Thamnopora sp. Steininger, 1831 - Devonian tabulate branching coral from the Jerome member of the Martin Formation, Verde Valley, Arizona

Thamnopora is a genus of tabulate corals that appeared during the Devonian. This coral type forms mounds and branching structures in Devonian coral reefs. Tabulate corals are colonial, with a sea-anemone-like coral polyp living in each of the tiny holes in the branching structure. Because the branching structure is somewhat fragile, tabulate corals often appear as broken fragments in the limestone matrix. The preservation of these corals is extraordinary. The structures are silicified, and these have been dissolved from the limestone with dilute muriatic acid.

Corals have disappeared and reappeared in the geological record, with Thamopora being replaced by the scleractinian stony corals toward the end of the Devonian 252 million years ago, as the result of a mass extinction event known as the Great Dying that killed 96% of all marine species and 70% of terrestrial species.

Fluctuations in coral populations have been related to rapid changes in sea level and a rapid reduction in atmospheric carbon dioxide.

The genus Thamnopora was described by Steininger in 1831, but the species of this particular specimen is undetermined and is indicated by the "sp" following the generic name.

This specimen is free of the limestone matrix. The last photo shows the colonial nature of these corals in detail.

Making multiple purchases? Click on the "combine shipping" button in the shopping cart. We'll send an invoice with combined shipping. A link in that invoice will bring you back to checkout, no hassle. 

Shipping: in a First Class package unless combined with other items. Click > here < for shipping rates. Use back button to return to this page.

Select a specimen: When more than one specimen is shown, you can select a particular specimen by telling us the number of coins in the photo or you can let us make the selection.