Dry Dredgers Field Trip
March 26, 2005
Brookville, Indiana
Page 7: More Brachiopods
In many layers on this site, people found the genera of brachipod, Strophomena.
The red arrow is there to point out that, unlike the more common brachiopod, Rafinequina,
the Strophomena shows the hinge opening on the convex side. You
will see a comparison photo of Rafinequina shortly.
Another distinquishing trait of the many of the Strophomena found that
day was that the half-shells found showed a large, rounded muscle scar. Again,
the comparison to the similar, Rafinesquina follows.
The Rafinequina ponderosa, shown above, were pretty abundant on
the site. They are the largest of the Rafinesquina genera in the
Cincinnatian. They are much larger than the Strophomena, and as
the red arrow points out, show the hinge opening on the concave side. This is an
easy way to tell them from Strophomena!
For the many half-shelled Rafinesquina found that day, it's
easy to tell them from Strophomena from the muscle scars and the
dentitions (above). Particularly of note, is the large shoe shapes that make up
the pedicle opening. Despite my picture above, which lacks 3D effect, they are
quite large and obvious to see.
That's all for this time! Our next field trip will be April 23, 2005. See you there!
T A B L E O F C O N T E N T S
Page 1: Introduction and Collecting Photos
Fossils Found that Day
Page 2: Best Finds of the Day
Page 3: Crinoids, Pelecypod and Cephalopods
Page 4: Snails, Coral and Trace Fossils
Page 5: Brachiopods
Page 6: More Brachiopods
Page 7: Yet More Brachiopods