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Featured Fossil Archive


This page links to past Featured Fossils of all geological time periods.

The Last Featured Fossil....


Crinoid column coated with pyrite crystals from the Silurian Waldron Shale

Fossil Type:

Pyrite-Coated Fossil


Crinoid Column


Waldron Shale


Wenlockian, Middle Silurian


Clark Co., Indiana


Fossils may be replaced by pyrite (pyritized) or encrusted by the mineral. With the former, the fossil takes on the composition of the iron sulfide, with the latter it coating in crystals. The triangular metal reflections are indicative of the octahedral crystal habit. Anonymous collection. Specimen is about 2 cm long.

Date Posted:

July 25, 2016


Archived Featured Fossils are now organized by geological time period - youngest to oldest.


      Micro-fossils          Worms          Arthropods: Non-Trilobite          Trilobites

Brachiopods                    Bryozoans                    Porifera (Sponges) 

Corals:               Rugose                    Tabulate                    Scleractinian

Echinoderms: Crinoids                    Echinoids & Asteroids             Extinct Classes

Mollusks: Bivalves               Cephalopods               Gastropods               Other Mollusks



Fish                           Mammals                 Reptiles



Algae                 Ferns & Horsetails / Primitive Plants           Angiosperms & Gymnosperms


Trace Fossils       Miscellaneous

Featured Fossil Home Page


Created April 13, 2012, updated July 29, 2016