What We Can Learn From Oysters

Left and right valves of Exogyra

A lesson we can learn from oysters is that even though they have no heart to feel and no brain to reason, many of their species build massive reef communities which provide protection for one another; and not only for their own kind, but for many other ocean organisms. Very fittingly,  they’ve been referred to as the “unshellfish”.

This extinct oyster was a large species that lived in the soft sediment of ancient shallow marine waters. It possessed a thick shell with a distinct pattern of ribbing and pitting representing growth lines. Many of its kind thrived during the Upper Cretaceous Period around 65 to 100 million years ago. Their shells opened to expose a foot and a siphon to filter food and take in oxygen from the ocean water.

 

CLASSIFICATION

Scientific Name: Exogyra, ponderosa

Common Name: Oyster

Phylum: Mollusk (large group of marine and fresh water invertebrates having soft bodies enclosed in a shell)

Class: Pelecypod or Bivalve (means hinged shell)

Order: Ostreoida (means true oyster with irregular shell and adductor muscle; pearl oysters are not true oysters)

Family: Gryphaeidae (includes honeycomb oyster or foam oyster characterized under magnification distinct shell structure)

Genus: Exogyra (extinct group of large shallow marine oysters possessing thick shells with distinctive spiraled peak and ribbing on left valve; right valve was smaller and flattened)

Species: Ponderosa

Exogyra, ponderosa (extinct oyster)

People and Oysters

In Greek mythology, the Greek goddess of love, Aphrodite, was said to have sprang up out of the ocean on an oyster shell. The term “Aphrodisiac”, meaning to heighten love, has been related to oysters ever since.  Also, the charismatic Casanova was known to have eaten twelve oysters a day, believing it would  enrich his love life.

 

Oysters have been a part of the human diet since the Greeks and Romans. Today, two-billion pounds are eaten every year around the world. Oysters are prepared in a variety of ways, but raw on the half shell is the most nutritious. Oysters contain rich sources of B vitamins, and scarce minerals such as calcium, iron, zinc, selenium and magnesium.

 

Hand crafted oyster jewelry making is a popular past time. Only one in 10,000 oysters produce a pearl so human intervention has found a way to culture them artificially, but it still takes about six years for the oyster to complete the process. Many artists also craft beautiful jewelry using the shells of various oysters.

 

Today many of these small oyster fossils (shown below) are found in abundance within shell banks along North American coast lines. They were originally likely washed ashore during storms and deposited on the beaches. Eventually, layers and layers of sand  buried them deep where they fossilized into limestone. I’ve made my best guesstimates to identify them.

 

Graphea, navia (from Triasic 210mya - Jurassic 150mya

Graphea, navia (from Triasic 210mya – Jurassic 150mya

Texigryphaea  oyster fossil (Cretaceous) 135mya - (Miocene) 40mya

Texigryphaea oyster fossil (Cretaceous) 135mya – (Miocene) 40mya

Texigryphaea fossil (Cretaceous) 135mya - (Miocene) 40mya

Texigryphaea fossil (Cretaceous) 135mya – (Miocene) 40mya

Graphea, navia  oyster fossil (Triasic) 210mya - (Jurassic) 150mya

Graphea, navia oyster fossil (Triasic) 210mya – (Jurassic) 150mya

scan_pic0008a

Exogyra, Graphea and Texigryphaea Extinct Oyster Fossil Rendering

 

 

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3 thoughts on “What We Can Learn From Oysters

  1. I found a large deposit of these oysters in Seal AL which is in the middle of the state near the Georgia, Alabama line. A new 4 lane section of Hwy 431 over a creek exposed these and other ancient shells. They look a lot like agate rock mixed with a blue gray clay. I collected a 5 gallon bucket in just a few minutes. However, it was difficult and “snakey” looking walk to the little creek.
    I have also found iron infused shell fossils on the other side of the Chattahoochee River in Georgia along this same fall line. This must have been some vast and abundantly stocked shallow sea that rich silt has filled and metamorphism has taken place. Now rich farmland. Although I haven’t found it yet myself siliconized logs have been found along this same line. Randall Creek near Fort Benning is recorded to have this “petrified” wood.

  2. i to have found a large number of these shells in north mississippi.Along wth large mamal bones i believe to be mastodon.thank u for the info it was very helpfull

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