''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 wh ...

quarries of the Wren's Nest in

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 The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago (Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozoi ...

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. ...

-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 b ...

in England, and comes from the Wenlock Limestone Formation in

Much Wenlock Much Wenlock is a market town and parish in Shropshire, England, situated on the A458 road between Shrewsbury and Bridgnorth. Nearby, to the northeast, is the Ironbridge Gorge, and the new town of Telford. The civil parish includes the villa ...

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 Church Stretton is a market town in Shropshire, England, south of Shrewsbury and north of Ludlow. The population in 2011 was 4,671.

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 BBC Online, formerly known as BBCi, is the BBC's online service. It is a large network of websites including such high-profile sites as BBC News and Sport, the on-demand video and radio services branded BBC iPlayer and BBC Sounds, the children ...

* * 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