''Calymene blumenbachii'', sometimes erroneously spelled ''blumenbachi'', is a species of

trilobite Trilobites (; meaning "three-lobed entities") are extinction, extinct marine arthropods that form the class (biology), class Trilobita. One of the earliest groups of arthropods to appear in the fossil record, trilobites were among the most succ ...

discovered in the

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

quarries of the Wren's Nest in

Dudley Dudley ( , ) is a market town in the West Midlands, England, southeast of Wolverhampton and northwest of Birmingham. Historically part of Worcestershire, the town is the administrative centre of the Metropolitan Borough of Dudley. In 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 23.5 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 third and shortest period of t ...

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 (geology), system, the second of six periods of the Paleozoic Era (geology), Era, and the second of twelve periods of the Phanerozoic Eon (geology), Eon. The Ordovician spans 41.6 million years f ...

-Silurian) is unique to the Wenlock series in England, and comes from the Wenlock Limestone Formation in

Much Wenlock Much Wenlock is a market town and Civil parishes in England, parish in Shropshire, England; it is situated on the A458 road between Shrewsbury and Bridgnorth. Nearby, to the north-east, is the Ironbridge Gorge and Telford. The civil parish incl ...

and the 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 Church Stretton is a market town and civil parish 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 BBC Sport, Sport, the on-demand video and radio services branded BBC iPlayer and BBC Sounds, t ...

* * 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