Fossil Shell Collection Maryland Middle Miocene

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  • Item Category: Natural History
  • Source: eBay
  • Sold Date: Mar 26, 2011
  • Channel: Auction House

This auction is for a small collection of Miocene shells found at a St Mary's formation site in St. Mary's County, Maryland. This is a private site and these shells are 8-10 million years old. This collection includes the following:

Ostrea sp. (oyster)
Panope goldfussi (geoduck sp.)
Mercenaria Campechiensis (bivalve)
Chesapecten sp. (extinct scallop-like species)
Anadara (Dallarca) idonea (bivalve)
Busycon sp. (whelk like species)
Turritella plebia (marine gastropod)
Naticidea sp. (moon snail variety)
Ecphora gardnererae (Maryland state fossil - predatory snail)
Bog iron

These fossil shels are interesting in that they are all from the same site. They also provide an interesting and educational represention of Miocene marine life. As shown in the picture, each fossil specimen is also accompanied by an information card.

In particular..
- the oyster specimen is a 6" half of an oyster;
- the moon snail specimen is a large 2" example of Lunatia heros;
- the geoduck specimen includes both articulated halves;
- the busycon specimen is a large 4" example of B. coronatum;
- the dallarca specimen includes both articulated halves;
- the chesapecten specimen is about 4" in diameter;
- the mercenaria specimen is about a 3.5" bivalve half and includes trace fossil evidence of predation;
- the ecphora specimen is a very large, mostly complete 3.25" example of the specific genus and species of the Maryland state fossil .

The first fossil described from North America was found in deposits of the St. Marys Formation. This fossil, the genus and species of Ecphora in this collection, was illustrated in a work on Mollusca published in England in 1685!

The St. Mary's formation is the youngest of the three Miocene deposits in Maryland. It typically consists of bluish sandy clay and fine sandstone. The silty and sandy content of the Miocene deposits in Maryland was derived from the erosion of older Coastal Plain deposits and crystalline rocks of the Piedmont region. The Miocene was a period of uplift in Middle America and the Antillean region, that was accompanied by folding of the crust of the earth and volcanism. Erosion of the recently uplifted areas produced extensive deposits of clay, sand and marl. Some of these sediments were consolidated, forming shales and sandstone. During this time, North and South America were united, and the island of Florida joined the Georgia mainland. The North American continent assumed approximately its present outlines.