Meristella atoka

Meristella (Hall 1860) is possibly the most commonly found shell in the Hunton group of Oklahoma. The specimen shown below is possibly M. atoka based on the book "Stratigraphy and Paleontology of the Hunton Group in the Arbuckle Mountain Region" 1958 Thomas Amsden and Arthur Boucot, Oklahoma Geological Survey, Bulletin 78 pgs:128-133.


Pedicle Valve


Front


Brachial Valve


Rear


Profile


This specimen came from an old estate collection of fossils that were collected in the 1960's to 1970's from the Haragan Formation at White Mound, OK. The Haragan formation is thought to range from the upper Silurain, 418mya, to the lower Devonian, 411mya ( Pridoli to Lochkovian). This would correspond to the Birdsong shale of Tennessee and the Helderberg Fauna of New York, Pennsylvania and Maryland.

Kozlowskiellina velata

Kozlowskiellina (Boucot 1958) is a new genera for me. When I first saw the shell below I immediately thought it was a Delthyris. The specimen shown below is possibly K. velata based on the book "Stratigraphy and Paleontology of the Hunton Group in the Arbuckle Mountain Region" 1958 Thomas Amsden and Arthur Boucot, Oklahoma Geological Survey, Bulletin 78 pgs:121-124. This species is similar to the genera Delthyris and species Spirifer perlamellosa but I am deferring identification to Amsden and Boucot since they, quite literally, wrote the book on brachiopods from the Haragan formation.


Pedicle Valve


Front


Brachial Valve


Rear


Profile


This specimen came from an old estate collection of fossils that were collected in the 1960's to 1970's from the Haragan Formation at White Mound, OK. The Haragan formation is thought to range from the upper Silurain, 418mya, to the lower Devonian, 411mya (Pridoli to Lochkovian). This would correspond to the Birdsong shale of Tennessee and the Helderberg Fauna of New York, Pennsylvania and Maryland.

Atrypina hami

Atrypina (Hall and Clarke 1894) is an odd looking shell to me. The wavy nature of its shell reminds me of an oyster. The specimen shown below is possibly A. hami based on the book "Stratigraphy and Paleontology of the Hunton Group in the Arbuckle Mountain Region" 1958 Thomas Amsden and Arthur Boucot, Oklahoma Geological Survey, Bulletin 78 pgs:115-116. The species was named for Dr. W.E. Ham of the OGS.

Pedicle Valve


Front


Brachial Valve


Rear


Profile


This specimen came from an old estate collection of fossils that were collected in the 1960's to 1970's from the Haragan Formation at White Mound, OK. The Haragan formation is thought to range from the upper Silurain, 418mya, to the lower Devonian, 411mya ( Pridoli to Lochkovian). This would correspond to the Birdsong shale of Tennessee and the Helderberg Fauna of New York, Pennsylvania and Maryland.

Atrypa oklahomensis

Atrypa (Dalman 1827) is a very common brachiopod throughout the Silurian and Devonian periods and is one of my favorite fossils. It is no suprise to me then to find it among fossils gathered from White Mound in Oklahoma. The specimen shown below is possibly A. oklahomensis based on the book "Stratigraphy and Paleontology of the Hunton Group in the Arbuckle Mountain Region" 1958 Thomas Amsden and Arthur Boucot, Oklahoma Geological Survey, Bulletin 78 pgs:116-121. The entry on this species indicates that while most specimens of Atrypa tend to be put in the A. reticularis this is not always the case. I need to do more research to be able to tell the difference, but I will defer to Amsden and Boucot at this time.


Pedicle Valve



Front


Brachial Valve


Rear


Profile


This specimen came from an old estate collection of fossils that were collected in the 1960's to 1970's from the Haragan Formation at White Mound, OK. The Haragan formation is thought to range from the upper Silurain, 418mya, to the lower Devonian, 411mya ( Pridoli to Lochkovian). This would correspond to the Birdsong shale of Tennessee and the Helderberg Fauna of New York, Pennsylvania and Maryland.

Orthostrophia strophomenoides

After a month to catch up I am starting my regular blog posts again with a series of ID posts concerning the fossils found in the Haragan formation of Oklahoma. Most of the specimens that I will be illustrating have come from an old estate collection and it's taken me many hours of research to ferret out the names of the many different fossils. The Brachiopods are the easiest since there are whole volumes describing them and their distribution in Oklahoma by the Oklahoma Geological Survey. So without further ado I will start with Orthostrophia:

Orthostrophia (Hall 1883) is fairly common genera in the Haragan Fm. and is found in great numbers at the famed site known as White Mound. The specimen pictured below is likely the species O. strophomenoides based on the book "Stratigraphy and Paleontology of the Hunton Group in the Arbuckle Mountain Region" 1958 Thomas Amsden and Arthur Boucot, Oklahoma Geological Survey, Bulletin 78 pgs:41-45.

Brachial Valve



Front


Pedicle Valve


Rear



Profile


The name of this genera tends to throw my mind for a loop because most shells (that I've studied so far) with "strophia" in the name tend to have convex pedicle and brachial valves. This specimen came from an old estate collection of fossils that were collected in the 1960's to 1970's from the Haragan Formation at White Mound, OK. The Haragan formation is thought to range from the upper Silurain, 418mya, to the lower Devonian, 411mya ( Pridoli to Lochkovian). This would correspond to the Birdsong shale of Tennessee and the Helderberg Fauna of New York, Pennsylvania and Maryland.