus eatoni. Like the similar (but older) rocks of the Utica shale in New York, most of the fossils are either partially or completely disarticulated. Most commonly found are articulated portions of the thorax/pygidium and disarticulated pieces of the cephalon.

Specimen #1 - A large slab with multiple examples


Note the disarticulated glabella from a Pseudogygites sp. Trilobite and Lingula cobourensis brachiopods.



Specimen #2 - Partial cephalon which is mostly just the glabella.
Specimen #3
Specimen #4


The Whitby formation is Ordovician in age (late Ordovician, Katian/Mohawkian stage).
These fossils were collected from the St. Mary's Limestone Quarry in Bowmanville, Ontario. I used William Hessin's book "South Central Ontario Fossils", 2009, Self Published, pg. 205 to help identify these fossils.