Balizoma

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Balizoma
Temporal range: Silurian
Neotype fossil (BU55) of the encrinurine trilobite Balizoma variolaris.jpg
Balizoma variolaris fossil; neotype of the type species
Scientific classification
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Genus:
Balizoma
Species
  • B. variolaris

Balizoma is a genus of trilobites from the family Encrinuridae established by David J. Holloway in 1980. [1] It has only been found in rocks of Silurian age. Its type species, B. variolaris (Brongniart, 1822), is currently the only named species of the genus, and is found in England. The neotype of B. variolaris was collected from the Much Wenlock Limestone Formation at Dudley, West Midlands. [2] That specimen was first illustrated in Sir Roderick Impey Murchison's classic book, The Silurian System . [3] B. variolaris was the original "strawberry-headed" trilobite of Dudley, so-named because of its nodular glabellar tubercles, and well known to early trilobite collectors. [4] Additional species were originally assigned to Balizoma, but were subsequently placed in other encrinurine genera. [5] [6]

Related Research Articles

The Silurian is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at 443.8 million years ago (Mya), to the beginning of the Devonian Period, 419.2 Mya. The Silurian is the shortest period of the Paleozoic Era. As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by several million years. The base of the Silurian is set at a series of major Ordovician–Silurian extinction events when up to 60% of marine genera were wiped out.

Roderick Murchison geologist

Sir Roderick Impey Murchison, 1st Baronet, was a Scottish geologist who first described and investigated the Silurian system.

Wrens 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 Britain. It is also a Local Nature Reserve, a national nature reserve (NNR) and Scheduled Ancient Monument. The site is home to a number of species of birds and locally rare flora, such as Small Scabious, Milkwort and Quaking Grass. The caverns are also a nationally important hibernation site for seven different species of bat.

<i>Dalmanites</i> genus of trilobites

Dalmanites is a genus of trilobite in the order Phacopida. They lived from the Late Ordovician to Middle Devonian.

The Ludlow Group are geologic formations deposited during the Ludlow epoch of the Silurian period in the British Isles, in areas of England, Ireland, Scotland, and Wales.

Calymene genus of trilobites (fossil)

Calymene is a genus of trilobites in the order Phacopida that are found throughout North America, North Africa, and Europe in primarily Silurian outcrops. Calymene is closely related to Flexicalymene, and both genera are frequently found enrolled. Calymene trilobites are small, typically 2 cm in length. The cephalon is the widest part of the animal and the thorax usually has 13 segments.

Ronald Pearson Tripp British paleontologist

Ronald Pearson Tripp FRSE was a British palaeontologist specializing in trilobites. He was self-taught in palaeontology and became an authority on the taxonomy of the trilobite order Lichida and the trilobite family Encrinuridae.

History of invertebrate paleozoology

The history of invertebrate paleozoology differs from the history of paleontology in that the former usually emphasizes paleobiology and the paleoecology of extinct marine invertebrates, while the latter typically emphasizes the earth sciences and the sedimentary rock remains of terrestrial vertebrates.

<i>Calymene blumenbachii</i> species of trilobite (fossil)

Calymene blumenbachii, sometimes erroneously spelled blumenbachi, is a species of trilobite discovered in the limestone quarries of the Wren's Nest 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 and is thought to have lived in the shallow waters of the Silurian, in low energy reefs. This particular species of Calymene is unique to the Wenlock series 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, 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.

Batocara is a genus of phacopid trilobites in the family Encrinuridae. The type species, B. bowningi, was described originally as Encrinurus bowningi by Foerste in 1888. In 1980, D.L. Strusz erected Batocara for 'Encrinurus' bowningi. Batocara also contains the species B. borenorense and B. fritillum.

Acernaspis is an extinct genus of trilobite that is known from the Silurian. It contains two species, A. elliptifrons, and A. salmoensis. It is sometimes found preserved in burrows of various forms, sometimes in association with multiple moults, suggesting that it used tunnels as refuges whilst in its vulnerable moulting stage.

Daytonia is a trilobite in the order Phacopida, that existed during the lower Silurian in what is now the United States. It was described by D. J. Holloway in 1981, and the type species is Daytonia werthneri, which was originally described under the genus Dalmanites by August Foerste in 1885. It also contains the species, Daytonia mekon. The type locality for the genus was the Brassfield Formation, in Ohio.

<i>Eodalmanitina</i> genus of trilobites

Eodalmanitina is a trilobite in the order Phacopida, that existed during the middle Ordovician in what is now France. It was described by Henry in 1964, and the type species is Eodalmanitina macropthalma, which was originally described under the genus Calymene by Brongniart in 1822. The type locality was in Loire-Atlantique.

<i>Frammia</i> genus of trilobites

Frammia is a genus of trilobites in the order Phacopida that existed during the middle and upper Silurian in what is now the Arctic regions of Canada and Russia. It was described by Holtedahl in 1914, and the type species is Frammia dissimilis. That species was subsequently considered to be a synonym of Frammia arctica. The genus also contains the species, F. bachae Adrain & Edgecombe, 1997, F. hyperborea, and F. rossica. The type locality was the Douro Formation of Cornwallis Island in Nunavut, Canadian Arctic.

Acastocephala is a genus of trilobite from the middle Silurian, known from the United Kingdom.

<i>Bumastus</i> genus of trilobites

Bumastus is an extinct genus of corynexochid trilobites which existed from the Early Ordovician period to the Late Silurian period. They were relatively large trilobites, reaching a length of 6 in (15 cm). They were distinctive for their highly globular, smooth-surfaced exoskeleton. They possessed well-developed, large compound eyes and were believed to have dwelled in shallow-water sediments in life.

<i>Mackenziurus</i> genus of trilobites

Mackenziurus is a genus of phacopid trilobites from the Silurian containing several species, including four named after members of the American punk band the Ramones.

Hedstroemia is a genus of trilobites in the order Proetida known from the Silurian period of Europe, Asia, and North America.

Timeline of eurypterid research

This timeline of eurypterid research is a chronologically ordered list of important fossil discoveries, controversies of interpretation, and taxonomic revisions of eurypterids, a group of extinct aquatic arthropods closely related to modern arachnids and horseshoe crabs that lived during the Paleozoic Era.

<i>Perryus</i> genus of trilobites

Perryus is a genus of phacopid trilobites that lived in what are now Canada, Greenland, and Siberia from the early Silurian to the middle Silurian from 438—430 mya, existing for approximately 8 million years.

References

  1. Holloway, David J. (1980). "Middle Silurian trilobites from Arkansas and Oklahoma, U.S.A." Palaeontographica Abteilung A. 170: 1–85.
  2. Tripp, R. P.; Temple, J.T.; Gass, K.C. (1977). "The Silurian trilobite Encrinurus variolaris and allied species, with notes on Frammia". Palaeontology. 20 (4): 847–867.
  3. Murchison, Roderick Impey (1839). The Silurian System. London: John Murray. p. 726.
  4. Tripp, R. P.; Temple, J.T.; Gass, K.C. (1977). "Calymene variolaris Brongniart, 1822 (Trilobita): Proposed use of the plenary powers to designate a neotype in harmony with current use. Z.N.(S.) 2189". Bulletin of Zoological Nomenclature. 33 (3&4): 250–252.
  5. Ramskold, Lars (1986). "Silurian encrinurid trilobites from Gotland and Dalarna, Sweden" (PDF). Palaeontology. 29 (3): 527–575.
  6. Edgecombe, Gregory D.; Chatterton, Brian D. E. (1993). "Silurian (Wenlock-Ludlow) encrinurine trilobites from the Mackenzie Mountains, Canada, and related species". Palaeontographica Abteilung A. 229: 75–112.