Calvert Cliffs, Maryland

Miocene deposits are exposed around the Chesapeake Bay. Excellent
exposures are along the western shore in Maryland. The fossils are
marine and include both vertebrate and invertebrate species. Here is an
example of one of the fossiliferous layers (Click on the photo for
additional location photos.):

Click on the photo to see additional views of the locale.

Miocene Fossils of Maryland lists 624 species of which 408 are mollusks.
I've used illustrations from this publication with species included in the Zone 10 page linked below:

Zone 10, Plum Point

The images on this page are from the St. Mary's, and Choptank formations and are exposed along the west shore of the Chesapeake Bay. The formations including the older Calvert dip slightly to the south so that as you go north you go into older material. The Miocene in Maryland has been divided into zones. I've put images of fossils from Zone 10 of the Calvert Formation on another page.

Here are additional links with information:

One of my favorite finds is a scallop with attached barnacles.

Scallops are very common and frequently both valves are present.

These are scallops from Zone 11 of the Calvert formation:

Here is another species of barnacle.

In this instance, these pieces were inside. They are the terga (Two trianglar pieces on the left) and
scuta (One of two on the right) that make up the operculum of a barnacle.

Numerousl Anadara (ark clams)

In this specimen, both valves are present.

  

The genus, Astarte, is also well represented.

  

As well as a number of other bivalves.
Most oyster shells are single valves but here is a specimen with both valves.    
 
 

There are a variety of gastropods.

 

  

Coral was present at the time indicating a more tropical climate than now.

This an alligator or crocodile tooth.