Westergaardodina

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Westergaardodina
Temporal range: middle Cambrian-lower Ordovician
Scientific classification
Kingdom:
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Genus:
Westergaardodina

Müller, 1959 [1]
Species
  • Westergaardodina asinina Bagnoli & Stouge, 2014 [2]
  • Westergaardodina brevidens
  • Westergaardodina quadrata
  • Westergaardodina matsushitai
  • Westergaardodina grandidens
  • Westergaardodina lui
  • Westergaardodina ani
  • Westergaardodina bohlini
  • Westergaardodina cf. calix
  • Westergaardodina proligula
  • Westergaardodina ligula
  • Westergaardodina cf. behrae
  • Westergaardodina tricuspidata
  • Westergaardodina bicuspidata
  • Westergaardodina amplicava
  • Westergaardodina nogamii
  • Westergaardodina moessebergensis
  • Westergaardodina curvata
  • Westergaardodina latidentata
  • Westergaardodina excentrica
  • Westergaardodina obliqua
  • Westergaardodina cf. ahlbergi
  • Westergaardodina auris
  • Westergaardodina communis
  • Westergaardodina concamerata
  • Westergaardodina dimorpha
  • Westergaardodina fossa
  • Westergaardodina gigantea
  • Westergaardodina horizontalis
  • Westergaardodina kleva
  • Westergaardodina microdentata
  • Westergaardodina polymorpha
  • Westergaardodina procera
  • Westergaardodina prominens
  • Westergaardodina sola
  • Westergaardodina tetragonia
  • Westergaardodina wimani

Westergaardodina is a species-rich genus of spine, U or W-shaped paraconodont [3] known from Middle Cambrian to Lower Ordovician strata. [4] [5]

Use in stratigraphy

Paibi, a village in Hunan, China, is the location of the Global Boundary Stratotype Section and Point (GSSP) which marks the boundary between the Miaolingian and Furongian epochs of the Cambrian Period on the geologic time scale. The GSSP was ratified by the International Union of Geological Sciences in late 2003. It established the first formally agreed upon subdivision of the Cambrian. Markers which occur near the boundary include the first appearance of Westergaardodina proligula and the Steptoean positive carbon isotope excursion, a large positive shift in carbon-13 isotopes. [6] [7]

Related Research Articles

<span class="mw-page-title-main">Tremadocian</span> Lowest stage of Ordovician

The Tremadocian is the lowest stage of Ordovician. Together with the later Floian Stage it forms the Lower Ordovician Epoch. The Tremadocian lasted from 485.4 to 477.7 million years ago. The base of the Tremadocian is defined as the first appearance of the conodont species Iapetognathus fluctivagus at the Global Boundary Stratotype Section and Point (GSSP) section on Newfoundland.

The Furongian is the fourth and final epoch and series of the Cambrian. It lasted from 497 to 485.4 million years ago. It succeeds the Miaolingian series of the Cambrian and precedes the Lower Ordovician Tremadocian Stage. It is subdivided into three stages: the Paibian, Jiangshanian and the unnamed 10th stage of the Cambrian.

<span class="mw-page-title-main">Ladinian</span> Age in the Middle Triassic

The Ladinian is a stage and age in the Middle Triassic series or epoch. It spans the time between 242 Ma and ~237 Ma. The Ladinian was preceded by the Anisian and succeeded by the Carnian.

The Darriwilian is the upper stage of the Middle Ordovician. It is preceded by the Dapingian and succeeded by the Upper Ordovician Sandbian Stage. The lower boundary of the Darriwilian is defined as the first appearance of the graptolite species Undulograptus austrodentatus around 467.3 million years ago. It lasted for about 8.9 million years until the beginning of the Sandbian around 458.4 million years ago. This stage of the Ordovician was marked by the beginning of the Andean-Saharan glaciation.

Paibi, a village in Paibi Township, Huayuan County, Xiangxi Tujia and Miao Autonomous Prefecture Hunan, China, is the location of the Global Boundary Stratotype Section and Point (GSSP) which marks the boundary between the third and Furongian epochs of the Cambrian Period on the geologic time scale. Paibi was selected over the Kyrshabakty River section, Malyi Karatau, Kazakhstan, and the GSSP was ratified by the International Union of Geological Sciences in late 2003. It established the first formally agreed upon subdivision of the Cambrian. The village gives its name to the Paibian Age in the Cambrian Period.

<span class="mw-page-title-main">Dob's Linn</span>

Dob's Linn is a small steep valley in Dumfries and Galloway, just north of the A708 road between Moffat and Selkirk, in Scotland. It is part of the Grey Mare's Tail Nature Reserve which is owned by the National Trust for Scotland. According to tradition, Dob's Linn is named for a covenanter, Halbert Dobson, who took refuge there from Government troops during The Killing Time in the late 17th century.

The Paibian is the lowest stage of Furongian series of the Cambrian. It follows the Guzhangian and is succeeded by the Jiangshanian Stage. The base is defined as the first appearance of the trilobite Glyptagnostus reticulatus around 497 million years ago. The top, or the base of the Jiangshanian is defined as the first appearance of the trilobite Agnostotes orientalis around 494 million years ago.

The Dapingian is the third stage of the Ordovician period and the first stage of the Middle Ordovician series. It is preceded by the Floian and succeeded by the Darriwilian. The top of the Floian is defined as the first appearance of the conodont species Baltoniodus triangularis which happened about 470 million years ago. The Dapingian lasted for about 2.7 million years until about 467.3 million years ago.

The Jiangshanian is the middle stage of the Furongian series. It follows the Paibian Stage and is succeeded by the still unnamed Stage 10 of the Cambrian. The base is defined as the first appearance of the trilobite Agnostotes orientalis which is estimated to be 494 million years ago. The Jiangshanian lasted until approximately 489.5 million years ago.

The Guzhangian is an uppermost stage of the Miaolingian Series of the Cambrian. It follows the Drumian Stage and precedes the Paibian Stage of the Furongian Series. The base is defined as the first appearance of the trilobite Lejopyge laevigata around 500.5 million years ago. The Guzhangian-Paibian boundary is marked by the first appearance of the trilobite Glyptagnostus reticulatus around 497 million years ago.

The Drumian is a stage of the Miaolingian Series of the Cambrian. It succeeds the Wuliuan and precedes the Guzhangian. The base is defined as the first appearance of the trilobite Ptychagnostus atavus around 504.5 million years ago. The top is defined as the first appearance of another trilobite Lejopyge laevigata around 500.5 million years ago.

Stage 10 of the Cambrian is the still unnamed third and final stage of the Furongian series. It follows the Jiangshanian and precedes the Ordovician Tremadocian Stage. The proposed lower boundary is the first appearance of the trilobite Lotagnostus americanus around 489.5 million years ago, but other fossils are also being discussed. The upper boundary is defined as the appearance of the conodont Iapetognathus fluctivagus which marks the beginning of the Tremadocian and is radiometrically dated as 485.4 million years ago.

Iapetognathus fluctivagus is a species of denticulate cordylodan conodonts belonging to the genus Iapetognathus. It existed during the Tremadocian Age of the Ordovician. It is an important index fossil in biostratigraphy.

Iapetognathus is a genus of cordylodan conodonts. It is one of the oldest denticulate euconodont genera known.

Paraconodonts (Paraconodontida) are an extinct order of probable chordates, closely related or ancestral to euconodonts. The order contains the superfamily Furnishinacea, itself containing the families Westergaardodinidae and Furnishinidae.

Furnishinidae is an extinct family of paraconodonts.

Eoconodontus is an extinct genus of conodonts of the Late Cambrian. It is a two-elements genus from the Proconodontus lineage.

Conodonts are an extinct class of animals whose feeding apparatuses called teeth or elements are common microfossils found in strata dating from the Stage 10 of the Furongian, the fourth and final series of the Cambrian, to the Rhaetian stage of the Late Triassic. These elements can be used alternatively to or in correlation with other types of fossils in the subfield of the stratigraphy named biostratigraphy.

Protoconodonts are an extinct group of Cambrian animals known from fossilized phosphatic tooth-like structures. They were originally described as an informal group of early conodonts, though more recent studies consider them to be more closely related to chaetognaths.

References

  1. Kambrische Conodonten. Klaus J. Müller, Zeitschrift der Deutschen Geologischen Gesellschaft Band 111 (1959), pages 434-485
  2. Upper Furongian (Cambrian) conodonts from the Degerhamn quarry road section, southern Öland, Sweden. Bagnoli G and Stouge S, 2014, GFF, doi:10.1080/11035897.2013.858768
  3. Murdock, Duncan J. E.; Dong, Xi-Ping; Repetski, John E.; Marone, Federica; Stampanoni, Marco; Donoghue, Philip C. J. (2013-10-24). "Descriptive terminology of paraconodont and euconodont elements. : The origin of conodonts and of vertebrate mineralized skeletons : Nature : Nature Publishing Group". Nature. 502 (7472): 546–549. doi:10.1038/nature12645. PMID   24132236. S2CID   4455633.
  4. Xiping, D.; Repetski, J. E.; Bergström, S. M. (2004). "Conodont Biostratigraphy of the Middle Cambrian through Lowermost Ordovician in Hunan, South China". Acta Geologica Sinica - English Edition. 78 (6): 1185. doi:10.1111/j.1755-6724.2004.tb00776.x.
  5. Muller, K.J.; Hinz, I (1991). Upper Cambrian Conodonts from Sweden. Fossils and Strata. Vol. 28. Oslo: Universitetsforlaget. pp. 1–153. ISBN   978-82-00-37475-6.
  6. "Proposed Global Standard Stratotype-Section and Point for the Paibian Stage and Furongian Series (Upper Cambrian)" . Retrieved 2006-06-30.
  7. "Another "Golden Spike" in China". International Union of Geological Sciences. 28 November 2003. Archived from the original on November 15, 2004. Retrieved 2006-06-30.