Crinoid Fossil (Double)
This fine and elegant double crinoid fossil (Seirocrinus subangularis) is over 170 million years old, Lower Jurassic Period, from the Holzmaden deposit in Germany. It is extremely rare and measures 50.5 x 27.5 x 1'' thick.
It is found in a lithographic shale of extreme hardness that was deposited in a marine basin, mostly preserving the fossils in perfect condition. These fossils are found in this 9 meters of thick shale, which is fine grained, and characteristically black in color. The color is derived from a high concentration of organic material.
Although resembling plants, they are members of the phylum Echinodermata, and fed by filtering plankton from the oceans. They anchored themselves with their stems, and used their crowns to collect nutrients.