Dry Dredgers Field Trip
April 28, 2007
Middletown, Ohio
Fossil Found on Site 1
Trilobites
The only trilobites found at either site that day were fragments.
The best of these was this spiney fragment of the incredible trilobite, Acidaspis.(see
below)
Brachiopods
At the first site, the most common Brachiopod was the large and impressive, Vinlandostrophia
ponderosa.
This first site exposed most of the Mt Auburn member of the McMillan
Formation. In this member, the Vinlandostrophia ponderosa have a diminished hinge
line that is both shorter and points downward towards the commissure. This
difference makes it a separate subspecies called P. ponderosa auburnensis.
(Note the profile in the next two photos)
Some of the Vinlandostrophia ponderosa were encrusted with
bryozoans. The specimen pictured below is completely encrusted on one valve and
not at all on the other side. I would assume that this is the side that was
facing upwards while the bryozoans were alive.
Another brachiopod found on site 1, was the beautiful Hebertella.
(next 3 pics)
Here's Mike's finds a about half way through the first site, to give you an
idea of the variety and kind of fossils found.
When you look at the ground in the area where these brachiopods were being
found, you see tons of broken brach's. It's kind of inspiring to look for the
whole ones, often sticking up partially from under the dirt and shale.
Another abundant brachiopod was the Rafinesquina.
Here we found entire pavements on the flat field illustrating how these animals
lived and died.
Among the inarticulate brachiopods found was the ubiquitous Petrocrania
scabiosa, seen in the shot below attached to a Vinlandostrophia ponderosa.
Next Page: More Fossils Found at the First Site
T A B L E O F C O N T E N T S
Page 1: Site 1 Introduction
Page 2: Site 1 Collecting Pics
Page 3: Site 1 Fossils Found: Trilobites and Brachiopods
Page 4: Site 1 Fossils Found: Cephalopods, Bivalves and Gastropods
Page 5: Site 2: The Site and Brachiopods Found
Page 6: Site 2: Inarticulate Brachiopods and Gastropods Found
Page 7: Site 2 Bivalves, Bryozoans and Cephalopods Found