Lochkovian

{{short description|First stage of the Devonian}}

{{Infobox geologic timespan

| name = Lochkovian

| color = Lochkovian

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| time_start = 419.2

| time_start_uncertainty = 3.2

| time_end = 410.8

| time_end_uncertainty = 2.8

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| timeline = Devonian

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| name_formality = Formal

| name_accept_date = 1985{{cite journal |last1=Chlupac |first1=Ivo |last2=Oliver |first2=William |title=Decision on the Lochkovian-Pragian Boundary Stratotype (Lower Devonian) |journal=Episodes |date=June 1989 |volume=12 |issue=2 |pages=109-114 |url=https://stratigraphy.org/gssps/files/pragian.pdf |access-date=18 December 2020}}

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| celestial_body = earth

| usage = Global (ICS)

| timescales_used = ICS Time Scale

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| chrono_unit = Age

| strat_unit = Stage

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| timespan_formality = Formal

| lower_boundary_def = FAD of the graptolite Monograptus uniformis

| lower_gssp_location = Klonk, Prague, Czech Republic

| lower_gssp_coords = {{Coord|49.8550|N|13.7920|E|display=inline}}

| lower_gssp_accept_date = 1972{{cite journal |last1=Chlupáč |first1=Ivo |last2=Hladil |first2=Jindrich |title=The global stratotype section and point of the Silurian-Devonian boundary |journal=CFS Courier Forschungsinstitut Senckenberg |date=January 2000 |url=https://www.researchgate.net/publication/260135817_The_global_stratotype_section_and_point_of_the_Silurian-Devonian_boundary |access-date=7 December 2020}}

| upper_boundary_def = FAD of the conodonts Eognathodus sulcatus and Latericriodus steinachensis Morph beta

| upper_gssp_location = Velká Chuchle quarry, Velká Chuchle, Prague, Czech Republic

| upper_gssp_coords = {{Coord|50.0147|N|14.3726|E|display=inline}}

| upper_gssp_accept_date = 1989

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The Lochkovian is one of three faunal stages in the Early Devonian Epoch. It lasted from 419.2 ± 3.2 million years ago to 410.8 ± 2.8 million years ago. It marked the beginning of the Devonian Period, and was followed by the Pragian Stage. It is named after the village of Lochkov in the Czech Republic, now part of the city of Prague.{{cite web |title=Lochkovian Stage |url=https://www.britannica.com/science/Lochkovian-Stage |website=Encyclopedia Britannica |access-date=2 October 2019}} The GSSP is located within the Lochkow Formation at the Klonk Section in Prague.

In North America the Lochkovian Stage is represented by Gedinnian or Helderbergian time.