Rafinesquina Colossus? Humongous?

[hrguy54]

If you are a fossil collector in an Ordivician area, the Rafinesquina is a pretty common find.

Here are pics of some typical pieces from my collection. The R. ponderosa (middle) are typically 4 to 5 cms wide.

 

Below is the view of them from the side, showing their basic difference in appearance.

 

 

Late last summer I came across 3 brachiopods on a maybe 30 degree roadcut south of Dayton, OH that are similar to the Rafinesquina. All three were within 2 feet of each other and broken "from the middle out" as if they had been stepped on...or maybe run over by a tractor mowing the roadcut? 

They were huge. I've never seen any so big. Not even pieces. 

Although they were mostly missing the tips of their hinge line they were still 7.5 to 9 cms wide. Here they are above and below my initial trio.

 

But they aren't just wider, they're just flat out bigger. Here are a side and a front view of one alongside a R. ponderosa.

 

 

 

I have found the "typical" Rafinesquina in other sites both north, south, east and west of this site. Within miles and up to 20 miles of this site and at higher and lower elevations.

I've gone back to the site and there were no others, nor any on the other side of the road.

 

Have any other Ordivician collectors come across these before?  I haven't seen any mentioned anywhere.

Although the literature disagrees, are these actually what the Ponderosa looks like?

[Tidgy's Dad]

Wow! 

Those are huge, but clearly must be Rafinesquina ponderosa. 

Brachiopod size is often dependent on the environmental conditions and availability of food, so for example I have specimens of Vinlandostrophia ponderosa from Maysville, Kentucky, that reach 2.5 cm wide, while others from the Cincinnati area I have are 4.5 cm across and can get bigger. 

Anyway, those are incredible.