Streptognathodus

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Streptognathodus
Temporal range: Kasimovian–Sakmarian
Scientific classification
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Streptognathodus

Species and subspecies
  • Streptognathodus acuminatus
  • Streptognathodus barskovi
  • Streptognathodus bellus
  • Streptognathodus bitteri
  • Streptognathodus brownvillensis
  • Streptognathodus chanutensis
  • Streptognathodus clarki
  • Streptognathodus clavatulus
  • Streptognathodus constrictus
  • Streptognathodus corrugatus
  • Streptognathodus curvatus
  • Streptognathodus elongatus
  • Streptognathodus excelsus
  • Streptognathodus farmeri
  • Streptognathodus flangulatus
  • Streptognathodus fusus
  • Streptognathodus holmesi
  • Streptognathodus holtensis
  • Streptognathodus isolatus
  • Streptognathodus makhlinae
  • Streptognathodus minutus
  • Streptognathodus multinodosus
  • Streptognathodus pawhuskaensis
    • S. pawhuskaensis deflectus
  • Streptognathodus postfusus
  • Streptognathodus rugosus
  • Streptognathodus ruidus
  • Streptognathodus simplex
  • Streptognathodus simulator
  • Streptognathodus spatulatus
  • Streptognathodus strigillatus
  • Streptognathodus subdivisus
  • Streptognathodus sulcatus
  • Streptognathodus sulciferus
  • Streptognathodus virgilicus
  • Streptognathodus vitali
  • Streptognathodus wabaunsensis
  • Streptognathodus walteri
  • Streptognathodus zethus

Streptognathodus is an extinct genus of conodonts from the Late Carboniferous to Early Permian.

Contents

Use in stratigraphy

Late Carboniferous

The top of the Kasimovian stage is close to the first appearance of Streptognathodus zethus. The golden spike for the Kasimovian stage has not yet been assigned (in 2008).

The Kasimovian is subdivided into three conodont biozones:

The base of the Gzhelian is at the first appearance of Streptognathodus zethus. The top of the stage (also the top base of the Silesian and the base of the Permian system) is at the first appearance of Streptognathodus isolatus within the Streptognathus "wabaunsensis" chronocline. [2]

The Gzhelian stage is subdivided into five biozones, based on the conodont genus Streptognathodus:

Early Permian

The base of the Asselian stage is at the same time the base of the Cisuralian series and the Permian system. It is defined as the place in the stratigraphic record where fossils of the species Streptognathodus isolatus first appear. The global reference profile for the base (the GSSP or golden spike) is located in the valley of the Aidaralash River, near Aqtöbe in the Ural Mountains of Kazakhstan. [3] The top of the Asselian stage (the base of the Sakmarian stage) is at the first appearance of the species Streptognathodus postfusus.

The Asselian contains five conodont biozones:

The base of the Sakmarian stage is laid with the first appearance of Streptognathodus postfusus in the fossil record. A global reference profile for the base had in 2009 not yet been appointed. The top of the Sakmarian (the base of the Artinskian) is defined as the place in the stratigraphic record where fossils of conodont species Sweetognathus whitei and Mesogondolella bisselli first appear.

Related Research Articles

The Permian is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period 298.9 million years (Ma) ago, to the beginning of the Triassic Period 251.9 Ma ago. It is the last period of the Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era. The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the region of Perm in Russia.

In the geological timescale, the Tithonian is the latest age of the Late Jurassic Epoch and the uppermost stage of the Upper Jurassic Series. It spans the time between 152.1 ± 4 Ma and 145.0 ± 4 Ma. It is preceded by the Kimmeridgian and followed by the Berriasian.

Cisuralian First series of the Permian

The Cisuralian is the first series/epoch of the Permian. The Cisuralian was preceded by the Pennsylvanian and followed by the Guadalupian. The Cisuralian Epoch is named after the western slopes of the Ural Mountains in Russia and Kazakhstan and dates between 298.9 ± 0.15 – 272.3 ± 0.5 Mya.

Anisian

In the geologic timescale, the Anisian is the lower stage or earliest age of the Middle Triassic series or epoch and lasted from 247.2 million years ago until 242 million years ago. The Anisian Age succeeds the Olenekian Age and precedes the Ladinian Age.

In the geologic timescale, the Artinskian is an age or stage of the Permian. It is a subdivision of the Cisuralian Epoch or Series. The Artinskian likely lasted between 290.1 and 283.5 million years ago (Ma) according to the most recent revision of the International Commission on Stratigraphy (ICS) in 2022. It was preceded by the Sakmarian and followed by the Kungurian.

In the geologic timescale, the Asselian is the earliest geochronologic age or lowermost chronostratigraphic stage of the Permian. It is a subdivision of the Cisuralian Epoch or Series. The Asselian lasted between 298.9 and 293.52 million years ago (Ma). It was preceded by the Gzhelian and followed by the Sakmarian.

The Bashkirian is in the ICS geologic timescale the lowest stage or oldest age of the Pennsylvanian. The Bashkirian age lasted from 323.2 to 315.2 Ma, is preceded by the Serpukhovian and is followed by the Moscovian.

In the geologic timescale, the Capitanian is an age or stage of the Permian. It is also the uppermost or latest of three subdivisions of the Guadalupian Epoch or Series. The Capitanian lasted between 264.28 and 259.51 million years ago. It was preceded by the Wordian and followed by the Wuchiapingian.

In the geologic timescale, the Sakmarian is an age or stage of the Permian. It is a subdivision of the Cisuralian Epoch or Series. The Sakmarian lasted between 293.52 and 290.1 million years ago (Ma). It was preceded by the Asselian and followed by the Artinskian.

In the geologic timescale, the Kungurian is an age or stage of the Permian. It is the latest or upper of four subdivisions of the Cisuralian Epoch or Series. The Kungurian lasted between 283.5 and 273.01 million years ago (Ma). It was preceded by the Artinskian and followed by the Roadian. It corresponds roughly to the Leonardian Stage, covering the span from 280 to 270.6 ± 0.7 Ma in the North American system.

Roadian Fifth stage of the Permian

In the geologic timescale, the Roadian is an age or stage of the Permian. It is the earliest or lower of three subdivisions of the Guadalupian Epoch or Series. The Roadian lasted between 273.01 and 266.9 million years ago (Ma). It was preceded by the Kungurian and followed by the Wordian.

In the geologic timescale, the Wordian is an age or stage of the Permian. It is the middle of three subdivisions of the Guadalupian Epoch or Series. The Wordian lasted between 266.9 and 264.28 million years ago (Ma). It was preceded by the Roadian and followed by the Capitanian.

Ladinian 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.

Tournaisian First stage of the Carboniferous

The Tournaisian is in the ICS geologic timescale the lowest stage or oldest age of the Mississippian, the oldest subsystem of the Carboniferous. The Tournaisian age lasted from 358.9 Ma to 346.7 Ma. It is preceded by the Famennian and is followed by the Viséan.

Viséan Second stage of the Carboniferous

The Visean, Viséan or Visian is an age in the ICS geologic timescale or a stage in the stratigraphic column. It is the second stage of the Mississippian, the lower subsystem of the Carboniferous. The Visean lasted from 346.7 to 330.9 Ma. It follows the Tournaisian age/stage and is followed by the Serpukhovian age/stage.

The Kasimovian is a geochronologic age or chronostratigraphic stage in the ICS geologic timescale. It is the third stage in the Pennsylvanian, lasting from 307 to 303.7 Ma. The Kasimovian Stage follows the Moscovian and is followed by the Gzhelian. The Kasimovian saw an extinction event which occurred around 305 mya, referred to as the Carboniferous Rainforest Collapse. It roughly corresponds to the Missourian in North American geochronology and the Stephanian in western European geochronology.

Gzhelian Seventh and final stage of the Carboniferous

The Gzhelian is an age in the ICS geologic timescale or a stage in the stratigraphic column. It is the youngest stage of the Pennsylvanian, the youngest subsystem of the Carboniferous. The Gzhelian lasted from 303.7 to 298.9 Ma. It follows the Kasimovian age/stage and is followed by the Asselian age/stage, the oldest subdivision of the Permian system.

The Moscovian is in the ICS geologic timescale a stage or age in the Pennsylvanian, the youngest subsystem of the Carboniferous. The Moscovian age lasted from 315.2 to 307 Ma, is preceded by the Bashkirian and is followed by the Kasimovian. The Moscovian overlaps with the European regional Westphalian stage and the North American Atokan and Desmoinesian stages.

The Norian is a division of the Triassic Period. It has the rank of an age (geochronology) or stage (chronostratigraphy). The Norian lasted from ~227 to 208.5 million years ago. It was preceded by the Carnian and succeeded by the Rhaetian.

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.

References

  1. Texas Pennsylvanian conodonts and their stratigraphic relations. CR Stauffer, HJ Plummer - University of Texas Bulletin, 1932
  2. Davydov, V.I.; Glenister, B.F.; Spinosa, C.; Ritter, S.M.; Chernykh, V.V.; Wardlaw, B.R. & Snyder, W.S.; 1998: Proposal of Aidaralash as Global Stratotype Section and Point (GSSP) for base of the Permian System, Episodes 21(1): pp 11-18, "Archived copy" (PDF). Archived from the original (PDF) on 2007-09-28. Retrieved 2007-09-28.{{cite web}}: CS1 maint: archived copy as title (link)
  3. The GSSP was first proposed by Davydov et al. (1998)