Sunday, March 29, 2015

Belemnitella mucronata cephalopod from France

My friend Gery sent me some specimens of Belemnitella mucronata from the Toarcian stage aged (Jurassic) rocks in Vendee Department, France. They are small and show the typical round cross sections. Had they not been labelled I would not be able to tell them apart from many other Belemnite fossils. These are just the internal "skeletons" of squid like animals that were surrounded by soft tissue and mostly were used to anchor muscles.




Friday, March 27, 2015

Tetrarhynchia tetraedra brachiopod from France

Tetrarhynchia tetraedra is a Rhynchonellid with a triangular shaped shell and strong plications that are reflected in the margins of the shell. There is a strong, wide sulcus with multiple plications as well. The specimen below comes from Moselle Department, France and dates to the Plienbachian stage of the Jurassic.

Pedicle valve
Anterior
Brachial valve
Posterior
Profile

Thank you to Gery for the great fossil!

Wednesday, March 25, 2015

Mesopholidostrophia semicircularis brachiopod from Eifel, Germany

The nacerous shell of Mesopholidostrophia semicircularis is typical of the genera. It can be seen in it's N. America cousins, Pholidostrophia nacera, which are common in the Givetian stage of the middle Devonian. The specimen of M. semicircularis shown below comes from the Eifelian stage (Devonian) of the Junkerberg formation near Gondelsheim, Eifel region, Germany.

Specimen #1
Pedicle valve
Anterior
Brachial valve
Posterior
Profile


Specimen #2
Pedicle valve
Anterior
Posterior
Profile

Examples of  Pholidostrophia geniculata from the Silica Shale of Ohio, Pholidostrophia nacrea from the Widder formation of Ontario, Canada and the Mahantango formation of Pennsylvania.

Monday, March 23, 2015

Athyris concentrica brachiopod from Eifel, Germany

I have yet another species of Athyris from Germany which makes three compared to the single species that I find here in New York and Pennsylvania.  Athyris concentrica comes from the Devonian, Eifelian stage, aged Junkerberg formation, near Gondelsheim, Eifel, Germany. The shell is generally round with a shallow sulcus and narrow concentric growth lines decorating the surface. This species looks very similar to A. vittata from Michigan.

Specimen #1
Pedicle valve
Anterior
Brachial valve
Posterior
Profile

Specimen #2
Brachial valve
Anterior
Pedicle valve
Posterior
Profile

Compare this species to others from Germany, A. tumida and A. amanshauseri or here in N. America, A. spiriferoides from New York.

Saturday, March 21, 2015

Spinatrypa aspera brachiopod from Eifel, Germany

Spinatrypa is somewhat common in the lower to middle Devonian of Europe while it is more prevalent in the US during the late middle to upper Devonian. To me this is an indication of the genera originating in Europe and migrating to the US as the continents moved closer during the Devonian. The specimen of Spinatrypa aspera below comes from the Junkerberg formation (Devonian, Eifelian stage), near Gondelsheim, Eifel, Germany. It is a robust, rounded shell with the typical rippled surface that one expects.

Specimen #1
Brachial valve
Profile
Pedicle valve
Posterior
Profile

Specimen #2
Brachial valve
Anterior
Pedicle valve
Posterior
Profile

I have plenty of other examples of this genera including S. aspera from Poland (of which I am having doubts my specimens are labelled correctly), S. spinoa from the Windom shale of New York (with and without spines preserved) as well as and S. rockfordensis from Iowa.