Calymene blumenbachii, sometimes spelled - erroneously -
blumenbachi, is a species of
trilobite discovered in the
limestone quarries of
Wren's Nest Hill in
Dudley,
England. Nicknamed the
Dudley Bug or
Dudley Locust by 18th century quarrymen it became a symbol of the town and featured on the Dudley County Borough Council coat-of-arms.
Calymene blumenbachii is commonly found in
Silurian rocks (422.5-427.5 million years ago) and is thought to have lived in the shallow waters of the
Silurian, in low energy reefs. This particular species of
Calymene (a fairly common genus in the Ordovician-Silurian) is unique to the Wenlock series in England, and comes from the Wenlock Limestone in Much Wenlock and Wren's Nest in
Dudley. These sites seem to yield trilobites more readily than any other areas on the
Wenlock Edge, and the rock here is dark grey as opposed to yellowish or whitish as it appears on other parts of the Edge, just a few miles away, in Church Stretton and elsewhere. This suggests local changes in the environment in which the rock was deposited.