2.35" Pyrite Replaced Brachiopod (Paraspirifer) Fossil on Shale - Ohio

Pyrite Replaced Brachiopod (Paraspirifer) Fossil on Shale - Ohio #129605

This is a brachiopod fossil of the species Paraspirifer bownockeri that has been replaced by glittering pyrite. It comes from the Devonian aged Silica Shale near Sylvania, Ohio. The brachiopod has been prepped free from the surrounding rock, though a large slab of the rock has been left attached for presentation purposes. Much of the time, brachiopods on rock from this location are prepped and then remounted to the shale, however this brachiopod has not been removed from the shale. The quarries where these brachiopods used to be found are now closed to collectors so they are much harder to acquire.

Pyrite crystals can be found at the top of the brachiopod. You can really feel the heft of the iron pyrite in this specimen and shale when you hold it in your hand.

Brachiopods are members of the phylum Brachiopoda. They are clam-like with wide shells composed of two halves called valves. They are filter feeders that live fixed to rocks or on the seafloor. Brachiopods first appeared in the early Cambrian as simple forms with non-articulating shells. Their diversity peaked during the Devonian, and there are currently 12,000 described fossil species of Brachiopoda from 5,000 genera. Most species of brachiopod died out during the Permian-Triassic Extinction but about 450 species still live today. They live in cold marine environments like polar seas or continental shelves and slopes. The largest fossil Brachiopod found is 7.9 inches (200 mm), but most are 2-4 inches (3-8 cm). Living Brachiopods also fall into this range.

Brachiopods are more closely related to Bryozoans than Mollusks. The easiest differences to identify are in the shells of clams, part of the mollusk family, and Brachiopods. Mollusk shells are divided into left and right while brachiopod shells are divided top (dorsal) and bottom (ventral). Mollusk shells are usually equal on the right and left. In brachiopods, the bottom shell is larger than the top. The other big difference is in how they feed: both are filter feeders, but mollusks extend their filter into the water and pull food into their shells. Brachiopods have internal feeding structures: water is drawn into the shell where the food is filtered out before expelling it out.