Tuesday, April 29, 2014

Cyrtospirifer sp. brachiopod from Lindley, NY

Sometimes collecting sites are ephemeral, exposed for a short time and then gone. A series of roadcuts were being excavated near the NY/PA border into the Wiscoy Fm., (upper Devonian, Fransian stage, equivalent to Lockhaven Fm. in PA) and the rubble was used as road ballast. While the rocks were exposed I managed to do some exploring of them and found this intact fossil of Cyrtospirifer whitneyi.

Brachial valve
Pedicle valve

Based on similar fossils pictured in the "Devonian Plates" book by the Maryland Geological Survey, 1913, Plate LVI, I'm going to call this Cyrtospirifer disjunctus.

Edit (04/29/2014) - I wrote this post originally in December of 2013 and since then have consulted the "Index of North American Fossils" which states that Cyrtospirifer disjunctus is "a loosely drawn species and the name probably should not be used for many post-Chemung types now placed here" (pg. 321). As the Wiscoy formation is considered part of the Chemung fauna C. disjunctus could properly be used here but a comparison to C. whitneyi from Iowa shows a closer resemblance both within the book (plate 121 - 53 to 55) and with a specimen I posted earlier.

Sunday, April 27, 2014

Curios from Madagascar

Below are two fossils from Madagascar that I recently picked up at a local show. The first is possibly an Alectryona carinata oyster based on a similar specimen on this website. My specimen did not come with any label other than "Madagascar". Based on similar species I'd venture to guess that this came from Cretaceous sediments.

The other Madagascar specimen I purchased was this polished clam. I don't normally go for polished fossils but these specimens were very nice with a slight translucency. In the end I decided it would be good for a desk specimen at work where I wouldn't be upset if it was broken or stolen. The label that came with these fossils indicated they were originally found near Mahajanga, Madagascar but I don't know what their age is.

It's too bad that many of the fossils that come from Madagascar are polished/slabbed or otherwise modified from how they were originally found. Some of this is due to making the fossils look "better" so they will sell faster to the general public. I've heard that Madagascar is one of several countries that don't want their fossil resources plundered and sent out of the country so they require that they be worked in country to provide more jobs. I can see the point of all this but sometimes I would just like a natural looking fossil.

Friday, April 25, 2014

A trio of Trigonia from France

I have three different Trigonia species to show you today, all from France and sent to me by my friend Gery.

First up is this Trigonia clavellata from the Jurassic (Oxfordian stage) cliffs near Villers sur Mer. Compare this specimen to a previously posted specimen HERE.
Left valve
Right valve
Left profile
Right profile

Also from Villers sur Mer is this single left valve of Trigonia reticulata

Lastly is Linotrigonia fittoni (Cretaceous, Albian stage) from near Courcelles
Left valve

Right valve

Right profile

Thanks to Gery for sending me these fossils!

Wednesday, April 23, 2014

A pair of Pleurotomaria sp. Gastropods from France

Here are a pair of Pleurotomaria sp. gastropods that come from a quarry near Evrecy (southwest of Caen), France that excavates rock from the Bajocian stage of the Jurassic. The rock is very distinctive with a tan color that is speckled with small red hematite nodules.

The first fossil is Pleurotomaria textilis still attached to the matrix.

Then we have Pleurotomaria granulosa. The shell is not as tall as P. textilis but it still has that distinctive decoration along the whorls.

Thanks to my friend Gery who sent me these fossils.

Monday, April 21, 2014

Blastoids from Michigan

A few years ago a member of the Fossil Forum gave me these two blastoids in matrix. What I know about them is that they came from the Alpena area of Michigan and are Devonian in age. I reached out to my friend Joe K. for some ID help and he suggested that it comes from the Thunder Bay formation and would be classified as a Heteroschisma subtrunctatum.

Specimen #1

Specimen #2

I need to get both specimens cleaned and prepped so that they are more visible. The Thunder Bay formation (or limestone, depending on who you are talking to) is the uppermost layer of the Traverse group in Michigan which places it as latest Givetian stage of the Devonian.

Saturday, April 19, 2014

Megistocrinus sp. crinoid calyx from Marilla, NY

It's not a great fossil but the specimen below is one of the few Crinoid calyxes that I have found. It's a weathered Megistocrinus sp. calyx that I found in the Deep Run mbr. of the Moscow formation.I found it in a creekside exposure of Buffalo Creek near Marilla, NY.

Here is the matrix with the bottom of the calyx sticking out on the right hand side.

A closer view of the side where you can see some of the geometry of the plates that make up the calyx. along the top of the calyx are some round knobs where the arms once were attached.

Another side view
A view of the bottom with the basal plates where the stem would have attached.
The patterns on the calyx plates are not those that would have been seen in life. Since the specimen has eroded due to exposure to the elements the marks on the plates are more likely a crystallization pattern that is preferentially weathered.

The Deep Run mbr. of the Moscow Fm. is stratigraphically older than the Windom shale and is not found along Lake Erie. The town of Marilla is located about 15 miles east of Buffalo and the exposure there of the Deep Run Mbr. is only about a foot thick. I need to find another exposure farther east so that I can explore this rock unit more.

Thursday, April 17, 2014

Some new finds from the Kashong Shale

This past spring I hunted among the eroded remnants of the Kashong Shale near Greigsville, NY and found a few interesting fossils.

This is a very narrow Crinoid holdfast that must have grown on a jumble of thin shell material.

It is not uncommon to find pieces of shell hash that have flat bryozoans incoporated in with them. This is a piece of matrix that has a Taeniopora exigua piece on one side...
... and some Sulcoretipora incisurata on the other side.

Lastly I found a portion of a crushed Blastoid that may have been a Nucleocrinus or Devonoblastus.

All the above specimens were found in the Kashong shale member of the Moscow formation which is middle Devonian in age (Givetian stage).