''Calymene blumenbachii'' Brongniart ''in'' Desmarest (1817),Desmarest, A. G. 1817. Calymène. in: ''Nouveau Dictionnaire d'Histoire Naturelle, Nouvelle Edition'', Tome 8, pp. 517 - 518. sometimes erroneously spelled ''blumenbachi'', is a species of

trilobite Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the ...

discovered in the

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

quarries of the

Wren's Nest The Wren's Nest is a geological Site of Special Scientific Interest in the Dudley Metropolitan Borough, north west of the town centre of Dudley, in the West Midlands of England. It is one of the most important geological locations in Britai ...

Dudley Dudley is a large market town and administrative centre in the county of West Midlands, England, southeast of Wolverhampton and northwest of Birmingham. Historically an exclave of Worcestershire, the town is the administrative centre of the ...

, 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 The Ordovician ( ) is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. T ...

-Silurian) is unique to the

Wenlock series Wenlock may refer to: Places United Kingdom * Little Wenlock, a village in Shropshire * Much Wenlock, a town in Shropshire ** (Much) Wenlock (UK Parliament constituency) ** Wenlock Priory, a 7th/12th-century monastery * Wenlock Basin, a canal ba ...

in England, and comes from the Wenlock Limestone Formation in Much Wenlock and the Wren's Nest in Dudley. These sites seem to yield trilobites more readily than any other areas on the

Wenlock Edge Wenlock Edge is a limestone escarpment near Much Wenlock, Shropshire, England and a site of special scientific interest because of its geology. It is over long, running southwest to northeast between Craven Arms and Much Wenlock, and is roughl ...

, 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.

References

External links

Dudley County Borough Council coat-of-arms
at Civic Heraldry
Wren's Nest
at bbc.co.uk * * Donald G. Mikulic & Joanne Kluessendorf, 2007: The legacy of the locust—Dudley and its famous trilobite ''Calymene blumenbachii. In: ''D. G. Mikulic, et al., editors. Fabulous Fossils, 300 years of worldwide research on trilobites. New York State Museum Bulletin 507, p. 141-170. https://web.archive.org/web/20140714172533/http://www.nysm.nysed.gov/staffpubs/docs/16439.pdf Calymenidae Silurian trilobites of Europe Silurian England Fossils of England Fossil taxa described in 1817 {{Phacopida-stub