Graptolite Fossils (Monograptus sp)
Monograptus sp, a graptolite fossil, in black shale. Silurian. Cliffs of Veryac'h, SW of Cameret, Brittany, France. Graptolites are an extinct class of animals in the Hemichordata phylum. The fossils represent the skeletal sheath of a colonial, soft-bodied marine invertebrate which was free-floating. The word graptolite means "writing rocks" due to the resemblance to hieroglyphs. They are a valuable index fossil for dating rocks from the Paleozoic Era.
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