Double-Sided Fossil Trilobite Death Cluster Matrix, Lake Erie, New York
Age: Devonian Period
Location: 18 Mile Creek delta at Lake Erie, NY
Species: Mostly Phacops trilobites.
Eighteen Mile Creek is one of the best places in Western NY to find trilobites (and other fossils as well). It exposes the Wanakah Shale, another Devonian unit. Here’s what UB’s Geology Department website has to say about it.
“At its type locality north of Eighteen Mile Creek along Lake Erie shore, the Wanakah Shale consists of about 19.8 m of medium gray, soft, fossiliferous shale and shaly mudstone with several calcareous bands and zones of larger concretions. The highest beds of the Wanakah Shale exposed just below the Tichenor Limestone contain a high diversity fossil assemblage termed the Demissa and Stictoporabeds of Grabau (1898, 1899). These units yield over 80 species of macrofossils and are particularly rich in brachiopods and bryozoans.
“At Eighteen Mile Creek, the Tichenor Limestone is a resistant, 30-40 cm thick ledge-forming crinoidal biospharite and biomicrite. It contains numerous large rugose corals (Heliophyllum, Eridophyllum) and heads of the tabulate coral Favosites hamiltoniae, large crinoid columns, fenestellid bryozoans and brachiopods. The large bivalves Plethomytilus, Actinopteria, and Goniopora, are locally abundant in the upper surface of the Tichenor Limestone”