Lochkovian

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.^[7] The GSSP is located within the Lochkow Formation at the Klonk Section in Prague.

Lochkovian
419.2 ± 3.2 – 410.8 ± 2.8 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Chronology
−420 — – −415 — – −410 — – −405 — – −400 — – −395 — – −390 — – −385 — – −380 — – −375 — – −370 — – −365 — – −360 — – Paleozoic S Devonian C M Přídolí Early Mid Late EM Lochkovian Pragian Emsian Eifelian Givetian Frasnian Famennian Tournai.           ← Hangenberg event, Famennian glaciation ← Kellwasser event (Late Devonian mass extinction)[1] ← Widespread[2] shrubs & trees ← Hunsrück fauna ← Rhynie chert[3] Subdivision of the Devonian according to the ICS, as of 2023[4] Vertical axis scale: Millions of years ago
Etymology
Name formality	Formal
Name ratified	1985[5]
Usage information
Celestial body	Earth
Regional usage	Global (ICS)
Time scale(s) used	ICS Time Scale
Definition
Chronological unit	Age
Stratigraphic unit	Stage
Time span formality	Formal
Lower boundary definition	FAD of the graptolite Monograptus uniformis
Lower boundary GSSP	Klonk, Prague, Czech Republic 49.8550°N 13.7920°E / 49.8550; 13.7920
Lower GSSP ratified	1972[6]
Upper boundary definition	FAD of the conodonts Eognathodus sulcatus and Latericriodus steinachensis Morph beta
Upper boundary GSSP	Velká Chuchle quarry, Velká Chuchle, Prague, Czech Republic 50.0147°N 14.3726°E / 50.0147; 14.3726
Upper GSSP ratified	1989[5]

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